skysight-inc/HackerNews huggingface dataset:
Θ⁻¹HΘ is a way to write a new Hamiltonian which is the “reflection” with respect to time of the original Hamiltonian H, see https://en.wikipedia.org/wiki/Hamiltonian_mechanics for an explanation of what the Hamiltonian is.

Θ⁻¹HΘ = H means that when you reverse time, your physics looks the same as it did before. Such a thing (time-reversal invariance) is being called “time-even”. In the same way a function f(x) would be “even” with respect to its argument if f(x) = f(–x).

The author of that comment is pointing out that if we assume the Hamiltonian is time-even, then we can’t have a particle with an electric dipole moment. This is because the contribution to the Hamiltonian from the dipole interacting with an external electric field would be time-even. That interaction can be expressed as a kind of dot product of two terms, an electric dipole operator part and an electric field part, and the action of our time-reversal operator Θ can be applied separately to each part. Since the electric field is time-even, that means the dipole itself must also be time-even.

But this can’t really work, because a solitary particle has spin but no other symmetries which could generate the electric dipole moment. The spin gets reversed if we run time backwards, a “time-odd” symmetry. So if we find a particle with a static electric dipole moment in nature, then there must be some contradiction in our assumption that the Hamiltonian was time-even.

The rest of his comment is a somewhat analogous kind of argument related to a slightly more complicated situation and slightly more complicated kind of symmetry.

See https://en.wikipedia.org/wiki/Electric_dipole_moment#Dipole_...
I'd like to offer a counterpoint to your views on medication. For those who suffer from acute, short-term anxiety over a specific event, for example an exam or an interview, beta blockers such as propranolol can be really helpful - as I understand it they interrupt the fight-or-flight adrenaline response to stop you working yourself into a panic. They were wonderful for me during exams and graduate interviews, and now I barely ever need them.
I still suffer from chronic anxiety, but that acute performance anxiety is not a problem for me anymore.
> The other side has nominated an unprincipled criminal who has shown utter contempt for accountability in the course of her public service.
This is really naive. Both sides are hardly saints. This sounds like a talking point from the GOP or Fox News.

So, after the Leavers won the #Brexit vote, we hear of these racist attacks on Polish immigrants by idiots emboldened by the vote result. I would not be surprised to see the same thing happen in the US.
Sun affects bluetooth? How?

The only times I've trouble with BT outside is when tons of people or shops are nearby (overcrowded 2.4 ghz spectrum I assume - bt, wifi, etc)
I couldn't agree more. I tend not to be a conscientious shopper but will very happily go out of my way to avoid spending a single penny with BP.

Utter scumbags - they should never have been let off the hook the way they were after that disaster. I fully expected the company to be on its knees at the very least but nope - they're trading happily ever after.
Congrats you've discovered the other half of the Dunning Krueger effect. The smartest people in the test will assume others might know more than them, because they know enough to know they aren't experts.
> a lot of the benefits fall apart if you don't have people working to maintain the build environment, automated tests, developer environments.

This is absolutely true. Without a very strong culture around testing and deep, continuous investment in infrastructure and tools, a monolithic repo would quickly devolve to being a giant midden heap of code.
The Top 5 Most Environmentally Friendly Vehicles for 2016
It's aimed at low power IoT devices. Wi-Fi is (relatively) very power hungry compared with Bluetooth LE.
We ran into the access control limitations as well. They are caused by the fact that for some reason AWS ES only supports resource based policies which is imho the wrong way around to manage your policies.

We did get it to work in a useable manner by having the ES policy apply to a role (i.e. the principal is a role).
If you than apply that role to your instances it will work for with instance profile based auth.
A talking point from Fox News? This has been all over the media for months, even if some left-wing outfits have been trying to downplay it. If a normal government employee did what she did, they'd be out of a job, barred from ever having a security clearance again, and potentially facing criminal charges for the reckless handling of classified data. They'd almost certainly be facing criminal charges for destruction of evidence.

Also, have you not seen the large number of violent anti-Trump protesters attacking Trump supporters and police?

