skysight-inc/HackerNews huggingface dataset:
As the original Author of Axe, that's an extremely inspiring story.

I also, as you can guess, first got into programming on my trusty TI-83+ when I started high school. Without really knowing the TI-BASIC language and lacking the link cable, I remember some time when I was in the library typing a Mandelbrot set program line for line from the computer, trying to figure out where all those random tokens were located. Once I finally got that working, I was hooked and started making all sort of different programs.

Some of the early programs I remember creating were mostly math programs and algorithms I learned from classes. But very soon I started getting into gaming. I had always wanted to make really cool games, but I always ended up limited by the capabilities of the calculator, and ended up mostly producing puzzle games; Minesweeper, Sudoku, Skyscrapers, etc. I also managed to make a text adventure and an 'AI' chat bot.

I wondered how people were able to make some of the more advanced games and eventually stumbled upon assembly. It took me a really long time to grasp all the concepts and it was very frustrating. Every instruction has a bunch of side effects, you have to remember what every register is holding at every point in time, and you have to memorize all the mnemonics. I was also annoyed that I couldn't program it on the go (Mimas didn't exist at the time) but that certainly didn't stop me! With nothing better to do during that bus ride to and from school, I actually printed out all the op-codes, ram locations, bcalls, ascii tables, token tables, and would literally type in the hexadecimal into the calculator to program! It was insane and really dangerous, constantly deleting the memory every time I typed a wrong character or forgot about the endianess. I eventually just gave up on that and stuck with programming assembly games on the computer in my free time.

By the time I learned enough assembly to produce my first full game, a PacMan clone, it was around the end of high school and it was then that I decided that I really wanted to make it easier for people like myself to be able to make actually good games on the go. It wasn't until a year later that I started creating Axe Parser for that purpose. Although I didn't have any formal experience with compilers, languages, or other relevant theory I started anyway, just doing what I figured would work best. It actually managed to succeed and after only a month of work, I was able to program a full game in about an hour! It was exactly what I wished had existed when I was in school, and it's super exciting to see there are students out there now that actually have this power and are making awesome stuff! Its even more thrilling when it influences people to get into coding more seriously. Warms my heart every time I see things like this :)

As for me now, I haven't touched z80 programming for a few years now. I'm working at an amazing start-up where I get to combine programming and mathematics to do some really interesting things.
This article fits in with another thread here earlier today where I commented about using any drug entails some finite risk of bad effects. The apparently common belief that "designer drugs" shouldn't be "illegal" is certainly not supported by the article.

I'm not sure what makes it so hard for some people to grasp the intrinsic dangers of ingesting "designer" drugs. Our physiology is complex and quirky, rendering all drugs capable of unpredictably causing serious side effects. And even if that's a rare event, in the case of barely (or not at all) studied compounds, it's still like playing pistol roulette with live rounds.

There's risk for the chemist too. While we might admire the skill to design and synthesize a novel compound, it's foolish to do so outside of a fully equipped and qualified lab to assure safety for the chemist as well as the environment. Of course, working in such a lab would no doubt imply a level of scrutiny about what the chemist is trying to do.

So obviously a designer drug is likely to be produced in conditions that don't favor purity and careful testing. It's no wonder there are tragic outcomes, but it seems human nature to try to do something "against the rules". But it's an entirely different matter when rules are the "laws" of legislatures vs. the laws of Mother Nature. She never cares what we "believe" or desire.

Designer drugs will continue to be a problem. The best we can hope for is that bad outcomes will yield here and there a clue to something useful. It's a shame, seems so often we have to learn the hard way.
And these shenanigans, too, would be entirely unnecessary if known drugs were legal and regulated, and people could take controlled risks instead of playing Russian roulette with newly synthesized drugs.
Ok, these guys claim to have invented a great engine, really just the pre-cooler. Why are they trying to build a plane instead of licensing it to others? That seems to be several orders of magnitude more difficult and increases the likelihood of failure.
You require one branch regardless, and the trivial version is one branch, i.e. already at the minimum amount of branches.
Yes, I am connected to the store's wifi. Can you point me to some code that actually can grab the mac address? As the title suggests -- I want to know how they do it.
Most artificial sweeteners were discovered by chemists accidentally tasting chemicals.
Yes, I am connected to the store's wifi. Once I am on their network, how do they actually grab it? What headers names do they inspect for, etc. I'd like to actually know the implementation details and code sample. I looked everywhere on Stackeroverflow and can't find anyone who has done this.
Some background: This company's engine is based on its previous design, the SABRE engine. That engine is designed to reach an altitude at 28km, flying at Mach 5 (which works out to be about 1.5km/s at that altitude, ~15% of orbital velocity at LEO). After that the engine is designed to switch to a rocket mode, where it burns fuel and oxygen it brought, rather than taking it from the atmosphere.

