Speed of light revisited yet still again

@rosborne979,

dalehileman wrote:
But might it not turn out that the photon does indeed have a little mass

Quote:

No, it won't. Things that have zero mass exist at infinite velocity, and things that have mass cannot move at infinite velocity

Ros you might want to restate this, might be a typo of some sort. What you seem to be saying is, "No it won't, but yes it will"

Quote:

Just take F=ma and replace the "m" (mass) with a zero and you can see how the lack of mass and the speed of light are related

No, sorry, Ros I can't. In fact your elaboration seems to confirm that the photon must indeed have mass--however tiny--else it wold move at an infinite velocity

Quote:

The speed of light isn't just an arbitrary velocity, it's an artifact of space-time boundary conditions

To your Earthbound Simpleton that sounds kinda vague, certainly doesn't appeal to the intuition

1 Reply

@dalehileman,

Sorry for the confusion Dale. When I say "infinite velocity" I'm referring to the speed of light, which is an "infinity" within the equation.

Even though the speed of light has a finite value relative to us, it is essentially an infinite velocity with respect to space-time. Time doesn't flow under "speed of light" conditions, so the concept of velocity is meaningless for things in that state (like photons).

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@contrex,

Okay I'll think before I post.
Also if light travels at the speed of light why aren't we crushed by light if light has mass?

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@rosborne979,

Quote:

it is essentially an infinite velocity with respect to space-time

Thanks Ros but your Boilerplate Philistine (me) won't understand

Interesting to note however, there might be some vague correspondence between the assertion and my nutty theory about time-at-a-distance, the reading on traveler Marty's watch as he encounters Earth

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@somewhatsolved,

Quote:

why aren't we crushed by light if light has mass?

Maybe very tiny, some sepoctillionths of a microgram

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@dalehileman,

dalehileman wrote:

Quote:
it is essentially an infinite velocity with respect to space-time
Thanks Ros but your Boilerplate Philistine (me) won't understand

Ok, then just forget that I used the term infinite and just realize that any time you reduce the mass of something to zero, then the tiniest force applied to it would instantly accelerate it to the speed of light. And because it has no mass it has no inertia and therefor the acceleration is instantaneous.

Remember too that everything we are saying is oversimplified to the point where it only tenuously meets the realities of physics, because you can never really take an "object" and remove all its mass, or you wouldn't have an object. A more realistic treatment would require that you realize that "massless" things and "speed of light" things are intrinsically linked such that they can never be separated.

You need to stop thinking of the speed of light as a velocity and start thinking of it as a boundary condition of space-time.

1 Reply

@dalehileman,

dalehileman wrote:

Quote:
why aren't we crushed by light if light has mass?
Maybe very tiny, some sepoctillionths of a microgram

This is like those guys in the Middle Ages arguing over the weight of the soul. Light has NO MASS.PERIOD.

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@rosborne979,

Quote:

and "speed of light" things are intrinsically linked such that they can never be separated.

Almost infringing on the philo realm

Quote:

….. and start thinking of it as a boundary condition of space-time

Leaves me in an intuitional fog, sorry Ros

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@contrex,

Yes but why?
Also is light a particle or a wave?

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@contrex,

Quote:

Light has NO MASS.PERIOD

How do we know that some time in the future Con we might find a particle EVER SO SLIGHTLY heavier than the photon which therefore goes EVER SO SLIGHTLY faster, the diffs being 'way too small for us to presently measure

1 Reply

@dalehileman,

dalehileman wrote:

Leaves me in an intuitional fog, sorry Ros

Try to intuit this...
People ask where the edge of the Universe is. If the Universe was two dimensional it would be like a big plate and it would have an edge. If the Universe were three dimensional it would be like a big bubble and it would have an edge/boundary.

But the Universe is four dimensional (space-time) so it doesn't have a physical edge, it has a dimensional boundary beyond which there is no space or time. So the "speed of light" is the edge of the Universe. Things which exist beyond it are outside of space and time which is why you can't intuit them, you can only infer them by comparing them to space-time as a reference frame.

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@dalehileman,

dalehileman wrote:

Quote:
Light has NO MASS.PERIOD
How do we know that some time in the future Con we might find a particle EVER SO SLIGHTLY heavier than the photon which therefore goes EVER SO SLIGHTLY faster, the diffs being 'way too small for us to presently measure

That's like asking if some day we will discover that parallel lines actually do meet if we measure them carefully enough.

The answer is no, they don't, and they never will. It's not a matter of accurate measurement or limits of knowledge, it's a matter of definitions. Or in the case of massless "particles" the definition of the math which we use them for. You would have to change the rules of the math rather than changing the particles themselves.

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@rosborne979,

Hey I just remembered there is something that travels faster than the speed of light.
According to the lead Physics Professor of a New York University there is a particle that travels faster than light and makes up the ever expanding boundary of our universe. Also Neutrinos technically do travel faster then light. But that jumps back to Star Trek ship physics.

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@somewhatsolved,

I didn't make fun of you, vut i will now, you arrogant little asshole. I just stated the varying light-distances between the earth and Mars. I did not quote any theories. You were wrong--get over it. You suck at this type of conversation.

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@rosborne979,

Quote:

But the Universe is four dimensional (space-time) so it doesn't have a physical edge,

Quite so Ros

Quote:

it has a dimensional boundary beyond which there is no space or time.

Except "beyond which" implies some sort of existence. There simply is no "beyond"

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So the "speed of light" is the edge of the Universe.

Ros I'm lost here, you'll hafta elaborate

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Things which exist beyond it are outside of space and time……..you can only infer them…….

Sorry Ros but to me totally contradictory. If the Universe is finite there simply isn't a beyond or outside

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@rosborne979,

Quote:

That's like asking if some day we will discover that parallel lines actually do meet if we measure them carefully enough.

No Ros it's not. I can't see any such comparison. I'm merely suggesting that someday we might have means for measuring such speeds within very tiny increments

Yes, no, Ros, the photon might be the fastest but it might not. We like to think of it as massless but we could be wrong. Maybe we'll find another "particle" three sepoctillionths of a nanogram lighter

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@somewhatsolved,

somewhatsolved wrote:

Hey I just remembered there is something that travels faster than the speed of light.
According to the lead Physics Professor of a New York University there is a particle that travels faster than light and makes up the ever expanding boundary of our universe. Also Neutrinos technically do travel faster then light. But that jumps back to Star Trek ship physics.

The expansion of the universe involves space itself expanding, causing distant objects to move away from us faster than the speed of light, not objects travelling through space faster than the speed of light.

No neutrino has ever been measured travelling faster than light speed except for one well known experiment which turned out to be in error. Experiments believed accurate show neutrinos travelling at the speed of light. The most popular theories of neutrinos involve a massless neutrino which travels at the speed of light, or a particle with a very low mass which can travel near the speed of light.

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@dalehileman,

dalehileman wrote:

...In this connection it's interesting to note that it all falls in place if we assume that somehow we're underestimating the speed of light, that it's not c but many times c....

And those countless measurements made for over a century that agree with each other?

dalehileman wrote:

That easily explains for instance if Polly leaves her home planet Mars at light speed...

Can't happen.

I see that you've learned nothing since last you posted on this subject. In particular, you have not acquired the correct understanding that would come with spending a few days reading a good write-up of special relativity.

Speed of light revisited yet still again

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