You need to add an extra newline to go to a new line btw.
Ah yep, friend of friend of Cade's here. Good work so far, I've been submitting bug reports all day - not because it's overly buggy but just because that's what I do :) good luck with the rollout. One question: where is the source code for the desktop and iOS apps available?
In Austria there's a law (might be an EU regulation) that requires the formerly state-owned phone company to rent the "last mile" cables to other companies. Made internet a lot cheaper (16Mbit ADSL costs around 25€ per month).

However, for some reason, private cable companies do not need to share their infrastructure, so if you want faster Internet you are still stuck with the local cable company.
If only the boxer can get at the distance of his hands without having something broken or crippled.

Primary head defense in most karate stances is distance.
Might be the first step in the recruitment process ;)
They also do this on the desktop, dont ask me how but they do. Just create a new account and add nothing, very soon it will suggest you possible friends and not much later these suggestions get scaringly accurate.
Both use the 2.4 ghz spectrum, so that makes sense - especially for bad microwaves.
I had an old microwave that completely tanked my 2.4 ghz Wifi back in the days (very poorly shielded).
That's not an accurate description of a comment that didn't only call the U.S. military terrorists, but U.S. citizens terrorists for paying taxes. By that logic Chomsky himself is a terrorist. That's absurd, and it's hardly politicized moderation to call it a bad comment for this site. (Actually I'm surprised that you'd defend this low-quality subthread to begin with, which started with a dose of political snark and descended from there. It ought to be obvious that that doesn't belong here, regardless of one's politics.)

The moderating principle is that comments should be civil and substantive. Heated rhetoric is neither, so it lowers the signal/noise ratio at both ends.

I'd be delighted to use more neutral, more precise, less pejorative language than I currently do to express what's wrong about that sort of comment. But I'm at the limit of what I know how to say, especially ex tempore. If you can think of a better phrase than shrill, etc., I'd like to know what it is—of course it would require suspending your politics to think of a good one, which isn't always easy to do.
How exactly does Windows 10 allow Microsoft to spy on you?
This is really a poor marketing job by the Bluetooth SIG. Bluetooth 4.0 added BLE, the low energy mode, but it didn't change anything about the power usage of existing modes.

BLE is almost and entirely different protocol, albeit implemented on the same chipset, which is running alongside the existing Bluetooth stack on your phone. Nothing in the Bluetooth 4.0 spec reduces the power usage of the Basic Rate and Enhanced Data Rate modes.
"Hitler's concept of concentration camps as well as the practicality of genocide owed much, so he claimed, to his studies of English and United States history. He admired the camps for Boer prisoners in South Africa and for the Indians in the wild west; and often praised to his inner circle the efficiency of America's extermination—by starvation and uneven combat—of the red savages who could not be tamed by captivity." (http://www.jewishjournal.com/sacredintentions/item/hitlers_i...)
macOS/iOS support for Bluetooth is very good at the core API level but ultimately that means you must use Objective-C for at least a small part of your codebase.
But the point is that they were widely read at some point, so they shaped the culture in ways that are now ingrained.

It's like Homer's epics: nowadays they are mostly restricted to students of literature or historians, but their influence on Western culture throughout history is massive.
Why You Should Care About Brexit
The name is and always has been dumb. I remember when MS first announced it and held evangelizing seminars for developers. Even they had trouble explaining it, and we all left with a vague notion of networked COM or SOAP.

The main limitation has always been the need for a Windows host. I've never considered running a Windows-based server for Internet deployment of an app. However, .NET has managed to persist, and if MS is serious about making it cross-platform, I'm going to seriously consider it for my next project.
There's been some articles on the subject (which is, admittedly complicated, since so many things shoot toxins into the air, and our understanding of its impact is still uncertain):

https://www.theguardian.com/environment/2015/oct/29/vw-emiss...

http://www.nytimes.com/2015/09/29/upshot/how-many-deaths-did...

I guess it's possible to look at these numbers, and compare them to the number of deaths caused by autos in general (even the ones that follow all the rules), and consider it a small thing; something that doesn't justify a massively disruptive response.