Since the an air breathing engine is much more efficient (10x) than a traditional rocket engine, it allows the launch vehicle to conserve mass that would otherwise be used to overcome the high drag encountered in lower altitudes. You can roughly think of this as a rocket with all of its mass being launched at 28km, with a velocity of Mach 5 already.

"Getting out of the atmosphere" is a pretty vague statement. Atmospheric pressure and density is about 1-2% that of the ground. So drag at these altitudes will be less. However, some quick and dirty calculations by me makes this seem like a relatively small number compared to the amount of energy it takes to actually get to orbit. Quick search indicates the same as well[1].

However, a "thick" atmosphere is something that has to be dealt with. For example, rockets also need to overcome pressures that exists at lower altitudes. If you take a look at any rocket launch videos, you will notice that the exhaust at higher altitudes (typically about 2-3 minutes after launch) will expand outwards with respect to the rocket itself. This means that the flow out of the rocket engine is "underexpanded", making the engine less efficient than it would be otherwise. By starting your rocket engine at a higher altitude, you can improve the efficiencies by designing your rockets to lower atmospheric pressures (I don't know if this is done for the SABRE engine, but this is theoretically possible).

So based on these, the main motivation for this is probably for the mass savings and efficiency. Additionally, this engine presents itself with potentials for complete reusability, which is very attractive as most current launch cost is from the unrecoverable launch vehicle itself.

[1]: forum.nasaspaceflight.com/index.php?topic=9959.msg189860#msg189860
Still on the front page from yesterday:

https://news.ycombinator.com/item?id=8747053
Where does this liquid helium come from, and more importantly where does it go after it's been heated? Im guessing they release it into atmosphere, so is there enough helium to mine for this plane to go mainstream?
and someone should tell these clojure people that Common Lisp and Scheme exists.

Unreasonable comment and not really constructive. Please stop.
This is bullshit, -273°C is absolute zero so unless the plane is on fire, it can't cool down the air by more than 1000°C.
You can make a SSTO even without airbreathing, this is how the VentureStar would have worked.

I think there are two benefits. One is that the oxygen takes up most of the fuel mass (e.g. the first stage of a Delta IV carries 173 tons of oxygen and 30 tons of hydrogen), so getting some from the atmosphere is a big weight saving.

The other is that even if the air-breathing part on works in lowest part of the atmosphere, the denser parts of the atmosphere costs a lot of fuel because the rocket has to go slow and incurs more gravity drag. For the Falcon 9, first-stage separation occurs at Mach 6, roughly the same speed that the Skylon would switch from air-breathing to liquid oxygen. But in fact, the first stage is the biggest part of the rocket.
It's not too late to make a difference
Perhaps you mouse slowly in the first place so it doesn't impact you.
Adventures with Sniffing the Network
My life is in my Dropbox (and yours should be too)
They might be trying to get some "lock-in" back, though I have no idea how.

Ballmer's Microsoft apparently missed the Mobile/Tablet revolution assuming that the desktop lock-in they still have could be leveraged. That didn't work for years, but seems to have been ignored until Nadella came in.

Intel might be trying to gain a lock-in by somehow putting the familiar x86 into mobiles/tablets, in the hope that developers would release x86 binaries that would make ARM undesirable. But that's an 80 degree inclination uphill battle. They either have a crazy card up their sleeve, or are unable to respond properly (and the $0 cost + $50 subsidy) is the best they can do at present while trying to craft that crazy card.
Interestingly, Intel spends a lot of die budget on on-chip instruction level parallelism, and their major instruction set-level enhancements have been increasing vector operation lengths. They've also invested somewhat heavily in GPGPU-style vector coprocessors in their Xeon Phi's.
Do you have enough cash on hand to survive (travel, emergencies, pay higher insurance rates and taxes) without using credit or loans for 12+ months (9 months out, 3 months back to get a job or start a business)? If so this is a risk you can probably take. If you do not have the cash on hand it is a risk you should probably not take at this time.

If you do not have the cash on hand I would recommend getting a job that pays a decent rate for a developer so you can save up to travel. If your benefits are right you can normally travel two to three weeks or more during the year but the travel would be much more emerging if you could actually take the 9 months to do so to enable you to do more.

