skysight-inc/HackerNews huggingface dataset:
For some context, there is a very intriguing formulation of General Relativity in terms of entropy. [1] What this suggests is, that gravity emerges from a underlying thermodynamical system. In OP the authors construct explicitly one of these systems.

Unfortunately together with the success of perturbative quantum gravity [2], this suggests that quantum gravity is just not experimentally accessible. (That's a thought by Freeman Dyson originally.) The formal argument would be, that a lot of different theories lead to the same thermodynamical limit, so that one can not determine the true underlying theory. Or put it in more hacker news terms, the problem is analogous to trying to learn about TCP/IP by looking at the output of black hole simulations, there is the layer of numerical mathematics in between, which is at least very hard to breach.

[1] Older guestpost by Grant Remmen on Carroll's blog:
http://www.preposterousuniverse.com/blog/2016/02/08/guest-po...

[2] For this discussion, it is basically cheating. You quantize gravitational waves on a classical background geometry. The approach works very well because gravity is weak, it also tells us nothing interesting, because one breaks the relationship between gravity and space time (the central feature of General Relativity) by hand.
How to Make Your Smartphone Battery Last Longer?
Magento is a for profit platform owned by eBay. He's already donated them enough of his time. It is open sores, not open source, although it's easy to confuse the two!
As long as one needs a programmer the year is a good rough estimate, the hard part is not the building but the gathering of requirements. Take the programmer out of the equation and thus the communication overhead between programmer and domain specialist and you save a lot of development time.
Mailing lists for instance. No real time, no formatting, not even clear threading structure.
The stochastic process that generated the observed data.
This is not very accessible for people with weak statistical backgrounds.
You should probably mention that it's your own book you are plugging here.
That's good to hear, thank you. I heard a while ago that CyanogenMod turned in a company. I mixed things up
How so? My Cyanogen phone is the worst I've ever had and I wouldn't recommend it to anyone.
This entire thread is a trainwreck.
The fine article explicitly says that's the intent of the law, but that local lawyers suggest it also could be used against adblockers.
Naive thoughts, compilers could emit ram-local instructions instead of register spill and the likes. Maybe not fancy stuff but I thought there could be a nice class of block swap, or block (inc) that could be generated without too much burden in terms of semantics.
Not really. What is observed is data, not a model/distribution. One can fit a given model to this data, but they do not, on their own, tell you which model generated them.
Maybe you've gotten it but I don't know. Here is a maybe over-tired coin-flipping example:

Say you have a coin that might be unfair, and you want to estimate its bias. You flip it a bunch of times, and it mostly lands heads.

Predictions of the coin's bias based on this observed data are usually going to be that it's biased some % towards heads. (unless maybe you have a strong prior, but that's a different topic)

But there is also a chance that really the coin is fair, or even biased towards tails and you just got unlucky in your flips.

There's a mismatch between the true model (the coins actual bias) and the observed data (the result of your flips) because of this chance of `unluckiness'
So did I and many others... :(

I really wish they had not chose "Cyanogen" as the company name.
Uber is pretty formidable in building and growing a two-sided market. I suspect it's tuned continuously, at high resolution (in space and time), with levers I mostly don't know. And that's got to be a big contribution to the complexity of the stack.

This of it this way. A standard e-commerce site, or SaaS with low-touch marketing... there are a crazy number of KPIs to monitor, loads of levers (e.g. what's the right discount to fix basket abandonment). The instrumentation to track all these conversation funnels (and to do A/B tests to see what works) is half the job.

But at least we have a common understanding of the metrics and the levers -- for SaaS, say, there are tons of similar services, and the knowledge is shared in the community.

Uber? How do you grow while maintaining market liquidity every evening of every week? If you artificially hike demand from passengers in a particular neighbourhood (say with coupons), does WOM amongst potential drivers work to increase the driver pool before the passengers get frustrated and move to Lyft?

