Foucault pendulum : My point of view

I want to know more about the perpetual motion machine at the Smithsonian Institute.

If that were the case, perpetual motion should be easily achieved on earth simply by placing a pendulum in a vacuum. So why has perpetual motion not actually been achieved?

(And, yes, I am aware that there is a "perpetual motion machine" I n the Smithsonian, but it is slightly more complex than it should be, according to your explanation.)

Because we have no perfect vacuum, in fact, they are impossible to achieve.
As such, there will always be some air resistance.
And then we get the other issue, friction/ energy loss in elastic materials.
If the string/whatever doesn't remain straight, such as because it is mounted in a fixed orientation, then it will flex. This flexing will cause it to heat up, losing some of the kinetic/gravitational potential energy (by converting it to heat).
If it isn't fixed, and instead the mounting point can pivot, then you get energy loss due to friction.

The closest we can get to a macroscopic perpetual motion machine is that of a large flywheel suspended by a magnetic bearing in as good a vacuum as we can make.

But even then, it isn't a perfect vacuum and there may be some interaction in the bearings, not sure.

Another possibility would be a photon (or a stream of them) travelling around a loop, but even then the material of the loop would absorb the photons over time, and you wouldn't see it anyway.

The only "real" perpetual motion machine we can get are quantum systems where they can't lose any more energy, but at that scale calling it motion isn't really all that accurate as it no longer acts as a particle in a certain position travelling with a certain speed, and instead begins to act more like a wave.

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Quote from: Definitely Not Official on January 02, 2017, 04:07:49 AM

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Indeed, if you use concrete walls 

Scientists have already reached 100 particles per cubic centimeter, it's hard but not impossible.

Quote from: JackBlack on January 02, 2017, 01:03:51 PM

Quote from: Definitely Not Official on January 02, 2017, 04:07:49 AM

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Indeed, if you use concrete walls 

Scientists have already reached 100 particles per cubic centimeter, it's hard but not impossible.

No. If you use any walls.

Even things like solid metals or diamond are permeable via diffusion.
Various atoms/molecules can occupy interstitial sites or vacancies and diffuse through the crystal matrix and thus get into the vacuum chamber.

Even if you used a finite energy barrier, there can still be quantum tunnelling through the barrier and into the chamber.
Yes, the potential (to tunnel through) may be small, but it is still quite real, and all it takes is 1 to loose the perfect vacuum, and you have quite a large number of particles on the outside.

The only way to make it completely impervious is to have an infinite potential barrier, which simply doesn't exist.
So a perfect vacuum simply can't exist

100 particles per cubic centimetre is still 100 too many in that cubic centimetre.
It is 100 million too many per cubic metre.

We can only ever get close to one, we will never achieve a perfect vacuum.

Quote from: Definitely Not Official on January 04, 2017, 03:26:57 AM

Quote from: JackBlack on January 02, 2017, 01:03:51 PM

Quote from: Definitely Not Official on January 02, 2017, 04:07:49 AM

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Indeed, if you use concrete walls 

Scientists have already reached 100 particles per cubic centimeter, it's hard but not impossible.

No. If you use any walls.

Even things like solid metals or diamond are permeable via diffusion.
Various atoms/molecules can occupy interstitial sites or vacancies and diffuse through the crystal matrix and thus get into the vacuum chamber.

Even if you used a finite energy barrier, there can still be quantum tunnelling through the barrier and into the chamber.
Yes, the potential (to tunnel through) may be small, but it is still quite real, and all it takes is 1 to loose the perfect vacuum, and you have quite a large number of particles on the outside.

The only way to make it completely impervious is to have an infinite potential barrier, which simply doesn't exist.
So a perfect vacuum simply can't exist

100 particles per cubic centimetre is still 100 too many in that cubic centimetre.
It is 100 million too many per cubic metre.

We can only ever get close to one, we will never achieve a perfect vacuum.

Hey Jack,

I like you dude, but watch out İntikam might say that your being dishonest bescause you said "particles" a lot 

So a perfect vacuum simply can't exist

100 particles per cubic centimetre is still 100 too many in that cubic centimetre.
It is 100 million too many per cubic metre.

