What does nothing look like?

[AndrewRrrrrr]

1 hour ago, andrew s said:

Not quite even if one accepts this view on vacum energy. Hawking's radiation creates real particles with the energy for them taken from the gravitational energy of the black hole.

Regards Andrew 

isn't it that a pair of particles is created, one inside the event horizon and the other outside. they cannot get back together so the one on the outside "becomes" real and the mass of the BH becomes smaller. anyway we digress.  I don't know what nothing looks like although I did watch a certain ex-PMs speech in the USA yesterday which was very close to nothing.  

[saac]

We been looking at this all wrong, it exists and here is what it looks like  

One of my favourite cartoons and so redolent of the long hot summer days of youth occupied with hours of doing nothing.

Jim

 

Edited April 13, 2023 by saac

[andrew s]

2 hours ago, 900SL said:

A lot of modern physics sounds like nonsense, it has to be said.

 

Virtual this, imaginary that, negative energy etc. I know this fits the observations, but my guess is somebody is having a right laugh here.

The issue is these are pop science terms, often used by serious scientists,  to try to make modern physics approachable to those without the mathematical background for the real thing.

For example "virtual" this and that normally stand for particular elements in an perturbative expansion of the equations of QFT. They are not "real" any more than the terms in the expansion of sin(x) are real.

Energy can be negative depending on where you decide to put the zero point. For gravity its typically set at zero an infinite distance from a mass. If you have a test mass at infinity and move it towards a real mass it gains negative energy!

However,  energy is bounded from below as if not atoms would not be stable and we would be nothingness.

Regards Andrew 

[andrew s]

1 hour ago, AndrewRrrrrr said:

isn't it that a pair of particles is created, one inside the event horizon and the other outside. they cannot get back together so the one on the outside "becomes" real and the mass of the BH becomes smaller. anyway we digress.  

Yes that's the pop science model the man himself gave. However,  you won't find it in his published peer reviewed papers.

The issue I was pointing out in your initial post on this was the energy came from the mass of the black hole not the vaccum. Maybe I miss understood. 

Regards Andrew 

[andrew s]

1 hour ago, Moonshed said:

Hi Jim,

I would agree with you in that all fields are an intrinsic part of the fabric of the universe. I can only think of one place where they may not exist, inside a black hole.

Cheers

Keith

They are thought to exist inside a black hole. Depending on the size of the hole you could pass the event horizon without noticing anything untoward.  

It is belived that black holes can have charge as well as mass and spin. So at least the EM field and the gravitational field exist.

Regards Andrew 

[saac]

15 minutes ago, andrew s said:

Energy can be negative depending on where you decide to put the zero point. For gravity its typically set at zero an infinite distance from a mass. If you have a test mass at infinity and move it towards a real mass it gains negative energy!

However,  energy is bounded from below as if not atoms would not be stable and we would be nothingness.

Regards Andrew 

This allows us to define gravitational potential as the work done to move a unit mass (test mass) from infinity to a particular point from the planet. The gravitational potential (V) at that point given by  V = - GM/r . The negative sign often causes confusion with students when we use this in the work up to escape velocity. They are used to the more familiar expression of gravitational potential first introduced as Ep = mgh.  But with Ep = mgh we have created an artificial zero point (reference point) of the Earth's surface and h becomes the height above Earth's surface. 

An easy path for students  to consider the negative term is to think about the work done moving a mass (m1) away from a second mass (m2). This requires an increasing amount of work to overcome the attractive force between the two masses. However the gravitational potential energy must increase towards zero at infinity  - it must therefore have been negative at all points in between   I think a similar convention is at play with electron energy levels (Bhor model) where the ionisation level is taken as the zero reference and levels below appear as negative.  It's a convention that can lead to confusion in exams, examination bodies not always sympathetic to ignoring signs when calculating differences between energy levels.  Poor student , Physics can be pedantic at times. 

Jim

[Moonshed]

To answer the OP’s original question “What does nothing look like?” Nobody has a Scooby.

I think that is self evident.

The End.

Edited April 13, 2023 by Moonshed

[Earl]

Well the question in my mind, outside of theoretical models does the state nothing actually exist or is there always bit of something be it virtual or not.

 

Edited April 13, 2023 by Earl

[Ratlet]

1 minute ago, Earl said:

Well the question in my mind, outside of theoretical models does the state nothing actually exist or is there always bit of something be it virtual or not.

 

I'm onboard with this.  Can an observer observe nothing, since in order to observe you must observe with something (em field, gravitational field) which implies the existence of something (the fields themselves).

I'm not sure if nothing makes sense.

[ollypenrice]

Mathematical physics aside, there is something odd about the idea somebody (by definition part of something) looking nothing.  Where would be the boundary between something and nothing? How would it be identified and defined?

I'm beginning to think that 'nothing' is a kind of infinity which exists only as an abstraction in our heads..

Olly

Edited April 13, 2023 by ollypenrice
False click

[Paul M]

23 minutes ago, Ratlet said:

I'm onboard with this.  Can an observer observe nothing, since in order to observe you must observe with something (em field, gravitational field) which implies the existence of something (the fields themselves).

I'm not sure if nothing makes sense.

This line of thought starts drawing paralelles with Schrodinger's Cat. Perhaps "nothing" does exist but at the point you (try to) describe/measure/quantitise it, it becomes "something"

And maybe, I've just explianed virual particles to myself! 😆

[saac]

Maybe nothing can exist but it is temporal, existing for the fleeting moment between the transient fluctuations of the quantum field and appearance/disappearance of virtual particles  

 

Jim

[Earl]

4 minutes ago, ollypenrice said:

Mathematiocal physics aside, there is something odd about the idea somebody (by defintion part of something) looking 

could that mean something measuring?