All of this is new. So how do you create the tech to track not just all the data you need, but all the data you might need, plus the capabilities to do tests to figure out what levers to pull? Hard.

I have no particular insight into this. But my guess is that Uber isn't flying blind - their growth has been no accident - and the complexity of their tech is due to instrumentation not operations.
I think it is just a hard problem. Many devices with many Android versions and many provider customizations. And, oh yeah, the carriers are often going out of their way to make rooting as impossible as they can. Screw up badly enough and you can easily brick a phone.
I think it is the carriers adding (or turning on) extra security features like Knox in the US.

https://en.m.wikipedia.org/wiki/Samsung_Knox
Nice to see Nim in the list!
Best Example of Robots.txt File for Indexing Your Site on Any Search Engine
Is My Website Regularly Indexed by Bing and Google?
This is probably simplistic, but in my safe, toy assembly language for teaching programming I simply avoid ever sharing (always refcounted) pointers between threads. Instead it pervasively uses channels for communication, and while channels are generic anything you put in them gets deep-copied on write. The deep copy is smart enough to preserve cycles, so say if you send in a linked list that contains a cycle the reader will see a linked list with an identical topology. It will just be utterly disjoint with the original linked list.

These design decisions allow me to provide safe pointer access and avoid all race conditions while teaching programming and concurrency, but they probably incur significant performance loss on certain programs. My hope is that the design constraints they impose on the programmer aren't insurmountable. We'll see.

(More info on the project: https://github.com/akkartik/mu#readme. On its memory model: https://news.ycombinator.com/item?id=11855470. On the deep-copy implementation: https://github.com/akkartik/mu/blob/07ab3e3f35/073deep_copy....)
The usual ones, I'm sure. Poor syntax for type lamdbas. Unification across kinds (hopefully possibly going to be backported to 2.11). All the ways of expressing union types (or indeed basic enums) are a bit clunky. Irrefutable patterns in for/yield constructs compile to a silly withFilter call. PartialFunction/Function having the wrong subtyping relationship. mapValues being lazy when all the other functions on the same interface are strict. Stream implementing the collection interface.

More than anything specific though, I don't want to be stuck on an old version as the language moves forward.
No. That's tax avoidance. Evasion is when you actually don't pay taxes that you legally owe, e.g. by hiding your income.

There is some idea that people and companies have a moral duty not to organise their affairs in a tax efficient way. But the laws they lobby for are just what create the distortions.
[The Eleventh HOPE] Live
Games vs. Stories, Revisited
LLVM generates bytecode in an intermediary step, not as the final product. The final product is still machine code. You do not run LLVM when you run your compiled program, the bytecode is not part of the final program, it is just used to help with compiler optimisations.

To further clarify this point, LLVM's bytecode format is called LLVM IR, where IR stands for Intermediate Representation. GCC has its own intermediate representation for the same reasons LLVM does.
I wrote something a while back that did this as a proof of concept/learning exercise... but it never took off:

http://forum.xda-developers.com/showthread.php?t=2391493
A lot of embedded code uses macros to deal with the register/configuration handling, rather than functions. I've seen loads of inline assembly in #defines.
C++ and recently, Haskell.

A lot of what I learned in Clojure I can now use in C++ since the C++14 version of the languages supports a lot of functional programming techniques (though not thoroughly). C++ today is not the language it used to be, and the ability to write and use standard library higher-order functions with my own simple anonymous functions is really nice.
Instead of implementing bots and trackers, someone could implement:

* Just a working 3 step tracker
* Gym high scores
* Display nicknames of gym pokemon
Don't worry, it's all coming to an end. All the trending languages either are statically typed ( go, swift, rust), or provide some kind of type hinting (elixir) to make up for it.

Unit testing is great, but it doesn't provide autocompletion, or help you analyze your codebase before a refactoring.
5 reasons why Trump will win
Not entirely true. I am not sure about the US but in Germany we have in times of very strong wind negative electricity prices. And that is to some degree the beauty of hydrogen: you can store it relatively well for some time, so you do not need to produce it right when you are charging your battery but when electricity is the cheapest.