We can only ever get close to one, we will never achieve a perfect vacuum.

Agreed, "a perfect vacuum simply can't exist", but what do mean by too many? It depends entirely on what the "vacuum" is intended for.
But look at some typical pressures, molecular density and mean free paths.


Note in particular the values at a pressure defined as an Ultra High Vacuum, 10^-10 Torr (normal air pressure is 760 Torr).
There are still 3 x 10¹² molecules/m³, but the mean free path (average distance between molecular collisions) is 5 x 10⁺⁵ m, 500 km!
And interstellar space (according to this site) still has about 3 x 10⁺⁵ molecules/m³.

Other sites might have a bit different values, but there are very few situations where the difference between an Ultra-High Vacuum and a perfect vacuum would be significance.

PS I hope I have all my powers of 10 sorted out!

Agreed, "a perfect vacuum simply can't exist", but what do mean by too many? It depends entirely on what the "vacuum" is intended for.
But look at some typical pressures, molecular density and mean free paths.

This will depend upon what your perpetual motion machine was intended for.
If you wanted to actually keep it running forever as a perpetual motion machine, then you would need a perfect vacuum (and some other conditions).
If you just wanted it to run for an hour to show off to your friends or a class or presentation, then you could probably do with a high vacuum, or just in atmospheric pressure with a big enough fly wheel.

Quote from: rabinoz on January 05, 2017, 01:02:49 AM

Agreed, "a perfect vacuum simply can't exist", but what do mean by too many? It depends entirely on what the "vacuum" is intended for.
But look at some typical pressures, molecular density and mean free paths.

This will depend upon what your perpetual motion machine was intended for.
If you wanted to actually keep it running forever as a perpetual motion machine, then you would need a perfect vacuum (and some other conditions).
If you just wanted it to run for an hour to show off to your friends or a class or presentation, then you could probably do with a high vacuum, or just in atmospheric pressure with a big enough fly wheel.

But what is the point of this "perpetual motion anyway"?
You cannot extract any energy from it, and it will never be perpetual, because there will be the inevitable friction loss due the support.

Quote from: JackBlack on January 05, 2017, 01:42:43 AM

Quote from: rabinoz on January 05, 2017, 01:02:49 AM

Agreed, "a perfect vacuum simply can't exist", but what do mean by too many? It depends entirely on what the "vacuum" is intended for.
But look at some typical pressures, molecular density and mean free paths.

This will depend upon what your perpetual motion machine was intended for.
If you wanted to actually keep it running forever as a perpetual motion machine, then you would need a perfect vacuum (and some other conditions).
If you just wanted it to run for an hour to show off to your friends or a class or presentation, then you could probably do with a high vacuum, or just in atmospheric pressure with a big enough fly wheel.

But what is the point of this "perpetual motion anyway"?
You cannot extract any energy from it, and it will never be perpetual, because there will be the inevitable friction loss due the support.

Something fun to look at?
Also, what about a magnetic bearing?

Quote from: Definitely Not Official on January 04, 2017, 03:26:57 AM

Quote from: JackBlack on January 02, 2017, 01:03:51 PM

Quote from: Definitely Not Official on January 02, 2017, 04:07:49 AM

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Indeed, if you use concrete walls 

Scientists have already reached 100 particles per cubic centimeter, it's hard but not impossible.

No. If you use any walls.

Even things like solid metals or diamond are permeable via diffusion.
Various atoms/molecules can occupy interstitial sites or vacancies and diffuse through the crystal matrix and thus get into the vacuum chamber.

Even if you used a finite energy barrier, there can still be quantum tunnelling through the barrier and into the chamber.
Yes, the potential (to tunnel through) may be small, but it is still quite real, and all it takes is 1 to loose the perfect vacuum, and you have quite a large number of particles on the outside.

The only way to make it completely impervious is to have an infinite potential barrier, which simply doesn't exist.
So a perfect vacuum simply can't exist

100 particles per cubic centimetre is still 100 too many in that cubic centimetre.
It is 100 million too many per cubic metre.

We can only ever get close to one, we will never achieve a perfect vacuum.

