Small satellites are radically remaking space exploration - <AUTHOR> https://arstechnica.com/science/2020/07/how-small-satellites-are-radically-remaking-space-exploration/ <comment><USER2> I'm also really excited by the opportunities low cost access to space and standardised low cost probes offer, but there is still a vital role for the big budget flagship missions.

The article imagines what we could do with 100 mini Curiosity rovers, but the reality is not much. A rover is a completely different proposition from a cubesat. The instruments Curiosity carried can't just be scaled down 100 times. Similarly if we're going to put a lander on Europa, there's a minimum size such a thing would need to be to work at all, be able to carry useful instruments and have enough power to transmit data back, and it's not tiny.

The fact is you build the probe and mission around the instruments you want to send, and that sets quite high minimum vehicle design parameters for many missions. The MarCO cubesats barely carried any instruments at all, they were mainly communications relays for the InSight probe. On their own they could do practically no science. Yes I know they were mainly a demo mission, but lets keep things in proportion. Add more instruments and you need more power so bigger solar panels, more powerful computers, more capable antennas, bigger batteries, more powerful thrusters, a bigger launcher and all of a sudden it's not a cubesat any more.

So I do apologies for pouring all that cold water. The stuff is really exciting and is genuinely opening up new and exciting opportunities, but let's not kid ourselves that the old way of doing things is over. It really isn't. If these new technologies created the impression that flagship missions are a waste of money and not worth doing, it would be a terrible shame. This isn't an SLS vs Starship type contest where one solution essentially deprecates the other. Micro-missions are a fantastic complement to traditional exploration models, but not a replacement.

<comment><USER3> What about a cubesat solar system relay system? Each with a few directional antennas pointed at the nearest neighbor in the grid. Maybe offset from the solar system plane to avoid impacts. It would take a few billion sats to blanket the whole solar system but they're cheap. If we built them in space we could have spares all over waiting to fill gaps.

I tried to do the math but failed. Pluto's orbital diameter, according to wikipedia, is about 4.4 billion km. That means the main solar system has a circumference of about 27 billion km. Starlink cubesats orbit at about 550km. Relay sats wouldn't need to punch through atmosphere so they could be farther apart.

I pictured a series of circles. The close to the sun the smaller. I'm sure if I'd listened in cal 1 I could use a summation to figure this out.

Losing a few sats periodically isn't a big deal and it won't bring down the whole network.

It might slow signals down to propagate through the mesh but communication is already slow in space. If a probe/ship needs to communicate quickly it can use its own high power dish or laser.

</comment></comment><comment><USER4> Eric Berger has a lot of really great stories about what's going on in the space industry. Smallsats have been the story of the sector for going on two decades now.

I've got a background in both space engineering and planetary science. One of the most exciting things that I see happening over the coming decade is commoditization of planetary probes. There's so much more of the Solar System that we still have to explore and the traditional flagship missions just don't give us enough access.

The best way to think of how smallsats augment our space science and exploration capability is in terms of the marginal value over traditional missions. For planetary science, the cost per bit of science data can drastically be reduced through the use of Commercial Off-The-Shelf (COTS) components.

There are a number of private companies looking to leveraging smallsats to deliver all-in planetary science missions, like Xplore [1].

As a space engineer, access to suppliers was really a major hurdle towards finding the optimal cost and risk sweet spot. If you're interested, we've published a series of articles shedding light on different products & services available on the market [2]. We've now got 1000s of space engineers every month from all over the world using these articles to drive better sourcing.

Better sourcing will ultimately lead to better missions, and drive the smallsat revolution towards completely remaking the way we think of both space science and exploration.

[1] [https://www.xplore.com](https://www.xplore.com)

[2] [https://blog.satsearch.co/2019-12-03-space-technology-on- sat...](https://blog.satsearch.co/2019-12-03-space-technology-on-satsearch).

</comment><comment><USER5> Shamelessly pitching our own small satellite project that can run mission of _your_ choice:

[https://www.kickstarter.com/projects/exodusorbitals/nova- a-c...](https://www.kickstarter.com/projects/exodusorbitals/nova-a-crowd- flyable-space-mission/)

<comment><USER6> Looks interesting! I see you have plans for a camera. I've previously looked into this and I know that camera hardware needs to be cleared by some government authorities and there may be some limitations due to security concerns or something?

Could you expand on this? What are the limitations and regulations on cameras in space for civilian sats?

<comment><USER5> Well, the answer is kind of long. We are going to have a meeting/workshop this week with legal company that specializes in space law. Two major points clear so far:

\- For our first mission camera resolution is not a big concern, we are not launching KH-11 grade hardware.

\- However, there is list of specific locations that need to be blacklisted for "national security considerations", depending on both of satellite operator jurisdiction and satellite users' nationality as well.

It is going to be messy and complicated, but in the words of our legal consultant: "difficult, but doable".

</comment></comment></comment><comment><USER7> Written by Eric Berger. I'm a big fan of his, you can read his other stories at [https://arstechnica.com/author/ericberger/](https://arstechnica.com/author/ericberger/)

</comment><comment><USER8> The development of some satellites is also radically faster and using COTS software, like shell scripting, python, etc.

This is a talk by Satellogic Gerardo Richarte on how they hacked control back of an orbiting satellite after a dev did an rm -rf / on a couple of it's computers [https://youtu.be/B88AYaQNlD4](https://youtu.be/B88AYaQNlD4) It's in spanish, but it's a great anecdote of "hackers in space"

</comment><comment><USER9> The smallsat market has to consolidate at some point. There's a lot of players now.

If Spacex entered the market I think it would be game over but they seem content to ignore it and focus on bigger payloads.

Last time I looked was blown away by the costs for a non-commercial 0.5U tubesat launch. $12,000 including all the hardware:

[https://www.interorbital.com/Tubesat%20Kits](https://www.interorbital.com/Tubesat%20Kits)

<comment><USER10> SpaceX does have a smallsat ride sharing program. The Starlink-8 launch was the first one (with 2 smallsats from SkySat), and the upcoming Starlink-9 also has 1 (BlackSky Global).

[https://www.spacex.com/rideshare/](https://www.spacex.com/rideshare/)

<comment><USER9> I stand corrected.

</comment></comment></comment><comment><USER11> a</comment>


Border security bugging travelers' conversations in Canada makes TSA look mild - <AUTHOR> http://www.thestar.com/iphone/news/canada/politics/article/1213052--ottawa-to-eavesdrop-on-travellers-entering-exiting-canada

<comment><AUTHOR> I remember a time when mere camera surveillance in public places was considered unacceptable.</comment>


How did Ramanujan solve the STRAND puzzle? - <AUTHOR> https://www.youtube.com/watch?v=V2BybLCmUzs <comment><AUTHOR> This one is full of mathematical _IDENTITIES_ ; that is, phi, pi and e are here, as is the square root of 2, infinite fractions, some types of algebra equations with x and y, Pell's equation, how some types of algebra equations have an infinite fraction equivalent (and this equivalent as expressed in counts of blocks on 2D graph paper), and Euclid's Algorithm.

It's quite the mathematical mash-up!

Well worth watching again in the future!</comment>


Show HN: Temporal Password Registry - <AUTHOR> https://temporal-password.pressbin.com <comment><USER2> Fantastic. I mean, how the hell did he come up with this, much less build a complete site around it?</comment>


Stimulus Update: $0.9T and counting. - <AUTHOR> http://online.wsj.com/article/SB123307183916519783.html?mod=djemITP

<comment><USER2> It's going to be interesting to see what's the next step when the stimulus doesn't work -- which I doubt it will.</comment>


360 degree panoramas of 7 famous world sites - <AUTHOR> http://www.panoramas.dk/7-wonders/ <comment><USER2> The only problem with these is that because they are panoramic they can't put the camera in the best position. For example, all the famous pictures of Macchu Picchu are taken from behind that little hut you see about 50 feet above where the camera is. The problem is that with a panorama, if you put the camera there then half the picture would be the back of the hut. Because of this you don't get as good of a view of the actual ruins. Similarly, all the famous pictures of the Petra treasury are taken from the opposing cliff, which again wouldn't work for the same reason. So although you get to see more of the surrounding environment, you get a less good view of the actual thing of interest. Still great pics though.

</comment><comment><USER3> wow!</comment>


Intercepting and Emulating Linux System Calls with Ptrace - <AUTHOR> http://nullprogram.com/blog/2018/06/23/ <comment><USER2> This was a great tool many years ago for scripting this functionality with Python: [https://github.com/tutufan/subterfugue](https://github.com/tutufan/subterfugue)

The tagline was "strace meets expect". You could write a Python script to control what happened when the process being traced made a syscall of your choice! This was super-fun and super-educational and also came with a little manifesto about ensuring users' control over software rather than the other way around.

