How the backpropagation algorithm works - <AUTHOR> http://neuralnetworksanddeeplearning.com/chap2.html <comment><USER2> This book is really coming together. It's been a while since I've put together a (100% not comprehensive) list of good places to start if you're looking to learn more and/or use deep learning in your projects.

 _Open source_

Pylearn2 (used to win kaggle galaxies competition): [http://deeplearning.net/software/pylearn2/](http://deeplearning.net/software/pylearn2/)

Theano (symbolic math library used by Pylearn2): [http://deeplearning.net/software/theano/](http://deeplearning.net/software/theano/)

Deep learning tutorials with theano (build your own neural networks): [http://www.deeplearning.net/tutorial/](http://www.deeplearning.net/tutorial/)

 _Demos_

Convnet JS: [http://cs.stanford.edu/people/karpathy/convnetjs/](http://cs.stanford.edu/people/karpathy/convnetjs/)

Sentiment Analysis: [http://nlp.stanford.edu:8080/sentiment/rntnDemo.html](http://nlp.stanford.edu:8080/sentiment/rntnDemo.html)

3d word cloud (webgl): [http://wordcloud.ersatz1.com/](http://wordcloud.ersatz1.com/)

 _Commercial_

Ersatz (I'm a co-founder, it's a PaaS providing neural network software with cloud GPU servers): [http://www.ersatzlabs.com](http://www.ersatzlabs.com)

 _Good Reading_

Deep learning of representations: looking forward [http://arxiv.org/pdf/1305.0445v2.pdf](http://arxiv.org/pdf/1305.0445v2.pdf)

Zero-Shot Learning Through Cross-Modal Transfer: [http://arxiv.org/pdf/1301.3666v2.pdf](http://arxiv.org/pdf/1301.3666v2.pdf) <\-- C'mon, that's pretty amazing...

Solution for the Galaxy Zoo challenge: [http://benanne.github.io/2014/04/05/galaxy- zoo.html](http://benanne.github.io/2014/04/05/galaxy-zoo.html)

Pylearn2 in practice: [http://fastml.com/pylearn2-in- practice/](http://fastml.com/pylearn2-in-practice/)

<comment><USER3> I while ago I posted a comment here on HN which got number of upvotes but no answer. Could you maybe take stab at it?

I've followed the developments in Neural Networks somewhat, but have never applied deep learning so far. This is seems like a good place to ask a couple of question I've been having for a while.

1\. When does it make sense to apply deep learning? Could it potentially be applied successful applied to any difficult problem given enough data? Could it also be good at the type of problems that Random Forest, Gradient Boosting Machines are traditionally good at versus the problems that SVMs are traditionally good at (Computer Vision, NLP)? [1]

2\. How much data is enough?

3\. What degree of tuning is required to make it work? Are we at the point yet where deep learning works more or less out the box?

4\. Is it fair to say that dropout and maxout always work better in practice? [2]

5\. What is the computational effort? How long e.g. does it take to classify an ImageNet image (on a CPU / GPU)? How long does it take train a model like that?

6\. How on earth does this fit into memory? Say in ImageNet your have (256 pixels * 256 pixels) * (10,000 classes) * 4 bytes = 2.4 GB, for a NN without any hidden layers.

[1] I am overgeneralizing somewhat, I know. It's my way to avoid overfitting.

[2] My lunch today was free.

<comment><USER2> Sure, I'll give it a shot -- feel free to email me if you have further questions, email is in my profile.

1\. I think it makes sense to try them for any classification, regression, or feature extraction problem. They don't work all the time, sometimes you really don't need the extra depth--one hidden layer can be fine, and they can be pretty slow to train (even with GPU). I've also seen people try to build their own, implement it wrong, get bad results, then complain NNs don't work. So test for yourself, just make sure you're not doing it wrong.

2\. It really depends. More is almost always better.

3\. Training a bunch of models using Bayesian optimization to optimize the model hyperparameters (so you don't have to pick them) and putting the last few in an ensemble and averaging results is pretty close to out of the box. This is the workflow we use with ersatz.

4\. Despite lunches not being free, you should probably use dropout. It's ridiculously good at preventing over fitting but can take longer to train (although there's been some work w/ "fast dropout" to speed it up)

5\. GPU gets you ~40x speed up over CPU. So if you're using CPU and I'm using GPU, I can do in 1 day what would take you a month and a half. And then I might train for a week or more on GPU (I think the imagenet models were trained for a week or two, but not sure how many GPUs used). Otherwise, computational effort varies.

6\. You use mini batches, so you load on as many samples as fit in GPU memory (with the model params) and then pull those into smaller batches. You rotate the "large batch" periodically. Neural networks can continue taking in new data and updating their model (online learning) and are particularly attractive for very large data sets.

General points: use GPU, don't build your own unless as an academic exercise, use dropout, test empirically on your own data. And check out Bayesian optimization of hyperparameters, I'm becoming more and more convinced it's better at picking them than human experts anyway.

<comment><USER3> Thanks.

</comment></comment></comment></comment><comment><USER4> This is a great explanation of backpropagation. For those who just want the formulas, my personal favorite has been stanford's ufldl resource:

[http://ufldl.stanford.edu/wiki/index.php/Backpropagation_Alg...](http://ufldl.stanford.edu/wiki/index.php/Backpropagation_Algorithm)

The general intuition behind backprop is that, taking prediction error in to account (think how many labels it got wrong) How far off were the predictions? Based on that go back and penalize the weights that caused the error by that much.

Multi layer perceptrons (as well as multi layer deep nets) have multiple layers whereupon you send the input through the network and make a guess.

Then you basically keep updating the weights (iteratively via gradient descent, conjugate gradient, LBFGS,...) till it doesn't change much. It does this by conducting a search navigating using the cost: or objective function. For more in depth, obviously the above book covers this quite in depth.

For those who want to just use deep learning, I will be giving talks at both OSCon and Hadoop Summit this year on distributed deep learning using 2 different frameworks I commit to [1] and [2]. Happy to answer questions!

[1]: [http://deeplearning4j.org/](http://deeplearning4j.org/) [2]: [http://github.com/jpatanooga/Metronome/](http://github.com/jpatanooga/Metronome/)

</comment><comment><USER5> Can I come up with a bit of criticism? This book does provide a great description of the details of the algorithm inner workings (very cute demons too). However, after reading this chapter (sorry I haven't looked at the other ones), there is still a feel of a bit of mystery about _why_ it works, and even more why it might not work. Possibly is is covered in other parts of the book, so I apologise if this criticism is not justified. I am personally a big fan of Christopher Bishop's book Pattern Recognition and Machine Learning, where backprop is described as an architecture for efficient computation of multiple stochastic gradient descents... I was involved with NNs before, but only after understanding where the algorithm for individual neurons comes from, I could properly appreciate the benefits of backprop (and understand the drawbacks).

</comment><comment><AUTHOR> This is chapter two of Michael Nielsen's book on Neural Networks and Deep Learning [1].

If you haven't heard about it before, I highly suggest you check it out.

[http://neuralnetworksanddeeplearning.com/about.html](http://neuralnetworksanddeeplearning.com/about.html)

</comment><comment><USER6> I can't emphasize enough how great it is the he actually provides CODE right from chapter one that implements a network with an arbitrary number of neurons at each layer using NumPy. I've read (arguably) better explanations of how neural networks function, but the code was always either archaic or nonexistent.

To me, the ability to learn artificial intelligence concepts but also pass them on to others in a way that they can be tinkered with signals a tipping point in the field.

I would like to see all of the basic building blocks of AI (such as Bayes classifiers, genetic algorithms, etc) packaged up this way into an API that is as approachable as OpenGL. Then I would like to see multiprocessing libraries like OpenCL/CUDA incorporated internally so that training can happen in milliseconds instead of minutes or hours. With enough eyeballs looking at these things, we might be able to get from heuristics and rules of thumb for training values to something more concrete. It seems like every time I learn a new paradigm it devolves into wishy-washiness because there are just not enough years in a researcher's life to discover the subtle rules at work behind the scenes. The progression seems to always be the same: failure to achieve success over 50%, then reaching 95% after some hours/days of tinkering, then finding the model hits a maximum of 99% and another model must be learned. Rinse, repeat. If that changes, and we're able to link up various models without having to choose arbitrary constants, machine learning will have arrived IMHO. We could throw hardware at it and let an array of agents evolve in parallel without human intervention until we see which arrangements work best. Eventually that could lead to a theory of mind that actually works because it could learn anything a human could learn, for the most part unsupervised.

I've learned just enough about this stuff to wonder about the endgame. I have a hunch that it will involve something akin to version control, so that an AI can try different approaches until it finds a solution, but with the ability to roll back in case it goes off the rails. Does anyone have a starting point for things like imagination in AI, or trial runs that happen in simulation before the AI acts in real life? And maybe how to merge new solutions into existing ones?

<comment><USER7> Author here. I'd love if you could give me pointers to your favourite explanations of how neural networks function (even better, if you can say what you particularly liked about them).

(I really enjoyed reading the remainder of your comment.)

<comment><USER6> Wow cool, sorry I didn't mean to sound critical, I should have used (perhaps) instead of (arguably). I had to search my bookmarks but honestly can't remember if one of these was the explanation I remember (it could have been in a book when Borders bookstore was still around):

[http://natureofcode.com/book/chapter-10-neural- networks/](http://natureofcode.com/book/chapter-10-neural-networks/)

[http://zerkpage.tripod.com/index.htm](http://zerkpage.tripod.com/index.htm)

[http://www.ai-junkie.com/ann/evolved/nnt1.html](http://www.ai- junkie.com/ann/evolved/nnt1.html)

Then I used to skim this compilation before it went away:

[https://web.archive.org/web/20030601074826/http://www.emsl.p...](https://web.archive.org/web/20030601074826/http://www.emsl.pnl.gov:2080/proj/neuron/neural/systems/shareware.html)

Mostly what I remember about the explanation that stood out was that it was concise. So the way it described backpropagation just "clicked" in a way that the previous articles that used tons of summation/matrix math/probability and calculus had not. I've read some positively atrocious papers where it was like the authors were showing their notation prowess rather than conveying information.