Diffusion is the least of the issues, walls thick enough can be made to keep air out. Outgassing is the main issue.

Quote from: Definitely Not Official on January 04, 2017, 03:26:57 AM

Quote from: JackBlack on January 02, 2017, 01:03:51 PM

Quote from: Definitely Not Official on January 02, 2017, 04:07:49 AM

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Indeed, if you use concrete walls 

Scientists have already reached 100 particles per cubic centimeter, it's hard but not impossible.

No. If you use any walls.

Even things like solid metals or diamond are permeable via diffusion.
Various atoms/molecules can occupy interstitial sites or vacancies and diffuse through the crystal matrix and thus get into the vacuum chamber.

Even if you used a finite energy barrier, there can still be quantum tunnelling through the barrier and into the chamber.
Yes, the potential (to tunnel through) may be small, but it is still quite real, and all it takes is 1 to loose the perfect vacuum, and you have quite a large number of particles on the outside.

The only way to make it completely impervious is to have an infinite potential barrier, which simply doesn't exist.
So a perfect vacuum simply can't exist

100 particles per cubic centimetre is still 100 too many in that cubic centimetre.
It is 100 million too many per cubic metre.

We can only ever get close to one, we will never achieve a perfect vacuum.

At the BASE experiment at the LHC, they achieved a vacuum so good that they couldn't find ANY atoms in it at all, so they set an upper bound of 3 atoms per cubic centimeter. They kept it like that for at least a year, which was about how long the experiment lasted. They got rid of diffusion by cooling the walls to 6K. So it's not impossible.

Quote from: JackBlack on January 04, 2017, 01:26:43 PM

Quote from: Definitely Not Official on January 04, 2017, 03:26:57 AM

Quote from: JackBlack on January 02, 2017, 01:03:51 PM

Quote from: Definitely Not Official on January 02, 2017, 04:07:49 AM

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Indeed, if you use concrete walls 

Scientists have already reached 100 particles per cubic centimeter, it's hard but not impossible.

No. If you use any walls.

Even things like solid metals or diamond are permeable via diffusion.
Various atoms/molecules can occupy interstitial sites or vacancies and diffuse through the crystal matrix and thus get into the vacuum chamber.

Even if you used a finite energy barrier, there can still be quantum tunnelling through the barrier and into the chamber.
Yes, the potential (to tunnel through) may be small, but it is still quite real, and all it takes is 1 to loose the perfect vacuum, and you have quite a large number of particles on the outside.

The only way to make it completely impervious is to have an infinite potential barrier, which simply doesn't exist.
So a perfect vacuum simply can't exist

100 particles per cubic centimetre is still 100 too many in that cubic centimetre.
It is 100 million too many per cubic metre.

We can only ever get close to one, we will never achieve a perfect vacuum.

At the BASE experiment at the LHC, they achieved a vacuum so good that they couldn't find ANY atoms in it at all, so they set an upper bound of 3 atoms per cubic centimeter. They kept it like that for at least a year, which was about how long the experiment lasted. They got rid of diffusion by cooling the walls to 6K. So it's not impossible.

But they also had particles inside it, meaning it couldn't be a perfect vacuum.
I can also find this quote from their website:

Bakeout is a procedure in which the vacuum chambers are heated from the outside in order to improve the quality of the vacuum. This operation needs to be performed at regular intervals to keep the vacuum at the desired low pressure.

So it seems it wasn't a perfect vacuum, at least not one that can be sustained.
Also, from searching it appears the number is 150 m^3. So how many atoms would that have with the upper bound of 3 atoms per cubic centimetre.

Their gauge not being able to detect the imperfections doesn't mean they aren't there.

Also, diffusion is only one problem, you also have the issue of virtual particles.

So no, not possible.

EDIT:
After searching some more, it seems the basis of their upper limit was that they haven't noticed any proton-anti-proton annihilation events.

So I would say that is very far from conclusive.