It's not hydrogen is all better as some people here on HN seem to think the argument is, it's just that both battery powered vehicles and hydrogen powered vehicles both have some advantages over the other that might be very beneficial if used together.
You still need someone to think out relations in your database and how to retain it faster with large data sets. If this work can be done by domain specialist only, then it can be done the same way using APEX, FileMaker etc. Without live example of the new technology it is difficult to say how it differs.
You still have to worry about that because it still receives the so-called "metadata".
Well. To fire someone from one day to the next is nearly impossible here in Germany. You always have some time (a minimum being defined by the law) of time between the day they tell you of their decision and your last working day. This time is there for your protection to enable you to seek another job.

That was what I was talking about. If I can get fired from one day to the next a company would at least have to pay me a hefty premium as I would be not better of then say a freelancer.
Is pricing understandable?
I tried to debug this from Hong Kong,
and the API calls definitely go to the US.

Maybe in Europe they resolve to a European data center, but in Asia they still seem to send everything via the US.
Biochar is also alkaline. Why not dump it in the sea? Then we get a two-fer: capturing carbon and de-acidifying the ocean.
Does anyone know about the legality of projects like this in the US?

I vaguely remember stories about game companies legally going after companies making bots.

Would uploading an API like this open someone up to a lawsuit? What about someone uploading a bot or a botting framework?
I would be willing to pay for content (and often times I am doing exactly that).

I am not willing to have an attack vector open for any media outlet to infect me via their revenue generating ads.
No, the "true model" he seems to be referring to is the mean of the distribution of the noisy observations. In the example, the distribution is the normal distribution and the mean is log(x), which he is referring to as the "true model".

The notation is pretty sloppy for someone handing out statistical advice.
It's a new API, and a much more low level one. Meaning you need more code to do stuff, but you have more control over each step, which wasn't available to you in previous APIs.

For example, capturing a game screenshot. In OpenGL you have a method glReadPixels which will flush the GPU queue, wait for operations to finish, read the screen pixels, convert them and put them into an array. All in one method, all outside of programmer's control, done somewhere in the driver. Meanwhile in Vulkan, same task requires programmer to flush GPU, wait for operations to finish, allocate memory for an image, create an image in linear format, transition image to proper state (transfer destination), transition swapchain image to transfer source, blit the pixels from swapchain image (which could be linear, could be tiled) to linear image, transition swapchain image back, map memory of the linear image. A single line of code in OpenGL translates to about 50 lines of Vulkan code (lot of it is stuff you'll write once and reuse everywhere else), but you have full control over each of the steps.
The point I'm trying to raise is the potential for publication bias. If publishing results that challenge the narrative is a risk to your career, you won't publish it. Meanwhile, the outliers in the other direction, which do fit the narrative, get published and picked up by others in the field. Here's an article echoing my concerns: http://www.telegraph.co.uk/news/science/science-news/1083714...
AFAIU, the distinguishing characteristic of Nexus devices is that they're unlocked.

Yes, per Wikipedia:

"All Nexus devices feature an unlockable bootloader[3] to allow further development and end-user modification.[4]"

https://en.m.wikipedia.org/wiki/Google_Nexus

http://android-developers.blogspot.com/2010/12/its-not-rooti...

http://www.engadget.com/2011/11/03/galaxy-nexus-gets-rooted-...

Note that this still does you comparatively little good if you don't have CyanogenMod to put on it. Mind, I didn't say "no good", I said "little good".

It's the CyanogenMod dev team at Cyanogen Inc who've been impacted by the layoffs. There's still the independent effort, but it's lost a major employer and investor.
Why run Linux in a VM instead of on bare metal? I installed Debian by following some of the instructions here: https://gist.github.com/andrewlkho/23b5b5bcf853b3473421

The initial install process is a bit (OK, more than a bit) convoluted, but after that you're just booting grub and doing upgrades just like on a regular PC.

