Light & Space-Time: Why So Fast?

[Akaisora]

Is there a reason why light ( electromagnetic waves) is the only thing that can move that fast through space-time? I understand that light doesn't have mass and it is affected by the geometry of space-time, but could there be a specific reason?

 

[PAllen]

Light isn't the only thing that moves that fast. Gravitational waves move at the same speed. If neutrinos were massless as once thought, they would move at this speed. The speed c is the speed of anything without rest mass, and also, the limiting speed of massive particles.

 

[Akaisora]

Light isn't the only thing that moves that fast. Gravitational waves move at the same speed. If neutrinos were massless as once thought, they would move at this speed. The speed c is the speed of anything without rest mass, and also, the limiting speed of massive particles.

Can this be related to the higgs field?

 

[ZapperZ]

Can this be related to the higgs field?

Not it can't, because the Higgs field does not couple to light.

Zz.

 

[Naty1]

...but could there be a specific reason?

likely there is, but we don't know it. So far physics mostly describes WHAT happens rather 'WHY". A lot of the Standard Model of particle physics [which describes particles and their interactions and characteristics] is based on experimentally measured observations...like zero mass for a photon, it's speed in a vacuum, the mass and charge of an electron, and many other key ingredients. The theories that have been developed fit these observations.

It seems that everything [ forces, particles, space and time, energy, etc] were once 'unified' [existed as a single entity] at the time of the big bang...at the start of our universe. Why the precise characteristics we observe around us actually appeared is still a mystery. For more on these ideas you can check out "fine tuned universe" and 'spontaneous symmetry breaking'.

Here is an example of modeling...How the Higgs mechanism is stuck on to the Standard Model:

http://en.wikipedia.org/wiki/Spontaneous_symmetry_breaking#Higgs_mechanism

...Without spontaneous symmetry breaking, the Standard Model of elementary particle interactions requires the existence of a number of particles. However, some particles (the W and Z bosons) would then be predicted to be massless, when, in reality, they are observed to have mass. To overcome this, spontaneous symmetry breaking is augmented by the Higgs mechanism to give these particles mass...

So when Zapper posted :

...the Higgs field does not couple to light.

it means that Higgs field does not change the characteristic of light...it has no direct affect on light, but does certain bosons.

 

[audioloop]

Is there a reason why light ( electromagnetic waves) is the only thing that can move that fast through space-time? I understand that light doesn't have mass and it is affected by the geometry of space-time, but could there be a specific reason?

read this, at the end, photon can have some mass

http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.111.021801
"experiments with electric and magnetic fields constrain the mass to less than 10^-54 kg"

it would be a possible upper limit.



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[ZapperZ]

read this, at the end, photon can have some mass

http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.111.021801
"experiments with electric and magnetic fields constrain the mass to less than 10^-54 kg"

it would be a possible upper limit.



.

Incorrect. That says nothing that it has or can have mass. It is just that up to that limit, there is none detected.

Zz.

 

[rbj]

Is there a reason why light ( electromagnetic waves) is the only thing that can move that fast through space-time? I understand that light doesn't have mass and it is affected by the geometry of space-time, but could there be a specific reason?

my spin is that the speed of any ostensibly "instantaneous" interaction (EM, gravity, strong nuclear force) is this same $c$.

so imagine that you're holding a large negative charge and I'm holding a large positive charge and we're restricting the motion along the axis connecting you and me but not along the other two. if i move my charge up a meter, your charge will follow it up. if i move mine to my right, your charge follows to your left (assuming we are facing each other). but, as observed by a third party who is equidistant from you and me, your charge does not respond instantly, but is delayed be a period of time that is proportional to the distance between us (and that constant of proportionality is $1/c$).

if i were to move my charge back and forth a million times per second, your charge would respond that many times also. i would be a transmitting antenna and you would be a receiving antenna and, at that frequency, you could also tune it in with an AM radio. if it were 100 million times per second, you could tune it in with an FM radio. and if it were 500 trillion times per second, you would see it as a blur of orange.

it would be the same if we were big as gods and both holding planets. any perturbation i make with the planet i am holding will be followed by a response with the planet you are holding. and it's the same constant of proportionality regarding the delay observed by the third party and the distance separating us.

so rather than thinking of it as the "Speed of Light" or even as the "Speed of EM", i think of it as the speed of all things ostensibly "instantaneous".