Quote from: Definitely Not Official on January 06, 2017, 07:58:48 AM

Quote from: JackBlack on January 04, 2017, 01:26:43 PM

Quote from: Definitely Not Official on January 04, 2017, 03:26:57 AM

Quote from: JackBlack on January 02, 2017, 01:03:51 PM

Quote from: Definitely Not Official on January 02, 2017, 04:07:49 AM

Perpetual MOTION is not impossible. If people cared enough for something so utterly useless, we could theoretically construct a perfect vacuum. But it wouldn't be a perpetual motion machine, because that would require getting energy out of it.

Nope.
We can get very close to it, but never quite a perfect vacuum.
Diffusion will allow gasses to pass through the walls.
The wall's themselves will have a certain vapour pressure, meaning the surface layer will separate and become gas.
Then you get the quantum fluctuations creating virtual particles.

There is literally no way to make a perfect vacuum in reality.

Indeed, if you use concrete walls 

Scientists have already reached 100 particles per cubic centimeter, it's hard but not impossible.

No. If you use any walls.

Even things like solid metals or diamond are permeable via diffusion.
Various atoms/molecules can occupy interstitial sites or vacancies and diffuse through the crystal matrix and thus get into the vacuum chamber.

Even if you used a finite energy barrier, there can still be quantum tunnelling through the barrier and into the chamber.
Yes, the potential (to tunnel through) may be small, but it is still quite real, and all it takes is 1 to loose the perfect vacuum, and you have quite a large number of particles on the outside.

The only way to make it completely impervious is to have an infinite potential barrier, which simply doesn't exist.
So a perfect vacuum simply can't exist

100 particles per cubic centimetre is still 100 too many in that cubic centimetre.
It is 100 million too many per cubic metre.

We can only ever get close to one, we will never achieve a perfect vacuum.

At the BASE experiment at the LHC, they achieved a vacuum so good that they couldn't find ANY atoms in it at all, so they set an upper bound of 3 atoms per cubic centimeter. They kept it like that for at least a year, which was about how long the experiment lasted. They got rid of diffusion by cooling the walls to 6K. So it's not impossible.

But they also had particles inside it, meaning it couldn't be a perfect vacuum.
I can also find this quote from their website:

Quote

Bakeout is a procedure in which the vacuum chambers are heated from the outside in order to improve the quality of the vacuum. This operation needs to be performed at regular intervals to keep the vacuum at the desired low pressure.

So it seems it wasn't a perfect vacuum, at least not one that can be sustained.
Also, from searching it appears the number is 150 m^3. So how many atoms would that have with the upper bound of 3 atoms per cubic centimetre.

Their gauge not being able to detect the imperfections doesn't mean they aren't there.

Also, diffusion is only one problem, you also have the issue of virtual particles.

So no, not possible.

EDIT:
After searching some more, it seems the basis of their upper limit was that they haven't noticed any proton-anti-proton annihilation events.

So I would say that is very far from conclusive.

No it's not inconclusive at all, let me explain:

Your source is about the LHC. BASE is not part if the LHC (yes I know what I said, I meant CERN). You can find info here:
https://home.cern/about/updates/2016/12/base-antiprotons-celebrate-their-first-birthday

"But they also had particles inside it, meaning it couldn't be a perfect vacuum."

Of course there are, they put them there. There was nothing stopping them from not putting any antiprotons there, but that wouldn't be very useful for their experiment.

"Also, from searching it appears the number is 150 m^3. So how many atoms would that have with the upper bound of 3 atoms per cubic centimetre."

Actually, for BASE it's about 1.2 litres. So about 3600 particles, but I don't see how that's relevant. It's the particle density that matters. You could have a chamber that is smaller and you'd have less.

"Also, diffusion is only one problem, you also have the issue of virtual particles."

So? We're not talking about virtual particles here. Or you could go out on a limb and try to block the majority of them.

"So I would say that is very far from conclusive."

I don't see how it's inconclusive. An upper bound of 3 particles per cc means that if there were more particles than that, it's a statistical impossibility that no antiprotons would be annihilated over more than a year. It would be something like having a raging bull (not DeNiro, the proverbial one) in a china shop for more than a year and not breaking anything. We're not experts, and the experts say that's how many there can be, so I think we should listen to them.

