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How the Higgs field gives mass to elementary particles

quantamagazine.org

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Re: How the Higgs field gives mass to elementary particles

#91

Post by itishappy »

leptons wrote: post #83
pdonis wrote: post #46

Earlier quoted context omitted.

> the entire theory of the higgs field and its discovery came from understanding that the model without it lacked sufficient gravity to match the world around us. No, it didn't. Mass is not required for gravity; only energy is. The energy was there before the electroweak phase transition; it just wasn't in the form of rest mass. It still produced gravity.

>Mass is not required for gravity; only energy is. E = MC^2 Can't have energy without mass, and mass leads to gravity.

The full equation is: E^2 = (p*c)^2 + (m0*c^2)^2.

https://en.wikipedia.org/wiki/Energy%E2%80%93momentum_relati...

Re: How the Higgs field gives mass to elementary particles

#92

Post by elashri »

leptons wrote: post #83
pdonis wrote: post #46

Earlier quoted context omitted.

> the entire theory of the higgs field and its discovery came from understanding that the model without it lacked sufficient gravity to match the world around us. No, it didn't. Mass is not required for gravity; only energy is. The energy was there before the electroweak phase transition; it just wasn't in the form of rest mass. It still produced gravity.

>Mass is not required for gravity; only energy is. E = MC^2 Can't have energy without mass, and mass leads to gravity.

Actually it is

E^2 = (MC)^2 + (PC^2)^2

The first term is describing the rest mass. You can redefine the mass term to make it E=mc^2 but now this mass does not correspond to the rest mass. And for sure you can have energy without having a rest mass. Actually for the early universe all you had was a form of radiation and energy.

Re: How the Higgs field gives mass to elementary particles

#93

Post by pdonis »

sieste wrote: post #69
pdonis wrote: post #50

Earlier quoted context omitted.

> Is that really so? As the article notes, no, this is not a correct description.

sorry for the confusion, I meant is it really the case that this is a commonly used description of the higgs field.

> is it really the case that this is a commonly used description of the higgs field.

For whatever it's worth, it's not a description I had seen before I read the article. It's certainly not one you're going to find in actual textbooks or physics papers.

Re: How the Higgs field gives mass to elementary particles

#94

Post by pdonis »

leptons wrote: post #83
pdonis wrote: post #46

Earlier quoted context omitted.

> the entire theory of the higgs field and its discovery came from understanding that the model without it lacked sufficient gravity to match the world around us. No, it didn't. Mass is not required for gravity; only energy is. The energy was there before the electroweak phase transition; it just wasn't in the form of rest mass. It still produced gravity.

>Mass is not required for gravity; only energy is. E = MC^2 Can't have energy without mass, and mass leads to gravity.

> E = MC^2

Is only an approximation for particular cases, not a general law.

Re: How the Higgs field gives mass to elementary particles

#95

Post by pdonis »

LegitShady wrote: post #52
pdonis wrote: post #46

Earlier quoted context omitted.

> the entire theory of the higgs field and its discovery came from understanding that the model without it lacked sufficient gravity to match the world around us. No, it didn't. Mass is not required for gravity; only energy is. The energy was there before the electroweak phase transition; it just wasn't in the form of rest mass. It still produced gravity.

The end of the electroweak epoch is estimated at 10^-12 seconds after the big bang. So while I understand that something existed prior to the universe as we understand it now, for the overwhelming majority of the existence of reality we have lived in a reality after the electroweak phase transition, and the universe we live in today and the features we recognize of it are a result of forces including the effect of th…

> and thus gravity.

No. The electroweak phase transition had no effect on gravity whatever; the stress-energy that was governing the expansion was the same before and after. Again, the source of gravity in GR is the stress-energy tensor, not rest mass.

Re: How the Higgs field gives mass to elementary particles

#96

Post by chrsw »

pb1729 wrote: post #76
throw0101d wrote: post #19

> Once upon a time, there came into being a universe. Searingly hot, it swarmed with elementary particles. Among its fields was a Higgs field, initially switched off. But as the universe expanded and cooled, the Higgs field suddenly switched on, developing a nonzero strength. Any particular reason/mechanism why the Higgs field suddenly (gradually?) switched on?

tldr is that it happened because the universe cooled down from a stupendously insanely high temperature to a merely insanely high temperature shortly after the big bang. First look at this picture [0]: https://en.wikipedia.org/wiki/Higgs_mechanism#/media/File:Me... The Higgs field is a complex number Φ (this number can vary at different points in space, we'll come back to this, so don't worry about it for now). You c…

I've always pictured the Big Bang as a big explosion. But maybe it's better to think of it as a big cooling?

Re: How the Higgs field gives mass to elementary particles

#97

Post by foobar1962 »

elashri wrote: post #90
antihipocrat wrote: post #84

Earlier quoted context omitted.

Is it possible for there to be other undiscovered fields with a similar mechanic - turning on when the universe hits a future heat threshold?

What you are trying to describe is what we call phase transition. So just to make it clear the reason higgs field working like that is that after the big bang and cooling of universe to about 10^5 kelvins (don't try to convert this to this strange unit of Fahrenheit) the field transitioned from high energy state to lower energy state. This is what gave rise to the higgs mechanism (what the article talks about). Now t…

> about 10^5 kelvins (don't try to convert this to this strange unit of Fahrenheit)

Challenge accepted... it's about 10^5 Fahrenheit.

Re: How the Higgs field gives mass to elementary particles

#98

Post by TheOtherHobbes »

calf wrote: post #72
emrah wrote: post #32

Earlier quoted context omitted.

Aether has a specific definition and it still does not exist. It was not rediscovered. QFT is not aether-like. Aether was a substance filling all space, while QFT fields like higgs are not physical at all (but rather give rise to physical properties)

How does something not physical give rise to physical properties? Saying that way makes it sounds like a logical conceit is being used.

It organises stuff instead of being stuff.

Which is less of a logical conceit, and more metaphysics.

No one knows what quantum fields are made of. There are various ideas (loop quantum gravity, causal dynamical triangulation, others...) but QFT defines what quantum fields do, not what their component parts are at a more fundamental level.

Re: How the Higgs field gives mass to elementary particles

#99

Post by itishappy »

chrsw wrote: post #96
pb1729 wrote: post #76

Earlier quoted context omitted.

tldr is that it happened because the universe cooled down from a stupendously insanely high temperature to a merely insanely high temperature shortly after the big bang. First look at this picture [0]: https://en.wikipedia.org/wiki/Higgs_mechanism#/media/File:Me... The Higgs field is a complex number Φ (this number can vary at different points in space, we'll come back to this, so don't worry about it for now). You c…

I've always pictured the Big Bang as a big explosion. But maybe it's better to think of it as a big cooling?

Is that so different from an explosion?

Re: How the Higgs field gives mass to elementary particles

#100

Post by [deleted] »

foobar1962 wrote: post #97
elashri wrote: post #90

Earlier quoted context omitted.

What you are trying to describe is what we call phase transition. So just to make it clear the reason higgs field working like that is that after the big bang and cooling of universe to about 10^5 kelvins (don't try to convert this to this strange unit of Fahrenheit) the field transitioned from high energy state to lower energy state. This is what gave rise to the higgs mechanism (what the article talks about). Now t…

> about 10^5 kelvins (don't try to convert this to this strange unit of Fahrenheit) Challenge accepted... it's about 10^5 Fahrenheit.

[deleted]
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