If you do have the cash on hand I would recommend you plan your travels and be on your way. Make sure you keep up on technology and keep your mind sharp if your plan is to go back to San Fransisco, CA (This is what the SF means, right?). As you know things move very quickly in the hot tech areas in the USA (Silicon Valley, DC Metro, San Fransisco area, NYC area, etc.)
Without knowing the specifics of your situation, I'd offer this general advice:

As you get older, long term international travel gets more and more difficult. It can be very valuable as an input on your perspective and worldview, which has long term benefit for ambitious people. PG addresses this in his lecture on doing a startup:

"You can do things in your early 20s that you can't do as well before or after, like plunge deeply into projects on a whim and travel super cheaply with no sense of a deadline. For unambitious people, this sort of thing is the dreaded "failure to launch," but for the ambitious ones it can be an incomparably valuable sort of exploration. If you start a startup at 20 and you're sufficiently successful, you'll never get to do it. "

I largely agree with his perspective. If you are naturally finding yourself at a 'break' (eg, finishing your degree) and you know it's something you want to do, I'd recommend doing it given it will only get harder to do later. Maybe if you aren't fully confident, try limiting your risk by committing to travel for a shorter period of time (eg, 3 months) then re-evaluate the value you feel you're getting from the travel to see if you should extend for another 3 months.

Traveling is hard to quantify the value for because you often won't see the benefits for a long time - it will often subtly affect your perspective in small but important ways over decades by increasing your general human empathy and understanding. And given you have a very employable degree, you will probably not have trouble finding work on your return, which is the biggest risk.
Ask HN: What do you do during idle time or between projects?
I work full time as a developer, but usually like to have some side project with the potential of becoming a business.

What do you do during your downtime between projects?

What are techniques you use to get yourself a new side project without it being contrived?

Currently I find myself reading as broadly as I can, and writing down ideas daily.
Imagine never hearing any birds chirping outside, something we had been witnessing here in Vienna - a silent but profound feeling of horror when I first realized it: https://en.wikipedia.org/wiki/Usutu_virus
Wow, the language used to code formulas in which it's dangerous to use the single-letter variables:

http://tim-smith.us/arrgh/atomic.html

"This also means that you shouldn't ever assign useful quantities to variables named T and F. Sorry. Other variable names that you cannot use are c, q, t (!), C, D, and I."

Note the contradiction of that limitation and the name of the language. Makes the name even more exceptional.

Is he right? What's with the scope? Can't I introduce a new T in my function thus just hiding the global one from it, but otherwise not disturbing anything? (I don't know R, I'm just asking, reading that the variables have the function scope)
I don't mean to be "that guy"... because this is, of course, about linux running 4k.

But much of the discussion seems to be around what the point is, whether it's useful, and so on.

As someone who's been using one of the new 5k iMacs since it came out (so that's 5120x2880 in a 26" display)... let me add a bit, hopefully without sounding like an apple fanboy.

First - running it at actual 5k, rather than at 3200 or 2560 HiDPI, is crystal clear, amazingly sharp, but too small at this size. With a 40" display it would be perfect, I imagine.
At full 5k, you can fit an amazing amount of stuff on a single screen, and it's handy for certain short troubleshooting sessions - but stuff can be so small it's straining. The stuff is still crisp though, if you can manage to focus on it. The detail is there. 12 point fonts are barely readable to my 40 year old eyes unless I get closer.

3k is just fine, and 2k is what you'd expect - but both are using HiDPI rendering and you get stunningly crisp fonts and detailed images and whatnot.

I wouldn't trade it for anything, even if I don't run in 5k all day long.
>Actually working in data science for a living for a few years, my experience is that the practical thing to do is to drop the outliers from your dataset

The website's numbers are not a dataset. Again, it is made up numbers by a random website. There is no evidence behind it at all. The study's numbers do not have outliers, you only want there to be an outlier by comparing the dataset to completely made up numbers with no basis in fact.
This is fascinating and makes me wonder if someone will try to build something similar for Ruby.
Let's see. The sabre engine has a closed cycle specific impulse of 450, which gives an effective exhaust velocity of 4.4 km/s. LEO requires about 7.8 km/s velocity while mach 5 is 1.7 km/s. In one case you accelerate from 0 to 7.8 km/s an in the other from 1.7 to 7.8 (for 6.1 km/s delta-v). The first figure gives a mass ratio of 5.9 while the second one gives you ratio of 4.0. You save about 1/3 of the initial mass if you only have to burn on a closed cycle from Mach 5 upwards.

In reality gravity is a tough mistress so actual rockets launching from a pad require about 9.0 km/s delta-v because they lose a substantial amount due to the gravity losses of climbing up from Earth's gravity well. This is especially true for the first few km's of altitude where the thrust-to-mass ratio is quite low. Potentially, the skylon will eliminate most of those gravity losses by effectively launching from 26km altutude at mach 5 (i'm ignoring the relatively modest fuel consumption for reaching this state - the specific impulse is about 3500).