Basically, you run OSX from an external drive, install linux on a VM to which your internal hard disk is attached, then chroot into that environment (via another VM running linux) and install grub on the internal hard disk.
I work on an uber-like system, but with ~3 backend devs rather than 100s.

We made the opposite decision, cloning our full stack for each new market.

That's great for scalability, but is a nightmare for devops.

If anything we want to find a way to move to one global system,
And then slice down the bits that can be local:

Eg. Create a local order matching service, but keep orders, payments, and user accounts global
> Also how similar is Vulkan to SDL?

They are not. You use SDL to create and manage your window and handle input, and use Vulkan or OpenGL to draw to that window.
Docker and Cassandra don't solve basic routing. They solve the fact you have have millions of people hitting you site, and many servers to manage.

You didn't have that problem in the 1970s
I honestly think you should rethink this, I do not think the article is biased and clearly states that hydrogen is not cheap. And as soon as we are getting fully self-driving cars, the hydrogen vehicle can drive to the fuelling station on its own and refill themself, so where is your problem there? They do not solve all the problems but so do electric vehicles. A combination of both might be far better.

Or in your words: Your comment definitely reads like a opinion piece from someone who has invested to much in Tesla stocks and now fears of losing some of his investment. People on HN have a history of hyping electric cars ... ;)
Turing's work was in algorithms, models of computation, and cryptanalysis. All that is considered part of Theory A, see e.g. http://blog.computationalcomplexity.org/2003/03/theory-and-t....
> Gates doesn’t blame the paucity of miracle technologies on the absence of a price on carbon

So governments introducing no regulations or taxes around carbon pollution isn't a problem? Would he have said that about ozone depletion or SOx/NOx emissions standards?

This reads like a typical free-marketer's apology for Exxon lobbyists and paid denialists screwing up international cooperation on global warming.

Also nothing in here about using less energy.
Show HN: Tech in Scotland
Hello, I’m the Edinburgh-based dev behind this and the events data source site.

Scotland has a great tech scene, with many events, many companies including two "unicorns", and several community hubs that do a great job of pulling the community together.

This site is meant to be an easy and quick access site that lists data from and points to other sources - we really want to encourage more Open Data, well, everywhere really. I’m looking for more sources of data that hopefully will appear soon.

On which note, I know there was another Scotland site recently - they have a list of companies and we are talking to them to see how we can incorporate that data into this to.

Our events are sourced from https://opentechcalendar.co.uk/ which I also run - anyone can add events, you don’t have to be the organiser to do so. Everything is versioned - like a Wiki. And data can be exported in several different ways.

While Open Tech Calendar is celebrating it’s 4th birthday today, this site has just launched - so any feedback or constructive criticism welcome. Post here or email hello at techin dot scot.

Thanks,
James

ps. The tech for this site is a bunch of PHP scripts. They grab data from API’s, make static files, upload them to AWS S3 from where AWS Cloudfront serves them - so we are already practicing the Open Data standard we want to promote! Meanwhile, Open Tech Calendar is a Open Source PHP app.
You know what`s funny? Our entire universe could be a Boltzmann Universe, that spontaneously appeared just three minutes ago.

Happy Birthday, everyone!
In mathematics, I would describe category theory as an offshoot of structuralism. The main idea is that instead of starting with some "premodel" of what you want to study ("I want to study geometry on surfaces, so I'm looking at subsets of R^3!") and then taking away structure ("...but what is the preferred center of the universe? I better only look at properties which are invariant under translations..."), you try to identify structure in your problem and then determine the consequences. This is obvious in retrospect. If your models describe reality and everything is built out of sets then is 0 an element of 2?

