Paralyzed man regains use of arms and hands after experimental stem cell therapy - <AUTHOR> https://stemcell.usc.edu/2016/09/07/paralyzed-man-regains-use-of-arms-and-hands-after-experimental-stem-cell-therapy-at-keck-hospital-of-usc/ <comment><USER2> The Australian of the Year (just announced yesterday, January 26th being our national day), was Emeritus Professor Alan Mackay-Sim [http://www.abc.net.au/news/2017-01-26/the-amazing-work-of- pr...](http://www.abc.net.au/news/2017-01-26/the-amazing-work-of-professor- alan-mackay-sim/8214882)

He performed pioneering work taking a type of adult stem cell from the nose and showing how it can be be used for spinal repair. A polish paraplegic, Darek Fidyka, regained the ability to walk following surgery in 2014 using this research findings. [https://en.wikipedia.org/wiki/Darek_Fidyka](https://en.wikipedia.org/wiki/Darek_Fidyka)

<comment><USER3> The paraplegic in question can now ride a bike! [http://www.bbc.com/news/health-35660621](http://www.bbc.com/news/health-35660621)

<comment><USER4> The former paraplegic in question can now ride a bike! [http://www.bbc.com/news/health-35660621](http://www.bbc.com/news/health-35660621)

FIFY

</comment></comment></comment><comment><USER5> This is very exciting. This type of work can even benefit people who aren't paralyzed — damaged cartilage can also be repaired this way.

When I ran track in college, I somehow developed focal cartilage defects in both knees. This brought my running career to a halt and made walking extremely painful for about a year. In an attempt to fix this, I had a type of surgery known as the OATS procedure performed. This is where the surgeon takes a plug of undamaged articular cartilage from a low load bearing region of the knee and swaps it with the damaged cartilage. Walking is mostly pain-free for me now, but it still hurts too much if I attempt to run.

As though one cartilage injury weren't enough, I somewhat stupidly decided to take up weight lifting after I couldn't run anymore and attempted to set down a barbell that was way too heavy for me. In doing so, I triggered a mild lower lumbar disc herniation. So now I have two permanent injuries. Luckily, neither injury is very severe, so some days I don't even notice the pain while other days it approaches mildly annoying "background noise".

These types of cartilage injuries are common, and arthritis is even more common. But the issue with cartilage is that once it's damaged, it doesn't heal on its own because cartilage has no vascular system. You can break all the bones you want and eventually they will heal, but damaged hyaline cartilage will not. The best that your body can do is to produce "low-quality" fibrocartilage in place of the damaged hyaline cartilage.

Fortunately, there's been a lot of research over the last decade on using mesenchymal stem cells (taken from your own bone marrow) to regrow true hyaline cartilage as opposed to fibrocartilage. The stem cells have actually been shown to differentiate into hyaline cartilage. For me, this has the potential to permanently alleviate both knee and back pain. Moving this research away from clinical trials seems to be taking forever for some reason though...

<comment><USER6> I started getting into weightlifting this past year, and doing deadlifts has always scared me.

I still do them, and try to do them with proper form, but it's always in the back of my mind that I might hurt my back due to the load.

Could you give me more detail on how you hurt your back? How heavy of a load was it? Was it during a deadlift?

<comment><USER5> It actually had nothing to do with deadlifts or bad form. I was working on my bench press and couldn't get the fifth rep up. I set the bar down on my chest and instead of calling out for help (to any of the fifty people standing nearby), I thought it would be less embarrassing to just roll it down to my knees and then stand up and set the weight down. Stupid decision. Once I got the weight to my knees, I severely underestimated my back-to-chest strength ratio and the weight plummeted to the ground, pulling my (arched) back down with it. I think it was about 215 lbs (97 kg).

The key to deadlifts is good form and not letting your back arch at all. I would recommend getting an expert trainer or an advanced lifter to help you practice your form if you are worried about it. It's worth the time to prevent an injury.

<comment><USER7> I was taught not to use a clamp on the bar when doing bench, so you can lean to one side and let the weights drop off if you get stuck.

<comment><USER8> Seems like questionable advice - sounds like a great way to accidentally drop a bunch of weights to the floor if you're at all uneven with your bar path (not at all unusual when fatigued).

<comment><USER9> Not only that, but even a little shift in the weights can cause problems with your lifts. Warmups (135 or so) I'll leave them off, but anything over 200 I'll put them on.

</comment></comment></comment></comment></comment></comment><comment><USER10> Given that their methodology uses embryonic stem cells, it'll be interesting to see how this plays out in the US with opponent Tom Price as head of Health & Human Services.

> The stem cell procedure Kris received is part of a Phase 1/2a clinical trial > that is evaluating the safety and efficacy of escalating doses of AST-OPC1 > cells developed by Fremont, California-based Asterias Biotherapeutics. AST- > OPC1 cells are made from embryonic stem cells by carefully converting them > into oligodendrocyte progenitor cells (OPCs), which are cells found in the > brain and spinal cord that support the healthy functioning of nerve cells. > In previous laboratory studies, AST-OPC1 was shown to produce neurotrophic > factors, stimulate vascularization and induce remyelination of denuded > axons. All are critical factors in the survival, regrowth and conduction of > nerve impulses through axons at the injury site, according to Edward D. > Wirth III, MD, PhD, chief medical director of Asterias and lead investigator > of the study, dubbed "SCiStar."

<comment><USER11> It's interesting that this article is months old (from September 2016) and is only now on the front page of HN. I suspect that it has something to do with our desire to argue the benefits of stem cell research to the new administration.

I certainly hope they listen, but I fear they won't. People opposed to embryonic stem cell research based upon religious beliefs aren't going to suddenly ignore what they believe to be instructions from their particular God, even if it has enormous benefits for society. I hope that Trump is more reasonable than that, but the hard-line pro-life stance he recently took through executive order doesn't make me optimistic that this kind of research will continue in the US during the next four years.

<comment><USER12> You don't have to believe in God to make the argument that an embryo is a developing human being who is therefore worthy of legal protection. There are plenty of secular pro-lifers. [1]

[1] [http://www.secularprolife.org/](http://www.secularprolife.org/)

<comment><USER13> I don't think anyone disagrees with that. The question is at which point the embryo becomes enough of a human where its needs outweigh the needs of the parents.

<comment><USER14> That's really not relevant, it can be stipulated that life begins at conception and it simply doesn't matter, no persons right to life trumps another persons right to bodily autonomy. It's not murder to let someone die if you're the only bone marrow donor that could save their life and you refuse to donate and it's not murder to get an abortion; not all killing is murder, nor is all killing wrong. As long as the baby requires use of the mothers body to survive, it's right to life is secondary to her consent to carry it and that's true even if you give a fetus the full rights any other grown person would have. No grown person could demand their right to life is more important than your consent to your control your own body, even if your refusal kills them.

<comment><USER15> _It 's not murder to let someone die if you're the only bone marrow donor that could save their life and you refuse to donate and it's not murder to get an abortion_

"One of those things is not like the other, one of those things..."

Not donating bone marrow requires doing _nothing_. Having an abortion require an active procedure.

<comment><USER14> > Not donating bone marrow requires doing nothing. Having an abortion require > an active procedure.

True, but simply not relevant to any point I made. No metaphor is perfect, but the point here is that your control over your own body trumps another right to life. You wouldn't allow the government to forcibly take your bone marrow to save a life, and that's no different than being forced to carry a pregnancy to term against your will in regards to the point of bodily autonomy. Another persons right to life ends when it depends on someone else's body to live. The other person has a right to not consent to use their body against their will.

<comment><USER15> _but the point here is that your control over your own body trumps another right to life_

I think you need to refine that stance.

As a parent, I certainly don't have control over my own body. If I fail to provide the necessities of life for my child, I will go to jail and my kid will be taken from me. The gov't can (and will) force me to do certain things with my body.

<comment><USER14> Child neglect has nothing to do with your body. You are free to give up your child for adoption if you don't want to take care of them. Abusing a child and being punished for it isn't remotely similar to anything being discussed here. You're yet again deflecting from the point and attempting to setup a strawman.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER16> Despite all the cynicism, there are still wonderful things about good old medicine and science.

90 days! Paralysis to utility!

Is someone going to tell me something like: oh, the nerve wasn't completely severed so recovery might have happened anyway?

Well, go ahead, but in the meantime I am enjoying this news.

<comment><AUTHOR> There has been a lot of uplifting news coming out of stem cell and gene therapy the last couple of days. :)

<comment><USER17> Even if this is but one small step towards wider treatment, this is worth taking a moment to be happy and thankful for. You know that this patient is!

</comment></comment></comment><comment><USER18> Here is the December 14 2016 update to that story: [http://keck.usc.edu/stem- cell-therapy-gives-paralyzed-man-se...](http://keck.usc.edu/stem-cell-therapy- gives-paralyzed-man-second-chance-at-independence/)

<comment><USER19> And further information from a few days ago:

[https://blog.cirm.ca.gov/2017/01/25/good-news-from- asterias-...](https://blog.cirm.ca.gov/2017/01/25/good-news-from-asterias- cirm-funded-spinal-cord-injury-trial/)

Looks like a second group of people is getting treatment with a higher dosage. The results of that will definitely be of interest to many. :)

</comment></comment><comment><USER20> Stem cells are showing more and more promise. One thing we know about them is that young stem cells are better than old ones. I think there is a lot of promise in stem cell banking.

