Gondolin

9 ms·

1.
by Gondolin 7y ago
Yes, the Busy Beaver function grows faster than the functions I gave, basically it behaves like f_{w^1_CK} (although this does not really make sense because w^1_CK, the Church Kleen ordinal, is not recursive). By "ultimate generalisati
2.
by Gondolin 7y ago
The ultimate generalization is to use an inductive definition based on recursive ideals. For instance the fast growing hierarchy f_alpha: https://en.wikipedia.org/wiki/Fast-growing_hierarchy Since ordinals are the ulti
3.
by Gondolin 7y ago
Yes, Emmy Noether was a pure genius (one of the greatest mathematician of all time), and was never named full professor (even though she had Hilbert support).
4.
by Gondolin 7y ago
It would be nice to know the priority of blocking elements between firefox default anti-tracker list, ublock origin, and privacy badger. When I see a tracker hit ublock origin does it mean that it bypassed firefox anti-tracker blocking, or
5.
by Gondolin 7y ago
Now that systemd-nspawn also has oci support, I wonder if podman/cri-o are going to switch to nspawn rather than runc.
6.
by Gondolin 7y ago
The Fibonacci example is interesting. If you want arbitrary precision, then the naive recursive method is exponential in $n$ to compute $F_n$. The loop method (recursive method with cache) is in $O(n^2)$. Indeed you only have $n$ steps in t
7.
by Gondolin 7y ago
On the other hand, constructive set theory is still rather a niche part of mathematics (this may change with the recent development of HOTT). It is hard not to use the LEM (and I am not good at it, I am not an expert on this subject. Expert
8.
by Gondolin 7y ago
Only speaking about arithmetic rather than full set theory: in (full) second order arithmetic theory all models of the natural number N are isomorphic (in a unique way). The big drawback is that this theory is completely undecidable, so we
9.
by Gondolin 7y ago
More precisely the effective topos is a kind of realizability topos with a nno where every function is computable. Such a (non trivial) topos cannot be classical, otherwise the halting problem would be decidable. However the effective topos
10.
by Gondolin 7y ago
Oh yes, it is very much alive. For instance any topos (with a nno) is a model of intuitionist set theory. And since topos are a very natural type of categories (a topos= acategory which has finite limits and a power object), intuitionist
11.
by Gondolin 7y ago
Some plants have a closed cooling system. And the million figure count fish eggs, which is somewhat cheating. And if you take into account the reduced wildlife area due to solar panel and wind farm needing more space than nuclear plants, I
12.
by Gondolin 7y ago
Again, a major accident would not take out half of Western Europe, this is fear mongering. A major accident would be severe, with a large exclusion zone and a lot of economic damage, but sill kill less than coal kill in Germany each year .
13.
by Gondolin 7y ago
No it is not zero CO2 output in 2050 but about 65% reduction only, or 80% if a 25% reduction of electricity consumption is achieved. This is 1) too late, 2) not even on par with France's electricity C02 production. And a nuclear accide
14.
by Gondolin 7y ago
Yes long term we should get rid of it (for fusion), but in short term the priority is climate change. And nuclear fision is a tremendous asset for climate change. There are still huge challenge of course, and we are unfortunately not at all
15.
by Gondolin 7y ago
I agree that Energiewende is important and that reducing the cost of renewable was sorely needed, but at the same time the decision to close the nuclear plants (rather than coal) was a gigantic mistake. 1) Because it costs a lot of lives. C
16.
by Gondolin 7y ago
Chernobyl: cannot happen. Fukushima: how many deaths? Even if the wind was blowing in the direction of Tokyo? But sure, let's close the nuclear reactor who killed nobody in Germany, and keep open the coal plants which still accounted f
17.
by Gondolin 7y ago
> Because it wanted to get rid of nuclear first and as fast as possible. And this killed a few thousand persons and rejected MegaTons of CO2 in the atmosphere that could have been avoided. > The next two decades will bring the end of
18.
by Gondolin 7y ago
So still 35% coming from fossil if the remaining nuclear plants are shut down. Again, Germany goals and effort are laudable, but you miss my point, it is not about nuclear vs renewable, but nuclear vs fossils as a complement to renewable. W
19.
by Gondolin 7y ago
This is the production capacity (you are right it is not a good measure), but I was replying based on the graphic. If I look at wikipedia: https://en.wikipedia.org/wiki/Electricity_sector_in_Germany Germany went from 6
20.
by Gondolin 7y ago
Germany's goal is laudable, but even if it manages to go full renewable by 2050 that's still 40 years of green house gas emissions it could have avoided had it gone both nuclear and renewable. Nuclear can be made smaller (molten s
21.
by Gondolin 7y ago
If I count lignite + coal + natural gas + mineral oil, it goes from 76.9GW in 2010 to 79.3GW in 2019. So it did not go down either. That's because Germany needs a back up energy source for now. It could have gone down by 10GW had Germa
22.
by Gondolin 7y ago
Germany has been taking coal offline after taking nuclear offline; and are replacing coal by gas (so they depend even more on Russia) instead of replacing it by nuclear or renewable. They produce 3x the CO2 of France, despite their commit
23.
by Gondolin 7y ago
Of course I am not stating that billions of death would happen overnight, like if we had a supervolcano explosion. Instead, it would be gradual, over 20-25 years. But you are right that I am overstating things, when I write billions I think
24.
by Gondolin 7y ago
Renewable are a way better source of energy than nuclear power and we should definitively invest on them. But currently they does not suffice (because we don't have enough energy storage capacity). So we need nuclear both - now, to com
25.
by Gondolin 7y ago
Again, coal related death are of the order of 1-5 millions by year. By contrast the worst estimate for Chernobyl is 200000 deaths. The closing of germany's reactor, which amount to around 60GWh, if it had been used instead to close c
26.
by Gondolin 7y ago
I am flabbergasted that some commenters here argue against nuclear because of waste and accidents, while ignoring that - coal produce radioactive waste too - it kills a lot more persons (without taking into account global warning) due to ai
27.
by Gondolin 8y ago
Any matrix implementation (with fast exponentiation) is going to be much faster, even in a "slow" language. For instance, in ruby, `Matrix[[1,1],[1,0]] * * 46` is instantaneous (real time: 0.000131s). We have to go up to the ten m