jules

33 ms·

301.
by jules 8y ago
"already understands these relationships so well" Is that true for complex numbers?
302.
by jules 8y ago
I don't understand what you mean, can you elaborate? Are you talking about perfect hashing? Or are you talking about doing multiple strcmps? Or about doing the state machine until you reach a unique alternative, and match the remainder
303.
by jules 8y ago
It's fundamentally the same issue, and the same difficulty. The reason I mentioned 2 charges orbiting around each other is to avoid getting into a discussion about the uniform magnetic field, and that maybe the extra radiation energy i
304.
by jules 8y ago
I don't think making a relativistic theory of charged matter that approximates anything in the real world is as easy as you think. Charged dust will behave in very complicated ways, so I'd have to see a differential equation that
305.
by jules 8y ago
Lexers don't do strcmps, they use a finite state machine to determine tokens. For instance if we have the tokens ALTER, AND, ANY, SELECT, FROM it will compile into a state machine like this: switch(str[i++]){ case 'A'
306.
by jules 8y ago
Why is this necessary at all? The lexer is recognising tokens with a finite state machine, so it already knows which keyword it's got.
307.
by jules 8y ago
Maybe setting up a Patreon account and posting what you did each week is sufficient. That seems to work for the youtubers, and it's more audacious to ask money for watching youtube videos than writing docs and promoting Rust ;-)
308.
by jules 8y ago
I'm not trying to play with words...by EM I mean Maxwell's equations and the Lorentz force law. I think that's the conventional meaning. The point is that these two are taught in an EM class as if it's a single coherent
309.
by jules 8y ago
Would it be possible to crowdfund that role? People on youtube apparently earn a living by making videos in which they film themselves watching other youtube videos, so it ought to be possible :)
310.
by jules 8y ago
> if you calculate the poynting vector you see energy is not really leaving the system in this case Isn't there? That wasn't what I learned. If you set the light charge in motion around the heavy charge, then space will fill wi
311.
by jules 8y ago
I understand differential equations ;-) That page describes Maxwell's equations and the Lorentz force law. That a naive approach cannot work can be seen by considering the following example. Take one charge initially at rest with huge
312.
by jules 8y ago
So what are the equations for those two charges?
313.
by jules 8y ago
I mean that the theory splits into two parts: the part that tells you the fields given the charges, and the part that tells you the charges given the fields. For instance, it doesn't tell you what two charges with given initial velocit
314.
by jules 8y ago
You can put an arbitrary metric on your space, but usually you wouldn't need metric dependent operations if you don't have a metric.
315.
by jules 8y ago
Yes, they operate on the same objects. The main operations on differential forms are the exterior derivative d and the wedge product f /\ g. These are independent of the metric. If you add a metric you get one extra operation called th
316.
by jules 8y ago
Yes, but the formulation in that paper is really not the best one. Electromagnetism is best formulated in geometric algebra of 4-space (3 space dimensions + 1 time dimension), not 3-space.
317.
by jules 8y ago
E&M is simple in the sense that the equations that govern the relationship between the charge distribution and the electromagnetic field are quite simple. And the equations governing how charges move in an electromagnetic field are quit
318.
by jules 8y ago
> I do support an open border. Why wouldn't you? Because the influx of people will be huge and will only stop if the incentive to move disappears, i.e. if the quality of life in your country is approximately equal to the quality of
319.
by jules 8y ago
If you know a more accurate model you can change the four functions at the top.
320.
by jules 8y ago
Let's analyse that. Suppose the frequency of the blue eye gene and the brown eye gene are the same in the general population, and suppose the prior probability of cheating is 10%. Then we can simulate this: from random import ran
321.
by jules 8y ago
The compiler could do that automatically. Suppose you're operating on the control flow graph and you are to specialise a basic block in some type environment. You can cache the result so that the next time the same basic block is speci
322.
by jules 8y ago
Do you know what's causing that? 1. Maybe monomorphisation overduplicates code, so that different invocations produce the same machine code in the end? 2. If that's not happening, maybe idiomatic Rust code causes a lot of code to
323.
by jules 8y ago
There's also http://algo.inria.fr/flajolet/Publications/book.pdf . The first chapter of this book is more or less equivalent to generatingfunctionology, but has a more modern flavour.
324.
by jules 8y ago
Euler was a master of generating functions. Here is a little taste. Start with a Haskell data type: data Tree x = Leaf | Node x (Tree x) (Tree x) The question is how many different Trees of size n are there, where n is the number of
325.
by jules 8y ago
It's quite difficult to simplify an existing language, even when adding a feature could theoretically simplify a language. For instance, higher kinded types are simple in principle: it's just removing an arbitrary restriction abou
326.
by jules 8y ago
It doesn't follow from consistency in itself. It is possible to imagine a formal system that is consistent but nevertheless doesn't predict the behaviour of calculators. If you presume that ZFC correctly models the behaviour of ca
327.
by jules 8y ago
It is more than formal consistency because to show a whole number solution to a^n + b^n = c^n and n > 2, one doesn't need to use a high powered formal framework like ZFC. Thus Wiles' proof of Fermat's last theorem, which u
328.
by jules 8y ago
> For men, desirability peaks around 50 and then declines. Perhaps within their own age group, but I don't believe for a second that a 50 year old man is more desirable than a 30 year old man. If that were true then the 50 year old
329.
by jules 8y ago
It wouldn't change much even if there were 10 metaphysics papers for every mathematics paper. The main difference is that math is rigorous: there is an agreed upon standard for correctness that is falsifiable in two ways. Firstly, a pr
330.
by jules 8y ago
Obviously you would not use that absurd shutdown procedure. You'd give a warning and tell the driver that the engine is going to shut off in X minutes, and after X minutes you decrease its max speed to 10 km/h for Y minutes before

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