The upper bound means that there could be significantly less than that, not to mention that statistically, even with 3 particles per cc there are regions of the size of 1 cc that contain no particles at all. I believe that if technology advances, even that figure could be improved upon, and you could very well have a tiny flywheel less than 1cm across magnetically suspended magnetically inside a chamber less than 1 cc large, with no particles in it, spinning practically forever.

No it's not inconclusive at all, let me explain:

Your source is about the LHC. BASE is not part if the LHC (yes I know what I said, I meant CERN). You can find info here:
https://home.cern/about/updates/2016/12/base-antiprotons-celebrate-their-first-birthday

"But they also had particles inside it, meaning it couldn't be a perfect vacuum."

Of course there are, they put them there. There was nothing stopping them from not putting any antiprotons there, but that wouldn't be very useful for their experiment.

"Also, from searching it appears the number is 150 m^3. So how many atoms would that have with the upper bound of 3 atoms per cubic centimetre."

Actually, for BASE it's about 1.2 litres. So about 3600 particles, but I don't see how that's relevant. It's the particle density that matters. You could have a chamber that is smaller and you'd have less.

"Also, diffusion is only one problem, you also have the issue of virtual particles."

So? We're not talking about virtual particles here. Or you could go out on a limb and try to block the majority of them.

"So I would say that is very far from conclusive."

I don't see how it's inconclusive. An upper bound of 3 particles per cc means that if there were more particles than that, it's a statistical impossibility that no antiprotons would be annihilated over more than a year. It would be something like having a raging bull (not DeNiro, the proverbial one) in a china shop for more than a year and not breaking anything. We're not experts, and the experts say that's how many there can be, so I think we should listen to them.

The upper bound means that there could be significantly less than that, not to mention that statistically, even with 3 particles per cc there are regions of the size of 1 cc that contain no particles at all. I believe that if technology advances, even that figure could be improved upon, and you could very well have a tiny flywheel less than 1cm across magnetically suspended magnetically inside a chamber less than 1 cc large, with no particles in it, spinning practically forever.

Yes, inconclusive.
I will skip the stuff about the LHC.
Yes, particle density is important. For a perfect vacuum, you need a particle density of 0.
That means 0 particles in that 1.2 L, or in that cubic centimetre.
Regardless of which you use, that is still infinitely more.
However, the smaller it is, the smaller the particle density you will need to maintain the same kind of motion as the path length between the object and the wall is shorter (assuming the particles are more likely to hit the wall than other particles).
This is because for large containers the particles need to travel a long distance in order to transfer momentum/energy between the flywheel and the container, for small containers, they need to travel a smaller distance.
Also, due to the smaller size of the flywheel it will have less momentum, and a greater surface area to volume (or mass and thus momentum and energy) ratio.

The smaller the flywheel and the smaller the enclosure, the better the system you need.

Yes, for the most part we weren't talking about virtual particles as others were a greater issue.

I pointed out virtual particles getting in the way right near the start.

Virtual particles are speculated to be the cause of the nuclear force, the force which holds nucleons together in a nucleus.
The only way to suppress them is by placing 2 objects very close together.

Statistical impossibilities are merely things which are below some arbitrary cut off regarding probability.
Regardless, that is still too many particles to be a perfect vacuum.

It is also nothing like having a raging bull in a china shop.
That would be more like having it in the atmosphere rather than that high a vacuum.

It would be more like having 3 magic raging flying bulls in a cube that is 100 000 km wide, which need to hit bits of china that are 10 microns wide, while they may also deflect the bull or pass through the bull without annihilating.

Perpetual motion isn't practically forever, it is actually forever.

Like I said to rabinoz, it all depends on what you want it for.
If you just want to show off, then you just need to get a decent vacuum and a decent flywheel.
If you just want it to last for a few billion years, then maybe get a roughly spherical flywheel with a radius of 6400 km and put it in the vacuum of space spinning at roughly 15 degrees an hour.

"Yes, inconclusive."

The people at CERN think it's conclusive, but apparently you think they're wrong.

"For a perfect vacuum, you need a particle density of 0."

