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Comment Just read the paper (Score 1) 111

and it's rather worthless. In a nutshell, they can prove that a quantum computer was used to generate a specific set of random numbers. No problem with that. But, there is no guarantee that those random numbers weren't copied and sent to another party. So, for crypto purposes, the resulting random numbers are worthless.

Comment Re: Depends, how much fuel per reactor? (Score 1) 190

You might want to do a bit more research about weapon grade plutonium. Pu-239 is used for weapons. And to get it out of a reactor, the uranium fuel is left in the reactor for a relatively short time. The reason is because Pu-239 easily absorbs another neutron and becomes Pu-240, which is quite unsuitable for weapons because it spontaneous fission far too frequently. In fact, it was this Pu-240 contamination that mandated the use of an implosion bomb such as fat man, instead of the simpler tall man device. If you leave the fuel in the reactor long enough, the resulting plutonium will have far too much Pu-240 to use for weapons, while still being perfectly suitable for power generation.

Comment Reasonable. (Score 5, Insightful) 56

One of the biggest things that prevent a superscalar out of order processor from being fully utilized is data dependencies between instructions. For, instance, assume you have a 4 way out of order processor and want to calculate:
A = B*C + D*E
There's three math operations in there, and you can do up to 4 at a time, so you ought to be able to issue all three operations at the same time, right? And the answer of course is "nope", because you can't issue the addition until after the results from the two multiplications have already completed.
So, let's assume that you have a idealized 4 way superscalar processor with out of order execution and every instruction will take just 1 clock cycle. But, the average code that the processor sees will 100% of the time be able to execute at least 1 instruction, 50% of the time at least 2 instructions. 25% of the time at least 3 instructions, 12.5% at least 4 instructions, and so forth, halving the percentage of the time that N+1 more instructions can be executed. So, on average, how many instructions per second will this processor handle?
Doing, the math, you'll see the answer is 1.875 instructions per clock cycle. So, in other words, less than half the theoretical capacity of the chip. Now, there is some specialized code that can fully utilize the capability of saturating all 4 execution units, such as matrix multiplications and such. But the average code has that 100/50/25/12.5/.... pattern.

Now, assume you want a faster processor. Adding the ability to execute 5 instead of just 4 instructions at a time would speed things up. So, instead of an average of 1.875 instructions per clock, we get 1.9375 instructions per clock and waste an even larger percentage of the possible power of the chip. The limit would be 2 instructions per clock.

But, if you add a completely separate set of registers and execute a completely independent thread, so that the two threads don't share any dependences with each other, we get, with the same code base, on average, 3.25 instructions per clock, with 1.625 instructions per clock on each thread. So, by going to hyperthreading, we increase the system performance from 1.875 instructions per clock to 3.25 instructions per clock (a 73% increase), but decrease the per thread performance since the two threads are competing with each other for execution resources.

So, yes, dropping hyper threading support will increase single thread performance. And will lower power requirements since more of the chip is idle since it will usually not be capable of using its full capacity due to data dependencies between instructions. Seems a reasonable compromise since a laptop isn't a server handling multiple high computational tasks simultaneously.

Comment Re: For anyone who cares about how it actually wo (Score 1) 176

Try to actually think about what you just said. If you used that net to capture and accelerate a slower ship, the energy required would have to come from somewhere. Effectively, in accelerating the passengers and associated cargo, you've decelerated the cycler and that energy loss needs to be compensated.

An Aldrin Cycler does not save any delta V. What it does is establish relatively spacious living quarters for humans to spend their time in during the trip. But the delta V and hence fuel to move those passengers, cargo, and consumables is not decreased by using a cycler.

Comment Re:For anyone who cares about how it actually work (Score 1) 176

You don't seem to understand a basic point about an Aldrin Cycler.
Namely, it doesn't save any fuel. The reason it doesn't save any fuel is because you have to rendezvous with it, expending all that delta V. Now, that doesn't make a cycler useless. It's still quite useful in that the passengers don't have to rendezvous with massive spacecraft capable of supporting them for the entire trip. They just need to use a spacecraft that has them, plus all the consumables needed for their trip and don't need to have any passenger accommodations greater than what they need for the hours to days needed to rendezvous. So, an Aldrin cycler doesn't save any fuel or delta V. What it does allow is for spacious living accommodations in which to live while spending time for the journey. And since those living accommodations are reusable for multiple trips, they only have to be accelerated once to handle all those trips.

Comment Re:Question (Score 1) 36

These are not your typical batteries. They're Nickel Hydrogen batteries. In a nutshell, they consist of a high pressure enclosure (~500 psi) filled with hydrogen gas, as well as the nickel based electrodes. See https://en.wikipedia.org/wiki/... for details.

Definitely not something that's easily broken apart.

Comment Re: Text of bill (Score 1) 50

Nice. But it looks like the bill is mostly political fluff. For instance, what purpose does the following quote have in regards to setting any standard of care in AI development?

California is leading the world in artificial intelligence innovation and research, through companies large and small, as well as through our remarkable public and private universities.

The above quote sounds like something in a Chamber of Commerce press release instead of a proposed law.

In any case, upon further reading, the true purpose of the bill is shown in section 5 where it establishes CalCompute. The rest of the bill is mere fluff.

Comment There is a way to easily store and use (Score 2) 34

I would agree that making and storing liquid hydrogen is costly and dangerous. Additionally, there's issues with leakage when it's in its gaseous form. But, there is a form available that has a proven history of ease of use as well as easily stored. Simply combine with carbon to produce chains of carbon. By using different lengths of chains, one can create anything from an easily used gas that can be liquified at room temperature as well as easily burned liquids that are liquid at room temperature and atmospheric pressure. If one is worried about carbon dioxide, the obtain the required carbon from atmospheric carbon dioxide, making the storage, transportation, and usage carbon neutral.

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