 

[Naty1]

my spin is that the speed of any ostensibly "instantaneous" interaction (EM, gravity, strong nuclear force) is this same c.

nobody claims any of those are 'instantaneous' except for Newtonian physics approximations.

edit: "i think of it as the speed of all things ostensibly "instantaneous".

not entanglement correlations.

 

[rbj]

are entanglement correlations one of the four fundamental interactions?

 

[bahamagreen]

Wikipedia : Photon : Experimental checks on photon mass

"Photons inside superconductors do develop a nonzero effective rest mass..."

 

[ZapperZ]

Wikipedia : Photon : Experimental checks on photon mass

"Photons inside superconductors do develop a nonzero effective rest mass..."

And electrons inside a heavy fermion ruthenates can have an effective mass more than 200 times its bare mass. What has this proven?

Unless you are willing to go out on the limb and say that these many-body interactions actually produces a valid covariant mass, this example from photon inside a superconductor has no relevance here.

Zz.

 

[Naty1]

A bit of underlying detail on Zapper's post:

...One of the results from the band theory of solids is that the movement of particles in a periodic potential, over long distances larger than lattice spacing, can be very different from their motion in a vacuum. The effective mass is a quantity that is used to simplify band structure by constructing an analogy to the behaviour of a free particle with that mass...For some purposes and some materials, the effective mass can be considered to be a simple constant of a material. In general, however, the value of effective mass depends on the purpose for which it is used, and can vary depending on a number of factors...

http://en.wikipedia.org/wiki/Effective_mass_(solid-state_physics )

edit: In other words, particle characteristics ARE affected by their environment.

 

[Nugatory]

are entanglement correlations one of the four fundamental interactions?

No. They aren't an interaction at all, they're correlations. It's tempting to assume that the correlations are caused by something happening between the entangled particles, but this assumption is both deeply problematic and not required by the formalism of quantum mechanics.


There's a relevant thread in the QM subforum: https://www.physicsforums.com/showthread.php?t=707429

 

[curious bishal]

As far as I have understood,light is the fastest thing in universe. But the most important thing is that it is only in the sense of our available technology and science. Scientists had already mentioned that, during the big bang, initially matter traveled and scattered at a great speed; even greater than the speed of light.
You can consider gravitational force as an example. Ligt takes around 8 minutes to reach us from the sun. If you suddenly remove the sun aside, will it take 8 minutes for the gravitational changes to take effect on the earth?
So the things,whatsoever that travels at higher speed than light are yet to discover and I m pretty sure that one day it will come out.

 

[audioloop]

Incorrect. That says nothing that it has or can have mass. It is just that up to that limit, there is none detected.

Zz.

interesting.
thanks for the clarification.





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another possible upper bound, studies of galactic magnetic fields suggest a much better limit of less than 3 × 10−27 eV.



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[Drakkith]

As far as I have understood,light is the fastest thing in universe. But the most important thing is that it is only in the sense of our available technology and science. Scientists had already mentioned that, during the big bang, initially matter traveled and scattered at a great speed; even greater than the speed of light.

Yes, this is due to the expansion of space, which does not have a speed limit. There are galaxies right now that are receding away from us at many many times the speed of light. But motion through local space IS subject to a maximum speed limit, c.

 

[kimster]

Is there a reason why light ( electromagnetic waves) is the only thing that can move that fast through space-time? I understand that light doesn't have mass and it is affected by the geometry of space-time, but could there be a specific reason?

i also think of that an i get ridiculed about that. light is made of particles and those particles are traveling the speed of light. those particles are traveling the speed of light and they have a limited mass. einstein said that in order to travel faster then light you would have to have infinite energy and an infinite mass.

 

[Dale]

those particles are traveling the speed of light and they have a limited mass.

Not just limited mass, 0 mass. Mass (aka invariant mass) is given by:
$m^2 c^2 = E^2/c^2 - p^2$

Since photons have $E=pc$ you get m=0.