ultrafilter

7 ms·

1.
by ultrafilter 2y ago
Your charge-based g-meter would also measure zero acceleration in free fall. https://en.wikipedia.org/wiki/Paradox_of_radiation_of_charge...
2.
by ultrafilter 3y ago
Near the end, the author claims that if a,b,c form a basis of R3, then the cross products a x b, b x c, and c x a are orthogonal. This is false. E.g., a=(1,1,0), b=(0,1,1), c=(1,0,1) implies a x b = (+1,-1,+1), b x c = (+1,+1,-1), c x a = (
3.
by ultrafilter 6y ago
If I have a keyboard, then for a relatively small dataset, such as my saved passwords, I prefer a text file over any database. Lookup workflow: decrypt file (with, say, gpg), find what I want (with, say, grep), delete decrypted file. (Not s
4.
by ultrafilter 6y ago
Set theorists have located the "end" for all practical and most impractical purposes. Let M be the minimal countable transitive model of ZFC. Declare a real to be useful if and only if it is in M.
5.
by ultrafilter 7y ago
If you're giving the book away, why not release the source (LaTeX, Word, whatever) in addition to your favorite subset of {PDF,EPUB,...}? Then readers who want a different format have a better chance of being able to produce it themsel
6.
by ultrafilter 8y ago
The author's more recent work is here: http://arc.cecs.pdx.edu/publications
7.
Surface codes: Towards practical large-scale quantum computation (2012)(arxiv.org)
1 points by ultrafilter 9y ago|0 comments
8.
by ultrafilter 9y ago
You're right. I should have written "halts last among its peers" or similar.
9.
by ultrafilter 9y ago
Every formal axiom system, whether about sets or anything else, can only prove that N of Busy Beavers halt, for some (not-too-large in practice) finite number N. If you just want to maximize N, right now your best bet is set theory plus a v
10.
by ultrafilter 9y ago
Nice overall; my only complaint is that you raised the question "Are LTC log returns normally distributed?" but only gave an uninterpreted graphical comparsion. I was hoping for a test statistic... https://en.wikipedia.
11.
The choiceless cardinals are inconsistent(arxiv.org)
1 points by ultrafilter 9y ago|0 comments
12.
by ultrafilter 9y ago
I put a copy of putty at a short but private url at my own domain so that I can get it over https.
13.
by ultrafilter 9y ago
Indeed, the source code only considers tax brackets, the personal exemption, and the standard deduction. I've read of an increase of $650 in the per-child tax credit combined with the loss of the per-dependent personal exemption and an
14.
by ultrafilter 9y ago
Yes. Perhaps the voting currency should be hours, not dollars. Make the first vote free. But N-1 more votes costs you N^2-1 hours from your "registered community service" account maintained by the government. No overdrafts allowed
15.
by ultrafilter 9y ago
The Carnot cycle is a poor model for steam turbine electric power plants. Rankine cycle efficiency of ~40% is the more relevant theoretical upper limit. https://en.wikipedia.org/wiki/Rankine_cycle
16.
by ultrafilter 9y ago
In the real world, Hamkins' program would search forever, never outputting anything. In the context of a "nonstandard" version of the line of natural numbers, "finite" no longer means what you think it means. In thi
17.
by ultrafilter 10y ago
The article has a link in a sidebar: https://arxiv.org/abs/1608.01008v2
18.
by ultrafilter 11y ago
I think your watch is slow and you think mine is slow in the following sense. For each of many events, I record their time t and position x while you, moving relative to me at constant velocity, observe a different time T and position X. Be
19.
by ultrafilter 11y ago
In contrast (but not contradiction) with your experience, as an MIT undergraduate math major applying for PhD programs, my advisor warned me that the math dept. doesn't admit their own graduates. I applied anyway and indeed was not adm
20.
by ultrafilter 11y ago
Theorems 1 and 3 are finitary and easier to physically interpret. As for Theorem 2, "With probably p a random foo has property bar" intends no interpretation of "random foo"; it merely claims that the set of foo's w
21.
by ultrafilter 13y ago
There's no relation to his incompleteness theorems. Gödel proved that every universe V of sets that satisfies the (ZFC) axioms has a subuniverse L that satisfies both the axioms and the continuum hypothesis (CH). L is constructed by tr
22.
by ultrafilter 13y ago
The man's escape strategy described in the post was discovered in 1952 by Besicovitch. It has a kind of discontinuity because, quoting the post, "There are 2 perpendicular paths. Choose the one closest to the center, or if the two