I haven't pulled the trigger yet, but do plan on banking my own stem cells while I'm in my early 30's because parts of me will inevitably start to break down in the coming decades, and I really like the idea of tapping my own young cells when I am old to heal some of that.

The only company I know of that is doing this is Forever Labs, [https://www.foreverlabs.co/](https://www.foreverlabs.co/), I am not associated with them, I just think they are on the right track with stem-cell banking and have spoken to one of the founders and was pretty excited about what they were doing and think its something worth supporting, which is why I'm writing this comment.

<comment><USER21> Thanks for this. I had no idea that young cells were better, even if that may seem obvious. I had to dig, but the price is $7000 for the procedure and lifetime storage or $3500 and then $250 per year for storage. Maybe competition in this could reduce the storage costs.

<comment><USER22> Ya, it is a bit steep. I'd love to see more options for this as well (especially here in Canada, where I don't believe there are any yet...)

</comment></comment></comment><comment><USER23> The patient's age being twenty-one may have made a difference in this happy news story. My dad had a slip and fall on ice at age seventy-two that left him paralyzed from the chin down until he died six years later. He had had a similar injury from a car crash (back when cars didn't have seat belts) at age eighteen, from which he recovered fully (although he wasn't so paralyzed from the first injury). So when he had his second injury, he at first thought he would also recover from that injury. Maybe because the second injury aggravated damage to his spine still remaining from his first injury, or maybe just because he was a lot older when injured the second time, he never recovered much at all from the second injury. His experience reminds me how many other people in a family are affected by spinal cord injuries, and thus how important it is to find better treatments for them.

So it's hard to say how wide a range of patients will be treatable with the new technique, but that's what medical research is for: to find out what helps for which patients. I hope further research continues on this and other treatments for spinal cord injuries.

</comment><comment><USER24> Can somebody explain the stem cell therapy to a complete laic like myself? I don't mean links to science articles, I mean a description you would attempt projecting at me if we were having a beer.

For me the stem cells are some sort of a magical Wolverine regeneration sauce. Never understood why they even work.

<comment><USER25> They are some sort of magical wolverine regeneration source. When you have a fertilized egg the first thing it does is start multiplying. But once you have a little cluster of cells they start making decisions (using bits of DNA to communicate) about what they should turn into - a skin cell, a bone cell, a brain cell or whatever. The trick with stem cells is to harvest them and keep them on ice just before they start making decisions. Then you transplant them into an injured body and they're all like 'hey ho, looks like I'm surrounded by nerve cells here so I'm gonna be a nerve cell too' (if you injected them into a spinal column) or 'woot, looks like I'm in a community of liver cells, I'm gonna turn myself into a liver cell' etc. etc.

The biggest problem is that you'd like a whole tank of stem cells that you could dip some injured person into and have them come out fully repaired, but getting stem cells to multiply without turning into anything in particular is a challenge so we have to cultivate them in very small quantities and it's relatively slow and expensive to do that.

I'll have a pilsener, please.

<comment><USER26> The trick is also making sure they don't get too excited and build a tumor, which would make things really bad.

But yeah, they're almost magic, except we understand it. Which is probably why large sectors of the religious public finds them so abhorrent: they take away yet another arrow from the inscrutable Fate they worship, they lift another bit of veil from the mystery of our existence. And it's a shame, because the objective need for strict regulation will be hampered by constant calls for pointless bans.

<comment><USER27> > But yeah, they're almost magic, except we understand it. Which is probably > why large sectors of the religious public finds them so abhorrent: they take > away yet another arrow from the inscrutable Fate they worship, they lift > another bit of veil from the mystery of our existence.

No, that's completely and totally not it. Folks oppose embryonic stem cell research because they believe both that embryos are human beings and that innocent human beings should not be killed. That's it.

Note that Mr. Bush continued to fund adult stem cell research, and continued to fund research on existing stem cell lines; what he didn't do was continue to fund the destruction of more embryos.

You may disagree with the idea that an embryo is a human being, and you may disagree that innocent human beings should not be killed, but you mayn't be uncharitable to your opponents.

</comment></comment></comment></comment><comment><USER28> It's exciting to know that paralysis will be a thing of the past in potentially our near future. Deafness/Blindness/Cancer/etc all benefits from these studies.

</comment><comment><USER29> It says it is a clinical trial, but I can't find the actual study, only another press release:

[https://www.sciencedaily.com/releases/2016/09/160914095610.h...](https://www.sciencedaily.com/releases/2016/09/160914095610.htm)

We really need to wait until the clinical trial publishes its results to know whether or not the treatment works. This person might have recovered naturally without any treatment.

<comment><USER30> It looks like a randomized trial hasn't started yet.

<comment><USER29> Are you sure? It says "The first early data results from a group of patients in this study will become available on September 14, 2016."

</comment></comment></comment><comment><USER31> One _really important_ caveat here-- nature abhors a vacuum, and spinal cord injuries are no exception. A chronic injury to the spinal column will result in scar tissue coming in over the wound, which is a totally separate issue from the initial injury. If your spinal cord injury is over a month old, you have a completely separate problem, ie, how to clear out the scar tissue so that nerve regeneration is even possible.

</comment><comment><USER32> Odd comment - what's neat to me about this article on HN is that nobody has said "clickbait" or misleading title. That this kind of title can represent reality shows what amazing times we live in.

The level of medical awesomeness is off the charts - so many people can now start to hope for not just a better life, but a radically better life.

</comment><comment><USER33> I know that directly correlating a recovery with a specific therapy is really hard to do. There have been many stem cell studies like this in the past which have shown similar seemingly miraculous results, even though it's not entirely certain whether the patient would have recovered otherwise or if something else was responsible. Paralyzed people inexplicably regain motor control all the time. I'd be curious to know how rigorous the study was in regards to control.

</comment><comment><USER34> Meanwhile, 9 years ago in China, people were already receiving this kind of therapy, but nobody believed them[1]. As Gibson has said, "The future is already here, it's just not evenly distributed."

[1][https://www.reddit.com/r/IAmA/comments/k1hts/i_am_a_28yr_old...](https://www.reddit.com/r/IAmA/comments/k1hts/i_am_a_28yr_old_american_who_went_to_china_to/)

<comment><USER35> It's crazy how arrogant a little knowledge can make some people, as seen in that Reddit thread.

<comment><USER36> I don't think wanting reasonable evidence before believing that a medical procedure works and works safely is the same thing as arrogance.

<comment><USER35> Yeah, wanting reasonable evidence before believing in the casual relationship between two events is fair.

But in this case, the Redditor can't provide scientific proof, because he's a layman. What he can provide is evidence that he couldn't walk, received stem cell treatment, and then could walk.

90% of the top level comments effectively said "No, impossible, there must be some other reason that you can now walk". That is to say, they feel that because there's no evidence that it's possible, it's impossible until scientists prove that it is possible. Well no, that doesn't make sense and it isn't usually how things work. These people's small amount of knowledge of the scientific method has caused them to arrogantly discredit potentially real phenomenon.

What's interesting is that one of the main top level comments which says "wow, I had a feeling this would be possible" is from an actual stem cell researcher.

<comment><USER36> I looked at that thread, and the non-negative-score comments seem to range from credulous to reasonably skeptical, with none that are fairly characterized as "No, impossible!"

In fact, given how sketchy the poster of that thread was being (e.g. linking to his non-medical blog when asked for medical details and saying he's too embarrassed to talk about it when asked again), I'd say people were pretty generous.

</comment></comment></comment></comment></comment><comment><USER37> After an accident such as this, is there a point at which it's too late to perform this type of injection? Asking for someone in a similar situation.

<comment><USER38> The article says that this study requires the patient to be stable enough for an injection 13-14 days post-injury. That's not to say we know it wouldn't help, but that's what this study is looking for.

</comment></comment><comment><USER39> I believe the same article was already posted here a few months back. Regardless, it would be interesting to know how much functionality this young man will gain after his rehabilitation. Stuff like this is hard to believe to be 100% effective, at least at this stage of our understanding and use of stem cells. But man this is absolutely astounding if it helps him regain even like 30% of his limbs.

</comment><comment><USER40> Congrats! I feel so happy for this guy. Awesome news!

</comment><comment><USER41> I remember an earlier article highlighting the potential benefits of olfactory stem cells for damaged brain tissue repair.

Engraftment of human nasal olfactory stem cells restores neuroplasticity in mice with hippocampal lesions

[https://www.jci.org/articles/view/44489](https://www.jci.org/articles/view/44489)

</comment><comment><USER42> Could this possibly lead to a cure for neuro-degenerative diseases like parkinson's and ALS?

</comment><comment><USER43> Could stem cell therapy be used to potentially improve existing muscular or neurological connections in normally functioning individuals? Kind of like a whole-body neurotropic.

<comment><USER44> I think that's not currently clear, I'd expect technologies such as CRISPR to have a far greater impact on enhancement of "normal" honestly. Some brain diseases are caused by the overriding of nuerons, so more is not necessararily better, for example.

</comment></comment><comment><USER45> Note that this was published several months ago, in September 2016. So if this news sounds familiar, that's probably why.