Yes, you get that by enclosing a space inside that chamber small enough to have (statistically) 0 particles. If that space is a sixth of a cc, you'd have a density of 0.5 particles per 1/6 of a cc. Which means that it's highly possible you wouldn't have any particles in there.

"Also, due to the smaller size of the flywheel it will have less momentum, and a greater surface area to volume (or mass and thus momentum and energy) ratio."

Which is not an issue if your vacuum is perfect.

"Virtual particles are speculated to be the cause of the nuclear force, the force which holds nucleons together in a nucleus."
We don't care about these as long as they won't stop our wheel.

"Statistical impossibilities are merely things which are below some arbitrary cut off regarding probability."

Hence the example of the raging bull. Some pretty wonky magical shit must be happening, if there are more particles than that.


"It would be more like having 3 magic raging flying bulls in a cube that is 100 000 km wide, which need to hit bits of china that are 10 microns wide, while they may also deflect the bull or pass through the bull without annihilating."

This analogy is misleading. The way you're presenting it is as if it's unlikely. But you see, what the researchers knew from their gauges was that there were less than 500 particles per cc. So if they decided there can't realistically be more than 3, they must be pretty confident that some bulls would have hit something by now. Mind you, that upper limit may be further lowered as time passes, we shall see.

"Yes, inconclusive."

The people at CERN think it's conclusive, but apparently you think they're wrong.

Really? Can you find me a quote from the people at CERN that say perfect vacuums are possible?
Remember, that is what the discussion is about, if they are. Not if they got it down to 3 particles per cubic cm.

Also, all I can find for that 3 particles per cubic cm was a claim by a post-doc researcher quoted on popular science pages.
Guess what, sometimes even they make mistakes.

"For a perfect vacuum, you need a particle density of 0."

Yes, you get that by enclosing a space inside that chamber small enough to have (statistically) 0 particles. If that space is a sixth of a cc, you'd have a density of 0.5 particles per 1/6 of a cc. Which means that it's highly possible you wouldn't have any particles in there.

You can't just hypothetically enclose something like that. You need to do it in a practical manner, or suggest a way to do that.
I'm fairly confident that any attempt to do that will result in particles being there, especially as you will need to deal with the out-gassing of the walls again, and diffusion through it.
But yes, vacuums inside vacuums are typically better than vacuums inside a normal atmosphere.

"Also, due to the smaller size of the flywheel it will have less momentum, and a greater surface area to volume (or mass and thus momentum and energy) ratio."

Which is not an issue if your vacuum is perfect.

And 3 particles per cubic cm is not perfect.

"Virtual particles are speculated to be the cause of the nuclear force, the force which holds nucleons together in a nucleus."
We don't care about these as long as they won't stop our wheel.

And chances are that they will.

"Statistical impossibilities are merely things which are below some arbitrary cut off regarding probability."

Hence the example of the raging bull. Some pretty wonky magical shit must be happening, if there are more particles than that.


"It would be more like having 3 magic raging flying bulls in a cube that is 100 000 km wide, which need to hit bits of china that are 10 microns wide, while they may also deflect the bull or pass through the bull without annihilating."

This analogy is misleading. The way you're presenting it is as if it's unlikely. But you see, what the researchers knew from their gauges was that there were less than 500 particles per cc. So if they decided there can't realistically be more than 3, they must be pretty confident that some bulls would have hit something by now. Mind you, that upper limit may be further lowered as time passes, we shall see.

No. Your example was misleading.
A raging bull is quite large compared to the shop as are all the bits of china, and they are macroscopic objects which means no simply passing through, and there is no strong interaction between the bull and china which can cause a very large repulsion.

I scaled it so the sizes are roughly accurate. The only issue is the speed, with it travelling at 73 m/s (assuming it is nitrogen, it goes up to 273 m/s if it is hydrogen), which would mean the magic bull would need to travel at a speed of 730 000 000 km/s.

And that is part of the issue with things like this. Regardless of how you tweak your analogy, you will have some aspect human's can't comprehend easily.

Your analogy is akin to an analogy of the Rutherford experiment which describes it as firing a cannon ball at a sheet of tissue paper and having the cannon ball be deflected back.