Unfortunately subterfugue hasn't been maintained in years and I think it hasn't worked with the last few major releases of the Linux kernel. It would be amazing to see a similar tool nowadays.

</comment><comment><USER3> Cool! I did this a while ago for some CPU-bound stuff, and ran into a bunch of performance bottlenecks.

Some things that helped me scale ptrace-interception up:

\- SECCOMP_BPF filter (getting these right matters a lot)

\- moving all of your intercept work to a single side (enter or exit)

\- ensure affinity between the traced and tracing processes

\- nuke vdso

\- remove vdso from the aux vector (otherwise good libc's will find it again)

At the end of the day unfortunately the better solution would have been to write kernel support for what I wanted to do, but it's a fun exercise in learning about system calls.

</comment><comment><USER4> It's a nice write up and the part on system call interception is only serving as an example, but be careful if you're considering ptrace in something where security matters.

See the answer on [https://stackoverflow.com/questions/4414605/how-can-linux- pt...](https://stackoverflow.com/questions/4414605/how-can-linux-ptrace-be- unsafe-or-contain-a-race-condition) for an example of a potential race. I believe OpenBSD's systrace had some issues like this.

</comment><comment><USER5> > The catch is that a process can only have one tracer attached at a time, so > it's not possible emulate a foreign operating system while also debugging > that process with, say, GDB.

This is actually possible. How? The obvious way... You intercept and emulate ptrace calls with ptrace.

[https://robert.ocallahan.org/2016/04/using-rr-to-debug- rr.ht...](https://robert.ocallahan.org/2016/04/using-rr-to-debug-rr.html) explains how this works in practice.

</comment><comment><USER6> This is (basically?) the technique used by PRoot, which has issues with using SECCOMP [1]. If anyone has the expertise, they'd doubtless be grateful of help with the problem.

PRoot is pretty useful as a pure-userland solution for jobs that container-ish things might otherwise do, e.g. user-mode installation of Nix/Guix.

[1] [https://github.com/proot-me/PRoot/issues/106](https://github.com/proot- me/PRoot/issues/106)

</comment><comment> yjftsjthsd-h That's cool:) It looks like this is how WINE works, too, if I read correctly ([https://askubuntu.com/questions/146160/what-is-the-ptrace- sc...](https://askubuntu.com/questions/146160/what-is-the-ptrace-scope- workaround-for-wine-programs-and-are-there-any-risks))

<comment><USER7> Hello, actually WINE works in a different way, it does not attempt to intercept system calls (it is not possible because Windows system calls work in an incompatible way), instead it reimplements Windows DLLs, and normal application code never calls syscalls directly, but always via the DLLs implementing the libc or other libraries. So the DLLs of the core Windows functions are simply replaced with the WINE implementation on top of the POSIX API.

<comment><USER8> So they essentially had to re-write the windows system files (the DLLs) to implement libc and other linux friendly stuff?

<comment><USER9> Yeah.

FWIW, Micorsoft's implementations of Win32 have swapped out the kernel a few times anyway, so it's not the biggest leap for a third party (DOS/Win32s, Win9x, WinNT).

Because of this, Microsoft considers the system call layer to be unstable, and appears to go out of their way to change the system call table every service pack. So the dll entry points are the stable ABI, and that's what 99.99% of developers rely on.

<comment><USER10> That's an oddly un-Microsoft move given their general attitude towards maintaining compatibility even for undocumented API…

<comment><USER9> They've backed away from their classic Herculean efforts at back compat over the past decade or so.

</comment></comment></comment></comment></comment></comment><comment><USER10> > The request field selects a specific Ptrace function, just like the ioctl(2) > interface. For strace, only two are needed:

PTRACE_TRACEME: This process is to be traced by its parent. PTRACE_SYSCALL: Continue, but stop at the next system call entrance or exit. PTRACE_GETREGS: Get a copy of the tracee's registers.

You have three things here ;)</comment>


Why the New MySpace will Crush FaceBook - <AUTHOR> http://www.banterant.com/2012/09/why-new-myspace-will-crush-facebook.html

<comment><USER2> Based on the video, it looks like it has a Windows 8 UI feel to it.

For my opinion, I think MySpace will not crush Facebook with just a UI change.

Or maybe, with that change, is Facebook still their direct competitor?</comment>


MyRealOnlineChoices: an ad blocker that conciliate privacy and economy - <AUTHOR> https://myrealonlinechoices.inrialpes.fr/ <comment><AUTHOR> This is a tool developed by members of my research team at Inria, Privatics. Note that I'm not involved in this project at all. We are a research group that mainly focuses on two topics: 1- understanding and formalizing privacy (that's what I work on), and 2- building privacy preserving systems (such as MyRealOnlineChoices).</comment>


I want to learn programming, which language would you recommend? - <AUTHOR>

I'm non-technical, and I've never done any coding.
I'm thinking of learning a bit of programming, mainly because - if I have some idea, (after validation) I can build a prototype and test it out with real users.
- Which programming language would you recommend and why?
- And is there any good source where I can learn it from?
Preferably a language that would help if I need to do some social network API integration.
Thank you! <comment><USER2> Python

Its easy to learn because it has a simple and clear syntax, yet is a powerful language. It allows you to learn various programming concepts one at a time (while other more complex languages may force a bunch of concepts on you before you can do anything useful) and anything you learn will translate to other languages, should you wish to learn others in the future.

Python comes packaged with a large library of pre-written modules and is supported by a lot of third party API's.

Python also has a very active and friendly community of users, so help will be easy to find, should you need it.

Learning Python: <http://wiki.python.org/moin/BeginnersGuide>

(PS, the same can probably be said for languages like Ruby, but I learned Python first, so have no real experience with Ruby)

<comment><AUTHOR> Thanks dkersten! I'll check out Python.

What do you think of PHP? Some folks were suggesting that, but I haven't yet checked it out.

<comment><USER3> If the ideas you hope to prototype live on the web, this is a reasonable choice. However, I don't recommend using PHP as a general programming language.

Python kind of works for everything, if you want to do web dev you can pick up Django, plenty of GUI libraries and it works on all platforms easily.

<comment><USER2> This is pretty much what I would have said if I'd checked the comments sooner. PHP works well enough for a web language, but if you want to do anything else, its not so great. Python works, IMHO, equally well for web, desktop GUI, shell scripts etc.

</comment></comment></comment></comment><comment><USER4> You need to pick a few languages, research them and find which one interests you the most. Take into account your and the languages philosophies, your end goal or even something as shallow as how the language looks to you.

Note: ruby has tryruby.org and python has trypython.org

Both are good candidates for a first language, and have _excellent_ books available online.

<comment><AUTHOR> Thanks jeebusroxors! Python seems a good choice from the comments here.

What do you mean by 'language philosophies'? can you pls explain a bit?

<comment><USER4> The example I had in mind was Perls There's more than one way to do it (TMTOWTDI).

Python is the opposite. They strive for one clear way to do things.

[http://en.wikipedia.org/wiki/Theres_more_than_one_way_to_do_...](http://en.wikipedia.org/wiki/Theres_more_than_one_way_to_do_it)

This may be above your head but just remember, the first language you learn will not be your last. If you end up picking lisp and hate it you can always learn c. _Programming_ is (for the most part) universal between all languages. Once you get the basics you only need to learn the syntax.

</comment></comment></comment><comment><AUTHOR> Thanks everybody! I'm going to start with Python. Will post my progress on HN after a while :)

</comment><comment><USER5> This is a little like going to IKEA and saying "I need to furnish my house, what should I buy"? Without knowing more about the intended use of the language, it's hard to give a good answer.

However, if pressed, I would say Javascript. It starts simple (but is not a simple language), you can build slick web pages with it, and you can even build native mobile apps for Android and iPhone (e.g. with using PhoneGap).

<comment><AUTHOR> I don't have a specific app idea in mind for which I want to learn programming. Mostly, I like consumer web apps, and which may require integration with facebook, twitter APIs.

I'm not looking to build a full blown app myself - rather a quick prototype to test it out with users and if there's traction, then it would make sense for me to team up with engineers and build it out.

Regarding Javascript - as you say, I too have _heard_ that it's not that simple. Some folks were suggesting to start with PHP. I though of checking with HN community on what they recommend.

<comment><USER5> PHP is also good, but if you want to do some heavy integration with service API I stand by my Javascript suggestion. It's not pedagogical, but then neither is PHP.

