[Alan McDougall (OP)]

“Light thinks it travels faster than anything but it is wrong. No  matter how fast light travels, it finds the darkness has always got  there first, and is waiting for it.”   

Terry Pratchett

Is light speed c the fastest speed in the universe?

Alan

[Semaphore]

In the universe, yes, I guess so. But space is expanding at an ever increasing rate so the further-most parts are retreating faster than the speed of light and have vanished, never to be seen again. Our long distant descendants - if we have any - will see the Milky Way but very little else.

[Alan McDougall (OP)]

In the universe, yes, I guess so. But space is expanding at an ever increasing rate so the further-most parts are retreating faster than the speed of light and have vanished, never to be seen again. Our long distant descendants - if we have any - will see the Milky Way but very little else.

There is no limit as to how fast empty space can go it does not contain mass and is therefore, not subject to c!

The Raisin Bread loaf analogy

Galaxies for instant are embedded into the fabric of space something like raisins on a loaf of raisins bread.

Equate the dough of the raisin loaf to the fabric of space and the raisin to galaxies. The galaxies or raisins cannot travel thought the dough/space-time at greater than the speed of light. But the loaf can swell or the universe expand at greater than the speed of light taking the embedded galaxies or raisin with it for the ride.

Galaxies just like all things that have mass cannot exceed the speed of light through the fabric of space time, but they can recede from each other at greater than the speed of light because they are embedded into the fabric of the expanding universe at large "I hope that makes sense?

[Semaphore]

That's what I said, init?

[IAMREALITY]

That's what I said, init?

It's exactly what you said lol.

[PmbPhy]

There are other speeds which are in excess of the speed of light. For example; if two long rods lying in close to the same plane are moving at speeds near the speed of light then their point of intersection can move faster than the speed of light. If you have a beam of light rotating in a plane and shines on a cylindrical wall then its possible that the spot on the wall will move faster than the speed of light. However in instances such there is nothing material moving faster than c. There is an SR text out which covers the subject of this thread. I'll take a look at it and get back to you.

[Semaphore]

How about quantum entanglement, or spooky action at a distance, as Einstein said?

[Alan McDougall (OP)]

That's what I said, init?

You did but I elaborated on it for those who are less informed than you!

[xersanozgen]

If something can be accelerated to the velocity of light, it will transform to a light. 

If something can be accelerated to the velocity of light, this object will transform to a light. To get faster speed than c is never possible even due to transport method or superposing .

However, if  we consider two objects that they gets their speeds independently without the other one; the distance between them can increase by a speed faster than c (but < 2c).  In other words, the collision speed is bigger than c on CERN experiments.

[evan_au]

the distance between them can increase by a speed faster than c (but < 2c).  In other words, the collision speed is bigger than c on CERN experiments.

It is true that if you were standing in a CERN detector, you would see protons coming from the left at almost c, and coming from the right at almost c. If you were Isaac Newton, you would say that the collision velocity is almost 2c.

But I am afraid that Isaac Newton and your good self have not understood Special Relativity.

Einstein pointed out that the observed velocity depends on your frame of reference.
If you now take the frame of reference of one of the protons, you see it coming - but at very slightly less than 1c.

See: https://en.wikipedia.org/wiki/Velocity-addition_formula
Note: It is so incredibly close to c that you will need a lot of digits on your calculator to see that it is actually less than c!

[PmbPhy]

90

the distance between them can increase by a speed faster than c (but < 2c).  In other words, the collision speed is bigger than c on CERN experiments.

It is true that if you were standing in a CERN detector, you would see protons coming from the left at almost c, and coming from the right at almost c. If you were Isaac Newton, you would say that the collision velocity is almost 2c.

In the rest frame of CERN the relative speed of the two particles (tardyons to be exact) is almost 2c. However relativity does no say that the relative speed of two particles can't be greater than c. It only say that there is no frame in which a tardyon can move at or greater than c.

[xersanozgen]

the distance between them can increase by a speed faster than c (but < 2c).  In other words, the collision speed is bigger than c on CERN experiments.

It is true that if you were standing in a CERN detector, you would see protons coming from the left at almost c, and coming from the right at almost c. If you were Isaac Newton, you would say that the collision velocity is almost 2c.

But I am afraid that Isaac Newton and your good self have not understood Special Relativity.

Einstein pointed out that the observed velocity depends on your frame of reference.
If you now take the frame of reference of one of the protons, you see it coming - but at very slightly less than 1c.

See: https://en.wikipedia.org/wiki/Velocity-addition_formula
Note: It is so incredibly close to c that you will need a lot of digits on your calculator to see that it is actually less than c!

Dear evan-au,

“But I am afraid that Isaac Newton and your good self have not understood Special Relativity.”

The answer of this phrase may be that: I am sorry, do you want to say “The Sun turns around the Earth”


Any way please we  ignore them. I don’t like polemic. We can talk by scientific arguments. We must can allow ourselves for new ideas; in this way, we can note and examine alternative hypotheses. Probably we can overcome ancient paradigms and we can approach to near absolute reality. The prize will can be great. you can discover new one of well known when it is wrong. We can discover the limits of our mental abilities.

“To allow ourselves“ is important and significant.

Please reconsider and examine that hypothesis:

We think a candle or a star as light source. The photons (which have released at a moment of time To) compose a spherical surface at the moment of Ti. The increasing speed of this sphere’s radius is c. And the increasing speed of this light sphere’s diameter will be 2c. (external or reference frame's observer. God's eye)

However an fictive observer (that is located on a photon) can always see the center point instead of the other tip of diameter (local or inside observer), because the image can travels by just the velocity c.

[xersanozgen]

90

the distance between them can increase by a speed faster than c (but < 2c).  In other words, the collision speed is bigger than c on CERN experiments.

It is true that if you were standing in a CERN detector, you would see protons coming from the left at almost c, and coming from the right at almost c. If you were Isaac Newton, you would say that the collision velocity is almost 2c.

In the rest frame of CERN the relative speed of the two particles (tardyons to be exact) is almost 2c. However relativity does no say that the relative speed of two particles can't be greater than c. It only say that there is no frame in which a tardyon can move at or greater than c.

 
An observer can perceive all of images by just the velocity c, even if the event realizes by a bigger velocity than c. If the observer is  an actor of an event/experiment,  data or perception will may be restricted or token/perversive.

We must leave the antropocentric estimations  anymore. SR had neglected this scientific requirement.

 

[DudleyC]

Yes according to our known knowledge and scientific proof.

[Navraj Sikand]

Read the theory of Navraj Sikand on this very website for your answer.

[yor_on]

Yes, and as I see it it's also equivalent to time. They go hand in hand through the universe, and consist of local observations.

[yor_on]

The problem physics has with our new understanding of the universe does not consist of why 'c' is 'c'. Because that is provably true, and there is no problem I have found with connecting it to a 'local time keeping' being equivalently 'constant' locally described. The real problem lies in how to connect it into one coherent 'universe' that we all see and believe in.