Your chapters have a good balance, although for someone who's been out of college for 15 years like me, it might be nice to have a tiny refresher about derivatives before you dive in, especially over several variables/dimensions. I mean like a paragraph, to explain the notation, because the knowledge is in my head but foggy. Everything else was very good, for example when you explained how bias comes from the threshold factor on the other side but makes notation easier. I don't remember seeing it explained quite that way before. Oh and the sigmoid function always seemed arbitrary too (and frankly turned me off from neural nets because it seemed too analog), but explaining how it simplifies derivatives makes perfect sense now.

Unfortunately with other books, I was also never able to find off-the-shelf code that was approachable or up to date, so I ended up forgetting everything I had learned and had to start over each time until I got tired of trying. I very much like your 72 line code example, where you provide a backpropagation function without explaining it yet. That's ok, as programmers we encounter that all of the time, and it's actually kind of fun to decipher the algorithm before reading how it works later. I believe it even allows for multiple hidden layers which is just fantastic.

As for the other stuff, well, I just look at it like this:

Ask a developer to write an iOS app that say, interacts with the twitter or facebook API and presents the user's N closest friends in a list view and then submit that to the app store, and they can do it from start to finish with no mystery (other than a little help from stack overflow). Each of those steps replies on some pretty heavy lifting like REST APIs, possibly SQL, message passing in objective-c, even a rudimentary understanding of security and encryption for networking and app submission, yet those things have become mainstream.

But ask a developer to do even the simplest machine learning task, like a little data mining or spam filtering, heaven forbid weak AI like image recognition, and it's a whole different can of worms. Why hasn't anyone standardized this stuff in the languages that developers use every day, as opposed to MATLAB or prolog or whatnot? Why can't I literally read a text file and pipe it through a shell script that does a Bayes classifier? Why doesn't iOS have an AI.framework to go along with its Social.framework? To me these aren't all that much to ask.

I really feel that we're still working at the assembly language or hand rolled affine texture mapping level from the 80s and 90s with respect to AI today. We don't have something like the web metaphor yet to catapult it into the mainstream. That said, I'm extremely optimistic that concurrent (or at least parallelized) languages like Octave/NumPy/Go, and the more approachable functional languages like Haskell/Scala/Clojure might help deliver APIs that we can interact with from more mainstream languages. To me, most weak AI problems have been solved now, and it's time that programmers have an intuitive understanding of how the algorithms work so that they can combine them in novel ways and get to strong AI in, well, my lifetime hah. Thanks for your efforts and keep it up!

<comment><USER7> Belated thanks, that's extremely helpful. I'll take a look at those links which are unfamiliar to me (I've already read the Nature of Code link, it's a great book.) Tidbits:

\+ Yes, the code presented "works" for multiple hidden layers. But it converges too slowly to be useful, except for very small networks. Later chapters introduce new ideas which help backprop converge faster, and which start to make multiple hidden layers quite feasible.

\+ On the broader machine learning front, I think scikit learn is a pretty nice general library: it's approachable, easy to use, and has reasonable docs. It'll be interesting to see how it develops.

\+ For neural nets in particular, elsewhere in this thread Dave Sullivan has done a nice job distilling out a list of good libraries. I think it'll be a while before there's a real out-of-the-box solution for neural nets, though, since setting parameters for neural nets is something of an art.

</comment></comment></comment></comment><comment><USER8> This seems like it will be a very interesting book. If anyone is interested, I have written a short and compressed intro to NNs, using very simple Python code:

[http://cjauvin.blogspot.ca/2013/10/neural- network-101.html](http://cjauvin.blogspot.ca/2013/10/neural-network-101.html)

</comment><comment><USER9> What are some problems where Deep Learning shines? Does it outperform other algorithms on those problems? Is there an understanding of why?

Context: I have some background in statistical sorts of machine learning algorithms and am genuinely puzzled by this "deep learning" phenomenon and why it's catching on.

<comment><USER3> Deep learning can expose hidden non-linear relationships in the data. It's state-of-the-art in applications such as object recognition from images and voice recognition. There have also been promising results in the natural language processing field. What all of these have in common is that they are "real" artificial intelligence, i.e. teaching computers things that they have been historically bad at compared to humans.

Search for a talk by Geoffrey Hinton if you are genuinely interested.

</comment></comment><comment><USER10> There's a really nice explanation at [http://galaxy.agh.edu.pl/~vlsi/AI/backp_t_en/backprop.html](http://galaxy.agh.edu.pl/~vlsi/AI/backp_t_en/backprop.html)

</comment><comment><USER11> Nice description of backprop for sure.

Aren't people using conjugate gradient descent to optimize NN weights now? Sure you need the partial derivatives but ... that's what GPUs are for, right? :)

<comment><USER12> Backprop lets you calculate the gradient efficiently. What you do with that gradient is up to you (I would try L-BFGS or something akin to a stochastic variation). So you could use conjugate gradient or some other optimization method

</comment></comment><comment><USER13> Can someone explain to me why NN's are always in layers?

<comment><USER14> From the first chapter of this book, it is described that each layer adds more abstraction. The first layer (input) works on individual pixels, the next layer on a part of the image. Each deeper layer can make more high-level decissions.

<comment><USER13> I understand why more layers adds complexity, but that doesn't answer my question: why layers instead of an arbitrary acyclic graph?

<comment><USER15> I'm not an expert, but my guess is because it makes it really easy to materialize the weights between layers as a 2d matrix and we have some really good library code out there for dealing with matrices.

There's probably room for experimenting with more novel constructions and even some papers out there looking into the matter.

<comment><USER13> Efficiency is the expected answer. I'm just wondering if there's a more theoretical reason, such as "every function that can be computed by a non- layered acyclic network can be computed by a complete layered network using only a small number of extra nodes/layers."

<comment><USER15> I think that it can. With some weights of 0 and some weights of 1, you can trivially map 'jumps' that skip from a node in one layer to a node a couple layers distant, by means of some incorporate-no-other-inputs intermediate nodes, right? Sigmoid function on 1 is still 1? Once you have those, it's just a matter of how many layers you need for any acyclic structure, I think.

Although if you wanted to come up with difficult scenarios, it's not hard to think of structures that would make some of those middle layers really tall, or add a lot of middle layers.

<comment><USER13> As I mentioned in another branch of this thread, selectively choosing edges between nodes isn't an option, because in the standard model you have complete incidence between nodes in adjacent layers.

</comment></comment></comment></comment></comment></comment></comment><comment><USER16> Or "Why I wish I was better at math."</comment>


CEO of PeerIndex appears to have purchased 20k Twitter followers - <AUTHOR> http://www.kernelmag.com/features/report/2709/peerindex-ceo-buying-twitter-followers/

<comment><USER2> that's 'influence' done right, no?

<comment><AUTHOR> Yeah. Funniest thing of the whole situation, if true, is that it's been done by people who are trying to measure social influence.</comment></comment>


Linus Torvalds on 2560x1600 - <AUTHOR> https://plus.google.com/+LinusTorvalds/posts/ByVPmsSeSEG <comment><USER2> Most OSes are _still_ not properly optimized for HiDPI displays(and may never will be at this point with everything going mobile).

I could be a running a 4k display but chose to use a '24 inch 1900x1200 because the text scaling b/t apps and the windows is inconsistent. I haven't tried ubuntu on a HiDPI monitor but I would guess that it has the same issues.

</comment><comment><USER3> This is not true in my experience. When I upgraded to a Retina laptop I barely noticed. Any other laptop feature seems more important.

Of course, one person's opinion doesn't matter much. Is there any data showing a large percentage of people care about this?

<comment><USER4> I switched from old Samsung laptop to MBP retina around 2013 and noticed that font quality improved and was content for quite some time (without being excessively. and then I switched back for a while to my previous setup and in that moment it became painfully obvious to me how this tiny detail improved work / interaction quality with the device.

so yeah - I'm with Linus on this one.

</comment></comment><comment><USER5> He has a point, it should be the standard. Although someone should tell this Linus guy he could just pick up a MacBook Pro with that resolution, and it comes with macOS.

<comment><USER6> Just spitballing here, but "this Linus guy" might rather a lighter laptop [1] with a better screen.

[1]: [https://www.cultofmac.com/162823/linux-creator-linus- torvald...](https://www.cultofmac.com/162823/linux-creator-linus-torvalds-i- love-my-macbook-air/)

<comment><USER5> My wife has a MacBook Air and I have a new Pro and there's surprisingly little in it when it comes to weight, and it would meet his resolution requirement.

[https://www.macworld.co.uk/review/mac-laptops/macbook-pro- vs...](https://www.macworld.co.uk/review/mac-laptops/macbook-pro-vs-macbook- air-3481192/)</comment></comment></comment>


New book on Silicon Valley says early Atari ran on cocaine and roller skates - <AUTHOR> https://www.polygon.com/2018/7/6/17542154/atari-book-valley-of-genius-nolan-bushnell-cocaine-roller-skates <comment><USER2> It's not a secret. Atari was notorious for drug use, drinking and hot tub parties. Go listen to episodes of ANTIC where they interviewed former employees [https://ataripodcast.libsyn.com/](https://ataripodcast.libsyn.com/)</comment>


COMING TO KICKSTARTER: Instagram's favorite way to print photos with LED tech - <AUTHOR> http://www.litpix.com/ <comment><AUTHOR> We're currently collecting email addresses of people who want to be informed of our launch on Kickstarter at [http://www.litpix.com/](http://www.litpix.com/)</comment>


Are Minds Computable? - <AUTHOR> http://arxiv.org/abs/1110.3002 <comment><USER2> "We must resist the temptation to believe that all thinking follows the computational model." - Peter Norvig, Paradigms of Artificial Intelligence Programming, page 147

The thesis of the author's argument is in the middle of the second page. Essentially, he claims that minds and biological systems continually interact with an environment in which not much is known a posteriori. Thus, he concludes that universal Turing machines cannot compute minds.

In the next sentence (top of the third page) he states "Still, this does not imply that minds cannot be computed." Huh? Aren't Turing machines (and equivalents) capable of performing all computations? Or do I misunderstand the Church-Turing Thesis?</comment>


A startup simulation game to test your entrepreneurial skills - <AUTHOR> http://hipsterceo.com/

<comment><USER2> yet another "I've nothing to show really but send me your email address anyway" post.