Quote from: Definitely Not Official on January 07, 2017, 05:11:25 AM

"Yes, inconclusive."

The people at CERN think it's conclusive, but apparently you think they're wrong.

Really? Can you find me a quote from the people at CERN that say perfect vacuums are possible?
Remember, that is what the discussion is about, if they are. Not if they got it down to 3 particles per cubic cm.

Also, all I can find for that 3 particles per cubic cm was a claim by a post-doc researcher quoted on popular science pages.
Guess what, sometimes even they make mistakes.

Quote from: Definitely Not Official on January 07, 2017, 05:11:25 AM

"For a perfect vacuum, you need a particle density of 0."

Yes, you get that by enclosing a space inside that chamber small enough to have (statistically) 0 particles. If that space is a sixth of a cc, you'd have a density of 0.5 particles per 1/6 of a cc. Which means that it's highly possible you wouldn't have any particles in there.

You can't just hypothetically enclose something like that. You need to do it in a practical manner, or suggest a way to do that.
I'm fairly confident that any attempt to do that will result in particles being there, especially as you will need to deal with the out-gassing of the walls again, and diffusion through it.
But yes, vacuums inside vacuums are typically better than vacuums inside a normal atmosphere.

Quote from: Definitely Not Official on January 07, 2017, 05:11:25 AM

"Also, due to the smaller size of the flywheel it will have less momentum, and a greater surface area to volume (or mass and thus momentum and energy) ratio."

Which is not an issue if your vacuum is perfect.

And 3 particles per cubic cm is not perfect.

Quote from: Definitely Not Official on January 07, 2017, 05:11:25 AM

"Virtual particles are speculated to be the cause of the nuclear force, the force which holds nucleons together in a nucleus."
We don't care about these as long as they won't stop our wheel.

And chances are that they will.

Quote from: Definitely Not Official on January 07, 2017, 05:11:25 AM

"Statistical impossibilities are merely things which are below some arbitrary cut off regarding probability."

Hence the example of the raging bull. Some pretty wonky magical shit must be happening, if there are more particles than that.


"It would be more like having 3 magic raging flying bulls in a cube that is 100 000 km wide, which need to hit bits of china that are 10 microns wide, while they may also deflect the bull or pass through the bull without annihilating."

This analogy is misleading. The way you're presenting it is as if it's unlikely. But you see, what the researchers knew from their gauges was that there were less than 500 particles per cc. So if they decided there can't realistically be more than 3, they must be pretty confident that some bulls would have hit something by now. Mind you, that upper limit may be further lowered as time passes, we shall see.

No. Your example was misleading.
A raging bull is quite large compared to the shop as are all the bits of china, and they are macroscopic objects which means no simply passing through, and there is no strong interaction between the bull and china which can cause a very large repulsion.

I scaled it so the sizes are roughly accurate. The only issue is the speed, with it travelling at 73 m/s (assuming it is nitrogen, it goes up to 273 m/s if it is hydrogen), which would mean the magic bull would need to travel at a speed of 730 000 000 km/s.

And that is part of the issue with things like this. Regardless of how you tweak your analogy, you will have some aspect human's can't comprehend easily.

Your analogy is akin to an analogy of the Rutherford experiment which describes it as firing a cannon ball at a sheet of tissue paper and having the cannon ball be deflected back.

So you're saying that the experts on this subject (Christian Smorra and his team were the ones who arrived at that conclusion, and they are the core members of the BASE experiment) are wrong about this. That claim should come with backing, not just saying they're probably wrong because you don't like the way it sounds.

"And 3 particles per cubic cm is not perfect."

No, but you can get it lower than that. In fact, it's almost certain it IS lower than that. Also, as you know, this is not homeopathy, you can't have less than one, more than 0 particles. You can get a smaller space, and chances are you're going to have 0 particles inside.

"You can't just hypothetically enclose something like that. You need to do it in a practical manner, or suggest a way to do that.
I'm fairly confident that any attempt to do that will result in particles being there, especially as you will need to deal with the out-gassing of the walls again, and diffusion through it."

I told you, diffusion and outgassing has been dealt with. As for a practical manner, I don't know, I'm not an engineer. I guess you could piece two hemispheres together remotely using magnets.