</comment><comment><USER46> Is there a greatly increased risk for cancer from stem cell use given these are cells that have a high rate of proliferation?

<comment><USER25> Maybe, but for most people cancer in the future vs being dead or paralyzed now is an easy decision. I'm not _aware_ of such an elevated risk, just saying that it would be an acceptable trade-off in many circumstances.

<comment><USER47> The follow-up article mentioned by another poster ([https://news.ycombinator.com/item?id=13494463](https://news.ycombinator.com/item?id=13494463)) mentions cancer as a risk of the treatment.

</comment></comment></comment><comment><USER48> Amazing, stem cell therapy has so much potential.</comment>


Ask HN: What do we do when our leaders are corrupt? - <AUTHOR> http://news.bbc.co.uk/1/hi/uk_politics/8039273.stm

<comment><USER2> Accept that for any value of political power y, there will be some corruption x.

Solve for the minimum of x. Don't get fooled by local minimums.

<comment><USER3> What about y = 0?

<comment><USER2> Yeah. I had been thinking of that. There should probably be a third term Z that has some sort of inverse proportionality relationship to y that represents cartels/warlords/etc that fill the power vacuum of a very low y situation. This would also cause x to be very high. (eg: Somalia)

<comment><USER3> I don't think I would distinguish between z and y. In other words, a high z is the same as a high y, and of course either one causes a high x.

<comment><USER2> Or -y is what happens when you don't have any y and so its an absolute value of y modified by some vector function v as to which sections of public life y (or the absolute value thereof) extends into...

For some metaphor m that is extended beyond a limit l, it becomes increasingly r, ridiculous. :)

<comment><USER3> Well, let me put it this way: Warlords have political power.

</comment></comment></comment></comment></comment></comment><comment><USER3> What do you do? You wonder if you really need them in the first place.</comment>


Decentraland shows the potential of blockchain and VR combined - <AUTHOR> https://venturebeat.com/2017/12/15/decentraland-shows-the-potential-of-blockchain-and-vr-combined/ <comment><USER2> > Proponents of decentralization say centralized VR platforms such as Facebook > Spaces and Microsoft's AltspaceVR will give their owners too much control > over the content users consume.

of course.

We've been doomed to that since Facebook bought oculus. They want another walled garden.</comment>


Best Buy vs. The Apple Store - <AUTHOR> https://m.signalvnoise.com/best-buy-vs-the-apple-store-abb16cf342c0 <comment><USER2> Completely agree with the article. The worst is that other stores are trying to replicate the apple store approach to retail. Customers not feeling comfortable to browse can't be a good thing for Apple.</comment>


The Tim Ferris way of testing ideas and how I did it. - <AUTHOR> http://www.docleyblog.com/2009/10/the-tim-ferris-way-of-testing-ideas-and-how-i-did-it/ <comment><USER2> There is an ocean of difference between 14% of visitors committing their email address to something, and that same figure actually pulling out their credit card.

A more prudent assumption would be 10% _of that 14%_ will actually pay for your product when it is launched.

I learned this first hand. Your mileage may vary of course, but it's incredibly easy to drive traffic and stimulate interest, enough that people will give you their email address or whatever other personal information you want. The moment you ask them to pay though, you're in another world in terms of conversions :) This MVP-type google ad testing doesn't really translate that well into real world data like purchase conversions. I don't think that's the point anyway.

It's good for seeing what people might be interested in, which is often something that startups aren't sure of :)

<comment><AUTHOR> I agree with you. Maybe a good idea would be to ask for a credit card, but not to charge it. I think this borders on being illegal though.

I am still pretty happy with 10%, since this was my cut-off for going ahead and building the product.

<comment><USER3> Instead of asking for the credit card information (which does sound illegal), I've heard of others who have placed a "Buy Now"-type button on the landing page or fill out form fields just up to the credit card fields (say, for a multistep payment process). A user who clicks on "Buy now" or fills out the first part of the payment form is a pretty convincing datapoint.

I haven't tried any of this myself since it raises a big issue for me: Doing this makes a promise that you don't intend to keep (at that moment). If trust is what gets users to buy, isn't it counter-productive to violate a user's act of trust?

I'd like to get over this because I can see how experiments like this can be useful and I hope you'll keep us all posted with your success rate. Some things I'm curious to know are:

* How much time passed between your AdWords test and your MVP launch? * Of the emails captured, how many participated in the beta and eventually became paying users?

Best of luck!

<comment><USER4> What would it take to make you feel comfortable about it?

<comment><USER3> That's a good question. My reservations mostly have to do with this:

 _Of the emails captured, how many participated in the beta and eventually became paying users?_

Which is really asking: Will those users really come back after you've broken that initial promise?

Other success stories say yes. And I speculate that there's a certain window of time that you need to deliver in to make it work.

There'll always be another question though, so I guess it can't hurt to just give it a shot.

<comment><USER4> About a month ago, I filled out an application/request with an NGO (Acumen Fund) about opening a local chapter where I live (Melbourne). My understanding that if they get enough requests, they'll try to get a local chapter going.

Now I got a response that they want to extend a 'special invitation' to use their 'to register on our brand new community site' where I can get involved and maybe new chapters will materialise.

The timing seems pretty convenient. I suspect that the request/suggestion form was really a list building excercise for the community site. It's a Ning. Those things need to cross a substantial chicken-egg hurdle before they are any use to anyone.

I admit, there was no blatant lie. It isn't really exactly the same thing. But it is sending out feelers & building email lists. They could have also put up a big 'join our community' button on the site that led to an 'sorry, under construction' page after you "sign up." Maybe they did. It was a little bit sneaky. I still joined & even started a group. I'm not angry with them. I'll even mention it to others.

BTW: <http://community.acumenfund.org/>

</comment></comment></comment></comment></comment></comment><comment><USER5> That seems hard to believe. I did the same testing strategy with my Job applier software (<http://fastjobapplier.weebly.com/>) and first of all I only got around 30 ad clicks total, and no one filled out the form. (I was thoroughly disappointed.)

Granted maybe I just suck at sales copy, or perhaps there just isn't demand out there for software that helps you apply for jobs.

Still though, a 10%+ conversion rates seems too high.

Do you find you're still getting a similar conversion rate now that you're actually selling the product?

<comment><USER6> yea 10% seems pretty high, I think it might have to do with saying the 1st month is free and you can cancel any time.

Therefore, the 10% rate isn't really a 10% sales rate but more of a 10% willing to try your demo. But 10% is still pretty good for that I think.

<comment><AUTHOR> I agree that 1st month free and cancel anytime might have something to do with it. If I do a test like this again, I will probably leave that out.

I will have these terms in my live product though...

<comment><USER7> The core issue isn't that you offer a month free, the issue is that your form doesn't measure purchase intent. You have no idea if 1% or 10% of your leads will convert into sales.

</comment></comment></comment></comment><comment><USER7> I've been itching to try this for some time. I would appreciate any war stories HNers could share.

<comment><USER8> Email addresses don't covert on a 1 to 1 basis to sales. (If. Only.)

After the autoresponder runs out (6 days in my case) they've only got only a moderately higher chance of conversion than my average trial user. (~5% vs. 2.8%)

I really, really don't like the Put Up Fake AdWords Ad, See Who Gets Suckered minimum viable product. Aside from misleading customers and hurting the AdWords ecosystem (they don't actually get offered what they clicked to get offered, which Google will come down on you like a ton of bricks for if they detect, incidentally), it _doesn't test your product_. It tests your ability _to write AdWords copy_.

I could get 14% conversion to stabbing toothpicks under your fingernails, but what does that tell you? The world has weird people in it, and I'm good at qualifying non-weird people out with my ad text and keyword selection? Whee?

Similarly, if I delivered an AdWords campaign that was _awful_ (low CTRs, low conversions), would that tell you the product is awful? Because I've done that before, too -- the first draft of my AdWords campaign for Bingo Card Creator was _terrible_. It took me almost a year before I figured out how to write AdWords decently. That was not an indication that the product was terrible (I sell it quite successfully), it was just an indication that I needed to adjust to a new way of copywriting.

If it can't tell you if an idea is good, and you can't trust it if it says the idea is bad -- what is the point, again?

<comment><USER9> I think you've hit on some good points, but missed a big one. Running ad words drives traffic to a site that currently has no traffic, better yet that traffic has shown some interest in the product you're claiming to have. If some of those people try to buy (or express interest in) this non-existent product, that says something.

You're not measuring how much traffic ad words brings in. You're using ad words as a traffic generator (ideally generating interested traffic), and of this traffic that comes to your site, you can determine if people are clicking through.

For ~$100 you can determine if there is _any_ interest at all. This can be powerful for people who really have no idea what the market will do. It's not perfect, but not useless.

<comment><USER8> _This can be powerful for people who really have no idea what the market will do._

These people should take their hands off the keyboard and not put it back on until they have spoken to at least one Real Person who has the problem that they are trying to solve. After they have done this, they will know if there is any interest at all. This produces _actionable insights_ : if they tell you they have a problem, then at least some people have the problem. If they tell you that the industry's favorite way for solving the problem costs $1,000, that immediately establishes that there is a viable market for solving the problem.

Compare this to the AdWords campaign: can you tell me what numbers you can get that say "This is a good idea -- do this" and what numbers you can get that say "This is not a good idea -- don't do this"? No -- subjectively "good" results don't imply purchasing intent, subjectively "bad" results don't imply lack of it. You'll get _noise_ \-- very precise noise, noise you can measure down to the click, but still noise.