<comment><AUTHOR> It's called marketing.</comment></comment>


Ask HN: How to Find the Best Info on Cancer Treatments? - <AUTHOR> Hi Everyone, one of my close relatives has been diagnosed with Stage IV Glioblastoma (GBM), and while there's literally tons of information online about treatments and procedures, how would one go about digesting it all ? For example there's 75 publications from the recent ASCO 2015 congress about GBM treatments, is there any tool out there to compare what works vs what does not work as well? Another question would be, how to find the best specialists in my Area for this kind of cancer?<p>Any help/advice is very much appreciated! <comment><USER3> I went through this - I was a caregiver for my partner who was diagnosed with GBM. It's a terrible disease, and by terrible, I mean most people have no idea. It's one of the diseases with an extraordinarily poor outcome ratio (under 5% past 2 years, depending on age, young people might be at 25% two years 5% three years) and terrible end of life scenarios. I can only hope that your family member is fairly old, it's a heartbreaking disease for someone young.

There is a standard treatment path for GBM. whole brain radiation with temodar, then a few other choices on recurrence. Any regional hospital / cancer center can do this.

If your family wants to get more aggressive, they have to get into one of america's cancer centers. For GBM, I remember UCSF, UCLA, MD Anderson, Duke, Sloan Kettering, Boston Women's ( Mayo never came up for GBM in my research but maybe I'm misremembering ). My method for finding these centers is to scrub the clinical trials database and see who is offering what trials.

In terms of how to ingest all the data --- I'll tell you what I did. I sat in UCSF's library for two days and read like a demon. I read all the articles on GBM going back 20 years, and when I didn't understand a term of concept, I pulled a textbook. As a "hacker" you'll find drilling down on one disease isn't _that_ much information. I was then capable of having realistic and high bandwidth discussions with all of the doctors involved, including some of the nations premiere neurooncologists.

Right now, interesting clinical trials focus around immune system treatments (monoclonal antibodies). That wasn't around when I did my thing, and my info is all out of date.

If you live in the bay area, you might have a friend at Genentech. You should scrub your linkedin friends. They're at the front of most oncology research, and main HQ is at the oyster point office.

Your local doctor(s) won't like moving to a regional cancer center. It's a terrible fact, but they'll tend to drag their feet, tell you won't get personal service, make record transfer difficult, and claim they can do the same treatments at home. Part pride, part truth, part profit motive.

<comment><AUTHOR> > If your family wants to get more aggressive, they have to get into one of > america's cancer centers. For GBM, I remember UCSF, UCLA, MD Anderson, Duke, > Sloan Kettering, Boston Women's ( Mayo never came up for GBM in my research > but maybe I'm misremembering ). My method for finding these centers is to > scrub the clinical trials database and see who is offering what trials.

Thanks for your advice, she lives in France, but I will try to see what is equivalent there, as well as what medical trials are ongoing in such institutions.

<comment><USER4> It looks to me like France has two main GBM groups: (1) Hospital Pitie- Salpetriere in Paris, and (2) La Timone Hospital in Marseilles.

This page from Expertscape will help you find the individuals in those institutions who know the most about GBM.

[http://expertscape.com/ex/glioblastoma/c/fr](http://expertscape.com/ex/glioblastoma/c/fr)

The page is not perfect (e.g. the top person is at Harvard, not in France, and the second person ranks high because of a clinical trial), but it's probably the most efficient place to begin your research.

</comment></comment></comment><comment><USER5> I'm a radiation oncologist. I strongly advise you ask your questions to an oncologist. The amount of information available is simply crazy and "normal people" can rarely appreciate the subtleties of a disease and its treatments. Unfortunately, 10 years of training is impossible to squeeze in a few hours of reading.

That being said, Grade IV gliomas are usually being treated with a combination of surgery, radiation and chemotherapy (usually temozolomide). Surgery is either a biopsy or a resection. Glioblastomas have multiple "roots" making them very difficult to remove. Even after surgery they almost always recur. Sometimes they're located in regions of the brain where the risk of surgery outweighs any benefit (for example, the patient would be left unable to talk after the surgery); then we do a biopsy and go on to the next "step", which is radiation.

Radiation therapy is given daily over a few weeks. Based on a few factors such as age and general condition, the radiation oncologist will determine the dose and number of treatments (fractions) he recommends. Between 15 and 30 treatments is usual in patients that are in reasonable shape.

Again, based on general condition and a few other factors, someone (a neurosurgeon, medical or radiation oncologist) will prescribe temozolomide. It's usually given during or after radiation. That medication really improved outcomes and is now considered standard of care in people that can tolerate it.

Despite our best efforts, the disease usually comes back. At that point options can be limited. Some people will try clinical trials, but before you start travelling with a loved one across the country, keep in mind a few important things: this is a deadly disease so quality of life becomes very important. Spending hours in hospitals trying out toxic treatments has an important impact on that. Moreover, I haven't seen any breathtaking preliminary clinical trial results on GBM lately (that includes virus, weed and the likes). Participating in trials should be seen as a way to contribute to cancer research; I wouldn't go into it expecting to find a cure.

If you really want to have access to the information physicians use, you should check out the NCCN guidelines on Central Nervous System Cancers. It's NOT written for the general population and I would not advise you to even look it up. It can be really confusing and bring in more stress than it's worth. As I said on top here, better talk to a physician.

I hope this helps.

<comment><USER6> Do you know what sources oncologists used to keep themselves up to date?

<comment><USER5> There are many. Personally I will read the NCCN recommendations and discussion section. They're updated frequently. UpToDate is another website I like. I subscribe to Medscape oncology for cancer related news. Meetings are also a good way to stay up to date with what's new. Read by QxMD is an app I use to keep up with what's being published in my field.

<comment><USER7> Path resident checking in. Would you consider doing a genetic panel similar to the recent work from the Cancer Genome Atlas project's recently reported classification for lower-grade gliomas?

[http://www.nejm.org/doi/full/10.1056/NEJMoa1402121](http://www.nejm.org/doi/full/10.1056/NEJMoa1402121)

<comment><USER8> Um, slightly OT: If you want to participate in research around the Cancer Genome Atlas for other cancers, how do you do that?

<comment><USER7> A) find out who at your institution is already involved,

B) contact the IRB or clinical investigations department, they probably need to verify their institutional existence and will then have a list of whichever investigators they have vouched for.

C) ask on reddit: /r/bioinformatics

D) they have contact info on the website.

</comment></comment></comment></comment></comment></comment><comment><USER9> My brother in law was diagnosed with the same grade GBM, over a year ago. He was given 4 months to live & told his tumor was inoperable. He traveled to NYC the day after diagnosis trying to seek consultation with some of the top neuro-oncologists in the world at NYU, Penn, & Sloan Kettering (where the surgery was performed).

He was 32 at time of diagnosis, he's an inspiration to me every day to persevere through any of my struggles that I perceive as difficult.

My advice, which was my sisters strategy in keeping her husband alive, is to get as many opinions as possible about the most aggressive treatment strategies available (depending on tumor location, etc) and formulate a plan to try and eliminate as much of the tumor(s) as you can. The occurrence rate on these grade tumors is insane, try anything you can to get into an amino therapy clinical trial, or any other trials that they may be eligible for. My brother in law participated in the MK-1775 trial.

I built a little WordPress site for him: youcanthurtsteel.com

Please email me, or message me if you have any questions that I can answer from my perspective & I'll do my best to convey what my family has learned about this terrible disease.

Here's a youtube clip: [https://www.youtube.com/watch?v=8Fo2uNqKMR8](https://www.youtube.com/watch?v=8Fo2uNqKMR8)

Also, [http://www.voicesagainstbraincancer.org/](http://www.voicesagainstbraincancer.org/) is one of the best foundations that you can help raise awareness for. He's become an advocate for their cause, [http://www.voicesagainstbraincancer.org/james-j-hanson- bio/](http://www.voicesagainstbraincancer.org/james-j-hanson-bio/)

Your friend, Nick

<comment><AUTHOR> Thanks Nick, please let me know how I can reach you (email or other).

<comment><USER9> firstname.lastname@example.com

Looking forward to hearing from you!

</comment></comment></comment><comment><USER10> Aw, that's terrible. Sorry about your relative.

> Another question would be, how to find the best specialists in my Area for > this kind of cancer?

I used to work in finance helping analysts evaluate biotech stocks, and one of my responsibilities was identifying thought leaders in the field and setting up consultations with them.

On metafilter someone asked a question "Let's say you wanted to find the very best ovarian cancer specialist in the US. How would you go about doing that?", and I answered[0] with the kinds of things I would do for my job. It might be helpful for you.

[0] [http://ask.metafilter.com/267385/How-to-find-the-best- doctor...](http://ask.metafilter.com/267385/How-to-find-the-best- doctor#3882746)

</comment><comment><USER11> 1: Seek out care givers and institutions who deal specifically with this cancer rather than institutions that are generally excellent.

2: Understand that most care givers will provide advice based on their circumstances. For example, a radiation oncologist will tend to discount surgery and will tend to advocate the machines they have access to and experience with. This is ok, but you need to keep this in mind when deciding treatment.

3: Select a care giver who will quarterback. It is imperative that the patient trust and respect this person. It is imperative that this doctor understands the patient's goals for treatment.

4: Have an honest conversation with the relative about how far they are willing to go and what their main goals for treatment are. What's more important: quality of life or a cure?

5: Get all legal affairs in order right away, such as a will, medical power of attorney, etc. Decide on end of life care before you get there. Assign a trusted person to act when patient is unable to. Get all paperwork signed, and file a copy with all care givers and institutions. Make sure the family understands what the game plan is and who will be calling the shots.

6: Get a folder and put _paper_ copies of all relevant documents in it, to include legal docs, test results, etc. Always get paper copies of all test results, etc. Always have this folder with you. Allow doctors to make copies as needed, but do not give away your only copy of any document. It's amazing how this one thing facilitates communication between all of the care givers.

</comment><comment><USER12> Duke's Polio Virus Trial Against Glioblastoma sounds very promising:

Clinical Trials for Adults | A Phase I Clinical Trial for Recurrent Glioblastoma Patients Opens for Accrual at the Preston Robert Tisch Brain Tumor Center [http://www.cancer.duke.edu/btc/modules/research3/index.php?i...](http://www.cancer.duke.edu/btc/modules/research3/index.php?id=41)

What '60 Minutes' Got Right And Wrong On Duke's Polio Virus Trial Against Glioblastoma [http://www.forbes.com/sites/davidkroll/2015/03/30/60-minutes...](http://www.forbes.com/sites/davidkroll/2015/03/30/60-minutes- covers-dukes-polio-virus-clinical-trial-against-glioblastoma/) [http://www.cbsnews.com/news/polio-cancer-treatment-duke- univ...](http://www.cbsnews.com/news/polio-cancer-treatment-duke- university-60-minutes-scott-pelley/)

Targeting Protein Synthesis Control for Cancer Therapy [http://neuro.surgery.duke.edu/gromeier](http://neuro.surgery.duke.edu/gromeier)

Matthias Gromeier, MD | Duke Neurosurgery [http://neuro.surgery.duke.edu/faculty/details/0238844](http://neuro.surgery.duke.edu/faculty/details/0238844)

<comment><USER13> Immunotherapies are all the rage in cancer treatment these days. Please, OP, read the parent post, and get information on how immunotherapies work. There have been LOTS of advances lately, in many medical areas, thanks to these new techniques.

