cevi

9 ms·

61.
by cevi 5y ago
The interpretations don't tell you anything that the calculations didn't tell you already (if an interpretation of quantum mechanics ever predicts something different from what quantum mechanics predicts, then it can be ruled out
62.
by cevi 5y ago
If you bet with the -1/x utility function, then the optimal strategy is to always bet about 10.1% of your money. I find this to give a good tradeoff between the variance and the rate of exponential growth.
63.
by cevi 5y ago
The rules of propositional logic (or first-order logic) would seem to fit: i.e. that fact that "A and B" has the same truth-value as "B and A", or the use of modus ponens as a deduction rule. These rules are usually left
64.
by cevi 5y ago
An example of a tricky case: which is bigger, sqrt(1000000) + sqrt(1000018) + sqrt(1000036) + sqrt(1000059) + sqrt(1000083), or sqrt(1000003) + sqrt(1000011) + sqrt(1000048) + sqrt(1000050) + sqrt(1000084)? (They agree to more than 20 decim
65.
by cevi 5y ago
These are both good points!
66.
by cevi 5y ago
Why would SHA-256 be vulnerable to quantum computing? Grover's algorithm only gives a square-root speedup for reversing hash functions, and that's in the best-case scenario where there are no engineering issues (e.g. the need for
67.
by cevi 5y ago
Perfect accuracy is an insane goal. Much better is to develop the skill of finding and correcting your mistakes. Part of this is doing frequent "sanity checks" - for instance, if you are computing an area, and you get the answer -
68.
by cevi 5y ago
The author claims to have a proof that NP = coNP = PSPACE along the following lines: first they describe their favorite axiomatic logical system, then they claim to have a method to compress quasipolynomial-sized proofs in this system to po
69.
by cevi 5y ago
I have ten or so tantalizing questions which I don't know how to solve stuck in the back of my head at all times. Some of these are truly hopeless (i.e. P vs NP), others seem like something I can probably figure out but just haven&#x27
70.
by cevi 5y ago
Direct link to the article: https://www.nature.com/articles/s41586-021-04203-w
71.
by cevi 5y ago
Finance is one field which is desperate for good coders, and which is using tons of outdated software. I'm sure there are other fields like that, too - think really old companies with critical software that can't be ported to newe
72.
by cevi 5y ago
The arxiv version isn't very different from the published version, if you end up facing a paywall: https://arxiv.org/pdf/1801.09488.pdf
73.
NP-hard SAT and CSP problems which admit exponentially improved algorithms(dl.acm.org)
5 points by cevi 5y ago|1 comments
74.
by cevi 5y ago
This is not a proof, just statistical evidence for the Riemann Hypothesis. If you are looking for statistical evidence for RH, the evidence collected by mathematicians already is significantly stronger than what they have...
75.
by cevi 5y ago
The Game of Life on an infinite grid, starting from a uniformly random pattern (i.e. each cell is either alive or dead with probability 1/2), gives you a whole multiverse which is governed by rules different from our own which probably
76.
by cevi 5y ago
It's important to acknowledge just how much randomness goes into the process every year - some years the US team is very strong, other years some of the competitors have a bad day. Students graduate, or decide to pursue a different sum
77.
by cevi 5y ago
Why not?
78.
by cevi 5y ago
I'm always happy to see a sober viewpoint on category theory - too many enthusiasts treat it as panacea. That said, I have actually used category-theoretic language to state interesting facts about relations! It turns out that relation
79.
by cevi 5y ago
Sadly, this page hasn't been updated since 2016. I'd love to see some of the more recent attempts at proofs collected somewhere!
80.
by cevi 5y ago
Unfortunately, randomly permuting the input takes O(nlog(n)) steps (you need at least this much time just to read in sufficiently many random bits). Perhaps a clever parallel architecture could reduce the runtime?
81.
by cevi 5y ago
No - I checked.
82.
by cevi 5y ago
The author says that mathematicians find math outside their own field to be boring and difficult to understand. As a mathematician, I think he's rather missing the point: - mathematics is boring to everyone right up until the moment
83.
by cevi 5y ago
Oh, I didn't know about this! "Get past chapter four of any textbook on quantum field theory" has been on my to-do list for quite a while.
84.
by cevi 5y ago
There is no solid math or physics which supports time travel. There are a lot of cases where people claim to have found some loophole or another in the impossibility proofs for time travel, sketching out a model that looks plausible at firs
85.
by cevi 5y ago
Unlike perpetual motion or free energy, the math and physics behind quantum computing is rock solid - the possibility is baked into the framework of quantum mechanics at an absolutely fundamental level. Even if it turned out that all of qua
86.
by cevi 5y ago
This is the topic of "clone theory": the study of which (multivariable) operations can be created by composing together a starting collection of operations. Post's lattice is a complete description of which gates can be gener
87.
by cevi 5y ago
Somehow this article avoided mentioning Smart Pipe ("Smartpipe, Inc., is a registered sex offender") the whole way through.
88.
by cevi 5y ago
I really like the ideas behind Bitcoin. However, the system requires every single on-chain transaction to be stored and mirrored on every single full node in existence. As more people adopt Bitcoin, and as time continues to advance, this ma
89.
by cevi 5y ago
Quantifiers are what is missing in probability theory but present in logic - while we could potentially write down mixtures of quantifiers and probabilistic symbols, we don't have great ways to interpret them or to reason about them. T
90.
by cevi 5y ago
I know someone who wanted to build up a solid mathematical foundation after years of considering themself to be bad at it, and ended up loving Spivak's book on calculus. (Another well-written book on calculus, in a very different style

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