Posted on 01/02/2021 8:54:00 PM PST by BenLurkin
It’s not just about speed. Quantum computers can solve problems that are not possible to solve on regular computers, or would take thousands of years to complete.
Yeah that’s when I ask for the check please :)
I just read a little about it. Somehow frozen molecules, if they have enough energy, will evaporate even at 0 degrees celsius.
That’s where I stopped reading :)
Yeah I read that encryptions that would take today’s computers 200 to 400 years to crack will take 2 to 4 hours for quantum computers to crack.
I guess updates will need to be made to protect sites. Not in the near future, I don’t think.
Or maybe. I don’t know :)
Does that mean the cat can finally be let out of that box and continue to live its lives?
I’m with you - when even the “simple concepts”, that we know we can grasp, become incomprehensible, it’s time to let the egg-heads work it out.
I also remember furiously scratching my head when scientists asserted that even Black Holes could “evaporate” and lose mass.
Don’t get discouraged, it’s truly not that complicated. Liquids at temperatures below their boiling point will evaporate; that’s certainly a familiar concept. Solids can do the same. It’s also possible for a solid to change directly into a gas without passing through the liquid phase, again think dry ice (that’s why we call it dry ice). Why can dry ice do this but not regular ice?
The answer is pressure. Dry ice is actually solid carbon dioxide. In order to exist as a liquid, any substance needs to have a certain amount of pressure to do so. There are no liquids in a vacuum. If you try to put water, for instance, in a closed, evacuated container, the water will boil, even at room temperature. If you have enough water and a tight container, it will eventually stop boiling. That’s because the water vapor in the container will exert a pressure and allow liquid water to exist. The pressure at which this happens is called the vapor pressure, and it depends on both the temperature and the identity of the substance.
This is not limited to liquids, but also occurs for solids. The vapor pressure of most solids is very small, though, so we don’t notice solids changing to gases very often. In the case of dry ice though, the vapor pressure is higher than atmospheric pressure at all temperatures above -78C. Thus dry ice evaporated. It does not melt, though, because of another pressure, the critical pressure. The critical pressure of each substance is simply the minimum pressure needed to have a stable liquid form. For carbon dioxide the critical pressure is far above atmospheric pressure, so we don’t see liquid carbon dioxide. The liquid does exist, but pressures must be high enough. If you buy pressurized tanks of carbon dioxide for a soda fountain, those tanks actually contain liquid carbon dioxide.
When talking about phase changes, we are accustomed to thinking that changes in temperature cause them, but as discussed above, pressure can also do so. You can boil liquids by reducing pressure. You can also liquefy gases by increasing pressure. Ice skating works because water is strange - increasing pressure on the solid makes it melt. The skate blade exerts a large pressure on the ice causing a temporary layer of liquid water to form and you can glide on that water. The triple point of any substance is a condition of BOTH temperature and pressure that allows all three phases to exist at once. If you’ve seen a triple point cell, it is actually evacuated to a low pressure. Both the temperature and pressure must be maintained to keep the equilibrium. Tapping on it changes the pressure.
It only seems complex because we live our entire lives within a very narrow range of ambient pressure. Varying the pressure is the cause of all these phenomena that you find unfamiliar.
The only problem is you just posted your objection to quantum mechanics using a device that can only function if quantum mechanics is correct. Your opinion of whether it makes sense or not is irrelevant; ALL experimental data is consistent with quantum mechanics and inconsistent with classical physics, even including relativity. QM may not be the final theory (and almost certainly is not because of its inconsistency with general relativity), but any new theory will contain QM as a limiting case, much like both QM and relativity contain classical mechanics as a limiting case.
The answer was 42.
hanks - now I feel even dumber...
Just kidding - I can grasp a lot but when my impression of Black Holes was always, “Nothing can escape, not even light”, it was a bit perplexing to find out they can “evaporate” too.
* * *
Nothing escapes is actually a very good approximation. The phenomenon that you refer to is Hawking radiation and it’s extremely weak. Essentially general relativity says nothing escapes, but when you factor quantum mechanics in that’s no longer strictly true. QM says that in high energy environments a particle-antiparticle pair can form. Just by chance, occasionally they will form with one on each side of the black hole event horizon, allowing one to escape. It’s very rare and quite weak, so nothing escapes is still a pretty good approximation
Thank you for that informative post. It’s been so long since my school days I’ve forgotten much.
AI also solved the Schrödinger’s Cat paradox.
It killed the cat before putting it in the box.
Correct.
But eventually, all black holes will wink out.
Quadrillions or quintillions of years will pass, but they, too, will disappear.
“By my calculations, the easiest way to help a human is simply to destroy it. There’s no point in prolonging a laughably fragile life.”
My son is studying physics at UA Huntsville.
I bookmark this stuff to send to him and to read myself so I can talk to him.
Thank you - that actually clarified it in my mind.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.