If you are a little more serious in your desire to learn programming, than you can learn Java. That way, you can go the GWT route when you need Javascript functionality.</comment></comment></comment>


Adding Easy SSL Client Authentication To Any Webapp - <AUTHOR> http://www.scriptjunkie.us/2013/11/adding-easy-ssl-client-authentication-to-any-webapp/

<comment><USER2> It's sad that I didn't realize he easy this was to implement now. I'm building several sites that implement bitcoins and this has clear advantages over simple usernames and passwords.

My thought is allow the user to authenticate with the SSL cert. If they're at an IP never seen before, require a password.

Thoughts? My concern is with people that have a compromised computer that has a Remote Access Toolkit installed on it. Perhaps always require the SSL cert AND a password pair? Not that passwords would be safe on an infected machine.

These days it seems that the only way to be sure is to require additional authentication from a second device such as a phone with a 2FA app like Google authenticator or Authy or a hardware device like a Yubi key. Even sending one- time text message confirmation xodes .

<comment><USER2> I'm embarrassed that I didn't notice my auto-correct mangling my comment. I'll comment from my desktop in the future.

I meant to say that it's amazing how easy this is to implement now and even sending one-time text message confirmation codes during every authentication attempt works.

</comment></comment><comment><USER3> Imho the gaping hole with client certificates at the moment is that, in current browser implementations at least, I don't think they are well secured.

Notice when using his demo pages you are asked by your browser for confirmation before you use your shiny new certificate, but otherwise no credentials are required. It's relatively easy for someone to steal client certificates from my machine whether I'm here or not.

        [wf9bhh4z.default]$ pwd
        /home/nly/.mozilla/firefox/wf9bhh4z.default
        [wf9bhh4z.default]$ strings cert8.db | grep nly.*junkie
        nly's scriptjunkie.us ID

... I'm not sure if this default behaviour is a switch that can be flipped somewhere, or whether they are actually encrypted, but that protection can only ever boil down to some other credential like the users Windows password (which will be weak).

When it comes down to it today, I feel a mobile solution, like Google Authenticator that can live comfortably in my pocket, is just more workable as a 'something I have' credential, and I then don't have to entirely trust whatever random PC I'm using. With QR codes it's even almost as convenient. (I also don't think password auth need be totally disregarded, see : [https://news.ycombinator.com/item?id=6767249](https://news.ycombinator.com/item?id=6767249) ).

That said, I commend the author for seeking alternatives to password authentication and doing all this excellent work to make it easy to use. It's good, desperately needed work.

<comment><USER4> In OSX, client certificates are stored in the Keychain, which must be unlocked with your password. The problem with almost every "security product" comes down to the fact that Windows (and Linux, I think) don't have equivalent protected-storage APIs integrated throughout the desktop environment.

<comment><USER5> linux has "equivalent protected-storage APIs integrated throughout the desktop environment",KDE has kwallet[1],GNOME has libsecret[2] and lxqt has lxqt wallet[3].Firefox has an extension to store its passwords in KDE's kwallet[4] and GNOME's gnome-keyring/libsecret[5].Chrome has support for both wallets[6]

all linux destributions ships with libsecret and that will be the API to target if anybody want to store sensitive information securely in a linux desktop session.

[1] [http://en.wikipedia.org/wiki/KWallet](http://en.wikipedia.org/wiki/KWallet)

[2] [http://lwn.net/Articles/490518/](http://lwn.net/Articles/490518/)

[3] [https://github.com/mhogomchungu/lxqt_wallet](https://github.com/mhogomchungu/lxqt_wallet)

[4] [https://addons.mozilla.org/en-US/firefox/addon/kde-wallet- pa...](https://addons.mozilla.org/en-US/firefox/addon/kde-wallet-password- integratio/)

[5] [https://addons.mozilla.org/en-Us/firefox/addon/gnome- keyring...](https://addons.mozilla.org/en-Us/firefox/addon/gnome-keyring- integration/)

[6] [http://productforums.google.com/forum/#!topic/chrome/r65mTFM...](http://productforums.google.com/forum/#!topic/chrome/r65mTFMrT9o)

</comment></comment></comment><comment><USER6> "Private keys cannot be guessed – Because users didn't choose them!" I don't follow this logic. Sure they're likely to have more entropy than a user- selected password (and almost certainly be longer). However, there's nothing about the fact that the key isn't selected about the user that makes it un- guessable.

<comment><AUTHOR> Private keys should have over 128 bits of entropy, which is enough to make it un-brute-forceable with at least the amount of energy likely to be obtained by any human organization on earth. [http://en.wikipedia.org/wiki/Brute- force_attack#Theoretical_...](http://en.wikipedia.org/wiki/Brute- force_attack#Theoretical_limits) That's what makes it un-guessable. Also, some users do choose passwords with at least as much entropy and are also unguessable. But most don't.

<comment><USER7> I use automated high-entropy password-generators and a surprising amount of websites cap lengths to 30-50 characters (or even 8 chars sometimes like a Canadian bank I won't name). Allowing super-long passwords would be a good starting alternative to SSL.

<comment><USER8> The problem with this is that some sites still only support max 20 characters.

</comment></comment></comment></comment><comment><USER9> Love it so much! An easy way to detect user and could prevent quite a lot of phishings attack.

One issue is the browser compatibility. It work on Chrome, but I tried it on my iPhone Safari and it doesn't work. Is there any way to fix it?

</comment><comment><USER10> As far as I can tell, client certs can't be cross-device. You would need a new cert on every device you plan to use with the site.

<comment><USER7> I've used PGP keys cross-device (using both android and osx clients), why can't SSL?

<comment><USER11> You can export and import certs between devices, the UI is just awful. Possibly more awful than all the PGP UIs, if such a thing is possible.

Certainly you can't drive this flow from the website alone. The best you can do is point your users at various browser-specific instructions.

<comment><USER12> At which point you're back to the same basic problem with passwords: the weakest link and root-problem is the average user's lack of knowledge. There wouldn't be such a mad scramble to find a decent alternative to passwords if everyone was using KeePass or the like, and no alternative is going to be near-future viable if it relies on something too complicated for the nearly- everyone who isn't using strong generated passwords.

2FA is working because all the user has to do is get a text. Anything beyond that level of difficulty is simply a non-starter at this point.</comment></comment></comment></comment>


Translation of Snowden's latest letter.  - <AUTHOR> http://www.huffingtonpost.co.uk/2013/07/01/edward-snowden-seeks-political-asylum-ecuador_n_3530542.html

<comment> brown9-2 _While the public has cried out support of my shining a light on this secret system of injustice, the government of the United States of America responded with an extrajudicial man-hunt costing me my family, my freedom to travel and my right to live peacefully without fear of illegal aggression._

What is extrajudicial about what the USG has done?

They have charged him with a crime in a court (which is very "judicial") and are seeking to have him brought back to the US. "Extrajudicial" would be imprisoning him with no charge or trial.

One does not have the right to live peacefully without fear of being charged with a crime (which again, how is the act of charging someone with a crime itself illegal?).</comment>


OpenSSH 6.8-6.9 PTY local privilege escalation exploit (CVE-2015-6565) - <AUTHOR> http://www.openwall.com/lists/oss-security/2017/01/26/2 <comment><USER2> This was fixed in 7.0, released in 2015-08-11.

</comment><comment><USER3> Sierra 10.12.3 appears to be running OpenSSH_7.3p1, LibreSSL 2.4.1

i.e. if you run latest macOS & wondering if this exploit affects you, you're all clear.

</comment><comment><USER4> >> I guess its either PoC||GTFO for users to update.

Sad but true.

Are there any supported systems still shipping an affected version?</comment>


"Memory foam" approach to unsupervised learning - <AUTHOR> http://arxiv.org/abs/1107.0674 <comment><USER2> _We propose an alternative approach to construct an artificial learning system, which naturally learns in an unsupervised manner. Its mathematical prototype is a dynamical system, which automatically shapes its vector field in response to the input signal. The vector field converges to a gradient of a multi-dimensional probability density distribution of the input process, taken with negative sign. The most probable patterns are represented by the stable fixed points, whose basins of attraction are formed automatically. The performance of this system is illustrated with musical signals._

Could anyone eli5 this?

<comment><USER3> They estimated how likely particular notes were, using a kind of averaging procedure that corresponding to simulating an elastic foam. They used a fourier transform to identify the notes in a piece of music: they then simulated the physical procedure of adding a stone to the foam at a location corresponding to the frequency, and time corresponding to when the note was played. The final shape of the foam then gives a density estimate of the data: the more often a particular note was played, the deeper is the dip in the foam at that location ('the foam evolves into a time-averaged density of the input').

Once you've done this, you have a curved surface. You can imagine a ball being released at some point and rolling around: it could get stuck in the bottom of a well ('a stable fixed point'), which corresponds to the 'most probable patterns' in the training data.