<comment><USER9> Suppose I came up with an idea that I absolutely knew was brilliant, let's say edible shoelaces. Unfortunately these edible shoelaces aren't cheap to produce. I'm a one man shop and have almost no money.

I make a fully functional website to sell this product, only I don't have the product yet. When people browse the site and have gone through the pricing page, etc... and finally click "buy" I simply tell them that we're out of stock.

Now I want to see if people are actually trying to buy this thing, so I start marketing but have a limited budget. I throw $1000 at ad words. If I get 100 people trying to buy my edible shoelaces at $20 each then I know that maybe it's worth investing in manufacturing the product.

How is this not useful data? Instead of going all out and spending money on manufacturing and a website, you only pay for the website and hold off on the manufacturing expense until you're confident it'll pay off.

<comment><USER10> Except that we are talking document management here, not edible shoelaces. Or anything that requires "manufacturing" in the made-in-a-factory sense of the word.

A fake ad survey for a document management system from someone who "works in the electronic Document Management and Records Management industry" is shouting out loud, "I'm too scared to actually sit and code this thing because it's hard and I might take too long to do it or completely fail to do it."

And I don't know why people like throwing money away. With $100, I'd rather buy 5 months of Linode server time than 12 email addresses. When the best entrepreneurs are saying be cheap, I think we ought to listen and _be cheap_. And with 2 weeks of time, I'd rather sit and code the most basic functionality of my app and show it to people I know who might need it.

</comment></comment></comment></comment></comment></comment><comment><USER11> Here's another (cheaper, although possibly less realistic) approach to this: I recently did some market research using Amazon's Mechanical Turk, and added a lead collection form as a bonus.

I put up a simple survey asking users about relevant background information and their experience with the problem my application is trying to solve. Included in this survey was a field to collect the user's email address. This field was very clearly marked as optional (it even appeared after the confirmation code that allowed turkers to complete the "HIT") and the label included something like "Your answers to this survey will help us to evolve the website to better meet your needs. If you'd like to be notified when the new site launches, please enter your email address here." along with an indication that users would receive exactly one email from us due to this form.

I was pretty pleased with the results of the survey--I received a lot of actionable information very quickly and cheaply (at about $0.10 per response) and I was pleasantly surprised that a little more than 10% of the respondants entered what looks like a valid email address.

I don't expect many of those 10% to convert (and lead generation wasn't the point of the excercise anyway) but I was very happy with the ROI on this survey.

Seeing who clicks on ads (and at with what copy) and later "soft" converts may be a more realistic test, but the MTurk approach is an order of magnitude less expensive.

</comment><comment><USER12> Actually, the figures here may be pessimistic. It takes a certain kind of person to submit their e-mail address when there is quite obviously no deliverable being explicitly promised to them for immediate purchase & download. If there were one, there might have been higher conversion.

</comment><comment><USER13> I don't get it. So you "sell a product", including a 30 day trial, but once the user signs up there's no product?</comment>


Show HN: Reciprocal marketing for independent content creators - <AUTHOR> https://wecombinate.com/about

<comment><AUTHOR> Hi guys, recently finished my side project MVP and looking for feedback and suggestions. I created this after realizing how difficult it is to get visibility as an indie software developer and author. I was hoping other indies felt the same and could help each other out.

Let me know what you think! :)</comment>


Google, Microsoft, Yahoo, PayPal go after phishers with DMARC authentication - <AUTHOR> http://arstechnica.com/open-source/news/2012/01/google-microsoft-yahoo-paypal-go-after-phishers-with-new-e-mail-authentication-effort.ars

<comment><USER2> This seems like yet another anti-spam measure that will not be implemented globally, therefore cannot be relied on, you still wont be able to strongly trust DKIM/SPF as a ham indicator. Also, many people's filtering setups wont even be able to create the kind of relies DMARC requires, so they wont be implemented either.</comment>


Ask HN: Where can I find easy to read code, that can be understood completely? - <AUTHOR> I only program my side projects on the weekends, when I come back to the code I realize how poorly it's been written, especially if I've skipped a weekend. I'm really striving to make my code readable. A great book I read is "The Art of Readable Code", and while it focuses on code readability from a micro-level (making a small code sample readable), I find more knowledge is needed to make a program readable when reading it from start to finish.
The code I find most readable is imperative code that can be read line-by-line. I find abstractions hide away important knowledge of understanding completely how things work. Additionally I prefer reading algorithmic code than reading a bunch of helper functions that are at a level of indirection away from understanding the code at hand. For this reason I try to write in more imperative style instead of OOP or functional. But I find that programs I write that can be followed line by line end up having a lot of variables that make it hard to keep track of everything.
I've tried to look for other projects that can be read line by line easily but I haven't found one yet. I'll end up spending way to much time trying to figure out what helper objects, functions, or structs are doing and they require jumping to a bunch of other files while trying to keep in my head what I read previously.
It seems these 2 things are at odds with each other: readable code vs code that can be read and understood completely. I don't want algorithms hidden away but when they are right there in place with the other code it becomes too much.
Is completely readable code even possible? I've heard "abstract just barely as much as you need" or "just use right level of abstraction" but that doesn't give me anything concrete I can do. Is there a project that you know about that was large but very easy for a new person to read and understand completely? Do you know how to write code like that?
Any ideas are appreciated. Thanks! <comment><USER2> I know there's a lot of code out there I cannot read and suspect we're hardly alone with that issue.

I comment my own code very heavily so I don't have to spend as much time studying it at a later date.

And I don't try to get too tricky either. I don't fret over converting a block of code into an obfuscated one liner. I avoid that instead.</comment>


The beauty of old-school backdoors - <AUTHOR> http://blog.ioactive.com/2015/09/the-beauty-of-old-school-backdoors.html <comment><USER2> Heh, I guess I'll share the one backdoor that was left in some the NVG510 (AT&T UVerse modem that you have no choice but to use) modem firmware. Now, you did have to solder on the board to get a serial console, but once you got that, you could quite easily get to a root shell. (by default, it was this "user" shell that was exposed in some non-US configurations on the network by telnet)

All you had to do was type "magic", and then once magic mode was enabled, type "!" and you got dropped at the root shell.

A shame they patched the firmware to remove magic mode and really locked things down after I published an app to root the modem via the web interface to fix various bugs in the firmware.. App eventually got pulled for ToS violation from the Play store, and just so happens a few weeks later AT&T pushed a firmware update that fixed all the exploits I knew of

<comment><USER3> Did the update fix any of the bugs?

</comment></comment><comment><USER4> Making a backdoor that relies on raw packets may net you benefits in terms of avoiding detection of network connections/syscalls by system tools (netstat and the like). Writing your own micro tcp/ip stack will also avoid having to throw libpcap into your backdoor. Of course, raw packet access is usually only reserved for root, so you'll have to fall back on the OS's network stack & calls to get this type of tool in, but eventually it makes for a more stealthy rootkit.

If you get really fancy you can fuck with network protocols in general and avoid getting caught by network detection & analysis. One good example is finding some traffic like DNS or ICMP that gets overlooked easily in graphs of network traffic and is already connectionless, so it's more difficult to catch someone constantly connected via backdoor.

Once I saw a backdoor use ICMP to do basic communication with a CNC, and when it got the correct reply it'd use another protocol (and host) to pass data. Only even realized that was happening after another compromise was found. And of course it was totally valid traffic so it didn't get picked up by any network sensors.

<comment><USER5> _And of course it was totally valid traffic so it didn 't get picked up by any network sensors._

That's the part of a lot of the backdoors and hacks that makes my head spin. No one can tell programmatically if certain traffic is "good" or "bad" \- you have to go through it and devine it's intent.

Given that, is it even worth anyone's time to try to secure systems, or should we all just adopt some zen-like acceptance of the futility of all action?

<comment><USER4> That's why you practice "defense in depth" \- multiple layers of security measures. This means not only security countermeasures at multiple points in your network, but multiple tactics to look for a compromise.

Yes, of course you should continue to secure your systems. But remember that the word 'security' means 'the state of being free of danger or threat'. Your systems are never completely free of that danger. _That 's_ the zen-like acceptance; I will never be secure, but I will work towards being secure. Enlightenment is when you realize security is not having a system at all.

</comment></comment></comment><comment><USER6> My favorite was from a pen test that I heard of back in the 1990s. Most people don't realize that Postscript is a full-featured programming language, and high end printer/fax machines used an operating system written in Postscript. To "print" a document you actually executed a program that resulted in a printed document.

Well, "print" the wrong document and your printer/fax machine just turned into a router for anyone who knows how to call up and send the right message...

</comment><comment><USER7> There used to be a rather negligent backdoor in some 3COM products - you could log in with username 'debug' and password 'synnet' to get a full admin shell with extra debugging commands. IIRC it wasn't printed in the user manuals, but was fairly obvious from poking around in the firmware updates. Fortunately the password could be changed, so it wasn't a completely irreparable security hole.</comment>


Qualcomm Report on LTE for Drones - <AUTHOR> https://www.skydrone.aero/blogs/news/qualcomm-releases-detailed-trial-report-on-lte-unmanned-aircraft-systems <comment><USER2> I hope the next revision of MAVLink (one of the most common message serialization/transport protocols used for UAVs) will have built-in encryption.

