Does somebody know what Vacuum is ?

How does science work? And what's all this about quantum mechanics?

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socratus
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Does somebody know what Vacuum is ?

Post by socratus »

Does somebody know what Vacuum is ?
1.
Book : ‘Dreams of a final theory’ by Steven Weinberg. Page 138.
‘ It is true . . . there is such a thing as absolute zero; we cannot
reach temperatures below absolute zero not because we are not
sufficiently clever but because temperatures below absolute zero
simple have no meaning.’
/ Steven Weinberg. The Nobel Prize in Physics 1979 /
2.
‘If we were looking for something that we could conceive
of as God within the universe of the new physics,
this ground state, coherent quantum vacuum might be
a good place to start.’
/ Book ‘The quantum self ’ page 208 by Danah Zohar. /
3.
And Paul Dirac wrote:
‘ The problem of the exact description of vacuum, in my opinion,
is the basic problem now before physics. Really, if you can’t correctly
describe the vacuum, how it is possible to expect a correct description
of something more complex? ‘
==.
Does somebody know what Vacuum is ?
==.
Socratus
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Resha Caner
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Re: Does somebody know what Vacuum is ?

Post by Resha Caner »

I understand that achieving a perfect vacuum is likely impossible, but I didn't realize that defining it would be. I thought a definition of a vacuum rather simple: a region of space devoid of all matter.

So, what are the difficulties with defining it?
Thundril
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Re: Does somebody know what Vacuum is ?

Post by Thundril »

A region of empty space contains energy fields, so it isn't really empty. In an area where the 'slope' of an energy field is zero, we can say there is no usable energy there. This we call the vacuum. But in fact the slope can't be exactly zero, by Heisenberg's Uncertainty Principle. So any point where there is 'nothing' actually contains, potentially, two equal and opposite particles (matter and anti-matter) which together add up to nothing. If a pair of these 'virtual' particles exist for a tiny moment, they immediately annihilate each other.
However if such a momentary appearance of virtual particles occurs exactly on the event horizon of black hole, they may get separated, and the ones that don't fall into the black hole become real particles. The flow of these particles away from the vicinity of the black hole is detectable as 'Hawking radiation', which is how we can verify that this phenomenon is real..
That's my fuzzy picture of it, anyway.
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socratus
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Re: Does somebody know what Vacuum is ?

Post by socratus »

mathematical idealization

when we mathematical model the scenario of an object
moving we try to model things as simply as possible,
so we consider a scenario where there is no impediment
to its motion that would be a perfect vacuum.
But in practice there is less that perfect.
So the Platonic realm of idealization gives way
to physical reality by concessions.
/ roger /
But in practice there is less that perfect.
/ roger /

But in practice there are many claims that perfect
vacuum energy has a physical relevance:
in Vacuum polarization, in Casimir effect,
in the cosmological constant, Lamb shift,
electron magnetic momentum anomaly.
=.
Is perfect vacuum only a ‘mathematical idealization’ ?

Socratus
=.
Thundril
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Re: Does somebody know what Vacuum is ?

Post by Thundril »

I think of 'vacuum' as a kind of description, rather than a 'thing'.
Casimir effect etc are expressions of relationships between things (in this case a pair of surfaces). Perhaps 'vacuum' is a word like 'distance' or 'polarization'; not quite a thing or quantity in itself, rather something like a quality, but more abstracted. So a thing has a polarization, a pair of things have a 'distance' between them, a vacuum is a degree of 'nothingness' compared to a surrounding 'somethingness'.
I dunno. Tricky, innit?
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Resha Caner
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Re: Does somebody know what Vacuum is ?

Post by Resha Caner »

Thundril wrote:A region of empty space contains energy fields, so it isn't really empty. In an area where the 'slope' of an energy field is zero, we can say there is no usable energy there. This we call the vacuum. But in fact the slope can't be exactly zero, by Heisenberg's Uncertainty Principle.
OK. More accurate in the details but essentially the same idea. I think, though, that you might be missing the point of a definition.
Thundril wrote:I think of 'vacuum' as a kind of description, rather than a 'thing'.
Casimir effect etc are expressions of relationships between things (in this case a pair of surfaces). Perhaps 'vacuum' is a word like 'distance' or 'polarization'; not quite a thing or quantity in itself, rather something like a quality, but more abstracted. So a thing has a polarization, a pair of things have a 'distance' between them, a vacuum is a degree of 'nothingness' compared to a surrounding 'somethingness'.
I dunno. Tricky, innit?
You're right about it being a description rather than a thing. That is what a definition is. In fact, "description" is basically a synonym for "definition." It defines an ideal - and ideals are never achieveable.

As I said earlier, it's impossible to find a perfect vacuum, but that doesn't make it difficult to define one. I can define it any way I choose, and consensus usually settles on the definition that is "useful."

So, the tricky part isn't finding a vacuum. I never expected one would be found. The tricky part is if the definition becomes an important foundation for a scientific theory. Since it defines an ideal that can never be achieved, it can't be tested, can't be falsified, and therefore can't be directly compared to the alternatives. So, new theories are judged on the consequences that follow from the definition, not the definition itself. That is tricky.
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Cerveny
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Re: Does somebody know what Vacuum is ?

Post by Cerveny »

The vacuum, physical space, it is not a thing it is a process. It is the process where a "possible" is becoming the reality, where a "possible" is gluing to the order, becomes a rule, where the future is freezing to a history of the Universe… The vacuum, physical space, it is limited, ordered set of "stem cells" of/for the matter that mediate local metric...
Last edited by Cerveny on Thu May 17, 2012 11:40 am, edited 2 times in total.
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socratus
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Re: Does somebody know what Vacuum is ?

Post by socratus »

Can Perfect Vacuum as a ' Nothing' as ‘ an Infinite Space’ as
an Absolute Reference Frame have Concrete Physical Properties ?
Socratus
=.
One Concrete Physical Properties of Vacuum is Absolute Zero.
What is Absolute Zero ?
Classic Physics says: It is a dead space.
Quantum Physics says: It is not a dead space.
There are ‘ Virtual Particles’ exist.
What is Absolute Zero ?
=.
Socratus
===.
P.S.
What is Absolute Zero ?
Where is a wise answer and where is a fool answer if these
two theories ( Classical and Quantum theories) are correct ?
==.
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socratus
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Re: Does somebody know what Vacuum is ?

Post by socratus »

Einstein and Socratus.
=.
Einstein, you was mistaken using your Gravitation theory
to the all Universe as a whole.
The Gravitation theory doesn’t work in the Universe as a whole.
The Gravitation theory is a local theory.
Why?
Because the detected material mass of the matter in the
Universe ( the cosmological constant / the critical density)
is so small ( the average density of all substance in the
Universe is approximately p=10^-30 g/sm^3 ) that it
cannot ‘close’ the Universe into sphere and therefore our
Universe as whole must be ‘open’, endless, infinite.
The Universe as a whole is an Infinite Pure Vacuum: T=0K.
More concrete:
§ 1. Vacuum: T= 0K, E= ∞ , p = 0, t =∞ .
=.
We have two (2) Worlds: Vacuum and Material and we need
to understand their interaction.
==.
Socratus
MJA
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Re: Does somebody know what Vacuum is ?

Post by MJA »

We live in One world,
Where theories faiths and dreams are made.
A place where unicorns have wings,
In a vacuum where the speed of light is C,
And God has a son named Jesus,
And dreams for many become true.
If your looking for the vacuum,
Try clicking your heals together 4 times.
Three will only get you to Kansas.

=
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