Edit to add: _" The vector field converges to a gradient of a multi- dimensional probability density distribution of the input process, taken with negative sign"_ You can think of the "vector field" of the dynamical system describing the movement of the ball as a bunch of arrows, giving the direction the ball would move if released from each possible starting point. If you trace these arrows end-to-end, you can see the trajectories that the ball could take.

Since the ball will roll downhill, the vector field of the system is (minus) the gradient of the potential energy/height. Also, because of how we formed the surface, its height 'converged to the probability density of the input process' (the more frequent an input was, the lower the corresponding dip in the foam). Thus, the vector field of the system converges to the gradient of the probability density of the input.

</comment></comment><comment><USER3> Another arxiv preprint by the same authors has more detail, and seems to be the essentially the same article but fleshed out more: [http://arxiv.org/abs/1111.4443](http://arxiv.org/abs/1111.4443)

<comment><USER4> Thanks for this. I was amazed the authors offered no comparison to any existing unsupervised DBN/ANN work.

</comment></comment><comment><USER5> Yay, someone with the sophistication required is working on this! As I've been thinking for a few years, intelligence is more about absorbing pattern from the world than it is about the deliberate process of constructing pattern from scratch within the system. It's is better to create a space where the pattern of the world can live, subject to some measure of objective utility, than it is to deduce some pattern from scratch using that same objective function.

God I would love to work in this field.

<comment><USER6> Cognition is pattern recognition, and we don't ever access the raw data, just the output labels - this is so Buddhist. In a sense we create our (inner) world because it is just patterns.

<comment><USER7> Recognizing patterns in data is so easy to do, that how easy it is, turns out to be a major problem in machine learning. You can always find some explanation that perfectly fits all the data you see, but that doesn't mean it will fit the data you haven't yet seen.

The challenge is finding the simplest patterns that will generalize to explain the most data, while wasting as little effort as possible on the irrelevant patterns. In high dimension data, the number of possible relationships to analyze explode, you can find patterns everywhere you look, so it's deciding where to bother looking with your limited resources that's hard.

That patterns are nothing special doesn't seem obvious to us because, evolution has done a pretty good job solving this problem(in the domain of inputs we evolved to deal with), and we only perceive those patterns that are likely to generalize.

</comment></comment></comment><comment><USER8> This sounds similar to Kernel Density Estimation. How does it compare to it?

</comment><comment><USER9> An implementation to play with would be very nice...</comment>


How do I fire my recruitment agent? - <AUTHOR>

It is accepted industry norm that a recruitment agent takes 15% give or take a few %age points. Last 20 years I've never had an issue, and I got to see all the rates my agents were paid. Until now.
I just found out my current one has been taking 52% and they negotiated down my price "due to market conditions" after the job offer.
These scumbags don't do freelancers any justice, and sure enough if the client had asked for a drop in rate they'd be on the phone asking you to suck it up. <comment><USER3> You just stop working with them (which you should probably have done many years ago, given the market).

Incidentally, what your employer paid your recruiter is their problem, not yours: if you're underpaid, demand a raise or leave.

</comment><comment><USER4> I wanted to learn more about how this works so sorry I'm not responding to your question, but when one has an agent, does the agent take 15% (or in this case, a mind blowing 52%) of the workers salary or that's just how much the hiring company pays the agent? Basically, is anything being deducted from the workers salary?

And there are mentions of a contract. What would this type of contract consist of?

The job candidate-agent relationship...is it like sports where agents can represent multiple job seekers but a job seeker usually only has one agent? And is there a legal side to this?

Sorry for all the questions, just trying to learn!

<comment><USER5> Normally, you (the contractor) is quoted a rate of £xxx/day, and the agency's % is on top of that and normally unknown to you.

You typically sign a contract with the recruitment agency, who has a back-to- back contract with the end employer. The contract basically just says you will be working at employer X for Z months.

There will be other legalise about intellectual property, confidentiality etc but that is the gist of it.

The flow of a job opening is normally that a hiring company will send the vacancy details to a shortlist of preferred recruitment agencies. These agencies will then submit CVs of candidates on their books back to the hiring company. Then the interview process etc starts.

To answer your specific question: agents can represent multiple candidates (a database of thousands) and a wise contractor would not rely on just one agency (my CV for example is probably with ~10 or so).

This is specific to the UK market - other markets may vary.

<comment><USER5> Also, recruitment agents are "employed" by the candidate and they will often say during negotiations "that the more you get paid, the more they make".

However, this is subject to the same issue that Freakonomics highlights vis Real Estate agents and house sales.

</comment></comment></comment><comment><USER6> It seems more like you just discovered your "real" market value. Welcome to reality!

The reason some people make more money than others is mainly because they posses key information that others don't have and this is part of the game.

Don't fire you're recruiter because YOU didn't know your true market value. Instead, use this "new information" to negotiate yourself a substantial raise next time you sit at the negotiation table.

The recruiter's markup is not disclosed to the contractor in my industry and it's not really important to me. What matters is "are you happy with what you're making?".

Fire your recruiter if he is incompetent, not if he's doing well.

<comment><AUTHOR> Firstly, I know my true market value, and have done for years - I always find a way to find out ;) and I haven't just got off the boat.

I also know what I can get away with making in this market, so what I'm making is not the issue _per se_ , although this is below my normal rate, and I agreed to this on the grounds that were presented to me - which turned out to be completely false.

I work with many recruiters, not just this one. This one happened to have a job available at the time I was available...

Lastly, they point blank refused to negotiate, at all. Hence the need to fire them.

<comment><USER6> As long as you're happy with your rate and with the service provided by the recruiter I don't think it should matter.

Companies don't disclose their markup on their products or else people would be shocked and wouldn't buy them. It's business as usual.

I suspect my recruiter takes home 50% of my rate too, i.e my OT (1.5) rate. On the other hand I get lots of OT, hence he cashes in on my first 40h and I take home the rest. Nobody complains because we're all making good money. Customer is happy, recruiter is happy and we're happy.

</comment></comment></comment><comment><USER5> It depends whether you are mid-contract or not, I'd have thought.

If it's the end of the contract, that's easy - don't accept their calls, don't go on any interviews they arrange etc.

If it's mid-contract, then it's trickier. You could either:

1) Leave and find a new role 2) Tell your agent that you know what their % is, and you want a raise or you will leave 3) Explain to the company that they are being over-charged, and see if their legal department will fight the agency to buy you out so you can contract directly or via a better agency.

Not sure that any of these guarantee success...

</comment><comment><USER7> I guess the only way to fire them is stay completely clear of them and id that's not enough maybe write a blog post exposing this behaviour.

<comment><USER8> "Stay completely clear of them" ... tell them at the appropriate time that they are fired and that if they ignore this and find you a job, you're not taking it, no matter what.

</comment></comment><comment><USER9> Depends on the contract.

</comment><comment><USER10> Holy cow. I cannot imagine how desperate the hiring company must have been to pay 52%. That is an indicator of very bad things I suspect.

Unless you have a contract with your agent (highly unlikely - people like 10x are starting this idea) then just do not use them.

An agency who is getting 50% out of a client company has photos of the CEO and two shameful-looking-sheep somewhere.

<comment><AUTHOR> I suspect you are right about the desperation thing, on the ground the client is under some pressure.

But look at it this way, if the client was asking for a small reduction in the rate the agent would be on the phone right away asking me to take a cut. They would also be getting a cut as their %age is based on my rate.

To be fair and honest, if the client is offering more to get you - <USER2> whatever reason - then that must filter down.

That just didn't happen here. The client therefore has also been mislead because they think that I am being paid appropriately. Instead the agent is profiteering.</comment></comment>


Networked-Aframe 0.2 Is Out – Multi-User WebVR in HTML, WebSockets or WebRTC - <AUTHOR> https://twitter.com/HaydenLee37/status/877907762365087745 <comment><USER2> Creator here. Happy to answer any questions.</comment>


Ask HN: Bad habits - <AUTHOR> What are your bad habits? Did you overcome them?  If so, how? If not, why? <comment><USER2> Checking time-wasting web sites much more than I should.

Before that, I had issues with keeping with the habit of exercising. I think I solved that a month ago by starting to use the Seinfeld method[1] to keep track of it. I will probably try to move everything I have trouble staying with to the calendar.

[1] [http://lifehacker.com/281626/jerry-seinfelds-productivity- se...](http://lifehacker.com/281626/jerry-seinfelds-productivity-secret)

</comment><comment><USER3> I have an addictive personality, which means I like doing everything too much: coding, writing, visiting interesting web sites, smoking, drinking, eating. Basically if it has any sort of positive feedback loop at all, I can make a bad habit out of it.

