The speed of light in a vacuum does not change. The speed of light in a non-vacuum medium can be different than the speed of light in a vacuum, however. And light passing from one medium to another changes speed (and is refracted). See https://en.wikipedia.org/wiki/Refractive_index
This study accounts for missing ordinary matter, not dark matter. The linked article makes this clear in the first paragraph. Sometimes I wonder if the first commenters (and often top commenters) on HN read the article at all or just respond based on the headline, because these comments often seem barely related to the actual article content.
> Unlike dark matter, ordinary matter emits light of various wavelengths and thus can be seen. But a large chunk of it is diffuse and spread thinly among halos that surround galaxies as well as in the vast spaces between galaxies.
> Due to its diffuse nature, roughly half of ordinary matter in the universe went unaccounted for and had been considered "missing"—until now.
Not being mean, genuine question: How would you improve the clarity of this?
It reduces notification display latency because they can be displayed directly by the system services managing push, without having to wait for an opportune time to fire up a service worker process. It does still allow customizing the notification with code, but even in that case, having the declarative notification as a fallback improves reliability.
iOS and macOS native app notifications already work the way Declarative Web Push does, not like classic Web Push. This is giving web apps the same ability to be battery friendly and more reliable that native apps already have.
again battery friendly how? because you install them first? please... as I said native apps still abuse notification system(and battery) pushing ads. Apple just hate the web platform, and them trying to push alternative solutions is just PR for how little they care about PWAs and their progression
Battery friendly because notifications can be coalesced by the OS and processed without having to fire up a full browser engine process and JS VM just to unpack the notification and post a visible notification.
Even in the case where the app needs local processing to show the best notification, having this as fallback removes the risk that the app misses the deadline to display a visible notification and therefore loses its push subscription (which is a behavior Chrome and Firefox have too).
We're also not removing classic Web Push, so web apps can deny themselves the benefits of Declarative Web Push if they don't like it.
The blog post documents a relatively long engagement process with the web standards process. Starting with publishing an explainer (pretty common for the browser engines), directly talking with the other browser engines and web developers at the W3C TPAC conference, making concrete proposals to the relevant web standards githubs, taking feedback, etc.
Can you elaborate on the carelessness here? What should've been more careful?
It's standards track and we've had positive signals from Mozilla and Google. Apple is just the first to ship in this case. Are you also mad when Apple is _not_ the first to ship a feature? Is there any way to win?
What’s the difference between a union type and a disjoint union type? In that C# proposal I couldn’t tell which syntax was which branch of your dichotomy.
It's not really meaningful to measure entropy of a single password, only of a distribution of passwords. You could assume a password comes from some distribution, but how would you know? Does "grefn" come from a distribution of "pick a 5 letter dictionary word and then randomly change one letter or a distribution of "pick 4-7 random ASCII characters"?
> It's not really meaningful to measure entropy of a single password
Here’s a ‘not meaningful’ formula then: E = L × log₂(R)
• E is the entropy, in bits, representing how hard the password is to crack.
• L is the password length (number of characters).
• R is the size of the character set (e.g., 26 for lowercase letters, 52 for upper/lowercase, 62 if digits are included).
• log₂(R) is the number of bits needed to represent each character.
I hear your point: a single password might not actually use all character types, so the actual entropy could be less than its potential. Maybe they could have drawn from a wider range and didn’t.
But for everyday user feedback, assuming the fewest sets seems fine to nudge people toward picking stronger passwords.
One definition for the randomness of a finite string is the size of the smallest program that produces it. The definition is dependent on how programs are interpreted.
If my string is "aaaa", does that mean its entropy is zero? There is at least information about its length. And by your definition, how do we know that this password isn't from a 256 character set? Does "Aaab" have 26 times the entropy of "aaab"?
Topics like this make more sense to me when the strings are infinite, or when the population of strings is known.
A good password generator should check that the random generation did not give too many repeats or that the password is not easily guessed by a simple common password list
At least the way it’s described in the Quanta article, it seems like the mathematicians assumed a charged scalar field, which is not something that exists in nature. All charged particles are associated with spinor (spin 1/2) or vector (spin 1) fields. A scalar field corresponds to particles of spin 0 - the only scalar field we know of is the Higgs field, and corresponding Higgs particle is not charged. If god-like powers include a way to change the laws of physics, then your take holds up, but proving something is possible if the laws of physics were different is not very interesting.
They did their calculations with a charged scalar field essentially because this stuff is really difficult, and you want to make life as simple as you possibly can. I think there are no obvious obstructions to it working with the electron field, it's just that it would be much more involved to actually calculate everything.
Probably someday someone will do it, but I don't think it's an incredibly interesting thing to do.
So, if you have two spin (1/2) particles together, this can overall act like either a particle with spin 1 or a particle with spin 0, right?
While 4 spin (1/2) particles could either act like a particle with spin 2, or like a particle with spin 1 (in one of three different ways) or like a particle with spin 0 (5 + 3*3 + 1 = 2^4 ) right?
So, what if we consider helium-4 nuclei in the spin 0 state?
There’s more evidence of Altman being personally involved in this incident than in him being personally involved in the OpenAI exit agreement, and he has denied the latter. I’m not sure I believe his denial in the latter case.
Having an NDA in exit terms you don’t get to see until you are leaving that claim ability to claw back your vested equity if you don’t agree seems more severely unethical, to be sure. But that doesn’t mean there’s more reason to blame it on Altman specifically. Or perhaps you take the stance that it reflects on OpenAI and their ethics whether or not Altman was personally involved, but then the same applies to the voice situation.
