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Quantum Physics Just Got Less Complicated
wabrandsma sends this news from Phys.org:
Here's a nice surprise: quantum physics is less complicated than we thought. An international team of researchers has proved that two peculiar features of the quantum world previously considered distinct are different manifestations of the same thing. The result is published 19 December in Nature Communications. Patrick Coles, Jedrzej Kaniewski, and Stephanie Wehner made the breakthrough while at the Center for Quantum Technologies at the National University of Singapore. They found that wave-particle duality is simply the quantum uncertainty principle in disguise, reducing two mysteries to one.
"wave-particle duality is simply the quantum uncertainty principle" gets a "no shit" straight away from me, though I guess a rigorous proof of it is kind of news.
Shhh. Don't make waves. :-)
"Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
TFS is so stupid there's no way I'm going to RTFA.
Comments like this are like urine stains on the wall next to public urinals. They appear so often and so consistently you'd think there was a contest, where the first one to miss, wins.
<blink>down the rabbit hole</blink>
Seriously guys, we need to drop the copenhagen interpretation already. Pilot-wave theory eliminates the need for quantum mysticism.
"Violence is not the answer. Violence is the question. The answer is yes."
Of course! This clears up everything! Now I understand quantum physics completely!
When someone says, "Any fool can see
Wow, loving all the ACs calling this obvious, who clearly didn't even make it to the abstract! "Such wave-particle duality relations (WPDRs) are often thought to be conceptually inequivalent to Heisenberg's uncertainty principle, although this has been debated."
Clearly, all you armchair physicists need to set those ivory-tower morons straight!
Here we show that [wave-particle duality relations] correspond precisely to a modern formulation of the uncertainty principle in terms of entropies, namely the min- and max-entropies. This observation unifies two fundamental concepts in quantum mechanics. Furthermore, it leads to a robust framework for deriving novel WPDRs by applying entropic uncertainty relations to interferometric models.
So they're looking at it in terms of entropies, and when they do, it resolves a debate about whether WPDRs are equivalent to the Uncertainty Principle AND generates new WPDRs.
There is a wide gulf between suspecting two phenomena are related, and having discovered the rigorous mathematical framework that lets you translate discoveries from one theoretical framework to the other without losing information.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I'd love to read a real comment (yeah, I know, it's almost like I'm new here) from someone who is actually capable of understanding the math here. It would be great to see a reasonable discussion on the actual implications here.
As to people saying "that's obvious" -- what you can intuit and what you can prove are not the same thing. The only thing prove by a "that's obvious" comment is that the person posting it doesn't have a clue.
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
If something gets simpler, the entropy of the universe decreases. It can't happen. It is the law, everything should get more and more complicated as time goes by. Why, the next generation will have easier time to pass Quantum Mechanics I PH304 MWF 10:00-11:30 than I did? Would not stand for it.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
"wave-particle duality is simply the quantum uncertainty principle" gets a "no shit" straight away from me, though I guess a rigorous proof of it is kind of news.
That's how science work. You don't base your decision on the mere principle that it more or less looks kind of logical.
(After all, it only looks "kind of logical" to your *brain*, which has spent the last few million years being optimized to help bipedal monkey survive together in the savanah. Actual science can some time feel "weird" and defy logic, because it defies the monkey-brain logic. - e.g.: the sum of all positive integer is a negative fraction)
You do thoroughly prove that by the numbers.
Yes, the double-slit experiment (where single particle behave like waves) strongly suggest that the uncertainty principle is at work (there's not *a signle photon* going through the slits, it's instead a function showing the distribution of the probabilities to pick it up at a certain place).
Now, we have mathematical proof that's indeed the case.
Science: the only place where it's actually correct to spend the time and mental ressource to formally prove that water *is* wet, and fire *does* burn. Because, along the way, you develop mathematical tools which come handy to do more advanced science.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
There's a gravity wave experiment in Poland looking at the simulation question. They've found our universe to cheat between the minimum length that would need to be simulated and the Plank length - it's all noise down there where we expected to find signal.
There could also be an undiscovered reason, but the shape of the noise matches to a few sigma that predicted by the 'spherical projection' simulation model, so that's a good place to look.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
Ok, let me give this a crack.
You build a box. That box contains a Geiger counter, which clicks if it detects the decay of a particle. Because you're a sick, sadistic fuck, you hook up that Geiger counter to a hammer such that if the Geiger counter detects the decay, it engages the hammer to smash a vial of poison, thus releasing it into the box. You then--because, as I said, have issues with sociopathy--put a cat in the box and close the lid. The box is very thick, completely opaque and completely soundproof. You have no way of knowing what's going on inside the box.
You wait an hour. In that hour, you do some maths that shows that there was a 50% chance that the particle decayed, triggering the Geiger counter, which triggered the hammer to break the vial of poison, releasing the gas and killing the cat.
The question becomes: before you open the box, is the cat alive or dead? Or is it somehow...both?
Your gut instinct is to say, "That's stupid. Of course it's either alive or dead. How the fuck could it be both?"
But the thing is, there are certain, non-cat-related experiments that we've done that REQUIRE the answer to be BOTH. Perhaps the simplest (and certainly the one we physicists learn about first) is the double-slit experiment. The basic idea is, you shoot a beam of something (light, gold atoms, DNA, doesn't really matter) at a slit, and it forms a pattern on a wall. It'll form this pattern even if you shoot your particles one at a time. Then, you close that slit and open another one, and fire your beam again. It forms a different pattern.
Now you open BOTH slits and fire your beam. What happens? Well, what you'd expect is to get a pattern that's the SUM of the pattern you get through each slit. That corresponds to the idea that the particles each go through either Slit 1 or Slit 2. But instead what you get is an INTERFERENCE pattern, which can ONLY happen if the particles are going through BOTH HOLES. And recall I said earlier--you get the same pattern even if you shoot your particles one at a time, which means THE PARTICLE MUST BE INTERFERING WITH ITSELF.
So back to the cat: is it alive or dead, or is it alive AND dead? According to the Copenhagen Interpretation, it's both. But that's why the cat thought experiment was devised in the first place: to highlight how RIDICULOUS that was. The crazy thing is that, seventy years later, we don't really have a better interpretation (at least not one that's widely accepted). So until someone builds this possibly-cat-killing box, we won't really know if the Copenhagen Interpretation is right, or whether something even stranger goes on when quantum events get amplified to the macro level.
One final note: practically speaking, there's no way to build this experiment, because of the whole "you have no way of knowing if the cat is alive or dead without opening the box" part. Isolating a system as big as a cat-box from the rest of the universe is not really feasible. You would also have to construct a particle decay detector that did not, itself, "collapse" the waveform of the decaying particle (otherwise the paradox is resolved before you ever make it to the cat).
Hope that was helpful!
I'm not sure I see what you did there...
Oh, now I do. Not sure where you're going with this, though..
You have a good point...
it's actually a set of points, but the correct point can't be observed without changing it's velocity.
Maybe you're thinking of The Feynman Lectures (which is college-level)? In Volume 3, Section 2-2 of his lectures, Feynman shows the deep relationship between the uncertainty principle and wave-particle duality. Feynman sez:
Now this property of waves, that the length of the wave train times the uncertainty of the wave number associated with it is at least 2, is a property that is known to everyone who studies them.
.: Semper Absurda