Some (rather basic) links from me:

[https://en.wikipedia.org/wiki/Immunotherapy](https://en.wikipedia.org/wiki/Immunotherapy)

[https://en.wikipedia.org/wiki/William_Coley](https://en.wikipedia.org/wiki/William_Coley)

</comment></comment><comment><USER14> One very important thing: your relative and people immediately affected should find a counselor and probably a physician that can provide medical intervention for the extreme stress and anxiety.

I was diagnosed with stage iv colon cancer a little over a year ago. I was in shock and emotionally completely numb, or so I thought. I started having anxiety attacks, but I didn't know what was going on - I thought I was dieing right then.

Eventually I wound up at the hospital where, after vitals and an interview about what I was feeling, they suggested what was really going on for me mentally and emotionally.

I now have anti anxiety medicines (Xanax) and I can tell when they're needed. I'm grateful for getting the psych support.

Ok, long winded, but basically a lot of what we deal with is made in our minds, and there is help available to mitigate the worst effects of this.

Good luck, and thanks to anyone here that works in the medical field, battling these diseases.

<comment><USER15> Do be careful with anxiolytics though, especially alprazolam (Xanax). They're horribly addictive drugs and very difficult to kick.

</comment></comment><comment> bro-stick Duke is conducting limited clinical trials (5 cases with 100% success and no known side effects, although the "cure" is violent (because of the rapid rate of cancer tissue destruction)) of an oncolytic virus, PVS-RIPO, an engineered poliovirus, on GBM. [http://corporate.dukemedicine.org/news_and_publications/news...](http://corporate.dukemedicine.org/news_and_publications/news_office/news/poliovirus- vaccine-trial-shows-early-promise-for-recurrent-glioblastoma)

 _The PVS-RIPO trial is available for recurrent glioblastoma patients with only one tumor. The tumor must be surgically accessible; the size must be no smaller than 1 cm and no larger than 5.5 cm, and the tumor must be located at least 1 cm away from the ventricles. Prior exposure to bevacizumab (Avastin) is permitted. For further information please contact the Preston Robert Tisch Brain Tumor Center at Duke at (919) 684-5301._

[http://www.cancer.duke.edu/btc/modules/Research3/index.php?i...](http://www.cancer.duke.edu/btc/modules/Research3/index.php?id=41)

Note: most clinical trials have other requirements such as age, gender, health condition, failed/doing/discontinuing other treatments, so it requires some persisence and research.

See also:

[http://killingcancer.vice.com](http://killingcancer.vice.com)

<comment> bro-stick Duke and U-Penn are also doing early clinical trials of T-cell therapies (using HIV and other virii to train the own body's T-cells to identify cancer) and other novel approaches for attacking GBM.

[https://www.clinicaltrials.gov/ct2/show/NCT02209376](https://www.clinicaltrials.gov/ct2/show/NCT02209376) (Novartis + U-Penn + UC SF)

[http://neuro.surgery.duke.edu/research/basic- research/duke-b...](http://neuro.surgery.duke.edu/research/basic- research/duke-brain-tumor-immunotherapy-program/research-initiatives)

</comment></comment><comment><USER16> Conference papers aren't much use here, really.

I'm no expert, but in your shoes I would be looking for the most experienced panel I can find, hopefully with neuro specialists preferably (e.g. a neuro- radiologist, neuro-oncologist, etc. as specialists). If there is a teaching hospital with a good reputation in your area they may be more current on techniques than a purely clinical one (but this isn't hard and fast). Don't ever be afraid to ask questions, and keep at it until get a clear explanation of the panels reasoning behind their suggestions.

Best luck to you and your relative.

<comment><USER17> I agree.

> _is there any tool out there to compare what works vs what does not work as > well_

That's what the medics really do. Get good medics and thrust them, but don't thrust them blindly. Read a lot to be able to understand the medics and the tradeoff they are making. [They are always making tradeoff.] Ask a lot of questions, dumb questions, intelligent questions, lots of questions. [But remember to be polite asking.]

Don't believe everything you read, it's full of snake oil written by crackpots and overhyped press releases written by universities.

I'll start with Wikipedia and MedlinePlus, to get a high level overview.

[And remember to sleep and eat healthy, you will be more helpful if you are healthy.]

Best luck to you and your relative.

</comment></comment><comment><USER18> Disclaimer: I'm a bioengineer, not a physician, so please seek further info from a MD.

> and while there's literally tons of information online about treatments and > procedures, how would one go about digesting it all ?

This is actually a problem for practicing physicians as well, as knowledge transfers slowly across the industry. Many professional societies (American Heart Association for example) try to address this problem by releasing clinical practice guidelines which are suggested best practices for managing different diseases. You should check if the American Cancer Society or another equivalent group issues such guidelines.

I would also strongly recommend consulting an oncologist or a neurologist, who will be able to point you towards the best treatment centers in the area and the best treatment options.

</comment><comment><USER19> Gliomas make up 80% of all malignant brain tumors. High-grade gliomas are fast growing, aggressive, and difficult to treat. Of these, glioblastoma multiforme (GBM) is the most common and the most fatal, with a reported survival rate of less than 10% in the first five years.

Interestingly, while GBM and gliomas have been highly resistant to traditional treatment, much of what is known about the demonstrated ability of cannabis to fight cancer comes from research conducted on GBM and glioma tumor cells.

Scientists hypothesize that because brain cells have the highest concentration of cannabinoid-binding receptors in the body, brain tumors also rich in these receptors may respond best to cannabinoids (chemical compounds such as THC and CBD as found in cannabis).

[http://www.cbdfarm.org/glioblastoma-and-cannabis- oil.html](http://www.cbdfarm.org/glioblastoma-and-cannabis-oil.html)

See for yourself how THC selectively kills GBM cells while leaving normal cells alone by watching this time-lapse video taken from an actual human tumor.

[http://www.cbdfarm.org/blog/medical-marijuana- news/cannabis-...](http://www.cbdfarm.org/blog/medical-marijuana- news/cannabis-kills-tumors-video.html)

[http://www.medicaldaily.com/cannabis-shrinks-brain-tumors- as...](http://www.medicaldaily.com/cannabis-shrinks-brain-tumors-associated- highly-aggressive-form-cancer-310720)

<comment><AUTHOR> Do you know if THC are now routinely used for treatment in some places, or is it just anecdotal evidence at this stage?

<comment><USER20> The advantage of THC / CBD is that they have comparatively benign side effects and even help the side effects of chemo and radiation. That being said, there's a lot of pie-in-the-sky stuff around weed and I wouldn't take it too seriously other than a quality of life thing. However, CBD especially is pretty harmless so if you can get your hands on it I doubt it would hurt. I recommended it for my grandfather who has some sort of late stage brain tumor due to lack of side effects, but he elected to forego any treatment not related to quality of life so I don't have any first hand anecdote to share. I think there is a CBD clinical trial but I'm not aware of anything very scientific outside of in vitro or animal studies. If you PM me I can put you in touch with some researchers.

</comment></comment></comment><comment><USER21> Enter the disease name in google and one of the first results will likely be the medical association that deals with the disease. Check out its web site. Others in the same situation are a good source of info so google for the disease name along with "support group" and also try the disease name and "forum". Abstracts of the medical literature summarize the state of the art and recommended protocols. Abstracts to all medical literature can be found at [http://www.ncbi.nlm.nih.gov/pubmed](http://www.ncbi.nlm.nih.gov/pubmed) . Enter the disease name in the search box on that page and then in the left hand panel click on Reviews to get all the abstracts of review papers. Registered clinical trials are shown at: [http://www.clinicaltrials.gov](http://www.clinicaltrials.gov) . In the search box on that page enter the disease name.

</comment><comment><USER4> I'd submit it's really not possible to digest the ton of information you've found with any confidence that you can pick the "right" path for your relative. After all, such large masses of information is why doctors specialize -- even they can't digest such quantities unless they spend large parts of their professional life living the information.

A better bet is to find an expert who has digested all that information, and use him or her as your guide. If you are not confident in the knowledge base carried in the brain of your relative's current doctor, you can find out the people in the world who know the most about GBM by looking here:

[http://expertscape.com/ex/glioblastoma](http://expertscape.com/ex/glioblastoma)

Disclosure: my cousin developed Expertscape.

</comment><comment><USER22> [https://www.google.com/search?rls=en&q=Glioblastoma+support+...](https://www.google.com/search?rls=en&q=Glioblastoma+support+group&ie=UTF-8&oe=UTF-8)

Start right there:

You need to find people who have gone through what your going through. Im sure some of them have already parsed this information, and would be better suited than any of us in helping to sort through it.

As for finding specialists, your current doctor, and the people he recommends are your best bets. The medical community is a strange one, and "best" is a hard term to qualify. The best doctor might have the lowest rate of curing paitents because they only take on the worst cases. The "best" doctor might be the one who understands the outcome and makes sure that your treatment matches your lifestyle and acceptance of outcome (time here vs quality of life).

Find those support groups, really go find them and USE THEM. They are going to help you and yours in a time that is going to be really rough to get through. If you knew me personally the fact that I was telling you "go find a support group" would probably shock you, as Im not the type of person you would expect to recommend or attend such a thing. They will help you, it will be hard, its going to suck, but you should do it!

</comment><comment><USER23> My daughter had cancer. Fortunately, she is still clear, but I have a pretty good idea what you are going through, both emotionally and with respect to finding qualified information. For what it is worth, I am very sorry your family has to go through this diagnosis and whatever comes next. Cancer sucks.

From everything my wife and I could find, there is no such clearinghouse that is publicly available for what is the "best info," or for readily comparing studies. Because the research on treatments is changing so rapidly, it really does take a scientist (read: your oncologist) to filter through the different papers and compare the stage-based 5y EFS rates, review risks of that treatment, and figure out the pro and con to your relative's situation to determine the best treatment protocol.