While systems can encrypt MAVLink messages in transit, I have not seen it actually done- everyone is relying on security of the physical layer (i.e. obscurity of telemetry radio frequency hopping/channel negotiation, WiFi security).

So in most implementations, MAVLink messages are actually transmitted in plaintext, over plain TCP/UDP connections.

<comment><USER3> Many of these systems are using the amateur radio service bands. Often 5GHz for video, 2.3-2.4GHz for control and telemetry and less frequently 1.2GHz, 900MHz and 70cm are also used. The FCC doesn't allow encrypted traffic on amateur bands except for specific cases such as satellite telecommand. I suppose that has discouraged adoption of cryptography.

What are commercial operators doing? Another limitation of Amateur bands is that they can't be used for commercial purposes, so licensed commercial drone operators must be using commercial bands where cryptography is permitted. Don't know myself; haven't looked into it.

<comment><USER4> > Another limitation of Amateur bands is that they can't be used for > commercial purposes, so licensed commercial drone operators must be using > commercial bands where cryptography is permitted.

I don't think so. I think we can agree that many, many commercial operators use DJI. There are also lots of amateurs using DJI. Both use the same firmware. There is no option for me to encrypt or unencrypt my Phantom which I could easily use commercially if I had my FAA Part 107.

<comment><USER3> I see. So they're operating in the ISM portion of 2.4 and 5GHz. In that case they can encrypt. So the original question seems a good one; why haven't they yet?

</comment></comment></comment></comment><comment><USER5> Here is a video of a home-built setup based on Raspberry-Pi [1] and an opensource software stack on a fixed-wing aircraft. For use on quadcopters the problem is the latency. Analog FPV systems can achieve around ~20ms latency.

[1] [https://www.youtube.com/watch?v=EjAuPoiAmHE](https://www.youtube.com/watch?v=EjAuPoiAmHE)

<comment><AUTHOR> You are right, with the current state oft LTE and a digital video pipeline we are not yet competitive to analog latency. On our Sky Drone FPV system we get a glass-to-glass latency of ~150ms which is good enough for controlling a drone at some altitude. It is not good enough for competitive racing though.

But I am confident the time will come. The next gen cellular network aka "5G" will reduce the network latency significantly and with some new technologies on image sensors (super high framerate, global shutter, ...), I am confident that it will eventually make analog setups obsolete.

</comment></comment><comment><USER6> > A network in communication with UAS must support a mechanism for intercept > by authorized parties in the event of an emergency. This intercept could be > simply for status information, for transmission of exclusion zones, or for > forced landing in extreme cases.

Oh man, lawful intercept features for UAVs, this sure is gonna be interesting.

<comment><USER7> Leaving aside the 'should they be allowed to question' \- let's hope they succeed in making unauthorized access impossible. That would really suck as a remote exploit.

Impossible... Hmmmm. Not a word you hear used very often in security circles...

<comment><USER8> Internet of flying things.

<comment><USER9> Internet of Flying High-Velocity Bricks...

</comment></comment></comment></comment><comment><USER10> I watched SkyDrone lie for a couple of years about how far song their supposed product was, so am kinda surprised to see them back in the limelight. Their website said "shipping next month" for over a year IIRC. I guess that sort of thing is the new normal...

<comment><AUTHOR> You are right, we indeed had some problems with our first product "Sky Drone FPV 1". Our new products are on stock and shipping though. Some background of what happened: [https://www.skydrone.aero/blogs/news/the-sky-drone- journey-s...](https://www.skydrone.aero/blogs/news/the-sky-drone-journey- since-indiegogo-3-years-ago)

<comment><USER11> Regarding the mistakes section, the technical side of that is something I've also experienced. When you're working with smartphone derived hardware and platforms you get a pretty sophisticated platform that can do a lot, but it also takes a lot of effort to get everything working and stable. And you'll need to know how to use everything from linux build tools to an oscilloscope. And then 18 months to 2 years later, a new generation or hardware is out so you get to start again :-/. Very labor intensive.

</comment></comment></comment><comment><USER12> On a side note: Qualcomm is the top patent filer in LTE domain before Intel, Samsung, and Ericsson. [1] [https://www.greyb.com/top-50-innovative-companies- of-4g-lte/](https://www.greyb.com/top-50-innovative-companies-of-4g-lte/)

<comment><USER13> patents are basically a form of currency now. sad.

edit: or rather, patents are the money, licensing is the currency.

<comment><USER14> To me they look more and more like the warheads of a MAD setup.

</comment></comment></comment><comment><USER15> This looks very interesting and I have two questions:

1\. How much cost in data are we talking about? There are some benchmarks on what 10min of video uses. Are you able to get cell data cheaper than a normal consumer?

2\. With a 107 certificate, is it legal to fly this past VLOS and without a visual observer? Trying to see how this works in the US.

<comment><USER10> No, 107 does not permit flying beyond VLOS. That requires extra permission from the FAA through a waiver. (I have my part 107 remote pilot's license)

</comment></comment><comment><USER16> 1\. Does the drone attempts to automatically land in case of loss of connectivity ?

2\. Do you plan selling the drone with ready-to-use sims ?

3\. Is it possible to set up the drone not to fly too far away from the controller position ?

</comment><comment><USER17> All I want to know is when can I fly my DJI phantom via cell network?

<comment><AUTHOR> Unfortunately DJI is not very open to third-party integration (at least for their consumer drones). So while you will get unlimited range with our LTE based Sky Drone FPV system, controlling a DJI Phantom is not possible. Any other drone with open serial telemetry port will work though - like all the PX4/APM based drones.

<comment><USER18> Off topic question if you may happen to know: I'm looking to invest ($10k or so) in one or more publicly traded small cap drone companies - do you happen to know of any? I'm not necessarily looking for drone manufacturers, but perhaps more so regular companies that are using drones to enhance their traditional business (aerial photography would be one example, but too obvious).</comment></comment></comment>


NSA Phone Program Cost $100M, but Produced Only Two Unique Leads - <AUTHOR> https://www.nytimes.com/2020/02/25/us/politics/nsa-phone-program.html <comment><USER2> I wonder if @Snowden's disclosures have largely led criminals away from phone/text (to encrypted apps), and whether the lack of ongoing utility of this surveillance program resulted in part from his disclosures.</comment>


Apple resumes iPhone X production due to weak XS sales, report claims - <AUTHOR> https://www.theverge.com/2018/11/22/18107795/iphone-x-production-resumed-weak-demand-2018-models-rumor <comment><USER2> These reports always come up within 4 months after Apple having launched a new device. I'm guessing some people are making a lot of money from this FUD, by hiring PR / Research firms that will do everything to make Apple look weak.

<comment> old-gregg I disagree. This never happened with iPhone 1 through 6, when a new iPhone had always been better than its predecessor in every way. After the 6, "upgrading" meant gaining some and losing some, that's also when Apple started to offer the old versions alongside the new ones on their site for far longer.

To provide some anecdata: I got myself an iPhone 6 Plus right after iPhone 8 came out because I needed a headphone jack. If I were to upgrade I'd probably go with the 8 Plus now because it comes with a superior battery life and a physical home button.

<comment><USER2> I fail to see how your personal experience (and preference) relates to my complaint about useless 'experts' that are predicting bad earnings, with Apple proving them wrong every time at the next earnings report. For about 5 years in a row this has been the case and it has nothing to do with the actual products.

</comment></comment></comment><comment><USER3> "The cheaper iPhone XR is thought to be particularly struggling, as budget- conscious customers opt instead for last year's iPhone 8, which continues to be available and is priced lower than this year's budget model."

No, no, no, no, no!

I wouldn't choose the 8 over the XR because the 8 is cheaper, it's because the XR has a bunch of crap I don't want. It's larger, I don't want larger. The camera has a sharp edge, making a case a necessity. I don't want a case. It has FaceID instead of the fingerprint reader. I don't want FaceID.

<comment><USER4> I bet you did not want large 5" screen before.

<comment><USER5> I don't know what the parent poster prefers, but i find the 4/4.5 screens a bit too small and anything larger then 5.5 a bit to big. 5 or 5.1 or 5.2 is my sweet-spot in screen size. Its just what fits my hand the best. Im currently looking at changing from the S7 Edge that i find a little too big and was looking at the XR and 8 in the store yesterday. The 8 fits exactly what i want in phone size, and im having a hard time finding good android phones with good battery life at that size.

</comment></comment></comment><comment><USER6> Ah the classic "Apple is doomed" article for this quarter.

</comment><comment><USER7> Just to be used as replacements for repairs I take it?

As a consumer looking for what to recommend to family and friends using iPhone 6 phones to iPhone 8 phones the iPhone X looks way better to me than the iPhone XR. People won't notice the CPU but that OLED screen!

I wish there was some kind of 'apple outlet' like clothing stores do so there could be a legit source of these X phones.

</comment><comment><USER8> Honest question - What do people here on HN see as more valuable: the iPhone brand itself, or Apple's technology development/production systems?

<comment><USER9> They are valuable in different ways IMO. I think it would be harder to replace the brand at this point though.

</comment></comment><comment><USER10> In Canada with our weaker dollar, Apple products have really finally gone into a truly laughable price point. These phones are $1500.

