There actually wasn't any appreciable fallout after the atomic bombs were dropped on Japan. Fallout is mostly generated when a bomb explodes close to the ground so that its neutrons are able to reach and transmute that ground into radioactive isotopes. The bombs dropped on Japan exploded high up to affect as large an area as possible. Many people suffered terribly from the ionizing radiation produced by those bombs, but all that damage was inflicted in the first microseconds immediately after the bombs detonated.
It's unfortunate that we only have one vocabulary for radiation to cover both a 100 uS dose of fallout and a 10 S one. If a quantity of rock drops on someone we have different words like "pebble" and "boulder" that tell us how concerned we should be. I was shocked to learn that "fallout" in the context of a nuclear war could mean something that could cause you to die in hours, not raise your lifetime risk of cancer somewhat.
At the time (the 1950s) evidence from fruit flies was essentially all the evidence there was. But as the article points out we have pretty good data showing it works the same way in humans.
Even before Linear No Threshold was a thing scientists were doing experiments showing that dosing fruit flies with radiation all at once would lead to a highly mutated second generation, but spreading that radiation out over the course of a month wouldn't.
I wish they wouldn't call these "open source" models. The output weights are open but that's more analogous to a binary. The source would be the training data and techniques that went into producing the binary/weights.
"Open weights" is also a term in wide use and accurately tells us what we're getting.
Except for a brief spike during Covid unemployment has been below 5% for a long time which has led to more wage growth for cooks and waiters than for programmers.
In all of human history nobody has ever had a glass of water with literally no arsenic in it, there are trace amounts in every lake, river, and well. Even the ultra-purified water used in bleeding edge semiconductor fabrication has a lot more than 1 atom of arsenic per glass. In the far future humanity might obtain the technology to create water with literally no pollutants in it but that age has yet to arrive.
Yeah. I don't have any doubts that this is something that can be done. But doing it cheaply enough to be worth while is the difficult bit. Elon does have reputation for delivering impressive things, but not for finishing them on the deadlines he sets.
Nobody (sane) is talking about putting nuclear reactors on Satellites in close Earth orbit so we don't have to worry about them generating heat. They've got solar panels that move some of the solar energy they absorb to a central location which presents problems in moving the waste heat back out so that spot doesn't get too hot. But that doesn't change the overall equilibrium temperature.
.03ns is a frequency of 33 GHz. The chip doesn't actually clock that fast. What I think you're seeing is the front end detecting the idiom and directing the renamer to zero that register and just remove that instruction from the stream hitting the execution resources.
There's been a lot of churn over the years but additions being done in the same timeframe as XORs has been pretty constant. The Pentium 4 double pumped its ALU but both XORs and ADDs could happen in a half cycle latency. The POWER 6 cut the FO4s of latency in stage from 16 to 10 and kept that parity as well. When you need 2 FO4s for latching between stages and 2 to handle clock jitter at high frequencies the difference between what a XOR needs and what an ADD need start looking smaller, particularly when you include the circuitry to move the data and select the instruction. Maybe if we move to asynchronous circuits?
For a 32 bit number you're looking at going from using 256 to ~1800 transistors in the operation itself. A modern core will have roughly 1,000,000,000 transistors. Some of those are for vector operations that aren't involved in a xor or sub, but most of them are for allowing the core to extract more parallelism from the instruction stream. It's really just a dust mote compared to the power reduction you could get by, e.g., targeting a 10 MHz lower clock rate.
There's a structure called a carry-bypass adder[1] that lets you add two numbers in O(√n) time for only O(n) gates. That or a similar structure is what modern CPUs use and they allow you two add two numbers in a single clock cycle which is all you care about from a software perspective.
There are also tree adders which add in O(log(n)) time but use O(n^2) gates if you really need the speed, but AFAIK nobody actually does need to.
That's all true, but on any modern x86 processor both the single pair of gates for the xor and the 10 or so for a carry-bypass 64 bit wide subtraction both happen with a single clock cycle of latency so from a programmer's perspective they're the same in that sense. There's still an energy difference but its tiny compared to what even the register file and bypass network for the operation use, let along the OoO structures.
There's only a few grams of hydrogen in the reactor's plasma, it's reaction with oxygen wouldn't be much more exciting than just losing containment. There are engineering challenges that have to be addressed but no worse than the 6 MW research reactor I used to walk by every day to my college classes in the middle of a dense city.
The proliferation risk of someone using the neutron flux to produce an atomic or dirty bomb are real but that exists no matter where it is.