Assuming a delta-v of 9.0 km/s needed for a single stage rocket gives a mass ratio of 7.7. This means that the skylon should save about 48% of the initial mass required by a SSTO rocket launching from sea level.
You know more than I do, and 97 percent of the world population. Start your own project and work to your strengths. This isn't a race or competition btw :)
>mathematics education

That's a pleonasm I think. Anyone care to argue?
The atmosphere is thick as soup, and that's why lift and flight are possible. Conventional rockets are way too heavy to fly (in the literal sense); they just bring tons of fuel and ditch the containers in stages.

SSTO instead brings little enough fuel (weight) that it can fly itself through the soupy part, which is much more efficient (by like an order of magnitude), on top of not requiring oxidizer for that phase. The longer you can stretch out the aerodynamic phase (i.e. the faster and higher you engines breathe), the less oxidizer you need to bring.

If you crunch the numbers (which apparently they did), you get that the equations work out to needing an engine that will stretch the aerodynamic phase up to mach 5. If your plane can't do that, getting to orbital velocity requires you to bring too much fuel for your plane to fly in the first place, and you might as well build a conventional rocket.
Right. But the whole point of EPIC was to do away with that part of the die budget entirely, and a lot more besides.

GPGPU programming has worked because nobody proposed to run general code on it from the beginning. It just so happens that there are some workloads that fit the vector processing model.

But lots still don't. Lots and lots and lots.
If John selects male on the census check box, dresses as a male, and tells everyone publicly that he is a male, there is just no way to know that he really wishes he were female.

He flat out said he'll check male unless it's an anonymous survey--and even if the survey is anonymous, he said he'd check male as long as anyone else is in the room with him.
The opening caught my eye:

In 2001, Kerith Conron was working on LGBT issues in Boston’s health department. She discovered that homeless transgender people were sleeping on benches because the shelters, which were segregated by gender, didn’t know what to do with them. As a result, transgender people weren’t included in the city’s assessment of who needed shelter.

Years ago, I took a class on Homelessness and Public Policy. I don't recall this coming up as an issue at all. But apparently this is a very serious issue, so serious it can bar you from access to basic services when things are at their very worst.
US Navy reveals its latest recruit: 'Silent Nemo' robofish
I would not be surprised if the "transgender community", to the extent it can have a group preference, prefers to remain basically uncounted. They are a miniscule percentage, and "man on the street" estimates of the size of small groups tend to wildly overshoot. This gives them more influence than they would have were their true numbers known.
I'd much rather take an illegal drug than a legal, 'under the radar' one. The personal risks of possibly getting thrown in jail are vastly dwarfed by the risks of ingesting an untested and completely unknown substance. The sad thing is that even the illegal ones often involve a terrible externalized human cost. Illegal drugs are consumed at scale, exploiting the producers and transporters, legal ones are consumed individually, personalizing the risk.

I've nothing against the yearning to alter one's consciousness, however temporary it might be. But alcohol might be the only way to do it without assuming either great personal risk or great moral hazard. And alcohol can be so, well, boring. One of the great sadnesses of the world we live in.
Terrorism incident unfolding in finance district in Sydney Australia
> nothing more than hype.

at least $10 Billions of dollars (still bleeding, though at a much lower rate these days), some goodwill from customers, and letting AMD become the premier 64-bit platform from a couple of years and having to play catchup -- Intel was practically forced to adopt the AMD64 architecture or they would have lost the lucrative market for PCs and servers.

All things considered, I'm not sure that the price Intel paid for killing PA-RISC was good value for money - it was a lot more than hype, even if in the grand scheme of things it wasn't much.
Agreed with your sentiments, but Khan is financed by Bill "Common Core" Gates and in May partnered with the College Board (hard core CCSS folks) so look for KA to get closer to CCSS, not further. Money talks and CCSS, as bad as it is pedagogically, has a surface plausibility that fools folks who have never taught. In this sense it is like the New Math of the Sixties, which tried to improve math learning by starting at the most fundamental concepts (eg, set theory in the first grade) when in fact those concepts were worked out over centuries by the brightest minds working on math. They confused the logical starting point with the pedagogical starting point.

The good news is that these catastrophes are dumped even faster than they come into ascendance and CCSS is confirming that trend. We just need to remember this the next time academic geniuses decide we are doing it all wrong and -- instead of offering a little professional development -- decide to offer all new standards, textbooks, and standardized exams.

I too have a soft spot in my heart for bold strokes, I just want them to come from folks who know what they are doing. The CCSS authors did not.

ps. I do not think thesis says what you think it says.
What weight does an interpretation hold? I would propose adopting a basic rule similar to Occam's Razor like: "The most mundane and reasonable interpretation is best."
>One is to have an editor that's easily called from other places
Emacs is even better than vim at this, ironically. emacs --daemon makes it easy to call emacsclient anywhere I want without worrying about the file already being open - a common pain in vim, at least for me before I switched.