Anecdotal evidence also is that anyone I know that has an X wishes they could go back to having a home button.

</comment><comment><USER11> Anecdotal obviously but I see everyone with the XR.</comment>


Building a Space Elevator in 7 Years? - <AUTHOR> http://lifeboat.com/blog/2010/05/space-elevator-in-7

<comment><USER2> Astronomy Cast had a nice show about space elevators. It seems that there are some serious problems. I think this is the right link:

[http://www.astronomycast.com/space-flight/ep-144-space- eleva...](http://www.astronomycast.com/space-flight/ep-144-space-elevators/)

Click here for the mp3: [http://media.libsyn.com/media/astronomycast/AstroCast-090629...](http://media.libsyn.com/media/astronomycast/AstroCast-090629.mp3)</comment>


Show HN: Exa, a replacement for ls written in Rust - <AUTHOR> http://bsago.me/exa/ <comment><USER2> I wonder if it's a good thing or a bad thing that I've never considered, even for a moment, replacing a tool like ls. My first reaction was that it's hubris to think "ls isn't good enough for me, I'll make something better." A bit more reflection has almost convinced me that it's a very good thing that people are always thinking and working on ways to improve things, even something that's taken for granted.

On a tangential note, I learned something new and thought that a few other folks might find this of interest: In the screenshots, we see a file with the name "Licence", which to my American eye looked like a typo. On further investigation I found out that "In British English, Canadian English, Irish English, Australian English, and New Zealand English the noun is spelt licence and the verb is license."[0]

[0] [https://en.wiktionary.org/wiki/licence](https://en.wiktionary.org/wiki/licence)

<comment><USER3> I'm not sure about ls. As for this tool all it seems to add is git status, but it's not working for me for some reason (not sure why) so I can't comment on the usefulness of this.

I do think some other coreutils could be replaced. cp for example, doesn't give you a progress bar so if you are copying a very large file it could take 2 minutes or 2 hours. I suppose you could create a wrapper for cp that repeatedly ls-es the destination directory to give you a progress of the copy.

<comment><AUTHOR> This has dropped off the frontpage, so I feel better about going off-topic: but you can use rsync instead of cp if you want a progress bar!

<comment><USER3> Ah yes, I always forget that rsync does basically everything!

</comment></comment></comment></comment><comment><USER4> A similar, but more broadly scoped project is uutils/coreutils [0], which is a cross-platform re-write of the GNU coreutils in Rust.

IMO, both the coreutils project and Exa are interesting for the same reason: they provide an example of Rust is one of it's niche environments - low level tooling.

[0]: [https://github.com/uutils/coreutils](https://github.com/uutils/coreutils)

</comment><comment><USER5> I find it interesting that so many are disparaging this for not being backwards compatible, etc., when there is simply no need. The title of the post clearly states it's a replacement for ls, so why should it be backwards compatible?

It's not like everything everyone ever makes has to be a perfect fit in every capacity. A guy made a replacement for 'ls' as a fun thing to do in a language he likes. We make toys all the time and if you don't you probably just don't even like programming. The fact that he'd share this with us because he thought other people might be interested is precisely why places like these are good.

We might as well just start disparaging every posted project for not being a solution to starvation around the world if we're going to condemn everything that isn't an immediate step 'forward'. Let people make things they think are neat and try to see the positive side of things instead.

If someone's selling you a product I can see this behaviour being warranted, but when someone is trying to show you something they made because they think it's neat, you don't jump on it as if he's trying to change the world with it.

<comment><USER6> > ...so many are disparaging this for not being backwards compatible...there > is simply no need...it's a replacement for ls, so why should it be backwards > compatible?

Because unless someone feels like editing every script or tool that makes use of ls, then it cannot be used as a replacement, i.e. You'll have to have both ls and exa on your hard drive instead of just exa. Also, people are used to the options of ls, and backwards-compatibility (in the form of a shell alias) is one less barrier to entry.

<comment><USER5> > Because unless someone feels like editing every script or tool that makes > use of ls, then it cannot be used as a replacement

It can be used as a replacement just fine, just not if you symlink/alias 'ls' to 'exa', which I don't see as relevant. 'fish' is a replacement for bash, but I don't remove bash because of having it and I still have plenty of scripts using bash. It's just that my personal usage is exclusively with fish.

> You'll have to have both ls and exa on your hard drive instead of just exa.

Yes. I don't think this is a problem.

> Also, people are used to the options of ls, and backwards-compatibility (in > the form of a shell alias) is one less barrier to entry.

I agree that it is a barrier to entry, yes, but this is clearly a toy created just to have fun with a language and make something that also happens to be fairly useful. It's not meant to take over the world, as far as I can see.

<comment><USER6> > not if you symlink/alias 'ls' to 'exa', which I don't see as relevant. > 'fish' is a replacement for bash, but I don't remove bash because of having > it and I still have plenty of scripts using bash.

You're not _using_ fish as a replacement for bash.

You're using them both alongside each other. There is, of course, nothing wrong with this, but it is important to know that that's what you're doing.

Because many of the scripts on your computer depend on bash (or another shell with sh-like syntax) it would be difficult or impossible to use fish as a replacement for bash.

Similarly, it would be difficult or impossible to _use_ exa as a _replacement_ for ls, because ls has options that exa doesn't.

<comment><USER5> I have replaced bash with fish, actually. To which extent is the question. If I replace it for all of my personal use, that's still replacement. You can pretend that the domain/extent of which you replace something is not important, but this will be a factor no matter what you believe.

 _I AM USING_ fish as a replacement for bash. Whether or not scripts that run on my machine use bash or not is entirely irrelevant to the point.

Your reasoning is that since there are things I am interacting with that use ls I won't be able to replace it by actively exclusively using exa. This is the same reasoning that would conclude that if you compile a language to C you have not replaced your use of C by using only this compiled language, since things that you use in turn still use C. You will still need things connected to C on your machine, but to say you have not replaced C for yourself is ridiculous in this example, as it is in yours.

Take the following situation:

Person A is working on a project and says to person B that he has recently replaced the Haskell parts of it with Common Lisp. Person B takes a look at A's repository and concludes that he has not. He still has a tool made in Haskell that he uses for one thing in his project. He didn't make this himself, it's a third party tool.

Now, in this scenario, wouldn't it be fairly sane to assume that while A has not completely eradicated all traces of Haskell in his project, he has still replaced Haskell with Common Lisp? His own usage has been completely replaced with Common Lisp. I think most people would think that is the important part of the statement he made in the beginning.

<comment><USER6> > I have replaced bash with fish

No, you're using both of them. If you are using scripts which themselves use bash, then you're using bash, albeit indirectly. You may not be using it in interactive mode, but you're still using it nonetheless. If you had replaced bash with fish, then you would not need bash on your computer at all.

Replace (in the context of Unix-like software) means _completely_ replace, as in: no longer needing the original for any purpose.

<comment><USER5> > Replace (in the context of Unix-like software) means completely replace, as > in: no longer needing the original for any purpose.

There is nothing about the context of Unix that makes this use case different than any other. If you yourself always blindly take "replace" to mean "completely replace", then that's fine. I would contend, however, that most regular people see the above scenario precisely like I outlined.

> then you're using bash, albeit indirectly.

This line, however, makes me think that you purposefully ignore the example because with your reasoning we are all using C no matter if we've never seen the language at all, if the case is that a language we use is compiled to C. By this reasoning users of Chicken Scheme and Gambit Scheme are using C, because both of these Scheme variants are compiled down to C.

I find it strange that you would be so interested in setting the limits for what other people constitute "use". I've told you several times that for _personal use_ I've _replaced_ bash with fish. This, apparently, is not enough for you. I made a scenario to illustrate how silly it sounds to say Person A hasn't replaced Haskell.

Someone calls you and you are in your study. Your friend Janet is in the living room downstairs. The person on the phone asks: "Is Janet there?". How would you respond to this question?

<comment><USER6> > There is nothing about the context of Unix that makes this use case > different than any other.

I disagree; the programs which make up a Unix-like system are designed to be modular (even extremely so, compared to {say} Windows), which greatly facilitated the development of GNU, a replacement for Unix.

"As the GNU Project's reputation grew, people began offering to donate machines running Unix to the project. These were very useful, because the easiest way to develop components of GNU was to do it on a Unix system, and replace the components of that system one by one...it was legitimate to use a proprietary package when that was crucial for developing a free replacement that would help others stop using the proprietary package...Today we no longer have any copies of Unix, because we have replaced them with free operating systems." \--from [https://www.gnu.org/gnu/thegnuproject.html](https://www.gnu.org/gnu/thegnuproject.html)

> With your reasoning we are all using C no matter if we've never seen the > language at all

Well, we kind of are. For example: if we haven't replaced all our copies of libc by 2038 with one that supports dates after 2038, then we're all screwed. Whether or not we 'personally' use C or not.

> Janet

Well, skipping over the fact that I don't know anyone named Janet (;-D) I'd say "Janet's downstairs, let me get her for you."

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER7> This would make some sense if it were backward-compatible with normal "ls" for basic things like "ls -l". That way, people could alias "ls" to "exa" and not break too many things. But it drops the group and adds Git markers (which are only occasionally relevant), so I don't see myself trying this.