This is further complicated by the fact that not all protocols and studies are publicly available. Some groups actively hide information from public view to prevent the "Web MD" effect. The treatment protocol we ended up with for my daughter is widely used and studied in some countries, but was never before used at the hospital we were at. We felt very comfortable with it when we reviewed the literature with our hem/onc, but as the doctor was part of a particular oncology group that shares research and studies, only they could find the critical information. At one point I was looking for more in-depth details, and because of the restrictions by the oncology group, our Dr had to be very careful about what they could and could not show us. I could read some studies in their office on their screen, but could never get a copy of the PDF.

Trust in your medical team. If you aren't getting the information your family needs, ask for more. If you still feel like you aren't getting enough information, then maybe re-evaluate if you have the right medical team.

Now, all of this is written as if you get to have contact with the medical team. If the close relative doesn't want you to have access, please respect their right to pursue the treatment your relative and their doctor have selected as most effective for their highly individualized case. Support them in their quest to get the right information, but don't pry and second guess. I come from a family of medical scientists and medical professionals, and believe me, there can be a very fine line between curiosity and help, and prying.

Good luck to you and your family.

<comment><USER24> What's the "Web MD" effect?

<comment><USER8> People self diagnosing and wanting certain very inappropriate treatments without understanding what's going on underneath.

Cancer(s) are different than athletes foot in that sense. You can look picture up on webMD, diagnose yourself, go to the drug store, and buy OTC medication to treat yourself.

You can't do that with brain cancers.

</comment></comment></comment><comment><USER25> I'm very sorry to hear about your relative and I hope we are able to hear of them again :)

As an aside, my mother (who I did post about on here once under a throwaway) had stage IV brain cancer — the complexities of I'm unsure of. However, she had great, great success with marijuana and it helped her tremendously. Chemo and radiation suck, but the marijuana makes it suck a bit less.

"Had"... she is in remission :)

</comment><comment><USER26> I'm extremely sorry to hear about your relative. My mother was going through S3 colorectal earlier this year. Two tips: 1\. Quackwatch.org - the work this retired doctor has done filtering the BS across the Internet is astounding. I even emailed him and he made himself available to talk to my mom. He said, "usually all they need is another voice to calm their fears". 2\. Listen to them. Don't tell them NOT to do something. Just focus on the context and the most likely outcome. 3\. Don't let them get "advice" from patients at the local acupuncture clinic or alternative treatments center. Or from Internet "testimonials". It's all about the first-hand. Talk to the oncologist and see if you can find patients that have been through it. My mother feared the ostomy bag absolutely. A week after she had it, she forgot it was there!

The hardest part will be before surgery.

</comment><comment><USER27> Talk to oncologists. They will contextualize the material, explain it to you through the lens of actual experience, and they will be happy to refer you to doctors with a different approach or opinion. If you're up front with them about wanting to geek out over papers, they will geek out with you and give you valuable perspective.

</comment><comment><USER28> Hi, someone who has lost 2 family members and a close friend to cancer here. Not a medical person so I won't touch on that other than to say be aware that whole brain radiation brings on dementia. They typically won't use it unless it is use it or you die and they count on the idea that if they are using it means that the patient doesn't have long. At least that's what I've been told by a friend who's wife has brain cancer.

My advice is to take full advantage of every minute you have with your relative. The doctors are frequently upbeat and paint a picture that is not realistic (my dad thought he had another 3 years, he was gone in 6 months. My mother in law thought she was going back to work, she was gone in 2 months. The doctors should have been more realistic).

One of my great regrets is not pushing to get all my mother in law's friends gathered for a party. She insisted that she didn't want to do it "until she was better". She was "fine", bed ridden, but alert, mostly not in pain, we could have had a party. What I should have said was "That's cool, we'll have another one. Let's do two, I'll set it up". Instead I folded and I regret it too this day, I'm a weird dude, I actually loved my mother in law, she was a cool lady.

tl;dr: go see your relative NOW. Hang out, drink some wine, tell some stories, or just hold each other.

</comment><comment><USER29> Sorry to hear about your relative, and it's great that you're helping. I work in healthcare and uptodate.com is a godsend. It's most likely what your doctor uses to stay up to date. Here's one starting point: [http://www.uptodate.com/contents/high-grade-glioma-in- adults...](http://www.uptodate.com/contents/high-grade-glioma-in-adults- beyond-the-basics)

And then you'll see this links to a lot of more detailed articles about particular conditions.

<comment><USER30> When I talked to my doctor friends, they all mention using this.

I used it when my mom was in the hospital and it was very useful. I was able to get access at the local university library and then export all the useful articles to PDF.

</comment></comment><comment><USER31> I'm terribly sorry to hear about your close relative. Given that it is diagnosed as a stage IV GBM, you are likely looking at some combination of clinical trial based and standard of care therapy. Do not attempt to sort through the confusing web of information on the web or from publications. Many of them need the kind of context that only an academic oncologist can interpret and dont always translate to an increase in individual survival rates in a clinical setting. First and foremost, find an academic cancer center near by, preferably an NCI certified comprehensive cancer center ([http://www.cancer.gov/research/nci-role/cancer- centers/find](http://www.cancer.gov/research/nci-role/cancer-centers/find)). Secondly if your relative is willing and understands the risks, find them an applicable clinical trial to enroll into. The biggest obstacles to effectively treating GBM are the location of the tumor(s), the existence of the blood- brain barrier and the highly aggressive nature of tumor growth. All the best and I really hope you and your relative can find the strength to get through this difficult phase.

</comment><comment><USER32> For treatment today you probably want to look at either Cochrane Collaborations - meta reviews of many published papers. You can also check out the NICE guidance. The evidence they use might be useful to see if stuff works or not.

[https://www.nice.org.uk/](https://www.nice.org.uk/)

[http://www.cochranelibrary.com/](http://www.cochranelibrary.com/)

</comment><comment><USER33> [http://www.uptodate.com/](http://www.uptodate.com/) has good information, but it is paid. From Clinicaltrials.gov you can get lots of information, and then start research on the molecule or protocol. Pubmed has lots of interconnected information. Best option is to find a specialist, a good understanding with doctor is important so that you can be more open with him.

</comment><comment><USER34> I was diagnosed with a low grade diffused tumour about a year and a half ago after having a seizure at 26. I understand the difficulty of having to grok through all that terse information. That said, I found [http://astrocytomaoptions.com/](http://astrocytomaoptions.com/) by Stephen Western to be a helpful portal of information.

All the best to you and your family.

</comment><comment><USER35> [http://www.cancer.gov/about-cancer/treatment/clinical- trials...](http://www.cancer.gov/about-cancer/treatment/clinical- trials/search) is helpful for finding clinical trials and allows filtering down to a region. Be aware that you can get treatment in major cities and get free lodging provided by the American Cancer Society. For example, in Boston you and your loved one can stay at Hope Lodge, [http://www.cancer.org/treatment/supportprogramsservices/hope...](http://www.cancer.org/treatment/supportprogramsservices/hopelodge/boston/boston- about-our-facility), for free and be within walking distance of Dana Farber and Brighams or take a train to MGH. Wish you and your loved one the best!

</comment><comment><USER36> This advice is just to check out personalized medicine, in which they determine the exact cancer you have and clinicians employ a medical database to put together treatments to target your exact cancer.

Check it out: [http://www.foundationmedicine.com/](http://www.foundationmedicine.com/)

-Warren

<comment><USER37> Very good advice. Another good resource is [https://www.patientslikeme.com/](https://www.patientslikeme.com/)

</comment></comment><comment><USER38> Sorry to hear about that.

My mother was diagnosed with glioblastoma. She had the "standard" treatment, surgery to remove as much of the tumor as feasible, radiation and chemo. In the end, she passed away in about 4.5 months from her initial diagnosis. The doctors had originally given her 1-2 years; I don't know if that was just an optimistic estimate in order to give some hope, or whether my mother just happened to be one of the cases which didn't survive the average estimate (everyone can't beat the average...).

Due to other life circumstances, I didn't have that much opportunity to research the issue, but my takeaway was basically that you can group stuff you find on the internet into 3 groups: A) research, results which may be inconclusive or at least not dramatically better than the standard treatment B) desperate grasping at straws, typically by patients or their kin, not experts in the field C) scams prying on the emotional anguish of the affected persons. So my conclusion and recommendation would be to trust your oncologist, and/or if you want another opinion, ask another oncologist. Unless you're an expert able to distinguish the wheat from the chaff, don't put to much trust into whatever you may find on the internet. (FWIW, I have a research background, although not in medicine; YMMV.)

Beyond the medicine and treatment thing, a few other points:

Realize that glioblastomas have _extremely_ poor 5-year survival rates (or however you wish to measure it). While a positive attitude is always important in dealing with any serious disease, the bottom line is that, most likely, your relative will pass away within a couple years. There is no miracle cure.

IOW, perhaps rather than obsessing over whatever cures may be brewing in research labs, focus on your relatives quality of life for whatever time she/he may have remaining. Also keep in mind that brain cancers are nasty in that they can change the personality of the patient, and towards the end they can get more and more incoherent, sleep more and more and eventually go into a coma. So if you have something important to say to or discuss with your relative, do it ASAP rather than wait until it may be too late.

My family, including my mother, took solace in that she had lived an almost full life, she was on the verge of retirement etc. I can only hope that your relative is also older, for a younger person I can only imagine how utterly devastating and hopeless it must be.

Best of luck to you and your relative.

</comment><comment><USER39> Where is your relative living? Typically the university hospitals have the best experts, ie UCSF and Stanford in the SF Bay Area (although for a GBM, I'd recommend UCSF). There are various ranking sites that list the best hospitals and in my experience, they're a good place to start.

I know it feels productive to start reading as much as you can about the disease pathology and treatments, and it won't hurt to be more informed, but for a stage IV GBM, your time would be much better spent trying to get hooked up with the best docs in the country. It's a terrible thing to deal with and some doctors have spent decades immersed in the research and literature -- let them be the experts but make sure you find someone who can give your relative a chance.

</comment><comment><USER40> There are folks that you or your close relative can talk to at [http://www.abta.org/](http://www.abta.org/) American Brain Tumor Association. They can point you to care options, support groups, and quality of life issues.

