ravi-delia

7 ms·

1.
by ravi-delia 11mo ago
Propellant is still used for rotation control. Reaction wheels can "saturate" if they compensate for rotation more in one direction than the other on net, so propellant is needed to get them back down. Ion engines, generally spea
2.
by ravi-delia 2y ago
I mean I guess you could say they have different semantics. They're just different types, int and Int64 aren't any more different from each other than Int64 and Int32. You can treat all of them exactly the same, just like how you
3.
by ravi-delia 2y ago
Ok, running this by you one more time. There is a type called "int" in the language. This is a 63-bit signed integer on 64-bit machines, and a 31-bit integer on 32-bit machines. It is stored in 64 bits (or 32), but it's a 63-
4.
by ravi-delia 2y ago
So the "one bit" you refer to is what makes the standard int 63 bits rather than 64. If you could do things with it it would indeed break the runtime- that's what tells it that you're working with an int rather than a po
5.
by ravi-delia 2y ago
The usual int type is 63 bits. You can get a full 64 bit int, it just isn't the default.
6.
by ravi-delia 2y ago
This is why we never should have invented the phonograph. People who want to listen to music can just buy a record, making it literally impossible for them to perform an activity humans ENJOY doing. Without it everyone would surely be makin
7.
by ravi-delia 3y ago
The question wasn't "why do protons have +1 charge", it was "why do protons have +1 charge, *considering electrons have -1 charge". The fact that possible charges are restricted to a few values is a much more satisf
8.
by ravi-delia 3y ago
Not so much for takeoff! Most rocket designs better than chemical rockets trade off thrust for specific impulse. That's an improvement in orbit, since delta-v is delta-v. But imagine a 10kg rocket- it's receiving ~100N of gravity.
9.
by ravi-delia 3y ago
You know what, that's a sufficiently cursed workflow that it wraps back around to adding nerd cred
10.
by ravi-delia 3y ago
It isn't
11.
by ravi-delia 3y ago
It actually bottoms out pretty low though. The apparent fractal dimension changes over scales, but is sufficient that ruler length really does make a huge distance in coastline length
12.
by ravi-delia 3y ago
I think what you're referring to is the false proof suggesting that pi=4. That is not what squaring the circle is, and does not in fact become smoother and smoother but rougher and rougher
13.
by ravi-delia 3y ago
Sure, but if you're gonna have a space heater (and people do) there won't be any difference in efficiency between any possibility, including computers
14.
by ravi-delia 3y ago
Large carnivores are kind of the pricey boondoggles of evolution. They work, they are successful, but they're balanced on a knifes edge. Every step a large carnivore takes consumes vastly more energy than it would cost a smaller animal
15.
by ravi-delia 3y ago
I mean this is a crazy thing to know about 37. And we know it!
16.
by ravi-delia 3y ago
In analytic number theory we usually only care about growth rates in a very coarse sense- up to scaling by some constant, and asymptotically. Because the log of any base is precisely the same up to constants, it doesn't actually matter
17.
by ravi-delia 3y ago
Population counting isn't an exact science, there were estimates suggesting we hit 8 billion about a year ago. But the 90s are right out- last big milestone was 7 billion in 2011.
18.
by ravi-delia 3y ago
So you can of course multiply some vectors- the real numbers are a vectorspace, and they have a perfectly nice product. Even R^2 can have a nice multiplication- (a,b)(c,d) = (ac - bd, bc + ad), the product of the complex numbers. However, i
19.
by ravi-delia 3y ago
> "Definition" - "Theorem" - "Corollary" structure looks like a silver bullet, it fits very well in a linear format of a book. Unfortunately, this format is totally inadequate when it comes to passing knowle
20.
by ravi-delia 3y ago
Hmm, I do see where you're coming from. To me, saying math is the study of formal systems is a statement of acceptance and neutrality- we can welcome ultrafinitists and non-standard analysts under one big tent. But you correctly point
21.
by ravi-delia 3y ago
> I think in 50 years we will look back on the way pure math was written today as a great tragedy of this age that is thankfully lost to time. That could very well be true. I mean just a 100 years ago mathematics (and most education) con
22.
by ravi-delia 3y ago
I think that "when you proceed to applications" is the issue there. Applications where? For applications in field theory, the spatial metaphor is exactly incorrect! For applications in various spectral theories, it's worse th
23.
by ravi-delia 3y ago
I absolutely see what you're saying with that. I think I'm definitely the target audience of the abstracted definition, but I've long held that every new object should be introduced with 3 examples and 3 counter-examples. But
24.
by ravi-delia 3y ago
> To me, each column represents a different dimension of the basis vector space, so the notion that X, Y, and Z might form independent "column spaces" of their own is unintuitive at best. I can't help but feel a treatment
25.
by ravi-delia 3y ago
Axler serves as an adequate first introduction to linear algebra (though it is intended to be a second, more formal, pass through. Think analysis vs calculus), but it isn't intended to be a first introduction to all of formal mathemati
26.
by ravi-delia 3y ago
What? Linear Algebra is easily one of the best understood fields of mathematics. Maybe elementary number theory has it beat, but the concepts that drive useful higher level number theory aren't nearly so clear or direct as those drivin
27.
by ravi-delia 3y ago
Oh neat, I thought it was still unoptimized compared to gengc (which afaik does still use write protection). I'll have to check it out, see if I have a machine it'll run faster on
28.
by ravi-delia 3y ago
If anyone is curious about how signals are used for garbage collection (specifically SIGSEGV) check out this article: https://medium.com/@MartinCracauer/generational-garbage-coll... It's handy for knowing which ar
29.
by ravi-delia 3y ago
VSCode actually also supports using git send-email. All you need to do is work on your code in exactly the same way, then use git send-email.
30.
by ravi-delia 3y ago
Multistep is fair, though for the record "multi" in this case means 2. One of those steps (the only thing that differs by OS) is installing git- I think you'd agree that gatekeeping by ability to install git is pretty reasona

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