Category theory provides useful tools for identifying structure. It's not necessarily a good vocabulary to talk about these things. Forcing everything into a first-order mold is typically confusing. On the other hand, there has been a lot of work using category theory to solve real problems. This has resulted in some sophisticated tools and a very "scalable" way of looking at things (e.g. universal properties and adjunctions are everywhere).

Category theory is needlessly complicated. There are many redundant side conditions, and the definitions are ... let's be charitable and call them idiosyncratic. This is just more apparent when you apply catgeory theory to programming languages. In semantics you already have a precise way of writing statements (type theory) and you know that everything you can write down is parametric. This eliminates almost all side conditions on most definitions in category theory. So yes, coming from Haskell, catgeory theory probably looks extremely complicated and not worth the effort to learn it.

However, some of the tools from category theory are as useful to computer science as differentiation is to engineering. There are plenty of questions to which you can calculate the answer using some elementary category theory. What is the dual concept to the reader monad transformer? What is the eta law for sum types? Can this data structure be a monad? If not, can I embed it into a monad (e.g. using codensity)? These are all simple questions, but if you don't know the general strategy for dealing with them it seems like I'm asking you to solve a puzzle instead of asking you to compute 7 * 4.
There's only so far throwing more resources at a monolithic app can take you.

At a certain scale you have to turn distributed. Uber is at a large scale
How would that have helped? The customer was already convinced she was doing the right thing.

She may well have had an automated call to confirm, I get them from my British bank whenever I transfer money to someone new.

Transfers are instant up to £20000, or something like that. This is very useful.
Howdy, Ubuntu on Windows an Intro from Canonical's Dustin Kirkland
The victim probably pays nothing in bank fees, most British people don't pay any regular fees.

There are special accounts that come with travel insurance, a personal advisor etc, which charge a fee.
Ask HN: Good books/research on diversity in workplace
What are some good books/research to show serious data how diversity affects workplace dynamics? (positive or negative)

Diversity tends to be propagated, at least in the UK, as the cornerstone of effective workplaces, but
one of the comments yesterday referenced a 2007 article from the Boston Globe about how greater diversity leads to a 'decline in social capital' [1] in communities. My reading (not sure if it's the right one, but that's one of my conclusions) from the Happiness Hypothesis [2] is that more homogenous groups tend to make people happier and easier to organise around a common goal.

Both sources go against the common narrative for diversity today in communities, but they don't write about companies.

Does anyone know of any serious studies that prove/disprove the effects?

[1] http://archive.boston.com/news/globe/ideas/articles/2007/08/05/the_downside_of_diversity/

[2] http://www.happinesshypothesis.com/
If I dump a SQL database to a file and see that the file size is 0kb in explorer I will assume there was something wrong during the export. Not that the data is hiding in another place which requires me to use special tools to inspect, how am I supposed to know these tools exist in the first place anyway? Explorer is clearly doing the wrong thing here.

This sounds like a bug in SQL server also, what if you try to transfer the data to another computer using a fat32 USB stick, then none of the actual data will be copied.
Not really. More an emphasis on people with vague notions having their vague notions cemented by other over-confident under-informed people with more-cemented notions.
I didn't pass judgement on anybody, but I understand how the question could come off that way. It's more that I just have a suspicion that the asshole brother probably has a very different story to tell. But, we'll never know.
I don't see what's testable or falsifiable in here. Okay, it's good to get rid of epicycles, and intellectually pleasing, but it still looks like the same objections apply as have been raised around string theory. Even if this is the 'theory of everything', will we not end up with shorter equations that describe the same observations?
There's one field in the app's request that's still unknown.
It's a header of seemingly encrypted data, along with a varying number of encrypted blocks (all the same length).

In those blocks could be anything, detailed gps co-ords, device details, there's a fair chance they can ban all these API users at the push of a button based on whatever's in those blocks.

Everything else is unencrypted - sent back and forth using the protobuf format, the formatting of the protobuf's were dropped on pastebin a few weeks ago.