</comment><comment><USER41> [http://www.theguardian.com/society/2012/feb/08/how- doctors-c...](http://www.theguardian.com/society/2012/feb/08/how-doctors- choose-die)

</comment><comment><USER42> A physician might be your best tool. In cancer, there are a staggering number of clinical trials (which are typically the mechanism to get the latest therapies before approval). In most cases, the standard of care is supplemented with the novel therapy.

If your family member is interested and willing to travel, it would be reasonable for them to ask for a second opinion at one of the major cancer centers and/or to ask if there is a trial in which they might participate.

If your family member wants to stay local, then I'd still ask their oncologist if there is a GBM specialist in the area whom your family member can meet.

</comment><comment><USER43> I'm no expert, but I've lost two parents to cancer, so I have a sense of the limitations to treatment. With every proposed therapy. Make sure you get an accurate idea of the range of possible results - best and average case time of survival and the impact on your loved one's quirky of life.

Most physicians will advocate the treatments that offer the best hope and prospect for survival, often overlooking the terrible cost to what time the patient has left.

Please don't lose perspective on the most likely outcome while holding out hope for the best.

</comment><comment><USER44> On finding specialists. Call all the oncologists you can in your area and ask them if they are specialist for this type of cancer, if they aren't ask them they know a specialist.

</comment><comment><USER45> That's what oncologists do. You aren't going to learn oncology in a week.

So don't find a treatment, find the best cancer treatment center you can get the patient admitted to.

</comment><comment><USER46> There is T.h.e. Brain trust that hosts online support groups for brain tumor patients and caregivers. I am on the adult ependymoma mailing list. It is a good way to find specific hospitals and doctors to get in contact with. The ependymoma list has a couple of doctors that regularly communicate on specific questions.

Their GBM specific list is here

[http://braintrust.org/groups/gbm/](http://braintrust.org/groups/gbm/)

Edit:spelling

</comment><comment><USER47> It doesn't really answer your questions but you might check out the Fred Hutchinson Cancer Research Center. They had one cure and one still alive out of 7 patients with a new treatment.

[https://www.fredhutch.org/en/news/center- news/2014/08/Gliobl...](https://www.fredhutch.org/en/news/center- news/2014/08/Glioblastoma-treatment-boost-brain-tumor-survival.html)

</comment><comment><USER48> U.S. News and World Report to find the best hospitals.

[http://health.usnews.com/best- hospitals/rankings](http://health.usnews.com/best-hospitals/rankings)

Castle Connolly to find the best doctors. A small fee but worth it.

[http://www.castleconnolly.com/doctors/](http://www.castleconnolly.com/doctors/)

</comment><comment><USER49> There are many suggestions here, but make sure to check Cancer Commons community out as they are trying to help patients and their close relatives for exactly this type of queries: [https://www.cancercommons.org/home](https://www.cancercommons.org/home)

</comment><comment><USER8> If you know people at Microsoft Research, they have computational biology groups based out of Cambridge, UK and New England (Cambridge, MA) in association with Harvard and a number of hospitals there.

The research topics they are (or were) looking into is actually Glioblastoma. Apparently as a cancer, it has an extremely complex protein, rna, dna pathway that is bidirectional, making it one of the most complicated and dirty big data sets out there. There are also a signfigant number of problems with Glioblastomas related to computer vision, dosing, ect. Either way, Microsoft research Cambridge/new england does a lot of research on Glioblastoma.

So for example: this paper on stiener trees for big data research was used to find new protein markers for glioblastoma - [http://research.microsoft.com/en- us/um/people/borgs/Papers/P...](http://research.microsoft.com/en- us/um/people/borgs/Papers/PathwaysViaSteiner.pdf)

Those protein markers may/may not be in early stage development for drugs - <USER2> is worth asking around about this.

Here is another about imaging in the brain:

[http://research.microsoft.com/apps/pubs/default.aspx?id=1643...](http://research.microsoft.com/apps/pubs/default.aspx?id=164382)

If you have contacts there, this would be a good place to go hunting for help.

Other things:

get help for you. This is stressful for you too. You may be healthy, but you do have worries, thoughts, and feelings about the future right now, and they deserve to be heard out and understood to the fullest for your own health. Do something about it in advance. It isn't selfish - if you are involved in the care of this relative, you need to be able to care about the highest quality you can, which means making sure you are taking care of yourself.

Call the big research hosptials for this type of cancer, and find out the name of patient advocate groups, and people who are allied. These groups usually have conferences, chat boards, email lists, ect. They host them where ever (facebook, websites designed for patients to come together, private websites they built themselves, google groups, what have you, don't expect awesome). They often pass around papers, studies, ect, among themselves. They talk about life issues. They'll be able to share some of the stresses you're going through in ways other people might not.

</comment><comment><USER50> I don't know anything personally, but I know someone who works at Foundation Medicine. They do genetic-based cancer therapy recommendations based on tumor sequencing. It might be worth looking into.

</comment><comment><USER51> [http://cancerhawk.com/navigator](http://cancerhawk.com/navigator) is a search tool to find local specialists for particular cancers types

</comment><comment><USER52> uptodate.com is a standard medical reference used by many doctors. Perhaps start there?

Warning: it's a subscription service.

</comment><comment><USER53> Isn't notable labs (yc '1x) working specifically on doing evidence-based prescriptions for GBM?

</comment><comment><USER15> I'd watch Louis Theroux's "Edge of Life".

</comment><comment><USER54> anon3315's [oddly] dead comment:

(See my comment below for context, currently undergoing chemo). Just wanted to comment that I'm a huge fan of Genentech. They developed Ritiximab (Rituxin) which I'm currently getting treated with. It's a monoclonal antibody as you mention and it's improved outcomes for my condition (DLBCL Non Hodgkins Lymphoma) by around 15%. It's given in combination with traditional 'CHOP' chemo and is called R-CHOP. It's also insanely expensive - about $5K per dose and I get 6 doses over 18 weeks.

I found my local doc was awesome when I got a second opinion from Mass General and then moved treatment to a major regional center in my local town. They moved very quickly and were cooperative. So didn't have a bad experience there personally, but YMMV.

<comment><USER55> Thanks. I posted about 1000 words below on this account and signed in on my non-anonymous account and they're completely invisible. I've been on here 4 years guys and just don't really want the world to know I have cancer. So would be nice to at least let it be visible and get downvoted rather than effectively delete something I took a good 20 minutes to write.

<comment><USER56> Your anon account got hit by a spam filter. Sorry; those are tuned more aggressively for new accounts. We've unkilled its comments and marked it legit so this won't happen again.

We're soon going to release a feature that will allow community members to unkill dead comments, so fixing this kind of situation won't depend on mods happening to see it for too much longer.

The only reason we knew about this to fix it was that a user helpfully sent an email. Please, everybody, follow the guidelines and let us know about problems that way, rather than complaining about them in the threads. It's physically impossible for us to read all the threads.

<comment><USER55> Thanks.

</comment></comment></comment></comment><comment><USER57> Mods should probably un-shadowban sibling commenter anon3315.

<comment><USER58> I've noticed people on HN are quick to punish with downvotes and shadowbanning. Why is that?

<comment><USER56> People on HN aren't quick to ban accounts, because only moderators can do that and we only do it in egregious cases.

People on HN _are_ quick to conclude that accounts are banned when they're not. That has been a local pastime for years. If some software we've been writing works as intended, though, this will soon change for the better.

</comment></comment></comment><comment><USER59> > People on HN aren't quick to ban accounts, because only moderators can do > that and we only do it in egregious cases.

But that's just not true though is it. :( In the past, rankbans have been given out rather spontaneously it would seem. Even to folks who one would not deem are problematic (like larrys, mindcrime, DanielBMarkham, etc.).

Anyway, it's fine.

<comment><USER56> [https://news.ycombinator.com/item?id=10090474](https://news.ycombinator.com/item?id=10090474)

</comment></comment><comment><USER60> This isn't a direct answer to your questions but I hate this disease with a passion and any discussions about mainstream research avenues that ignore other less well-accepted forms of treatment get my emotions in a whirl. (My sister died of brain cancer.)

Please consider researching the benefits of marijuana in your efforts to help your relative. It provides tremendous relief for pain and nausea and cannabinoid treatment causes cancer cells to commit suicide. [1]

My thoughts are with you and your family.

[1] [http://valme.io/c/diseases/cancer/52qqs/enough-of-this- nonse...](http://valme.io/c/diseases/cancer/52qqs/enough-of-this-nonsense-as- this-molecular-biologist-states-cancer-cells-commit-suicide-when-exposed-to- the-primary-psychoactive-component-of-marijuana-thc-marijuana-laws-must-be- eliminated)

</comment><comment><USER55> Hi. I'm a regular here but posting anonymously for privacy reasons. I was diagnosed with Stage 3e Non-Hodgkins Lymphoma earlier this year (about 12 weeks ago). I had to climb a very steep learning curve very quickly and start treatment asap because it's a fast moving disease and early treatment is key. (In my case)

I don't know much about GBM, but I wanted to give you some general advice. My first oncologist seemed great, but my wife pointed out that he was 'interviewing for the job' and there is no reason to not find the best available doc. So I googled like crazy, found a few great lymphoma clinics and settled on Mass General in Boston after chatting to them on the phone. I flew out there (6 hour flight) and spent a week getting a second opinion including PET/CT scan. It was so very very worth it. From the amazing doc there I got a referral to a world-class local clinic and well known oncologist in my local town and started treatment within a week.

So I'd encourage you to A) Move quickly, especially if it's aggressive and B) Get a second opinion to make sure you get the best treatment available.

It's actually difficult to do both. But what I found is that the first oncologist I worked with was actually not moving as fast as he could have. The local hospital had about a 9 day wait time for my initial PET/CT scan and my doctor could have scheduled it a day or two earlier but he just didn't get around to it. By flying out to Mass General I got my scan earlier because there's less of a wait and I got a doctor and team who move very very quickly.

With what I have (DLBCL Non-hodgkins Lymphoma), there are various genetic subtypes and tons of literature. I had my pathology sample sent to mass general for further DNA level analysis and ended up with a ton of literature and the doc was happy to have conversations as technical as I would like. What I realized is that I don't have the background to understand much of the literature. (I'm smart, but not in medicine) Also the percentages you deal with when you read about outcomes become meaningless because the studies are done on groups and every individual case is different. So what seems to be the best approach is to get access to the best minds in the business and have them guide you on diagnosis, interpreting results and treatment. I have now worked with three oncologists and two of them have been incredible and are world- class in their field. That seems to be working out quite well.

