foxes

32 ms·

331.
by foxes 6y ago
I just had a flip through this book, yes all the differential geometry is there, but I think its a bit of a let down. If I think "functional" I want to think more abstractly in terms of categories, functors, functions. The Lisp co
332.
by foxes 6y ago
I would guess most mathematicians do not truly fully use ZFC at all. I think there is a lot of mathematics that is done which is actually independent of ZFC, its more expressive than needed (if we look at reverse mathematics).
333.
by foxes 6y ago
There is a trick in physics I am reminded about. In infinite dimensions there is no way to have a Gaussian measure on just an infinite dimensional Hilbert space. It needs to be embedded inside a bigger infinite dimensional space and then yo
334.
by foxes 6y ago
I definitely think acronyms hinder understanding. I avoid using any in a talk. People have to expend effort thinking about what it means, distracting them. Also another big issue for me is using names to refer to some particular object, whe
335.
Science is getting harder to read(natureindex.com)
2 points by foxes 6y ago|1 comments
336.
by foxes 6y ago
What is the natural mathematical abstraction to describe object oriented programming? I always feel object oriented languages are some sort of poor approximation to some sophisticated functional programming concepts (lenses, comonads, etc),
337.
by foxes 6y ago
Maybe a good example that ties both together is some sort of filter on a list? If you add more constraints (more processing) the list gets smaller. Suppose I have a function f : x -> y. x -> y is also a functor in y. If you have an x-
338.
by foxes 6y ago
Yes that is not bad, a good example.
339.
by foxes 6y ago
Contravariant functors are actually really nice. The classic example from maths is the spectrum (Spec) of a ring R. As a functor, Spec(R) = the set of prime ideals of R. An example anyone can understand: all the multiples of prime numbers p
340.
by foxes 6y ago
For algebraic expressions you get an expression if you expand in dual numbers. But what about something like cos(x). Either you can lazily evaluate the power series or you know its sin(x).
341.
by foxes 6y ago
As an Australian I support blocking Sky news "content".
342.
by foxes 6y ago
Sounds a bit like Ethereum but without a cryptocurrency?
343.
by foxes 6y ago
Speculation in an absence of information. There are definitely biological organisms that suffer the same mistakes as our curve fitting. Eg the bird that pecks the red dot on the mothers beak. Its selected to pick the biggest red dot, so if
344.
by foxes 6y ago
I do love diagrams, I love thinking about some problems in terms of diagrams, eg Feynman diagrams, some enumerative problems, knot theory etc. It can be kind of deep. I think they are good for when you can do some graphical manipulation to
345.
by foxes 6y ago
Quantum mechanics is unitary time evolution? Apart from measurement its all linear, look at the Schroedinger equation... there's no chaotic dynamics. A trivial result? Pity I cant read the rest of the article behind a paywall.
346.
by foxes 6y ago
Ok then. I ran 30km today, I can play some video games if I want.
347.
by foxes 6y ago
I don't necessarily think the focus was on the computational model aspect. Yes quantum computing is theoretically purely described by quantum mechanics so it doesn't add anything new. But his point was that actually implementing p
348.
List of Suicide Crisis Lines(en.wikipedia.org)
5 points by foxes 6y ago|2 comments
349.
by foxes 6y ago
Everyone pays too much attention to Twitter. I think it is responsible for radicalising many people. People seem to get easily swept up and not apply the same filtering as they do in real life. Not to mention Twitter/Facebook etc acti
350.
by foxes 6y ago
I agree with the blog that science is about doubt/falsification. But if we want to be pedantic, we should make some distinction between scientific models/theories and the scientific process. A model is some description of reality.
351.
by foxes 6y ago
In gravitational wave detectors. Heard of the Casimir effect? Two plates can experience a force from vacuum fluctuations.
352.
by foxes 6y ago
I disagree completely. You have to be aware of the context. It's like having hundreds of different programming languages. You work in a particular context and you get used to it. I assume you come from a non mathematical perspective.
353.
by foxes 6y ago
Happens to me too on Firefox 77. From the main page to the user page, everything shifts right a few pixels.
354.
by foxes 6y ago
Aren't all these delivery businesses living in a false vacuum? It seems like a lot of these companies are basically a giant multivariate ponzi scheme.
355.
by foxes 6y ago
Yep, the real problem is conservatives/right wing.
356.
by foxes 6y ago
I agree that conciousness of people is not "special", but why the need to add in an extra meta physical quantity of "conciousness". I agree it is probably a spectrum, but I think it is more just an emergent quantity. Peo
357.
Navy Officially Releases Controversial UFO Videos(thedrive.com)
1 points by foxes 6y ago|0 comments
358.
by foxes 6y ago
If you compute the curvature it starts flat, does a few bump and then flattens again (this curvature is not a very smooth function however). An n-ellipse is not quite the right curve. Apple used a bunch of Bezier curves. I think their desig
359.
by foxes 7y ago
I'm sorry, slight rant, but I do not think notebooks are good for a completed piece of software. Maybe it's good for development/brainstorming but once you are done the code needs to be extracted into a more traditional forma
360.
by foxes 7y ago
Out of clarity this is an "algebra over a field" vs a more general concept of an algebra over a ring. More generally an algebra A, over a ring R, an R-algebra , is a ring A equipped with a map Hom(A,Z(R)). Algebra over a field is

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