Fortunately I began suspecting this early in life, so I didn't end up a coke- head or worse. Instead I've learned to balance all of my bad habits in a way that continues to optimize productivity for me. So for example after smoking for five years in my early 20s, I quit cold turkey. As for eating, I'm learning to control my blood sugar levels. I'm finding there is a blood- sugar/caffeine/alcohol feedback system that I'm dismantling. But then there are big problems that I'm still working on, like procrastination and too much web reading (which are related!) I probably lose dozens of hours a week on these. Sometimes I make progress, such as no TV (except for movies) Still others seem intractable, like enjoying coding so much I keep over-coding things.

I think as you get older you begin to realize how screwed up you are -- if you are introspective at all, that is. Some folks aren't introspective at all, or if they are they aren't able to critically see what needs fixing. These are the ones to be pitied. But introspection always has kind of a sad quality to it. I know for me it was a lot more fun when I used to think I was bullet- proof.

<comment><USER4> Your post is pretty close to where I am, 'cept I gave up smoking when I was 12 (I still fancy a ciggy occassionally!), apart from a few occassions since.

I was speculating whether or not computers make me overall less productive or not - I'm convinced they do. I need other people around to work with, then I can get "addicted" to helping and progressing the task rather than anything else.

Sadly I'm working largely autonomously despite efforts to change that.

<comment><USER5> You gave up smoking when you were 12 ??? Wow, most people that smoke would not even have started by that age...

Apologies if it is too much of a private question, feel free to ignore: At what age did you start ? Were your parents aware ?

<comment><USER4> 10; parents, probably though I thought not at the time - it wasn't exactly a big habit, probably like one a week! Just one of those things one does to try and be cool and fit in. Then I realised it's stupid. I was probably a little under 12 then.

My mates folks owned a pub, his parents definitely knew we were getting our fags there.

</comment></comment></comment></comment><comment><USER6> Responding negatively to generic posts that ask questions yet reveal nothing about the poster's reasons for the question nor contain any elaboration on the poster's part as to their own <insert inane question topic of discussion> in the post.

<comment><USER7> Up-voting clever comments that add no value, but are such a pleasure to read and understand.

</comment></comment><comment><USER8> Workoholism.

I enjoy getting away from the computer and having fun just as much as anyone else, but with my mostly-full-time freelancing work + writing most of the codebase for a startup on my own, I have the bad habit of telling myself that if I do some extra work one night I can stop a little early the next night. But the next day comes around and I'll do the same thing all over again.

</comment><comment><USER9> Pack a day smoker.

Quit cold turkey 3 years ago - through willpower. Not impossible & not easy.

<comment><USER10> A smoker myself - Not that much anymore, but still a smoker. Need to find that willpower.

Also, exercise procrastinator. My problem is I don't put on weight, so weight loss (or maintenance) is not an incentive. But I know I need to work out, and have been doing some lately, even if it is a stiff 1 hour walks in the evenings

<comment><USER11> As a former smoker, let me recommend the drug Champix to you. It really worked for me. Quite the miracle drug, actually - you just kind of stop wanting to smoke, and keep forgetting about it. Before you know it you haven't smoked for weeks, and you don't want to, either.

Strongly recommended.

<comment><USER12> Watch out for Chantix.. it really messes with your brain chemistry. I couldn't use it: it gave me insane technicolor nightmares. After a week of sleep deprivation I gave up on the stuff.

<comment><USER11> Ha! That's very true. You do get very vivid dreams. Maybe that's a problem if you're the type to have nightmares but for me they were quite .. agreeable, lol.

</comment></comment></comment></comment></comment><comment><USER13> Procrastination - I haven't been able to overcome it yet, things that mitigate it is - keep track of tasks, make them small easily achievable. Also make a new list every morning.

<comment><USER14> Procrastination has many, many causes. I strongly recommend Burka and Yuen's book "Procrastination: Why You Do It, What to Do About It" and Rubin's "Overcoming Indecisiveness".

</comment></comment><comment><USER15> 1) Social Media sites (reddit, hacker news, slashdot, facebook) 2) Nail chewing 3) Excercising

And no-I've never been able to overcome bad habits. My short attention span when it comes to learning has helped me though-since I'm quick on the uptake when I go from subject to subject it lets me suck up a lot of info. And nail chewing..I wish I could quit but unfortunately my fingers are always there and I end up chewing them when I'm concentrating.

<comment><USER16> I've dealt with nail chewing my entire life. In the past year, I've (mostly) overcome it.

My solution: chewing gum. Keeps my mouth busy so I don't bite my nails. I go through a lot of gum, but I've broken the habit of biting my nails, so I'm slowly weaning off the gum.

<comment><USER17> why didn't i think of gum?

</comment></comment></comment><comment><USER18> Reading this site while I should be working. (Not being snarky, it's completely true.)

I also do art direction for film and video productions which has led to an insane need for me to save _anything_ I think may someday come in handy. Suffice it to say I have a huge pile of junk that I just cannot get rid of and it's growing.

</comment><comment><USER19> Sleepwalking. It's been a couple years, but I still write my hotel room number on my hand when I travel.

<comment><USER20> Is that a habit that can be broken?

</comment></comment><comment><USER21> All sorts of bad habits crop up left and right. Instead of going with the "willpower" method I've adopted what my friends and I call the "moneymouth" method (short for put your money where your mouth is). Exploit your honesty and financial sensibility by making bets to architect your habits.

Real examples: I'm lazy and get up late, but this system got me up before 7am daily for 3 weeks. I wanted to begin practicing guitar, I practiced for 30 minutes daily for a month with this. Right now I'm riding my bicycle 100 miles a week. I am not generally known for my extreme willpower to do stuff like this, I think I just found a functional self-exploit.

</comment><comment><USER5> HN. No. Because there is just too much good stuff here and too little time in a day.

The 'noprocrast' is great, and I use it occasionally but then you see that google has a new beta out or that friendfeed gets bought and it gets disabled again...

</comment><comment><USER22> I suppose this would be the perfect place for the following joke: Most of my bad habits have had gray hair and foreign names. I don't have any at the moment, so I guess that makes me perfect (for now).

On a more serious note: My sense of humor is a bad habit that gets me into hot water. (Thus I imagine this post will be badly downmodded into serious negatives. ;-) ) I have half-baked plans to do a blog or webcomic or something as an outlet in hopes of spending less time in hot water.

</comment><comment><USER23> Keeping Colloquy/IRC up while I'm working. Just can't find the strength to close it like I could with email or Twitter.

Disabling highlight notifications helps a lot though...

</comment><comment><USER7> Avoiding direct questions about bad habits by answering something like "I would have told some of my really bad habits if HN allowed anonymous comments".

</comment><comment><USER24> Super Procrastinator, I mean I'm here and I should be working.

</comment><comment><USER25> Nail biting.

Yes and no. Now it's not as bad as it used to be.

<comment><USER26> Every time you notice that you are biting your nails or have the hands close to your mouth slap yourself in the face. Do it hard the first couple of times trying to surprise yourself. I ended years of nail biting doing this, in fact it works so well that I even wrote about it a couple months ago (in spanish: [http://deadsunrise.net/post/10-Como%20dejar%20de%20comerse%2...](http://deadsunrise.net/post/10-Como%20dejar%20de%20comerse%20las%20u%C3%B1as) )

You can do other things like screaming or standing up fast or some other unusual action, it will help you to identify the habit and stop it.

</comment></comment><comment><USER27> I have many bad habits. My absolute top-success in overcoming them was getting rid of smoking cigs. And I really mean, getting rid of it, even in my thinking. You see, the nicotine addiction is just the minor part in smoking, it is not that hard, other drugs are harder to get rid of in my experience. But the manipulation in your thinking that comes with years-long smoking, that is astonishing. And the main factor that makes it hard to quit smoking is a deep fear that life will never again be as awesome as it was with the cigs (even if the smoking destroys so much life moments all the time).

I got rid of it by reading the book "Easy way out" by Allen Carr. I highly recommend his stuff. I did read the book 3 times in a row until all the thinking damage in my head was gone. But then it was gone and after smoking heavily for 8 years I am now out for over 6 years.

If you think about quitting smoking, try Allen Carrs method, I truly recommend it, from man to man ;-)</comment>


Ask HN: Why have been articles about terrorism attack in Nice been flagged? - <AUTHOR> Similarly off-topic articles are never flagged (see for example [1])<p>[1] https://news.ycombinator.com/item?id=11917265 <comment><USER2> As someone who flagged one, because they were articles that clearly were simple direct breaking news articles of general interest with no hook for discussion beyond people's prejudices. They are important news articles, but not something that people are going to miss without HN and not something well suited to the kind of discussion HN exists to foster.