I would also add that it's not just about finding a great doctor. It's important to find a great team. That means: admissions nurse, scheduler (very important because with some treatments it's critical you don't miss a dose or schedule), other nurses who administer treatment and so on. The team at Mass General Lymphoma clinic is amazing. If you're reading this and do have lymphoma, get in touch with 'Mutsi' the admissions nurse, and try to get scheduled with Dr Effi Hochberg who is an amazing amazing guy and affiliated with Harvard Medical School. I'd hope that your friend can find a similar clinic that has a great team and doctor and is really great at treating GBM.

Some further unsolicited and anecdotal comments that might help your friend:

I've just finished my third cycle of R-CHOP (my particular flavor of chemo), feeling great and looks like I might actually beat this thing. Getting a CT scan in about 3 weeks to find out more.

I've kept this whole thing private except for a small group of about 15 very close friends and relatives who know. They have been incredibly supportive and what has really helped me is just talking to my friends in person or on the phone. I'm generally a very positive and energetic person and I seem to be offering them more life advice than them giving me support, but just talking about anything, whether related to the disease or just unrelated stuff, it REALLY helps keep me energized and positive and generally happy. So I'd encourage you to make yourself available without being overbearing and suggest your friend connects with those close to them and stays in touch. What I've done is send out an update every 3 to 6 weeks to my core group just letting them know how I'm doing etc and that leads to further conversations.

Also I've managed to keep mountain biking and running during chemo which is a little unusual, but it's kept me sane. Some advice I got was to not 'stop everything' while dealing with this. I don't know what your friend's physical situation is but if they can keep their life as normal and ongoing as possible it will (in my experience) keep them much more positive and energized and generally happy. Symptoms vary so much and I know this from my treatment facility and seeing the huge spectrum of physical conditions as people go through treatment - so totally understand this may not be possible. But if it is I'd encourage it.

Getting a diagnosis like this is crazy. You actually have to develop a sense of humor about it I think because it's just one of those things that is supposed to happen to other people. Not you. I think everyone has their own way of dealing with it, but for me what has worked is to have a bit of a sense of humor about it and then to focus on the problem aggressively and stay positive.

Best of luck to you and your friend.

<comment><AUTHOR> Thanks for sharing your story, this is somewhat comforting. We'll try our best.</comment></comment>


Practical Guide to Bare Metal C++ - <AUTHOR> https://www.gitbook.com/book/arobenko/bare_metal_cpp/details <comment><USER2> [https://news.ycombinator.com/item?id=12138374](https://news.ycombinator.com/item?id=12138374)

</comment><comment><USER3> I traditionally haven't been the biggest fan of this book. Most of what they list is stuff that just looks like using C++ just for the sake of it, with no real benefit over a C codebase.

For instance they don't appear to use RAII at all, even in places where it's an obvious win (InterruptLock).

<comment><USER4> I tried searching the book for RAII and there are no hits...

Do they really not cover it or is the search busted ?

<comment><USER5> I don't think RAII is a concept complex enough to write a book about it... Probably a blog post or Wikipedia page is enough to explain it fully.

<comment><USER3> It's worth a chapter in this book IMO.

As the maintainer of a C++14 proprietary RTOS, it's probably the most convincing argument to the C guys as to why C++ can benefit embedded codebases. Like not being able to forget to re-drop thread priority when you've temporarily increased it.

Or one of my favorite patterns is returning the object representing the temporary higher priority. If the caller doesn't do anything with the return value, the destructor is called and thread priority reverts to what it was. However, it gives you a chance for the caller to hold on to that high priority object, and get more work done essentially atomically.

<comment><USER6> But the compiler doesn't optimize out the constructor, right? It can't.

In an RTOS of all places, that seems awfully expensive. One generally avoids wasted resources in embedded -- the trade-off is it requires more care during development.

I've never seen RAII work well in an embedded system. Not being able to handle exceptions or errors during destruction ruins everything.

<comment><USER7> Disabling exceptions has solved this. There are no need for exceptions in the kernel, and the cost is high.

<comment><USER8> Isn't table-driven stack unwinding cheaper than having a bunch of functions each check an error code and return to their caller?

<comment><USER3> The practicalities of bare metal programming means that a lot of the time an individual work item has to jump contexts (ie. stacks and register sets) in a way that doesn't map cleanly to C++ style exceptions.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER9> Without exceptions most of your STL containers become unsable, unless aborting is an option when otherwise bad_alloc would get thrown.

Also without exceptions you really need double initialize pattern for your class types. I.e. a ctor that cannot (and will not throw) and then a "error_code Init(...)" method that can return an error code.

<comment><USER10> Yea, I've always wondered, for shops that try to make that "C++ but without exceptions" policy work, how do you handle things like vector::push_back() or map::operator[] failing? Just throw up your hands and crash?

<comment><USER11> I didn't read the book but if you're "bare metal" you want to avoid dynamic allocations in the place. Secondly, if you really run out of memory then you've screwed up something really badly and yes, in these situations your best option is to let the watchdog eat your poor carcass.

<comment><USER12> What you really want to do in these cases is log debugging info to a noinit section of memory or nonvolatile memory and then reset the processor. Then the firmware can check for and report any logged errors on startup. If you do this religiously you might make it to fifty with most of your hair.

<comment><USER3> Also, for those programmers who have some input on the EE's designs, a stuff option for MRAM is amazing. It's essentially equivalent to battery backed SRAM, but one chip. We stick logs and hardware exception stack traces/register dumps in there on dev units.

</comment></comment></comment></comment></comment><comment><USER13> RUST

</comment><comment><USER14> This is a fine "long answer" to the question _how do I write C++ on bare metal?_. The short answer is _don 't_, medium is _if you don 't know why every major operating system at every size is written in C, then you have a lot of learning to do_.

<comment><USER15> Windows is well known to have portions of the kernel written in C++, and MacOSX has huge portions written in ObjectiveC. The greater part of Android is Java-based.

Only Linux is really purely C-based, since Linus really hates C++ with a passion. But there's a reason why even the GCC project has moved over to C++.

[http://lordjeb.com/2013/09/19/modern-c-in-the-windows- kernel...](http://lordjeb.com/2013/09/19/modern-c-in-the-windows-kernel/)

<comment><USER14> "Only linux" And every BSD, Magenta (a brand new kernel), ThreadX, FreeRTOS, QNX, Integrity, HP-UX, SeL4, Illumos, TI-RTOS, RTEMS...

XNU does not appear to have any Objective-C in the kernel, and it has no C++ in the scheduler, syscall handler, or any other critical section. I doubt Windows has C++ in any such place either.

Inside the XNU tarball (the actual kernel inside OS X) there are 1,078 C source code files containing 652,124 source (not comment, not whitespace) lines. There are exactly 10 Objective-C files containing a total of 1787 code lines, and it's not certain they are even built as part of the kernel binary.

To be fair, there is some amount of C++ in XNU these days. XNU contains 97 C++ files totalling 68,673 code lines, it seems mostly in iokit[50kSLOC] and libkern[17kSLOC] (infrastructure to support the iokit C++ code, maybe).

<comment><USER15> > I doubt Windows has C++ in any such place either.

[https://msdn.microsoft.com/en- us/library/jj620896.aspx](https://msdn.microsoft.com/en- us/library/jj620896.aspx)

Hint: This exists for a reason.

Another note: Window's Kernel exposes an API for custom user-mode task- scheduling (Called UMS). Its API is accessible from C++: [https://msdn.microsoft.com/en- us/library/windows/desktop/dd6...](https://msdn.microsoft.com/en- us/library/windows/desktop/dd627164\(v=vs.85\).aspx) . When you get to the ConcRT stuff (which is built on top of UMS), its C++ code for sure: [https://msdn.microsoft.com/en- us/library/ee207192.aspx](https://msdn.microsoft.com/en- us/library/ee207192.aspx)

Nearly direct-access to the GPU is also done through a little C++ API called DirectX.

[https://msdn.microsoft.com/en- us/library/windows/desktop/dn7...](https://msdn.microsoft.com/en- us/library/windows/desktop/dn788656\(v=vs.85\).aspx)

DirectX is very C++, using namespaces and stuff. Its a bit wonky because DirectX itself is older than C++98, but its clearly a C++-based API. Its very efficient and performant too.

<comment><USER14> > Nearly direct-access to the GPU

Not sure what you consider "near", but I certainly wouldn't consider even Direct3D 12 to be anywhere "near" direct access to the GPU. It doesn't expose the shader ISA, it doesn't expose the command stream format, it doesn't expose the register sets.

The user mode scheduler is not the system scheduler, thus my statement holds.

<comment><USER15> > Not sure what you consider "near", but I certainly wouldn't consider even > Direct3D 12 to be anywhere "near" direct access to the GPU. It doesn't > expose the shader ISA, it doesn't expose the command stream format, it > doesn't expose the register sets.

Of course, none of those are important.

The important bit to expose are exposed. IE: The memory-model of the GPU. CPU memory space vs GPU memory space, such as Residency: [https://msdn.microsoft.com/en- us/library/windows/desktop/mt1...](https://msdn.microsoft.com/en- us/library/windows/desktop/mt186622\(v=vs.85\).aspx).

Indeed, the ability for C++ to create abstractions that can track memory spaces in DirectX is proof positive that C++ has useful features applicable to the OS developer.

[https://msdn.microsoft.com/en- us/library/windows/desktop/mt6...](https://msdn.microsoft.com/en- us/library/windows/desktop/mt613239\(v=vs.85\).aspx)

\</comment></comment></comment></comment></comment></comment><comment>-

Note that both CUDA and OpenCL support C++ features as well. The RAII feature of C++ alone is a huge benefit to anybody tracking what bits are where in OS settings. Have you tried to use C++ in the last 10 years?</comment>


Scientists to unveil new Earth-like planet - <AUTHOR> http://m.phys.org/news/2016-08-scientists-unveil-earth-like-planet.html <comment><USER2> Project Longshot estimates 100 years to reach Alpha Centauri B. And that's assuming we launch tomorrow. Add 4 years to receive the telemmetry.

[https://en.wikipedia.org/wiki/Project_Longshot](https://en.wikipedia.org/wiki/Project_Longshot)

<comment><USER3> That's ~1000 times the velocity of our fastest probe so far when you exclude gravity assist. Stopping at the other end doubles travel time.

<comment><USER4> > Stopping at the other end doubles travel time.