But, from my perspective, VW made a conscious decision, and an ongoing choice over many years, to violate the law, and caused illegal levels of dangerous emissions in exchange for greater profits.

So...I don't think I'm responding irrationally when I am extremely critical of a company that would make those decisions over a span of many years, knowingly trading human life and human health for greater profits.

I'm critical of internal combustion auto companies, in general, but I'm not calling for them to be destroyed, and I don't go out of my way to talk trash about them. I'm pretty specific in my ire toward VW (though others have suggested several car manufacturers are pulling similar tricks and emitting illegal and dangerous levels in real world environments), and if that's the case, I'd consider those to be criminal companies, as well. I hope such companies will also be investigated, and also face consequences. But, "everybody's doing it" shouldn't be a defense when the stakes are this high.
Sentry Best Practices for Node.Js
If the attacker has a ubertooth, and is present when the key exchange happens.
Searching for gene matches with BLAST on Ubuntu
Does Snowden use a speakers bureau? I suspect that if you sell speeches to highest bidder vs talk on specific conferences thats relevant to the subject you want to bring awareness, you are going to earn different amount of money. It the same way that civil rights lawyers has a different earning perspective than say a high profile defense lawyer or a company lawyer.

Is the $1.25M/yr in any way anchored to Snowden, or is it just speculation? Do Daniel Ellsberg also earn 1.25M/yr through speaker fees? The Wikipedia article about him fails to mention his vast riches.
Is there any schools today teaching real Ninjutsu?
How Startups Redefine the On-Demand Economy with App Development
Sudden acceleration is less serious than "if you put a lot of heavy stuff on your car keys, it may turn the key when it's in the ignition box"?
Not sure if it's popular elsewhere but Ju-Jutsu training has been pretty intensive and helpful - not sure if it helps in a real fight through, but I guess with a few years of regular training you are better off - https://en.wikipedia.org/wiki/German_ju-jutsu
Twitter v1 was amazingly simple and well documented.
So true.
At first I couldn't believe it, but it is IMPOSSIBLE to completely remove a paired bluetooth device from windows.
After having connected my wireless keyboard to my mac for a day, I tried to reconnect it to windows.
It fails silently and doesn't show up any more in available bluetooth devices. The connection to my mac obviously changed the pairing code, while windows still tries the old one.
I googled for hours, tried everything from uninstalling bluetooth drivers to removing entries from the registry.
Windows always silently re-adds the keyboard to the installed devices and fails at pairing.
So I've got 2 choices left: Buy a new keyboard or reinstall Windows. Yay!
its common to put "ask HN:" for posing questions like this. Without it I was expecting a link to resources.
Unless you're writing LaTeX frequently. :)
And for thr profane:

http://www.larry.denenberg.com/Knuth-3-16/
>and a lot programmers simply don't get it and are making an utter mess instead.

Then maybe those programmers should go back to JS ES5?
As it's 2.4ghz it may also be partially spectrum pollution.

That said - that seems rather impressive for Bluetooth, I've had one reinforced concrete wall pretty consistently screw up most bluetooth signals in my experience, so I'd posit that you're getting unusually good reception there.
> Plus, they use GPLv2, just not GPLv3.

Also, btrfs is GPLv2. So that agrees with my point -- if they didn't mind using free software they could use that code.
You can perfectly do it by walking or by bike. But still, how are you going to buy fresh meat/fish or even some fruits/vegetables by shopping only once a week? I go shopping usually 3 times a week, and it is a very enjoyable and relaxing activity.
They have a USB => Lightning cable. Plug it in briefly.
There's a difference between a car that's tuned to passively give good values at emission tests and making a device that detects emission testing, activates a procedure that involves changing the dynamics of the engine.
"Dumbing down" in the sense like ISPs are supposed to be "dumb pipes". I'd like the cloud to be a dynamically allocated compute resource - i.e. the end-user rents out computing power and provides both the data and the code that runs against it (which may or may not be licensed from a third party). The goal is to separate out the code providers and compute providers, and to keep the user always in control of their data.
The standard does support multiple simultaneous devices.