This is, of course, subjective, and people can disagree, but HN replies on subjective and largely community-driven moderation to maintain its character.

<comment><AUTHOR> I understand why they have been flagged, but I think flagging is used inconsistently, and wanted to hear opinions on why that could be.

<comment><USER3> Flagging can't be expected to be consistent, because what gets flagged depends on who happens to be online when a story they happen to want to flag gets posted, and what mood they happen to be in.

Sometimes stories which probably should be flagged (in my opinion, far more than _are_ flagged) quickly gain traction, which seems to negate attempts to flag them later.

This may be a good time to remind people that they can hide stories as well as flag them now.

</comment></comment></comment><comment><USER4> As per HN Guidelines:

"Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon. ... If they'd cover it on TV news, it's probably off-topic."

[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

As for your example [1], I remember that there were dozens of articles about the same topic that were killed by flagging, because they were off-topic for the same reasons as the current story (TV news/politics/crime). You just happened to find one that slipped through the cracks.

<comment><AUTHOR> _All_ (7 / 8 ?) articles about the France terrorism attacks have been flagged.

I have been able to find 5 non-flagged articles about Jo Cox:

[1]: [https://news.ycombinator.com/item?id=11917265](https://news.ycombinator.com/item?id=11917265)

[2]: [https://news.ycombinator.com/item?id=11916826](https://news.ycombinator.com/item?id=11916826)

[3]: [https://news.ycombinator.com/item?id=11919151](https://news.ycombinator.com/item?id=11919151)

[4]: [https://news.ycombinator.com/item?id=11942191](https://news.ycombinator.com/item?id=11942191)

[5]: [https://news.ycombinator.com/item?id=11945171](https://news.ycombinator.com/item?id=11945171)

And one flagged:

[6]: [https://news.ycombinator.com/item?id=11923941](https://news.ycombinator.com/item?id=11923941)

<comment><USER5> Only one of them made the front page, and it only had 3 comments. Generally things that aren't complete spam don't get flagged until they make the front page and someone with flag privileges at the time sees it.

<comment><AUTHOR> How do you know they didn't make the front page? I would like to verify your explanation.

<comment><USER5> You can't easily AFAIK, but they have so few points that it looks pretty unlikely. The one with comments has 20 points and the next best is 6 points. You'll note that the flagged on at 10 points, so it might have made it?

Why do you think it is?

<comment><AUTHOR> Frankly, I have the impression that even though HN is supposed to be apolitical and cosmopolitan (since technology and science, central topics to HN are so), in reality HN is extremely anglophile (British + American centric, with some Israeli vestiges)

I can not fathom a terrorist attack killing 100 people in Los Angeles being flagged out of existence in HN; I can imagine that if 20 articles appear about a specific incident, some will be indeed flagged, but surely not _all_.

Flagging is probably right according to HN guidelines, so that is what should happen for all off-topic articles, but this is not what HN is doing.

I think the guidelines should be updated to reflect this fact: "flag off-topic news unless they are relevant to the Anglo community"

<comment><USER5> I think you might want to reconsider. I'd note that the Orlando nightclub shootings were flagged[1]. This of course wasn't as bad as in Nice in terms of fatalities, but is somewhat comparable (insofar as that is possible. What a horrible thing to have to compare). Comments there seemed to try to imply it was some kind of conspiracy, but I think the behaviour there was exactly the same as with this attack. I think we are seeing fatigue over terror attacks - people are just numb to the tragedies and feel like discussing it is useless.

I'm not sure if you are French or lost people in Nice, but if you are you have my sympathy. I was in France only a few months back, and this event made me both sad and angry.

HN is certainly Silicon Valley centric, but that is expected given its origins and audience. However, my impression is that coverage of EU tech issues gets more coverage than most places. There is certainly more coverage of US politics than other places, but the majority of that is related to tech issues.

(I'm not from the US, Canada or UK, nor do I live in any of those places)

[1] [https://news.ycombinator.com/item?id=11888228](https://news.ycombinator.com/item?id=11888228)

<comment><AUTHOR> No, I am from EU, but not french.

Maybe you are right, but this morning the first think I saw about the terror attack was on HN via Feedly, and I was very surprised to see that _all_ articles were flagged, including one about Facebook activating a special crisis mode, which stroke me as strange since recently I have seen lots of politics around here.

<comment><USER5> The majority of politics on HN is about tech or politics impact on tech, or new (and often quite strange!) economic theories and experiments.

Do you know how the flagging system works? Normal users get the right to flag and/or vouch for stories periodically, after they have been on the site a while. The details of what stays on the front page isn't publicly known, but it is a combination of comments and upvotes vs flags vs vouches.

So if there is a lot to say about a topic, it is more likely to stay on the front page.

The Turkish attempted coup made the front page (which of course isn't US or Anglo-centric). I think that is mostly because it is an unfolding situation and people have new things to say about it.

(I have flagging rights at the moment. I didn't flag it, but I rarely flag things.)</comment></comment></comment></comment></comment></comment></comment></comment></comment>


MIT investigates power generation from the meeting of river water and seawater - <AUTHOR> http://newsoffice.mit.edu/2014/energy-from-salt-water-0820

<comment><USER2> There was a prototype salt power plant in Norway that eventually was abandoned:

[http://en.wikipedia.org/wiki/Statkraft_osmotic_power_prototy...](http://en.wikipedia.org/wiki/Statkraft_osmotic_power_prototype_in_Hurum)

The competition in energy generation is fierce.

For those wondering how this works, basically when you have two liquids with different salt concentrations separated by a semipermeable membrane, the liquid with the lowest concentration tends to get pulled into the one with the higher concentration - this builds up a pressure difference that can be used to drive a turbine.

Interestingly, the same thing happens in living organisms - saltwater fish loose water to the sea so they would dehydrate if it weren't for special precautions, while freshwater fish have the opposite problem, they would end up too diluted if their body didn't have means of getting rid of the excess water.

</comment><comment><USER3> some of the most vital and complex ecosystems, responsible for huge amounts of life on the planet. I think I would rather look elsewhere.

<comment><USER4> Most of the potential comes from temporary streams where rain gets into the ocean, and those smaller water streams are just easier to deal with.

You don't need huge dams when you can only process a (relatively) little bit of water per m^3 of plant.

</comment></comment><comment><USER5> Unfortunately, even if this works, it will likely have less and less application over time. California has very little fresh water reaching the ocean, and as population increases, and drought increases, we're sending less fresh water to the ocean.

And, over time, it takes more & more energy to make water fresh/clean in the first place, and to move fresh water around.

So, any power generation scheme that requires using fresh water is not on a good trajectory. It's good science experimentation though, & may spark other more useful ideas.</comment>


Wildfires, Once Confined to a Season, Burn Earlier and Longer - <AUTHOR> http://www.nytimes.com/2016/04/13/science/wildfires-season-global-warming.html <comment> o0-0o If you remove controlled burns or natures free will...

Nature finds a way!</comment>


"Scientific Discovery Is Not Valuable Unless It Has Commercial Value." - <AUTHOR> http://jonathanturley.org/2013/07/09/the-rise-of-the-science-philistines-canadas-chief-science-regulator-announces-that-scientific-discovery-is-not-valuable-unless-it-has-commercial-value/

<comment><USER2> DNA, quantum theory, and yes quite a few early vaccines were developed without any commercial goal in mind. Some of the biggest scientific discoveries were done purely for the sake of discovery (i.e. basic science). This mentality is toxic and will tank innovation in this country. This is not isolated to the NRC. If you look at how the NIH (the biggest source of research funding in the US) has changed their mission in the past few years, you will see that translational science is being emphasized. Short term this will definitely lead to more cures (the e.bola vaccine and HIV vaccines are the best examples), but long term this will have the effect of stunting basic life science research. Don't think its a big deal? Ask why the NIH is now funding 0 basic science PhD students. That's right not a reduction, zero basic science pre-doctoral fellowships. I'm really glad someone posted this article

<comment><USER3> My favorite example of science for humanity's sake was the development of the polio vaccine. Its always sad to see someone like this who values commercial benefits over scientific progress become head of a scientific organization.

</comment></comment><comment><USER4> Commercial value is not valuable unless it's used to make a scientiic discovery.

