Name: 電子會在絕對零度移動嗎？ (Do electrons move at Absolute Zero?)
Uploaded: 2021-01-14T10:32:06.000Z
Duration: 8 min 26 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

So if we consider with my my little set of atoms gone when the atoms go all right, if the absolute zero all movement stops, does that include the orbiting electrons around the nucleus of an atom?

程度副詞

No, that's a really, really good question, cause that embodies, I would argue At least three modules were electro modules worth of material.

First of all, at the absolute zero of temperature, you can't get there.

But even if you could, and people and get down to very low temperatures, the electrons are still whizzing around.

There are fluctuations in particles on dhe, their summer caused by thermal ex citations that the temperature that you've just talked about and some are just intrinsically quantum mechanical.

And so even if you call the system to absolute zero, which you can't.

But if you could, then they'd still be the quantum fluctuations.

And I think therefore they could still be effectively orbits around.

First of all, you can't reach absolute zero on.

You can look at that actually put aside, all the quantum mechanics toughen.

Let's just look at the thermodynamics that was done centuries ago.

Something called the third Law of thermodynamics Loosely stated, and I don't wantto raise the ire off all the professional physicists loosely stared about.

The third law tells us, is that you can never in a finite number of steps, you can never reach absolute zero at high temperatures, the atoms of vibrating quite strongly about their equilibrium positions these weaken regard.

These little bonds here is being like springs, and so the atoms of vibrating.

And then as we cool down, these vibrations get less and less and less.

But even as we approach up zero, we can never get rid of the zero point energy motion.

So the atoms will still have this zero point energy emotion associated with quantum mechanics.

At the quantum mechanical level, we have the Heisenberg uncertainty principle in the Heisenberg uncertainty.

Principle tells us we can never precisely know the position of something because we know precisely the position, often electron.

Then we have a huge uncertainty and its momentum and a huge uncertainty in its energy, which means it could in principle, how about you know a very, very large energy according to quantum mechanics.

Again using Heisenberg's uncertainty principle, electrons are confined in a small space in the atom so called ball radius, which is about 10 to the minus 10 meters on again, according to the laws of quantum mechanics.

If they confined in that space, um, they have strongly confined in there for listen, uncertainty in the momentum and velocity, So they certainly wanted rest, even at absolute zero Quantum Mechanically, you still have vibration because you have a small amount of uncertainty about where the position of an electoral nucleus or anatomies if the universe is expanding slower than the state a lot.

Why hasn't the light from the Big Bang already passed us?

It's a mistake to think of the Big Bang happening at a particular place.

It's just at the time, everywhere was very close together, and since then, everywhere has been flying apart from everywhere else.

But of course, we were kind of in the middle of the Big Bang when it happened, because we wanted part of that everywhere.

And so the explosion, the light that that explosion created was all around us then, and it streamed away from us.

But bits of the explosion that we're not where we are has been travelling towards us, and some of that's arrived.

The Big Bang is, isn't isn't at a fixed point in the unspecified you like.

It's not that it happened there and it didn't happen everywhere else, space and time are created from the big Bang.

So if you like, as the universe is expanding, its always got a remnant of the big Bang in it, and we actually see it.

Is this thing called the cosmic microwave background?

The cosmic microwave background is very weak.

Source of light is very wimpy sort of radio waves, because the explosion has calmed down a lot just cause of the expansion of the universe.

In fact, you can see it for yourself if you turn on your television and it's not tuned to any particular channel.

So you just see that fuzz on the screen about 1% of the little fuzz that you see there the parent noises.

Actually, your television detecting cosmic microwave background photons.

So you can actually see the light from the big Bang yourself.

This is the beauty of looking out in astronomy.

What we're not only looking out at distances were looking back in time.

And so one way of thinking about if you if you imagine where it a the center of a big sphere on dhe the surface of that sphere is is that blanket of radiation, and it's just propagating to us and its proper getting from all directions.

So so now you can see that whichever direction you look, you're going to be able to see some remnants of this radiation It.

I mean, it does interact with each other, and in some sense it does go pastors.

But it's also coming from other directions that one of the most amazing things about this radiation, of course, is that it's still uniform it Zoe almost completely uniform in temperature.

That's showing that the universe is what is called ice a tropic.

If I look out that direction far enough and look out in that direction far enough and can measure the temperature of the radiation coming back towards me, it's it's almost the same.

It's the differences between that radiation.

Once you've taken out certain effects, like the fact that when moving through the Milky Way and stuff like that once you once you take those out, those differences in those temperatures is is only about 10 to the minus four degrees.

Well, I love playing cricket, not batting, but I always love.

But Laboulaye, when I was a kid, I wasn't very good, but I did.

Yeah, making batsman hurry a little bit, but I was never very good at it, but a great fun I used to be.

I play football with all the boys and enjoy myself, and I haven't kicked me out yet, so I guess that's okay.

A side football team used to play football at my college has a go people.

This was kicked him by one of my defenders.

I actually think physical exercise is bad for you to keep away from.

Keep away from it if we didn't do it even more, child, I used to play five a side football and I've got a a knee bandage on still because I interrupted the ligaments in my knee.

But unfortunately, sooner or later it caught up with me and I ended up falling awkwardly and tearing a whole bunch of ligaments.

Which kind of put into it, Am I good at sport?

I used to be a rower and I used to be a runner, and I'm trying to become one again.

So when nature tells you that you really can't walk around without a bandage, you give up the sports I love spot on.

I would like to think I'm really good at it, but I'm no good enough thio have ever I played at school and I played at university and I represented my local town It's swimming.

I was all right, but I never I never made it to the full level of professional in anywhere Near is good.

My father bought two tickets for the World Cup in 1966 on Dhe.

He would go with either me or my brother in law in on Dhe.

As it turns out, as my brother in law reminds me in, didn't go to the cup final, I did.