Your hardware? Not always.
Mozart´s Requiem: the autograph and the missing corner
How is defrauding consumers a "US vs Germany issue" and nothing else?

Also VW got off with a slap on the wrist here.

The US did nothing wrong here. People don't drive around needlessly, they drive because they live in places that often have no viable alternative. Why on earth should they be punished?

Your comments are bizarre and naive. Is you point just anti-Americanism?
We detached this subthread from https://news.ycombinator.com/item?id=11990553 and marked it off-topic.
I got a 2015 TDI Jetta in May of 2015. It gets wonderful mileage when I'm on the highway. 51-52mpg on long hauls on the interstate with cruise control set.

I'm honestly torn between taking the total amount of money or the $5,100 and letting them fix the car. I just hope it doesn't kill the fuel economy too much.

...and what downsides are there to holding on to the car if they have a fix?
Yes. For most people a good bike is a well maintained, comfortable bike with racks, fenders, chain guard and so on. For someone training for a triathlon a good bike is light, aggressive, a trillion gears etc.
Muhammad Ali and what it takes to achieve greatness
What the ISO C++ committee added to the C++17 draft at the Oulu 2016 meeting
How did Sam Altman make his money?
Introduction to the Serverless Paradigm (webinar)
It reminds bug shaped toy learning code.
Should hopefully be fixed now. The MathJax was loading over http, not https.
Along these lines, it has been argued that the ancient Greeks could have discovered Lucas-Lehmer with their contemporary technology: https://infoscience.epfl.ch/record/215073/files/MGFinal.pdf
I suspect that comes down to the protocol used.

I had no problem connecting a keyboard and phone (as modem) to a N800 back in the day, while also playing music from the phone to a pair of bluetooth headphones. But that was if i used PAN For the data connection between N800 and phone.

If i used DUN, either the music or the data would occasionally skip.

And that may well be what gives Bluetooth its reputation. So many choices for the various OEMs in terms of protocols/profiles, on top of a more complex air interface (channel hopping).

Given all of it, one may well be better off comparing Bluetooth to USB than wifi. As wifi is Ethernet over a single radio channel.
I had chronic rhinitis, probably linked to air pollution (near Paris). I have done a checkup of my sleep quality.
It has shown a slight Sleep apnea disorder. I am taking corticoids (nasal spray) since 2 month. My nose is a lot better, but the main improvement in about my memory and my concentration.

I think memory is very important for programming. I can work a lot faster since I take this treatment.
https://en.wikipedia.org/wiki/Piconet
Google says deep learning is the future. So I tried it myself
So you're saying Allied war crimes were in no way comparable to Axis?
I was referencing the anti-expert rhetoric that was popular among the leave campaign. I'm sure many leave voters had their reasons but there was also a significant anti-expert segment.

Do you have current statistics on the Scottish spending deficit? Last time I looked there was one but it was far from huge, especially when you account for defence and administration savings from being a small country.

The arguments for the EU aren't purely economic.
No, they are not.
Other modern inventions that people think are ancient:

1) Scots wearing different patterned kilts to denote clans. This was mostly invented by Sir Walter Scott

2) Druid rituals. Druids were wiped out by the Romans, and the only accounts left of their rituals are Roman. What we now think of Druid rituals are a mixture of Roman writings and stuff made up in the 19th century.
I still do. The ability to stream music in my kitchen is the reason I bought a 5GHz router.
Announcing jto/validation 2.0
I went the 'new keyboard' route when I needed to repair my Logitech K811 - I now have two keyboards on my desk, one for the mac, the other for the PC.. Absolutely ridiculous, but saved me wasting a day of installation (and inevitably having to re-pair the K811 in the future)
This can be good advice for some. It might not be choice for someone with depression. Deeper problems are not solved by a vacation.
Nice. Are you guys using Jetsons for cpu+gpu?
So it was precedented before? When has there been equally little wars, equally much prosperity and cooperation (measured relative to the state of civilization at the time)?