</comment><comment><USER5> Well throw the Polio vaccine out then.</comment>


Brane Craft - <AUTHOR> http://www.nasa.gov/feature/brane-craft <comment><USER2> Well it is out of the box thinking, not sure how practical it is though. Sadly a paper on "Brane Craft" does not show up on The Aerospace Corp's website, although Siegfrieds work on cubesats does ([https://www.google.com/url?q=http://www.aerospace.org/wp- con...](https://www.google.com/url?q=http://www.aerospace.org/wp- content/uploads/2015/04/Think-Big-Fly- Small.pdf&sa=U&ved=0ahUKEwjn85_nkorMAhUBU2MKHVNqCjYQFggKMAM&client=internal- uds-cse&usg=AFQjCNHfgX3casQ0ChFAOfnTh6vT6InQMQ))

One of my favorite "low cost / unconventional" de-orbit ideas was candle soot clouds. Basically a cloud of carbon black that is deployed in orbit, it coats objects that pass through it asymmetrically resulting in asymmetric thermionic emissions when exposed to sunlight, creating a small net impulse which pushes the stuff out of orbit. Not sure how you would prevent it from killing stuff you wanted to keep though.

<comment><USER3> Wouldn't that only work if the object did not rotate at all?

<comment><USER2> As I recall the paper covered rotation (all space junk seems to have a rotational component) the energy comes from solar insolation which is always in a consistent direction relative to the orbital motion.

</comment></comment></comment><comment><USER4> More things should be described as "propagating through spacetime"

<comment><USER5> Elon's don't propagate through spacetime. They pull the frame of the universe I the opposite direction.

<comment><USER6> I think we should have a new unit of measurement called the Elon. "He traveled about 45 million Elons at a rate of 25 kiloelons per second"

</comment></comment></comment><comment><USER7> This is one of those things where I am not sure if I just don't understand the core concepts, or if the person talking to me is a complete nutter.

Isn't a 'brane' a mathematical object? Is there any basis in science for turning a physical 3d object into a M2-Brane?

At first read I thought he was just talking about a space probe in the form of a thin sheet that could propel itself in a novel way. Now I think he's talking about dropping the ship out of the third dimension.

Can anyone here ELI5?

<comment><USER8> I assume it's some kind of solar sail.

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

<comment><USER9> Nope. They describe the propulsion quite clearly. It's solar panels and an ion drive. The material they are ionizing is a liquid stored between the two sheets.

</comment></comment></comment><comment><USER10> I wonder who does the 'graphic depictions' for NASA. Must be quite fun.

<comment><USER11> I would apply for that position at once.

<comment><USER12> Can you depict a black hole that's not black?

That'd be 101 of space illustration.

<comment><USER11> I'm actually not so sure about that. Either put some non-blackness around a black circle, or (probably more interesting) obscure the black hole by the effects of its gravitational lens.

</comment></comment></comment></comment><comment><USER13> Today is the anniversary of the Vostok 1 launch, the first manned spacecraft. If anything will make it to the front page of Hacker news today it should be that.

<comment><USER14> Starshot is on the first page, and apparently they timed the PR for the anniversary. [https://news.ycombinator.com/item?id=11480840](https://news.ycombinator.com/item?id=11480840)

</comment></comment><comment><USER15> It'd be pretty cramped onboard the 2D Branecraft

<comment><USER16> Yes. It is too small.

Therefore:

The relevant Hugo winner has you & thousands of others uploading your personalities into on onboard "neural mesh", resulting in everyone calling it the "Brainship". An in-voyage accident due to forgotten space junk sends you somewhere unexpected in space and/or time. During the trip the onboard community fragments and develops in a petri dish of experimental post- corporeal societies that promptly go to virtual war over control of the craft. The Bra{in|ne}boat encounters strange new lifeforms, which by a series of loosely connected plot devices involving convoluted theoretical and/or fictional mathematics, enable one small motivated group on board to seize control and return the device to Earth, over the objections of another group. In the intervening thousands of years, humanity has evolved radically and is facing destruction due to techno-industrial political forces wielding unimaginable power. The inhabitants of the Brainevessel join forces and use the wisdom and/or alien friends they gained during their epic voyage to save humanity, and the warring factions are subsequently reconciled and redeemed. One faction stays behind to help humanity recover, whilst the other goes on an unspecified voyage back to the stars aboard the upgraded Mindyacht. The End.

(c) every science fiction author since Homer.

<comment><USER17> Sounds... Stross-y. :)

<comment> T-A Yep, that was pretty much Parts II & III of "Accelerando": [https://en.wikipedia.org/wiki/Accelerando](https://en.wikipedia.org/wiki/Accelerando)

<comment><USER16> I'd actually recently re-read Greg Bear's "Eon" and mashed it up with a bit of Greg Egan. No doubt there'll be echoes of many other novels besides.

<comment><USER17> Given your tagline of "(C) Every science fiction author since Homer" I think you pretty much nailed it. :D

</comment></comment></comment></comment></comment></comment><comment><USER18> Just out of curiosity, how do satellite launchers account for space debris[0]?

0.[https://upload.wikimedia.org/wikipedia/commons/a/a1/Debris-G...](https://upload.wikimedia.org/wikipedia/commons/a/a1/Debris- GEO1280.jpg)

<comment><USER19> "Space is big. Really big. You just won't believe how vastly, hugely, mind- bogglingly big it is..."

A lot of it comes down to things just being far apart. We're used to the surface of the earth - a 2D surface, but space is 3D. There's orders of several orders of magnitude more room and not a lot of objects in it.

Secondly, the orbits of these objects are tracked and in a database. It's a pretty easy task to check if your planned launch path comes near anything.

<comment><USER20> Space is big, low earth orbit isn't - it's easy to end up with a runaway debris cloud that completely blocks access to space.

Space will still be really, really big, but short of Jeltz showing up, kessler syndrome will close our access to space.

<comment><USER19> Kessler is overhyped. The lower half of low earth orbit isn't a problem because everything there falls to earth in a year or two unless it is actively keeps itself in orbit. Outside of LEO, there's massively more room, and massively less stuff. So the only area we need to consider is "high" LEO.

As a thought expiriment, consider the worst case - a hyper intelligent, pan dimensional being disassembles all spacecraft in high LEO. let's assume that's 1,000 US tons worth. ( I have no idea.) if these spacecraft pieces were spread into a sphere the size of the earth, that would be 1/40 billionth of a cm thick.

Since a sphere doesn't orbit, let's turn it into lethal 1cm cubes, all magically evenly distributed, orbiting at the same altitude, magically not colliding. That's one death cube every 4 square Km. What are the odd of flying a rocket through that layer? Pretty good actually. The layer is only certain death if you stay in it. We'd still have access to the solar system, geosynchronous orbit, and mid/low LEO even in the alien intelligence worst case Kessler syndrome.

( I have only worked this out on the back of a napkin. Corrections to math appreciated)

</comment></comment></comment></comment><comment><USER21> As CubeSats and FemtoSats are picking up support, we need LEO trash collectors even moreso.

<comment><USER22>
        LEO trash collectors

doesn't the atmosphere do a good enough job? seems that most things in LEO will decay within a few years

<comment><USER23> Unfortunately no. The curent amount is already serious and, if we were continue at our past rate, we'll make space inaccessible.

Orbital Debris Quarterly is a good resource on the subject.

[http://orbitaldebris.jsc.nasa.gov/newsletter/newsletter.html](http://orbitaldebris.jsc.nasa.gov/newsletter/newsletter.html)

<comment><USER24> (I'm not an orbits expert, but I do work for Planet Labs, and we're sending up piles of cubesats.)

The actors puting objects up in orbit are trying hard to be good neighbours these days. Our cubesat missions are designed such that should we completely lose control over a satellite the orbit will naturally degrade and re-enter the atmosphere on a ~10 year time scale. Our hardware deployed from the ISS is gone in less than two years. It's my understanding that it is required of us (and most groups in general) to plan our missions such that they will naturally de-orbit within 25 years.

</comment></comment></comment></comment><comment><USER20> Nice idea using them for clearing orbital debris, but the $1bn cost of doing it "conventionally" seems a reasonable price to pay for continued access to space.

If we don't do something, we will end up trapped on this ball of rock by lethal kessler syndrome.

Why isn't there legislation mandating that space operators tidy up after themselves?

Wait, stupid question, we can't get that right even on earth.

</comment><comment><USER25> And here I was thinking it would be a craft to travel the multiverse.

</comment><comment><USER11> I can't decide whether this is a late April fool's joke or just an unorthodox concept.

</comment><comment><USER26> The description seems totally at odds with the babble about 2D Branes.

</comment><comment><USER27> How does it do propulsion?

</comment><comment><USER28> Looks like a magic carpet to me.

</comment><comment><USER29> Bane craft - ah, you think darkness is your ally?</comment>


IBM opening new Computer Science focused High School in NYC - <AUTHOR> http://vox.fastcompany.com/1692372/ibm-reveals-details-about-its-nyc-high-school

<comment><USER2> The fast-tracking angle is interesting: this is essentially high school plus community college rolled into one, but with an apparent hope that it'll be closer to a 4-year-college degree in quality due to greater preparation in the high-school years and coordination between the high-school and college curricula (it's one six-year curriculum, not a 4-year HS followed by 2-year college). Plus some employability boost from IBM's preferential hiring.