</comment><comment><USER8> I would not joy until exa is tried over a fs with more than a million files. Huge file numbers are a thing now and it is becoming to be an engineering challenge.

<comment><AUTHOR> exa can certainly handle a million files. Try running "exa -lRT ~" and watch it produce a tree view of your entire home directory!

However, by 'handle', I actually mean 'run without crashing'... if you run that command, it'll be several minutes before it produces any output. exa aligns its output into a tabular format with every column having the same length, which means it actually has to stat and examine every file in the list before it's able to output the first line. This is annoying, but (as far as I know) unavoidable.

<comment><USER8> I have not yet looked into the code but if it's using glibc and corresponding getdents code path with suboptimal buffers, it most probably will be slower then ls.

more information about the getdents buffer issue: [https://www.olark.com/developers-corner/you-can-list-a- direc...](https://www.olark.com/developers-corner/you-can-list-a-directory- with-8-million-files-but-not-with-ls)

Again, beware before downvoting me to oblivion I have not yet looked into the code.

<comment><AUTHOR> I don't even have downvote privileges yet!

I was unaware of the getdents issue - thanks. However, it is most definitely slower than ls, because I've only tested it on large directories, rather than using it with large directories daily, so I haven't found places to optimise it quite yet. I'm not sure if using Rust will let me avoid that buffer issue, as right now I'm just using the function provided in its standard library.

<comment><USER9> You can call the raw system call using, for example, kmc's syscall! macro: [https://github.com/kmcallister/syscall.rs](https://github.com/kmcallister/syscall.rs)

I do wonder if it's worth it eventually for libstd to speak the syscall interface directly, instead of going through another language's standard library (and whatever bugs or design decisions that standard library might have).

</comment></comment></comment></comment></comment><comment><USER10> Works pretty good! I really like the symbolic-link-preview. But I think it would be better when you just add -l when you enter things like -h, -T, -b, ... or allow an option for that.

<comment><AUTHOR> Thanks! Years ago I wrote a wrapper for ls that just added colours and did highlighting - but not only was it much slower, I couldn't do things like preview a symlink's path because that information wasn't available in ls's output. So exa was born.

And as for automatically adding --long when you use --tree or similar: this is something I've hummed and haahed about, and I'm still not confident that I've done it the best way, so I'm open to suggestions here. It seems that most tools just seem to ignore it if you pass in two conflicting options, or redundant options, and personally I'd much rather have the user always give correct behaviour than potentially get it wrong without knowing. But I'll just have to see how people end up using it.

</comment></comment><comment><USER11> Not tried yet. Wonder if it's got the option to display the size of directories. On the screenshots, the directories are shown with '-' just like the case with the ls.

<comment><AUTHOR> Do you mean recursing into a directory and summing the file sizes of its contents? exa doesn't do this, sorry, but it's something I've been thinking of adding.

ls actually displays the 'file size' of the directory, which I've left out, as that number has never benefitted me, ever.

<comment><USER12> On ZFS, the number of entries in a directory is reported as the directory's file size in bytes. Pretty nice, but unfortunate if a tool would hide it.

</comment></comment></comment><comment><USER13> I am using it right now and it is great! My only complaint is that it is a lot easier to type `ls` than `exa` :) (all the letters are on different key rows with the same hand)

<comment> _-_-_-_ If `e` isn't already used by another command or function in your environment, you could do something like this in .bashrc, .zshrc, or wherever you put your aliases:

        alias e='exa -1'
        alias ea='exa -a1'
        alias ee='exa -hla'

Note, that's a number "1" in the first two, and -h here includes the headers, which is different from ls -h, which exa appears to do by default. Other than the one entry per line printing, it's similar to the ubuntu default aliases for ls.

</comment></comment><comment><USER14> I think this is actually most interesting as a demonstration of Cargo's support for "features" ([http://doc.crates.io/manifest.html#the-%5Bfeatures%5D-sectio...](http://doc.crates.io/manifest.html#the-%5Bfeatures%5D-section)), which is a concept I haven't encountered in other package managers before. Is it something that Cargo inherited from Bundler?

<comment><USER15> Though it's not a package manager, configure scripts have had this for a while -- e.g. ./configure --no-git. Still, it's certainly cool to have it built into Cargo!

</comment></comment><comment><USER16> It would be useful to re-implement the basic UNIX utilities (at least the ones in BusyBox) in Rust. But _without_ all the extra bells and whistles this program has. Lots of embedded systems need a reliable set of tools.

An exploit was discovered in "files" recently. Somebody put a decoder for Linux executable files in it, creating a security hole.

<comment><USER17> What is 'files'?

<comment><USER18> GNU "strings" may have been meant, as it had this issue recently.

<comment><USER17> Thanks for clarifying.

</comment></comment></comment></comment><comment><USER19> I just hope that it's backward compatible with ls, as of the moment, it's not a replacement.

<comment><USER20> It's not a drop-in replacement, it's an alternative.

</comment></comment><comment><USER21> Another alternative is lsp: [https://github.com/dborzov/lsp](https://github.com/dborzov/lsp)

Unlike exa it fully supports Windows and does not have any external dependancies (as it is written in Go, everything is included already).

</comment><comment><USER22> Am I the only one who, while I think this is awesome utility and idea, find that unless you are Rust enthusiast, likelihood of using it is very low.

I think there is a need for such utility, if it could be made in more portable fashion. I am not installing rust just for this.

<comment><USER23> If the binary could be distributed, then there's no reason you'd need to install Rust to use it.

<comment><AUTHOR> I'd really like for that to happen (compiling to a standalone binary is one of the reasons I picked Rust), but I have no idea how to go about doing it...

<comment><USER9> You could just distribute the executable you get when you run `cargo build`. rustc / cargo statically link the Rust standard library into the app, so it should work fine on a machine without Rust installed. It'll still dynamically link C libraries.

One catch is that (especially if you're using C libraries other than libc, but sometimes with libc) you'll need to worry a little bit about forwards- and backwards-compatibility of those libraries. It's somewhat safer to find a semi-old distro like Ubuntu 12.04, build there, and see if it works everywhere newer.

This is kind of a pain, and the long-term answer is to get Rust into the distros so that they can build software written in Rust. (This doesn't require rustc being installed on any machine other than the builders.) In the short term, a cross-distro package generator for binary crates sounds like a maybe- fun project....

<comment><USER24> Isn't it possible to statically link C libraries too?

<comment><USER25> Not glibc, which is the issue here.

<comment><USER24> Then not sure how its supposed to distribute Rust programms... Maybe some installer at least..

<comment><USER25> Basically every system has libc on it already, so it's not a big deal. Unless you build on a new system, and then distribute to an old one. Most people pick which systems they'd like to target, and build against the lowest available version.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER26> How do you pick the colours? The website uses a dark background. If I ran this tool on my terminal (with a white background), would the colours still be readable?

<comment><AUTHOR> It uses the colours you pick in your terminal. I made the website dark because I like that colour scheme, and it's what I look at all day, so copying it for the website was a natural fit :)

A few of the filetypes use colours in the 256-colour range, but these should work well too - the grey colour you see for non-existent '-' table cells in the columns view is the exact middle grey value (colour #244) because it's the only one that's guaranteed to work with light-backgrounded terminals.

<comment><USER27> Forgive me for veering off topic, but would you mind sharing the terminal theme?

<comment><AUTHOR> Well, it's originally the Tomorrow Night theme, but I've tweaked all the colours to my own liking (such as making the bold colours slightly lighter) that it's not really officially that anymore. But it's a great theme, and the nearest.

</comment></comment></comment></comment><comment><USER28> This is the sort of thing that Rust is meant for. Correct, well-designed low- level tools. It's not an application language; it's a systems language.

<comment><USER29> Well, yeah, maybe, but I've never felt like missing something from ls…

<comment><USER30> xml or json output option would be nice.

</comment></comment></comment><comment><USER31> It seems awesome, specially the --tree option. I would love to try it, but

        Download and install Rust Nightly for your platform.
        Install libgit2 and cmake using your favourite package
          management system (or pass --no-default-features to the
          next step)
        Run git clone https://github.com/ogham/exa.git to download
          the latest version of exa.
        Run cargo build in the new directory to compile exa.
        Move the resulting target/exa executable into a directory
          in your $PATH, or add an alias for it in your shell.

<comment><USER32> But what? This is some code that some dude wrote and published courteously open-source, it's written in a rather-newborn language and it is for computer- savvy users. Were you expecting a binary installer?

<comment><USER31> I wasn't. I am not complaining, just saying that there is too much friction in all this. Happens with every programming language.

</comment></comment></comment><comment><USER33> A better ls! I love the git integration.

</comment><comment><USER34> It is very promising but sadly the alignment of the column mode looks very buggy at the moment.

<comment><USER34> Actually, I just updated the repo and rebuilt exa and this issue is gone. As soon as the integration with gitlib2 becomes fast enough, this will be a perfect ls replacement.

</comment></comment><comment><USER35> slightly overkill on the coloring ;)</comment>


Use of nuclear technology gets green light in Rwanda - <AUTHOR> https://www.newtimes.co.rw/news/use-nuclear-technology-gets-green-light-rwanda <comment><USER2> "Living near a nuclear energy plant is like living near a nuclear bomb which can explode and cause more damages [said an MP]..."