"Really? Can you find me a quote from the people at CERN that say perfect vacuums are possible?"

The funny thing is that I didn't know it was possible, until a guy doing a PhD at CERN told me so.

"And chances are that they will."

And... how?

"I scaled it so the sizes are roughly accurate. The only issue is the speed, with it travelling at 73 m/s (assuming it is nitrogen, it goes up to 273 m/s if it is hydrogen), which would mean the magic bull would need to travel at a speed of 730 000 000 km/s."

Exactly. The point of the analogy was to show how unlikely it is. If you tell a person that it's like keeping a bull in a china shop for a year and not breaking anything, they know immediately how unlikely it is. If you tell someone that at the upper limit is like having 3 flying bulls in a massive cube moving at an insane speed, the poor guy is just going to get confused. How likely is that?

So you're saying that the experts on this subject (Christian Smorra and his team were the ones who arrived at that conclusion, and they are the core members of the BASE experiment) are wrong about this. That claim should come with backing, not just saying they're probably wrong because you don't like the way it sounds.

Nope. I am not saying it is probably wrong because I don't like the way it sounds. That isn't even the core of my objection.
I can find no evidence that it is anything other than a statement from Christian Smorra. I can find no indication that his team backs it.
And I know this might be hard for you to accept, but people can make mistakes.

No. I am not the one that needs to back me not accepting your claims.
If you wish to make a claim, you are the one that needs to back it up.
Having someone say something isn't backing.

"And 3 particles per cubic cm is not perfect."

No, but you can get it lower than that. In fact, it's almost certain it IS lower than that. Also, as you know, this is not homeopathy, you can't have less than one, more than 0 particles. You can get a smaller space, and chances are you're going to have 0 particles inside.

Yes, you likely can get it lower, but this is density, not absolute numbers. If you want to use absolute numbers you need to use it for the entire volume.

You also can't just magically isolate a space from it.

"You can't just hypothetically enclose something like that. You need to do it in a practical manner, or suggest a way to do that.
I'm fairly confident that any attempt to do that will result in particles being there, especially as you will need to deal with the out-gassing of the walls again, and diffusion through it."

I told you, diffusion and outgassing has been dealt with. As for a practical manner, I don't know, I'm not an engineer. I guess you could piece two hemispheres together remotely using magnets.

Yes, you told me. You are aware that doesn't make it true? You can be wrong.
The issue with placing 2 hemispheres remotely is that you will be compressing a volume, potentially trapping any gas that is in it meaning you would need a larger empty volume. You also have the issue of making sure you get a section with no particles in it rather than a section with particles in it.
You then get the issue of making sure it remains with no particles in it, as all high vacuum systems that I know of require constant pumping to maintain that state.

"Really? Can you find me a quote from the people at CERN that say perfect vacuums are possible?"

The funny thing is that I didn't know it was possible, until a guy doing a PhD at CERN told me so.

Really? so rather than provide any quote from any authority at CERN, you just say a guy doing a PhD told you so?

"And chances are that they will."

And... how?

By having your chamber small enough that they will be able to travel the distance between the wall and the flywheel transferring momentum between them.

"I scaled it so the sizes are roughly accurate. The only issue is the speed, with it travelling at 73 m/s (assuming it is nitrogen, it goes up to 273 m/s if it is hydrogen), which would mean the magic bull would need to travel at a speed of 730 000 000 km/s."

Exactly. The point of the analogy was to show how unlikely it is. If you tell a person that it's like keeping a bull in a china shop for a year and not breaking anything, they know immediately how unlikely it is. If you tell someone that at the upper limit is like having 3 flying bulls in a massive cube moving at an insane speed, the poor guy is just going to get confused. How likely is that?

The issue is that you make it far more likely than it is.
A raging bull in a china shop would likely destroy quite a bit in the first few seconds.
3 particles per cubic cm (or even some more) would not be destroying the anti-protons in a few seconds.

You skew the analogy to be so heavily in your favour it isn't funny.
Yes, mine is quite difficult to comprehend, but at least it is more accurate.