 

[saac]

Here is something:

Scientific American - Endless Creation Out Of Nothing

 

Perhaps it not only exists but it was necessary in order for the universe to appear.

Jim

[ollypenrice]

3 minutes ago, Earl said:

could that mean something measuring?

 

If you mean that 'nothing' cannot be measured, then I'd agree. I'm starting to see 'nothing' as one of those infinities of which physicists are suspicious.

Olly

[billhinge]

On 10/04/2023 at 19:03, ollypenrice said:

No, I'm not having this. To quote Wittgenstein (and give my point a bit of gravitas ) language is public and if I asked you, or anyone else looking at my car, what colour it was you would say black. You would not say, 'It has no colour, it manifests the absence of colour.'  Come on now, admit it! 

Olly

You fell into the trap, what you think is black is actually very, very, very , very , very , very dark blue

 

[bosun21]

My way of thinking is that the definition of nothing is a vacuum in which every solitary atomic particle has been removed basically leaving nothing 🤔

[Moonshed]

2 hours ago, bosun21 said:

My way of thinking is that the definition of nothing is a vacuum in which every solitary atomic particle has been removed basically leaving nothing 🤔

By removing all atomic particles that still leaves time, and other dimensions, plus gravity, not sure of what else, so we haven’t arrived at nothing yet.

Back to the drawing board 🥸

[bosun21]

14 minutes ago, Moonshed said:

By removing all atomic particles that still leaves time, and other dimensions, plus gravity, not sure of what else, so we haven’t arrived at nothing yet.

Back to the drawing board 🥸

Define time and gravity? Neither have any substance to them. If we are going to go along those lines we can say because you are thinking about it your thoughts are in it. 

[Moonshed]

15 minutes ago, bosun21 said:

Define time and gravity? Neither have any substance to them. If we are going to go along those lines we can say because you are thinking about it your thoughts are in it. 

Time and gravity do not have any substance to them but nonetheless they are very real and are an intrinsic part of the universe. My point is that by removing all atomic particles from a vacuum they would still remain thus meaning that the vacuum would not become nothing, it still contained something.
I don’t follow your point about thinking about nothing puts my thoughts in it. How does that work?

[ollypenrice]

10 hours ago, bosun21 said:

My way of thinking is that the definition of nothing is a vacuum in which every solitary atomic particle has been removed basically leaving nothing 🤔

My understanding is that, in such a vacuum, new particles would spontaneously appear. There is a minimum energy density which is non-zero. That's why I think it is likely to be one of those infinities which have no physical existence.

Olly

[bosun21]

7 hours ago, Moonshed said:

Time and gravity do not have any substance to them but nonetheless they are very real and are an intrinsic part of the universe. My point is that by removing all atomic particles from a vacuum they would still remain thus meaning that the vacuum would not become nothing, it still contained something.
I don’t follow your point about thinking about nothing puts my thoughts in it. How does that work?

Time is not a physical substance. How does that work?

[Moonshed]

1 hour ago, bosun21 said:

Time is not a physical substance. How does that work?

If, as you suggest, you take a volume of space which is a vacuum and then remove all atomic particles you have not created nothing. As @ollypenrice said “My understanding is that, in such a vacuum, new particles would spontaneously appear. There is a minimum energy density which is non-zero. That's why I think it is likely to be one of those infinities which have no physical existence.” That alone negates your vacuum being nothing. 
As for time, I agree it is not a physical substance, but nonetheless it would still be there as you haven’t removed it, you only removed particles. Time was described by Einstein as the fourth dimension to the three we are familiar with and is at right angles to them. As time is an integral part of the very fabric of the universe it cannot be removed.

It is impossible to take any volume of space and reduce it to nothing. If it is possible for nothingness to exist it would have to exist outside of our universe, but that would necessitate there being an outside to the universe. If the universe is infinite, as many top cosmologists and scientists believe it to be, that may well mean that it is impossible to have an outside.

I hope my further explanations have helped you to understand my argument.

Cheers

Keith

[bosun21]

27 minutes ago, Moonshed said:

If, as you suggest, you take a volume of space which is a vacuum and then remove all atomic particles you have not created nothing. As @ollypenrice said “My understanding is that, in such a vacuum, new particles would spontaneously appear. There is a minimum energy density which is non-zero. That's why I think it is likely to be one of those infinities which have no physical existence.” That alone negates your vacuum being nothing. 
As for time, I agree it is not a physical substance, but nonetheless it would still be there as you haven’t removed it, you only removed particles. Time was described by Einstein as the fourth dimension to the three we are familiar with and is at right angles to them. As time is an integral part of the very fabric of the universe it cannot be removed.

It is impossible to take any volume of space and reduce it to nothing. If it is possible for nothingness to exist it would have to exist outside of our universe, but that would necessitate there being an outside to the universe. If the universe is infinite, as many top cosmologists and scientists believe it to be, that may well mean that it is impossible to have an outside.

I hope my further explanations have helped you to understand my argument.

Cheers

Keith

I agree with you about it apart from the infinite universe. If it is indeed infinite then what about the multiverse which many astrophysicists talk and theorize about ? This is too much to comprehend in the morning.

[ollypenrice]

Of course, the fact that time and space may both be illusory complicates things still further.   Things do, indeed, appear to be separated in the dimensions of time and space - most of the time. In some circumstances, though, they don't. The entangled photons experiment provides one example.  

We are happy with the idea that time slows to a standstill at the speed of light. At a standstill, I don't see how it can separate events. What if space, too, can reduce to zero? If it can, then where would we put our hypothetical vacuum?

🤪lly

Edited April 14, 2023 by ollypenrice
False click.