False vacuum?

[Daecon]

I'm not sure which sub-section would be most suitable for his topic, so feel free to relocate it if appropriate.

 

I've been reading about the false vacuum on Wikipedia, but I'm having trouble getting my head around the details (it sucks being uneducated).

 

If I'm understanding correctly, one of the aspects mentioned was that if we live in a metastable false vacuum, the true vacuum would have different laws of physics, which would mean our current laws of chemistry and therefore biology would be quite different. Is that right?

 

That's one the points I'm having trouble comprehending, how would a lower vacuum state (if I'm using the term correctly) mean different physical laws? Could anyone provide any hypothetical examples of what that would be like?

 

(As an aside, could it be theoretically possible to have two separate but equally low vacuum states, or does that not make sense?)

[MigL]

The 'simple' example I've often seen used is a thermodynamic one ( but it just seems more confusing to me ).

You can, under suitable conditions, cool water to below 0 deg. and it will remain liquid. This is a 'false' energy level, and the smallest disturbance will cause it to flash-freeze and become a solid. This 'symmetry break' will cause the system to lose certain properties and gain others.

 

The one I like to use is the drop of a pencil from a tabletop. It is conceivable that the pencil will land on its tip, perfectly balanced, and be in a rotationally symmetric state. This state, at a false zero energy level, is extremely unstable, however, and the slightest disturbance will cause it to fall over to its true zero energy state. This state has had its symmetry broken as the pencil now points in a particular direction and has lost rotational symmetry.

I'm sure Mordred will also explain the 'Mexican hat' potential ( which looks like a rounded 'W' ), and the false vacuum energy would be perfectly balanced atop the middle hump of the 'hat', this would again be unstable and a symmetry break would cause a 'roll down' to the true zero state in the 'brim' of the 'hat'.

 

Confused yet ?

 

In all cases, a symmetry break is involved in the transition from a false zero state to the true zero state.

The last one that occurred would be the electroweak symmetry break, which caused weak interaction bosons to gain mass, and separate from the EM interaction. I leave it up to you to try to figure out how our universe would work without a weak interaction.

There may have been varying numbers of symmetry breaks before the electroweak break ( and group theory dictates how many ), but they are still trying to find the 'best fit' to what is observed in elementary particle physics. And that, of course, is incomplete and constantly changing ( thanks LHC ).

Edited April 1, 2016 by MigL

[EdEarl]

@Deacon

 

(it sucks being uneducated).

You are obviously trying to become educated; in addition, that you are reading about false vacuum means you know things that the vast majority of people don't know. Pat yourself on the back for me. You ask a good question and are working to learn.

[Mordred]

I like your answer Migl it's well thought out. I think I'll wait to see how much the OP understood before adding to your excellent explanation.

 

+1

Edited April 1, 2016 by Mordred

[Daecon]

I think I'm following.

 

A symmetry break to a lower zero energy level would cause the gauge bosons to have different physical properties? An example being gravity separating from electroweak and then later, weak separating from electromagnetism?

 

So I'm guessing it's not possible to predict what changes will happen if such an event were to occur?

 

(Although now I realize I should probably read up on spontaneous and explicit symmetry breaking, too.)

Edited April 1, 2016 by Daecon

[Mordred]

Not bad, a good way to understand it in more detail is to Google Higgs metastability.

 

http://www.google.ca/url?q=http://arxiv.org/pdf/1210.6987&sa=U&ved=0ahUKEwimkrGn4O7LAhVQxWMKHSF_ABEQFggRMAA&usg=AFQjCNFs4oyWK_egHU-PrVlPeJGr_hWRvg

 

Little secret add pdf at the end of a search. Ie "Higgs metastability pdf"

 

It will help avoid pop media hype style articles.

[Daecon]

Thanks for that. I'll admit that most of it went over my head, but at least I understood the abstract.

 

So the Higgs boson having a mass of 127 GeV implies our vacuum is the true vacuum, but if it has a lesser value, that would imply our current vacuum is only a metastable one - and current analysis indicates its mass is about 125 GeV?

 

I don't quite get the significance of the mass values, but I can think about that at a later time.

 

So from what I gather, if a specific particle somehow gained enough energy, that could be enough to "push" it over the ridge and into a lower vacuum state, which would act as a nucleation particle leading to a catastrophic ground state change? (Likewise, it may happen randomly through quantum tunnelling at some point over the next trillion years or so.)

Edited April 2, 2016 by Daecon

[Mordred]

The Higgs mass is important for setting the vacuum expectation value.

 

Particles of the details you need is to understand how thermal equilibrium works with the coupling constants of each of the four forces.

 

Without going into the gritty details I'll give a brief description.

As you increase temperature via volume change. Ie smaller volume of the Universe in the past.

 

The coupling constants start to become the same strength. For example you can no longer distinquish the strength of coupling constant for the strong or weak force.

 

As you can no longer distinguish them they have symmetry.

 

at temperature above the vacuum expectation value, the strong, weak and electromagnetic force all become indistinct.

The Higgs field itself has 4 components those four components all have symmetry. The particles that are normally distinguished by their interactions with the Higgs field and the three forces also become indistinct from one another.

 

Here is a quick lecture showing the components of the Higgs field. There is a brief correlation to the above.

 

 

http://www.google.ca/url?q=http://www2.ph.ed.ac.uk/~playfer/PPlect17.pdf&sa=U&ved=0ahUKEwju3dGVxPDLAhWKk4MKHYH1CoUQFggVMAE&usg=AFQjCNG5MOS24Ts73nVxWc6fMdaqRcnrmQ

 

 

http://arxiv.org/abs/0810.3328 A Simple Introduction to Particle Physics

 

http://arxiv.org/abs/0908.1395 part 2

 

 

GUT theories

 

http://arxiv.org/pdf/0904.1556.pdf The Algebra of Grand Unified Theories John Baez and John Huerta

 

http://pdg.lbl.gov/2011/reviews/rpp2011-rev-guts.pdf GRAND UNIFIED THEORIES

These articles will help. Keep in mind there are alternative particle physics models.

 

Ie SO(10) MSSM super symmetry as opposed to

 

SO(10) MSM minimal standard model

S0(5) an older standard model the first GuT model.

 

 

That should give you plenty of study material.

Edited April 2, 2016 by Mordred

[Daecon]

That's awesome. Thank you so much.