This is typical of people who aren't educated about nuclear power. To have a minimally functioning fission bomb you need enrichment north of 98% whereas nuclear power plants use fuel that is only enriched to 2%. It's like comparing the hydrogen peroxide you but at the grocery store to the purified stuff that's used in liquid rocket experiments. Yes, there is uranium in a nuclear power plant just as there is in a nuclear bomb but the type and enrichment is so different as to make them practically not the same thing.

<comment><USER3> "This is typical of people who aren't educated about nuclear power."

This is typical of people who are aware of Chernobyl and Fukushima. There have not been utility-scale many nuclear power plants in the history of the world. The fact that two out of ~600 failed catastrophically makes natural gas, wind and solar look really safe by comparison (especially since they are all cheaper and do not produce radioactive waste that lasts forever). How many catastrophic energy plant failures can you name that were not nuclear?

<comment><USER4> The Banqiao and Shimantan dam failures in China killed ~170K people.

The Machchu-2 dam failure killed 5K people in India.

The South Fork dam failure killed 2K people in the US.

Coal mining directly killed over 100 people annually up until the mid 1980s, and continues to kill 10-30 people annually.

Oil drilling in general kills about 100-110 people annually.

There's not much good data for wind turbines, but generally wind power kills 10+ people annually, either due to fires in the turbine housing or falls.

There have been a number of deaths at various power plants, often due to electrocution or steam boiler explosions.

The only truly safe power utility-scale power source in widespread use is solar.

BTW: Fukushima killed 1 person directly due to the nuclear material. Even Chernobyl only killed between 30 to 80 people directly, depending on how you count it.

If you want to count _indirect deaths_ due to Chernobyl and Fukushima, then you also have to compare that to indirect deaths due to traditional power. You don't want to know how many people diesel, oil, and coal kill annually!

<comment><USER5> > The only truly safe power utility-scale power source in widespread use is > solar.

Apparently a fair number of people die from solar as a result of falling off of roofs.

<comment><USER4> I'm only considering utility-scale power. Those are ground-level, not rooftop installations.

If you want to include all forms of "home" power generation, including heating and cooking, then wood fireplaces are mass-murderers, killing tens of thousands due to particulate pollution and carbon monoxide poisoning. Not to mention homes burning down and killing the occupants.

</comment></comment></comment></comment></comment><comment><USER6> I spent a month in Rwanda in late 2018, and it's an extremely impressive little country.

It fascinates me that we hear so little of them, our media only wanting to bring us the gripping headlines (which are of course all bad)

\- By far and away the cleanest country I've ever been to on the planet (WAY better than Canada/USA/Australia)

\- They have a thriving tech sector, developing phone apps, hardware and other software that is in use all over East Africa

\- Extremely well educated, kind and considerate population. The young people especially were very eager to speak English and discuss the outside world. They knew more about a ton of stuff than I do (just a simple Software Engineer / traveller)

\- Their economy is booming.

I wish them all the best!

<comment><USER7> My trip was in 2014 and I concur with how clean and beautiful it is. In addition to the capital being an impressive city, another amazing opportunity awaiting you there is visiting mountain gorillas. I just uploaded a video of my experience a few days ago:

[https://vimeo.com/stephenhuey/gorillas](https://vimeo.com/stephenhuey/gorillas)

<comment><USER6> It's half the price in Uganda!

Here's me:

[https://www.youtube.com/watch?v=M1vhZ03OKKE](https://www.youtube.com/watch?v=M1vhZ03OKKE)

</comment></comment></comment><comment><USER8> What is Russia's geopolitical angle here?

The gulf between peaceful nuclear program and weapons-grade nuclear program is vast and easily detectable.

>A Plenary session of the Chamber of Deputies on Monday, June 15, 2020, voted the law approving the ratification of the agreement between Rwanda and Russia, on cooperation in the construction of the Centre of Nuclear Science and Technology on the territory of Rwanda.

>The agreement was signed in the Russian city Sochi, on October 24, 2019.

>The Centre will develop integrated nuclear energy solutions which the Ministry of Infrastructure expects to be beneficial to the advancement of several sectors of the economy especially agriculture, healthy, education, sciences and industry.

<comment><USER9> Russian companies build reactors and other similar tech. Like any other country, Russia is helping domestic industry grow. Same thing done by most big European countries, the US, China, etc.

<comment><USER8> Do you mean they're helping their domestic peaceful nuclear energy industry grow?

<comment><USER10> It is a mutually beneficial deal. Nobody's "helping" anyone here.

<comment><USER11> The "help" is the government supporting a private enterprise. Cronyism that "helps" the political class and the company, but possibly not Russian citizens. Or maybe it does. Maintaining a domestic nuclear industry is certainly strategic.

<comment><USER10> All big strategic companies are supported by their respective governments one or the other way. Nothing is wrong about it. And the Government will have their cut in return eventually. I think it helps Joe Schmoe in the end as well.

</comment></comment></comment></comment></comment></comment><comment><USER12> Here is the symbol used in the US for food that has been irradiated the process called radurization. I'm not sure how common it is and I've never looked for the symbol. I do recall years ago how people were upset about "radioactive food" due to irradiation. It's done using gamma rays or x-rays not particles.

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

<comment><USER13> Many if not most modern plant cultivars had at some point irradiation used on them to increase mutation rates to find interesting mutations with higher yield, higher resistance etc.

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

This has worked especially well in rice, chances are between 5% and 25% depending on country you're eating rice from a cultivar that has been bred using radiation.

That's done in these cool-looking atomic gardens where you have a radiation source in the middle and then plants are seeded in circles around it. The inner-most circle dies, the outer-most circle stays the same, the middle is interesting to breeders, you can see those on google earth, there's a picture here: [https://99percentinvisible.org/episode/atom-garden- eden/](https://99percentinvisible.org/episode/atom-garden-eden/)

It's one of the things the consumer would be very upset about if told, but has been living fine with for decades, like the fact that your insulin, your washing powder, and your contact sense solution is made by genetically modified bacteria.

<comment><USER14> Yep, this is funny - people have problem with GMO where we have atleasts some idea what the modification did but at the same time most of what people eat was created by radiation induced random mutation.

</comment></comment></comment><comment><USER15> While i'm not fundamentally anti nuclear the long lead time and high cost of installation surely makes renewable and battery storage a serious contender against nuclear at this stage, right?

<comment><USER16> Rwanda is a small country, about the size of the Massachusetts state in the US, but with double the population. It's in the mountains, lots of forests and lakes. No deserts. Not a lot of unused land where you can mount solar panels. Nuclear makes sense for them.

<comment><USER17> Rwanda is roughly 6.5 million acres in size. Half of its roughly 200MW of total generating capacity comes from hydro and solar, the other half coming from natural gas and biomass thermal generation. To replace existing thermal generation would be ~12k acres of solar, and another ~12k acres for every additional 100MW in solar generating capacity desired (or inter connectors to other grids in the region). I also assume that rooftops are available for solar.

<comment><USER18> Their current generating capacity is not coming close to meeting their needs, with around 85% of it's energy use coming from firewood.

<comment><USER17> Your point is taken. I think it's incredibly valuable the fuelwood used for cooking and lighting is deprecated for off grid solar solutions, not only for health reasons but to stem the deforestation Rwanda faces from it's reliance on fuelwood for its energy needs.

</comment></comment></comment></comment></comment><comment><USER19> Hope that plant gets built, but I mean just look at Bulgaria, where corruption is rampant. We haven't been able to complete the Belene Nuclear Power Plant for 30 years now.

Doubt the Rwandan plant will get built any time soon.

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

</comment><comment><USER20> Rwanda is a very interesting player in Africa. They are experimenting with many technologies that the West can only dream of. They use drone deliveries for emergency medicines as well with good success, between plants that manufacture them and hospitals dozens of kilometers away.

<comment><USER21> I highly doubt your second sentence is true

<comment><USER22> They do have a very proactive government that deploys experimental technology in highly public pilots. That you doubt it's not true is purely because it's an African country.

<comment><USER23> Maybe what he's getting at is that the technologies the west "can't dream of" were invented in the west. Drones, for example. The west doesn't use drones to deliver medicine because it has very well developed infrastructure to deliver medicine.

It is cool Rwanda is doing this but I would guess the west has dreamed of drone deliveries of things and decided that its current system is ok.

</comment></comment></comment></comment><comment><USER24> > the Minister said that [some of] the imported foods into Rwanda are > preserved using nuclear technology

Huh, anyone knows what this is referring to?

<comment><USER25> You can blast foods with gamma radiation and then can it or otherwise put it in an airtight seal. The gamma radiation kills all foods and microbes that would cause it to decay. Gamma radiation is just photons (unlike alpha and beta radiation) so it doesn't case the food to become radioactive.

It would enable canning food without preservatives.

<comment><USER26> Typically you put the food in the can and the cans the box and then blast the whole box in one go.

Very useful for countries with limited access to refrigeration.

This is also a common method for sterilizing single use medical stuff, band- aids, sutures, iv tubes etc.</comment></comment></comment>


Ask HN: Why isn't there a dedicated Hacker News IRC channel? - <AUTHOR>

There is #startups @ freenode, but HN isn't just about startups. <comment><USER2> Who has the time? What would be the point?

</comment><comment><USER3> theres probably another irc channel for whatever you want to talk about</comment>