I do worry a bit about lock-in at an early age, though. A 14-year-old is young enough that a decent proportion may turn out not to really want a career in computer science after all, especially because I suspect decisions on whether to go here or not will in many cases be either made by or strongly pressured by parents. Will the curriculum be broad enough that a 20-year-old who's successfully completed it could plausibly get a job doing something _other_ than working for IBM or a similar company? Or could they even leave at 18 with a normal HS degree and go to a 4-year college in a different major? The article is unclear about whether the 6-year-to-associates-degree part is mandatory, or if there's a possibility of opting to earn a normal high-school diploma after 4.

<comment><USER3> At that early age I wonder how much CS specific training is going to be given. Also with IBM's current focus on not just being a tech company anymore I would dream that the education is a bit diversified.

Maybe having a specific goal to drive for will make it easier students and teachers to focus on a certain goal but I don't think that it'll make the students less able to switch tracks if needed.

</comment></comment><comment><USER4> I wonder what the curriculum will be like. Are they going to teach computer programming basics and methodoligies or is that school going to be a "corporate coder" machine which spews out .Net or Java developers suited for a cubicle job for IBM?

</comment><comment><USER5> _Students will be chosen to attend using the standard New York City lottery system--one third of selected students will be below grade level, one third will be at grade level, and one third will be above._

I want to thank flipp, Fast Company, and IBM for saving me $10: I don't need to go see "Waiting For Superman" now because it's all in this sentence. Why wouldn't they just start with the most qualified applicants and fill slots until there are none left?

<comment><USER6> I've never gone through the system, but my first guess would be it's probably so that all the slots aren't given to kids from ideal, wealthy homes, raised with tutors and computer camp, but that there's some room in there for kids who might be really bright, but also dealing with effed up home situations that knock a couple points off their standardized testing. Or who are bored as fuck in their current school but would really come alive at a CS-focused school where they can learn alongside the most qualified applicants. Because school isn't a consulting firm or a hedge fund.

<comment><USER5> I can understand adjusting for socio-economic class, but why bring in kids that are working below grade level? Why not place them in a remedial program instead?

</comment></comment></comment><comment><USER7> Its interesting but I can't bring myself to trust the motivations of IBM.

There are two possible scenarios here: First IBM is being straightforward and they are trying to help redevelop the US education system. Second they are trying to develop a cheaper source of US labor.

The recent history of IBM would indicate the latter scenario is more likely.

</comment><comment><USER8> Nice, maybe Google would be interested in doing something similar in the Bay Area? And by next September please so my high-school aged junior nerd kid can enroll? Thanks!

</comment><comment><USER9> Reminds me of <http://steve-yegge.blogspot.com/2006/07/wizard-school.html>

</comment><comment><USER10> Somehow, without knowing the details, this makes me excited. Could there be a school where you actually learn something useful? It seems like an earth shattering concept.

</comment><comment><USER11> Very cool. Though I can't imagine the gender ratio there will promote a huge social aspect...

<comment><USER12> Well, it is in NYC, so I doubt the more sociable guys will have any trouble finding some extracurricular poontang.</comment></comment>


Men and women can't be just friends - <AUTHOR> https://www.scientificamerican.com/article/men-and-women-cant-be-just-friends/ <comment><USER2>
       researchers brought 88 pairs of undergraduate opposite-sex friends into…a science lab.

Ok, so this research has nothing to do with men or women - just horny near- adults.

<comment><USER3> read on...

>> Males were significantly more likely than females to list romantic attraction as a benefit of opposite-sex friendships, and this discrepancy increased as men aged—males on the younger end of the spectrum were four times more likely than females to report romantic attraction as a benefit of opposite-sex friendships, whereas those on the older end of the spectrum were ten times more likely to do the same.

<comment><USER4> Yeah, but what was the age range they tested? If they're comparing 22 year- olds to 18 year-olds, they're still only covering a small range.

<comment><USER5> _Accordingly, we aimed to compare the extent to which emerging adults (late adolescence to mid-twenties) and young and middle-aged adults (late twenties to about 50) experience attraction to their cross-sex friends_

From the linked paper. That's for the follow-up study.

</comment></comment></comment></comment><comment><USER5> FYI, this is from 2012, The paper is under the link "New research"[1].

1: [http://bleske-rechek.com/April%20Website%20Files/Bleske- Rech...](http://bleske-rechek.com/April%20Website%20Files/Bleske- Rechek%20et%20al.%202012%20Benefit%20or%20Burden.pdf)

</comment><comment><USER6> First off, this is too vague of a generalization based on their sample size. It makes for a nice casual read but I can't take it too seriously. Though, I must note, my anecdotal experience also makes me think this is more of a norm.

This also agrees with observed primate behaviors. Males have an incentive to identify potential mates while female have incentive to pick one out of the many available. (Male can impregnate many females in a year, female can only bear one child at a time.)

Friendship and romance also have overlapping characteristics. Example: "bromance" where it's not sexual but outsiders might see characters typically associated with romance.

It's too big of a topic and I would probably write an essay.

</comment><comment><USER7> Ya, I don't buy this. I know this is just my experience, but I've had plenty of "just friends" who were members of the opposite sex, and nothing bad ever happened.

<comment><USER8> Just speaking for myself: I have never persued a friendship with a woman if I was not at least attracted to her.

I don't see female colleagues at my current job as friends and I feel the same about the girlfriends of my friends. Those are just platonic relationships to me that I am not interested in deepening in any way.

<comment><USER9> That is so odd to me. Why would you pursue (platonic) relationships with men if there's no attraction? Are you only attracted to women? (I'm assumig you're male.)

Or are you talking about sexual attraction? Do you view women as only sexual? I am simply trying to figure out what men provide that women can or do not.

Personally (as a man) I can't make heads or tails out of how to interact with other men outside of work; I am precisely the opposite of you.

<comment><USER8> I am only sexually attracted to woman of course.

But at the same time I think men are generally more fun to be around. Woman are in some way 'less funny' on average.

</comment></comment></comment></comment><comment><USER10> Apparently the writer of the article can not comprehend the difference between attraction and action.

I can find someone attractive without trying to have sex with them. Men and women can be "just friends", and this is not incompatible with "men are more likely to find friends sexually attractive."

Whether this is due to biology, sociology, culture, or space aliens is anyone's guess.

</comment><comment><USER11> Am I crazy or is their surprisingly little quantitative data? Are we talking a 5% effect or 80%?

</comment><comment><USER12> Ah, the undergraduates. The most studied group in America!

</comment><comment><USER13> About 1/2 of my friends are female. Over the years, I've had a few of my expressions of interest rejected. However, I've had quite a few female friends "give up because I didn't get the message they were interested". I've been abused, called stupid, asked if I was gay, etc by female friends who were interested in me. I once had to ask a mutual (female) friend what happened because I couldn't get a word out of one woman. "You can't be THAT dumb, can you?".

I call bs on this one. I've had too many instances of being explicitly hit on (about 1 in 3 of good female friends at a guess) to believe the "women aren't attracted to male friends".

However, I have plenty of female friends who I just like because they are amazing people.</comment>


The super-fast world of droplet dynamics - <AUTHOR> https://phys.org/news/2020-02-camera-action-super-fast-world-droplet.html <comment><USER2> In a related way, high speed video is indispensable for development of microfluidics as well.

E.g.

[https://www.youtube.com/watch?v=lnVB9MauOrU](https://www.youtube.com/watch?v=lnVB9MauOrU)

[https://www.youtube.com/watch?v=atqSHClrfz4](https://www.youtube.com/watch?v=atqSHClrfz4)</comment>


Microsoft Open Sources Its Azure Container Service Engine - <AUTHOR> https://techcrunch.com/2016/11/07/microsoft-open-sources-its-azure-container-service-engine-and-launches-deeper-kubernetes-integration/?ncid=rss <comment><USER2> the dc/os update is only available to new customers though. Deployments are always stuck with the version they were deployed with. IMHO ACS is nothing more than a template, not an actual service that you deploy your containers to (like Google's Container Engine)

<comment><USER3> It is true that there is no update path at this time. Our focus is on ensuring the software runs best on Azure. Upgrading a container service is a complex affair with different users wanting different experiences. With the open sourcing of ACS Engine (also part of this same announcement) we are providing a channel through which users can work with our team to define optimal upgrade strategies that will eventually be rolled into the service itself.

</comment></comment><comment><AUTHOR> Microsoft open sources its Azure Container Service Engine and launches deeper Kubernetes integration</comment>