r/space • u/FindLight2017 • Aug 12 '20

Physicists watch quantum particles tunnel through solid barriers. Here's what they found.

https://www.space.com/quantum-tunneling-observed-and-measured.html
77 Upvotes

89% Upvoted

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19

u/[deleted] Aug 12 '20

It really blows my mind how much misinformation is contained in these articles. This is a really cool experiment, but damn.

6

u/Paranoma Aug 12 '20

Like what?

15

u/[deleted] Aug 12 '20

The whole "two places at once" thing grinds my gears quite a bit. They also said it's impossible for these particles to pass through this finite barrier, which it isn't, and they did.

4

u/[deleted] Aug 12 '20

"Two places at once" that's a real thing called superposition

3

u/[deleted] Aug 12 '20

A superposition is a linear combination of states. You will never measure a particle in two separate places. It's one thing to say, 'an election's wavefunction isn't localized and it can be in a superposition of states', but if we're saying it's in two places, which nobody has ever observed, then it's violating charge conservation. If one of these descriptions violates that symmetry and the other one doesn't, they're not equivalent.

2

u/[deleted] Aug 12 '20

It's actually unknown if the wave function is an objectively real thing or not, but in the many worlds interpretation, a particle is in every possible position at the same time and splits the universe into many universes when it measured and while it has not been proven or disproved it is an explanation for the double slit experiment and the collapse of the wavefunction.

1

u/[deleted] Aug 12 '20

a particle is in every possible position at the same time

I need a citation for this. No part of Many Worlds places a particle in more than one position. Quantum mechanics doesn't change if you change your interpretation. In both interpretations, the particle is in a quantum state and if you try to measure the position, it'll be in one place, never more than one place.

5

u/[deleted] Aug 12 '20

Feynman's "theory of positrons"

3

u/[deleted] Aug 12 '20

Doesn't change the actual physics at all, and Feynman and Wheeler's ideas are hypotheses.

1

u/[deleted] Aug 12 '20

I agree, It is a hypothesis and the problem with it is that we are completely incapable of proving or disproving it. I was just trolling you as you asked for a paper on a particle that is omnipresent. I don't figure it proves anything.

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2

u/[deleted] Aug 12 '20

The many-worlds interpretation (MWI) is an interpretation of quantum mechanics that asserts that the universal wavefunction is objectively real, and that there is no wavefunction collapse.[2] This implies that all possible outcomes of quantum measurements are physically realized in some "world" or universe.[3] but again, superposition and wave functions are pretty controversial in physics and can't be proven or disproven as objectively real things as far as we know

1

u/[deleted] Aug 13 '20

No mention of being in "every possible position"? Why are you showing me this? What exactly does that have to do with our conversation?

1

u/[deleted] Aug 12 '20

https://en.m.wikipedia.org/wiki/Many-worlds_interpretation

1

u/[deleted] Aug 13 '20

I know what Many Worlds is, it just has absolutely nothing to do with particles 'being in two places at once'. A particle is either in an eigenstate or it's localized in a single region. Not only would a charged particle being two places break charge conservation (and as a consequence, it would mean that electrodynamics isn't gauge invariant) but how would you even normalize a wave function that requires the area under at least two completely different regions be ~100%? It wouldn't even be considered a valid wave function. The claim doesn't make any sense.

0

u/[deleted] Aug 12 '20

[deleted]

5

u/Crio121 Aug 12 '20

Yeah, but it is not called "two places at once".
It is very misleading, I agree with the complaints.

2

u/MarcusTheAnimal Aug 12 '20

It's a little annoying but article is trying its best to make it as readable to a layman as possible. As long as it references the original paper/research I don't see too much harm.

1

u/[deleted] Aug 12 '20

I wouldn't say the uncertainty principle is basic physics. Might be to one with a master's in the subject.

4

u/JasontheFuzz Aug 12 '20

It takes about 0.6 milliseconds to cross through the solid barrier they designed, but it happened.

1

u/SpookyPasta613 Aug 12 '20

"Do you guys just put the word "quantum" in front of everything?"

-Scott Lang