Prática de Shadowing: FINALLY: A Proof that Particles Take All Paths At Once? - Aprenda a falar inglês com vídeo

Quantum particles can take every possible path at the same time.

This is an 80 -year -old interpretation of the mathematics, which comes from Richard Feynman.

But now a team of physicists in China say they've shown that this is more than an interpretation.

They say they've experimentally proved that this is physical reality.

So can we finally stop arguing about the interpretation of quantum physics?

That'd be huge progress.

I mean, it's only been 80 years by physics standards that's basically express delivery.

Let's have a look.

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In ordinary physics, if you throw a ball, then the ball takes one particular path, depending on its initial place and velocity.

That's if you throw the ball.

If I throw the ball, I'll tear a body part I didn't know exists, and then the ball will get lost in the bushes.

Still, physicists insist it's all strictly deterministic.

In quantum physics, this isn't the case.

Rather, Feynman said, what you do for a quantum particle is that you look at every possible path,

not just the straight connection from a start to an end point, but every connection.

For each path, you calculate a quantity called the amplitude.

You sum them all up and from that you get the probability of the particle to go to a particular place.

But just where it goes isn't determined.

It's called a path integral, and Feynman showed that it gives the same result as using the wave function and the Schrödinger equation.

But the neat thing about Feynman's method is

that it gives you a visual interpretation of what's going on and also tells you exactly what's so strange about quantum physics.

The particles can go all these different paths at the same time.

Or do they?

This condenses 80 years of quantum foundations into three words.

A lot of physicists think that yes, this is really what the particles do and not just this.

Many of them even think it's evidence that we live in a multiverse.

For example, a press release from Google about their quantum computer claimed they'd done an experiment that, quote, gives credence to the notion

that quantum computation occurs in many parallel universes in line with the idea that we live in a multiverse, a prediction first made by David Deutsch.

The problem is that by construction of the path integral, you can never observe the paths.

You only have observed the particle at the final point.

If you were to observe the particle in between, then you'd only ever observe one path.

The authors of the new paper now say they've shown that, yes, the particles actually go all these paths.

In their own words, the paths are, quote, more than mere mathematical artifacts and reflect a physical aspect of quantum reality.

Let me be clear, the question is not whether Feynman's path integral is correct or not.

It makes, provably, the same predictions as Schrodinger's formalism.

It's been tested a million times and we know it works.

The question is whether we can experimentally settle what really happens.

So what did they actually do in their experiment?

They used single photons one at a time.

They let the photons travel from one place to another and put a grid of measurement locations in between,

basically, 17 along the direction of travel and 5 transverse to it.

They take two of these grid points and measure what the amplitude of the photon does between them.

And that, they find, fits exactly to Feynman's prediction.

So, New Scientist writes, Richard Feynman's 80 -year -old quantum postulate has now been validated.

Okay, but in this case, the New Scientist article is more reasonable than the paper itself.

Does it validate Feynman's path integral?

Yes, totally.

It's a beautifully direct confirmation that the math really adds up the way he said.

Then again, no one doubted this in the first place.

Does it prove that the particles really go all possible paths when no one looks?

No, of course not, because they didn't find out what the particles do when you don't measure them.

They put in additional measurements just to then find that the particles were at one particular path, which again, no one doubted.

So I'm sorry, but I give this paper a 9 out of 10 on the bullshit meter.

Nice experiment, all right, but crappy interpretation.

Why am I telling you about this anyway?

It's because this is a neat illustration of why the foundations of physics are stuck.

The problem that these guys tried to answer is the exact same problem

that Albert Einstein tried to answer already and failed and which John Belvin tried to answer.

Namely, does a quantum particle really do all the things at the same time

when we don't look or does it really only do one thing?

So not only did the authors of the paper misunderstand the task, they also didn't realize that this is exactly what Bell's inequality is about.

Now, as I've said many times, the conclusion from Bell only follows once you postulate that superdeterminism is ruled out, which has never been ruled out.

So actually, the current situation is still inconclusive, but experiments like the one in the new paper won't settle it.

So in summary, Richard Feynman is still right, we still don't know how to interpret quantum physics, and John Bell is still dead.

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Thanks for watching.

See you tomorrow.

O que é a Técnica de Shadowing?

Shadowing é uma técnica de aprendizado de idiomas com base científica, originalmente desenvolvida para o treinamento de intérpretes profissionais. O método é simples, mas poderoso: você ouve áudio em inglês nativo e repete imediatamente em voz alta — como uma sombra seguindo o falante com 1-2 segundos de atraso. Pesquisas mostram melhora significativa na precisão da pronúncia, entonação, ritmo, sons conectados, compreensão auditiva e fluência na fala.

Prática de Shadowing: FINALLY: A Proof that Particles Take All Paths At Once? - Aprenda a falar inglês com vídeo

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O que é a Técnica de Shadowing?