Considering what an unfriendly place the world has been in the past centuries (diseases, terrible working conditions, decade-long wars) this is not an unreasonable statement to make. These things still exist, but certainly less pronounced when averaged over time and space.

Edit: See http://singularityhub.com/2016/06/27/why-the-world-is-better...
People forget that a worker is also a consumer. An Indian or Chinese worker is now a consumer of goods like Ford cars, Coca Cola, Intel chips, etc.
What was the reason for adding font handling of all things in the Kernel? I know that the low-level graphics primitives were added to the Kernel round NT4 (apparently for performance reasons), but why is the font processing there too?
You have elected MEPs that make many of the decisions. Additionally in the UK currently you have a FPTP system that is arguably undemocratic and an unelected House of Lords (which I don't necessarily disagree with) so surely there are bigger easier fish to fry.
Dragonfly Fintech selected to implement blockchain based payment solution
Very much similar to the African concept of Ubuntu, which is nothing more than a modern popularized dreamed up concept.
Finland is Nordic, and Estonia is not, so Estonia is not as Nordic as Finland.
I noticed Digital Ocean added an India datacentre too - https://www.digitalocean.com/company/blog/introducing-our-ba...
> It's annoying when you try to change the shared language, which is convention-based, to reinforce your opinions.

I disagree.

> It's usually called "name-calling"

Well, no, it's not. While that might be the case sometimes, it's not necessarily so, and in particular it's obviously not the case in the case we're discussing here.

> Trying to shape the language to try to reinforce specific views of reality is always very very suspicious.

I disagree. And I disagree for a very simple reason: More often than not the existing usage is not neutral in the first place, it just happens to have been first (and sometimes not even that), and that's not always just an accident either. So, the existing usage is as suspicious as the attempt to change it, which is why the appropriate response in my opinion is to take the opportunity when someone suggests a new convention to examine whether the existing one is maybe more suspicious than what is being proposed.

> Well, whether they do or not is up to them. It's the principle of democracy, liberalism and tolerance: people are entitled to decide, entirely subjectively, what's best for them, as long as it doesn't damage others.

Well ... no. Or at least, that's besides the point.

People are entitled to decide what they prefer, but people are not entitled to decide how reality works. So, people are entitled to decide that they want to smoke, to take a random example. But people are not entitled to decide that they want to smoke and not die early due to side effects from smoking. They might wish that it were so, but smoking objectively comes with certain health risks, and you have to decide either for smoking with these risks or no smoking without the risks.

Now, some smoker might not know about the health risks of smoking and therefore put a positive value on smoking, while at the same time valueing the health risks that objectively come with smoking negatively with a greater magnitude than the value they put on smoking. It would be completely besides the point to argue against that by saying that it's a principle of democracy that they are entitled to continue smoking. Sure they are. But it's an empirical fact that once it was established public knowledge that smoking is bad for your health, many people adjusted their valuation of smoking to a negative value and quit.

Also, it isn't even so clear whether the use of Facebook isn't damaging others. Facebook has a network effect, which in economists' terms is in the category of externalities. In so far as network effects of proprietary systems tend towards creation of a monopoly and thus slowing of innovation and many other abuses that monopolies tend towards, there probably are negative externalities--or in other words: damage to others.
That's where a wifi speaker is good.
DHL's Parcelcopter drone delivery in action
Its because it is a complex combination of hardware and software protocols.

With wifi you have a single channel, and basically ethernet. On top of that anything goes as far as software is concerned.

With Bluetooth you have channel hopping radios, a pairing system for devices, and a bunch of profiles/protocols that define anything from basic serial data to encoding agnostic audio.
Cryptography pioneer Marty Hellman calls for compassion in threats
>I realize I don't need to have caffeine to work.

Impressive. Once I said to my coworker that I'm not drinking a coffee because I can't sleep at night. She replied she drinks coffee because she can't stay awake in the daytimes without coffee.
TemplosOS and especially HolyC and the editor are one of the few instances of something done wonderfully right, but for the wrong intentions, rather than the other way round.

His embedded models for example in the editor are stunning.