Wow, I knew the physics but never realized the implication: where on earth hitting the brakes is easy and costs next to zero energy, in space breaking takes just as much energy as accelerating.

<comment><USER5> I know it's a game, but Kerbal Space Program really helped hammer home a lot of the things I guess I understood in the abstract. Delta-V is Delta-V. Every change in velocity (ignoring external influences) is cost out of the same budget. Braking is just accelerating in the opposite direction.

<comment><USER6> Before I played KSP I had a lot of hilarious misconceptions about the physics of rocketry and space travel.

On my first attempt to get into orbit, I loaded up my rocket with as many engines and boosters as I could strap on and fired the rocket straight up. The rocket breached the atmosphere but to my surprise the rocket came straight back down. I literally thought that launching rockets into orbit meant shooting them really high until they were "in space" haha. I then quickly learned that being in orbit means having a horizontal momentum that is balanced with the gravitational pull of a given body. This balance produces a curved elliptical trajectory.

<comment><USER7> And you have to _decelerate_ to catch up to the station in orbit. If you accelerate you will fall back.

That's because if you fire your rockets to accelerate you end up in a higher orbit, i.e. your circle is much bigger, and vice versa, to overtake/catch up you want to fall to a lower orbit. That's also not intuitive to someone with "earth-experience".

<comment><USER8> Yet objects in higher orbits like the moon are going way slower around the earth than low earth orbits.

What's the deal with that?

<comment><USER9> Higher circular orbits are indeed slower than lower ones. The shuttle goes around the earth in 90 minutes, the moon takes 28 days. Geosynchronous orbit, where one orbit takes one day, is in between.

What's confusing about transfers is that elliptical orbits are orbits where your velocity varies based on where you are in the orbit. Your speed is highest at perigee and lowest at apogee. In fact, your speed at perigee will be higher than the speed of an object in a circular orbit at that altitude. The reverse is true at apogee; your speed will be slower than an object in a circular orbit at the same altitude.

So if you and your docking target are both in circular orbits, and you increase your speed in order to catch up, then you will simultaneously be raising the other side of your orbit, half a turn away. The difference at your current location will be minute, but will grow every continuously over that half a turn. If you're docking in the next few seconds it won't be a problem (the docking mechanism will handle a small offset, and it equalizes your speeds provided the difference isn't too much). If you're still several minutes away, however, you might find that the extra radial velocity means that you fly over the top of your target.

If you miss and continue to follow your new orbit you will indeed find that your overall time to orbit is now higher than your target's. It may be many orbits before you again have a close approach with your target, although if the difference in speeds is small then it may appear from your perspective that you are in fact orbiting your target.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER10> It took 9.5 years for New Horizons to reach Pluto (just 32 astronomical units distant). At that rate, it would take a probe more than 80,000 years to cross the 271,000 AUs separating Earth from this exoplanet.

<comment><USER11> That presumes a constant velocity. Any extra-solar ship would certainly need a different acceleration profile. Ion engines come to mind: low acceleration, but constant for a very long time. If you're going a far distance, they're ideal.

<comment><USER12> While you have a valid point, here's what it works out for ion engines.

Assume you want 1,000 years to Alpha Centauri and your ship boosts the entire way. (It'll take a few pictures as it flies through the system.)

      s = 1/2 a t^2
      a = 4.22 light years * 2 / ((1000 years)*(1000 years)) = 8 E-5 m/s/s

Sounds great, right? But the final speed is:

      v = a * t = 4.22 light years * 2 / (1000 years) = 2.5E6 m/s = 0.8 c (!)

Let's say your engine has a ISP of 8000 s, which is about 10x better than anything we have.

Then from the rocket equation you'll need a dry weight (payload, engines, etc.) to propellant ratio of

      e^(2500000 / (9.8 * 8000) = 70,579,094,313,732 = 71 quadrillion
      eg, 1 gram of spacecraft requires 70 kilotons of propellant

But wait, there's more! It takes power to push 70 kilotons of propellant backwards at 80,000 m/s.

      E = 1/2 * m * (v^2) = 2E20 Joule
      Since E = m c^2
       => total annihilation of over a ton of antimatter

Almost certainly more as that assumes 100% efficiency. And of course that extra ton isn't propellant, so it hits you in the rocket equation.

Note: I am not a rocket scientist and likely made mistakes. Even if I'm off by a few zeros, it's enough to show that an ion engine isn't going to get something to Alpha Centari within a few centuries.

<comment><USER12> Oops! There's a couple of missing zeros. The 2.5E6 m/s = 0.8 c should be 0.8% c. That mistake doesn't continue to the rest of the calculation.

</comment></comment></comment></comment><comment><USER13> I don't think there are electronic or software components today that can withstand interstellar space travel for thousands of years, even at the distance of proxima centauri.

Distance is irrelevant when it comes to space travel. Unless an object is within the vicinity of the Oort cloud, we stand very little chance of actually leaving this solar system in a controlled fashion.

<comment><USER14> Well, the key is to not take thousands of years about it. Honestly, I doubt we will ever have thousand year missions, unless our lifespans commensurately grow, as humans don't have a great track record when it comes to long term projects.

There are ways, but they are expensive and not without risk. Nuclear pulse propulsion (orion) can yield vast acceleration, and fusion rockets, while unproven, are feasible. You then have less exotic options such as laser driven light-sails and nuclear powered ion drives.

If we were prepared to throw half a trillion bucks at the problem we could see a flyby in our lifetimes - but without a damn good reason, it won't happen.

</comment></comment><comment><USER15> I wonder if the James Webb Space Telescope will be able to image it since it's so close.

<comment><USER16> Can anyone "do the maths" on this. I don't feel well enough equipped, but I'd love to know the feasibility of this, or what we would be able to image if anything.

<comment><USER17> A planet the size of the earth at the distance of proxima centauri is about 6.582⋅10^-5 arcseconds wide (a 20'000th of an arcsecond)

angle(in degrees) = size / distance / pi ⋅ 180°, take times 3600 for arc seconds

[https://www.wolframalpha.com/input/?i=(diameter+of+the+earth...](https://www.wolframalpha.com/input/?i=\(diameter+of+the+earth\)%2F\(distance+to+proxima+centauri\)+%2F+pi+*+180+*+3600)

I didn't find a easy round number for James Webb, but Hubble's angular resolution is 1/10th of an arcsecond, at least a factor 2000 too low to even resolve the planet's disk as one pixel.

[https://www.spacetelescope.org/about/faq/](https://www.spacetelescope.org/about/faq/)

<comment><USER12> [http://jwst.nasa.gov/faq_solarsystem.html#angularresolution](http://jwst.nasa.gov/faq_solarsystem.html#angularresolution) says:

> The specification is that the telescope is diffraction limited at 2 μm, > which means a Strehl ratio of 0.8 and a wavefront error of 150 nm rms. With > a 6.5 m telescope, 1.22 λ/D = 0.077 arcsec at 2 μm. The smallest pixels > (NIRCam 0.6-2.5 μm) are just 0.034 arcsec. But a lot of the wavefront error > is due to imperfect alignment of the parts, and it's possible to do better > for a small part of the field of view.

A telescope can still detect something smaller than its resolution. We can see stars with our eyes, after all. Even astronauts in space, where there is no atmosphere to move the light around. Here are some of the best attempts at direct imaging with a telescope: [http://www.planetary.org/explore/space- topics/exoplanets/dir...](http://www.planetary.org/explore/space- topics/exoplanets/direct-imaging.html)

The problem is the planet is dim and close to a bright star. If this planet is 1 AU out, then there's a 0.77 arcsec between it and the the star, which would make it easier to distinguish the two.

<comment><USER18> Quantum telescopes should get us beyond the diffraction limit

[http://arxiv.org/pdf/1508.04275v4.pdf](http://arxiv.org/pdf/1508.04275v4.pdf)

</comment></comment></comment></comment></comment><comment><USER19> Moving matter around takes far too long for star travel. We need to figure out how to assemble machines from long distances using light. (Something like [https://en.wikipedia.org/wiki/Optical_tweezers](https://en.wikipedia.org/wiki/Optical_tweezers))

<comment><USER20> Why not just launch a seed factory and send the instructions to build via light?

That seems a hell of a lot more practical and cost effective

<comment><USER21> Also more possible haha. It's all fun and games until you predicate the success of your project on trying to collimate a laser beam from here to alpha centauri, so that it can manually assemble a (dielectric!) robot one piconewton at a time.

</comment></comment></comment><comment><USER22> This is extremely exciting! The million dollar question is of course "how Earth-like?". If the answer is "very" we might actually have found a viable place for an off-world colony!

Getting a probe there in a reasonable time is entirely feasible if can figure out how to keep the darned thing accelerating without stupendous fuel requirements. I'm confident we'll figure that out sooner or later.

<comment><USER23> Keep dreaming. If we cannot even understand or live in accordance with the life support systems of what is literally the most habitable and human- friendly planet in the Universe then there's no way in hell that we will be able to successfully colonize a lifeless planet.

Stop thinking about outer space when we are in the middle of an anthropogenic mass extinction here on planet Earth.

<comment><USER24> I'm going to assume this is a serious comment and that you are attributing global warming as the cause of the feared extinction.

In that case I think you should dial it back a bit. Humans are pretty adaptable. Even assuming the changes in temperature and sea-level are on the high end of predictions, we will adapt. People will move, infrastructure will be built, and so on. Mass extinction certainly isn't going to happen from global warming as we understand it today.

You might argue there there will be mass casualties, but that is also uncertain, difficult to quantify, and is quite a different thing than 'mass extinctions'. Of course, mass casualties due to weather has and is already a problem -- it isn't something that is uniquely associated with global warming.

<comment><USER25> > Mass extinction certainly isn't going to happen from global warming as we > understand it today.

I assume the parent is referring to the [https://en.wikipedia.org/wiki/Holocene_extinction](https://en.wikipedia.org/wiki/Holocene_extinction) which is certainly happening, and has been for thousands of years.

Climate change is a rather recent contributor, albeit a very serious one of which we've only glimpsed the beginning.

</comment></comment></comment></comment><comment><USER26> I vaguely recall a quote saying that if an Earth-like planet was ever found around Proxima Centaury, an international project to build an interstellar probe would begin immediately.

Well, we'll see.

</comment><comment><USER27> Can't wait for the "small furry creatures from Alpha Centauri" memes.

</comment><comment><USER28> It's probably Trisolaris</comment>