Is time measured only as the speed of light? If so, is it the effect of gravity on photons that slows time?

Answer 1

Where did you get that definition? Speed of light isn't a tool to measure time, no way. Time is the space between to events. And our (mankind's) definition of time is based on the desintegration of caesium (see atomic clock or method to determine the age of archaeological findings).
If you need or want further explanation how that works, send me an email.

By known physics, gravity shouldn't have any effect on photons because photons are said to have no mass at all.
Where did you get that statement from that this would slow time?
But we know it better:
We do know (for sure), that there is a gravity effect: If you imagine light as beams, then these beams will be bent near huge stellar objects.
However, that doesn't slow time ... not at all.

And the only thing that is thought to "slow" time (only in theory) is traveling at the speed of light. But this is a prediction made from the theories from Einstein ... we don't have any possibility of delivering or receiving an evidence.
There are other theories saying that rotation of a special kind might be suitable to slow time ...

What we can slow down, is the movement of light itself.
Is it possible you mixed something up in your mind with speed of light and time?

If you are taking about units like "lightyear" or similar, then we arn't talking about time, but about distances. A lightyear is just a unit of distance. E.g. our next neighbor galaxy, Andromeda, is in a 2.000.000 lightyears' distance. In another unit, it's in a distance of 0.8 mega-parsec. Right the 2 million light years also name the time it's light takes to travel from there to us: 2 million years, but it is still a measurement for a distance, not for time.

Anyway, don't forget how little we know about the universe. As long as we don't know more, time is and remains just the "space" between 2 events. This kind of space (often understood or explained as the 4th dimension) can neither be compressed nor expanded nor slowed down nor accelerated. It is just there.
It is our definition of units (seconds, minutes and so on), that tells us how big that "space" is.

Answer 2

The idea of speed - of light or anything else - presupposes an idea of time, because speed is distance travelled per unit of time. We measure time according to observable physical processes, such as the Earth's orbit around the sun (a traditional year), or the behaviour of caesium atoms (the scientists' definition of a second, see first link). The effect of gravity on photons is not relevant. The slowing of time is a relativistic effect, if you hold clock A, and someone holding clock B travels past you, you will observe that clock B is running slow (and the holder of clock B will observe that clock A is running slow). That is why the scientific definition of the second says that the caesium atom in question must be "at rest". The slowing of time in this way is a readily observed physical phenomenon, eg the decay rate of muons (see second link).

Answer 3

I think you have some of the principles in general relativity mixed up.

According to general relativity everything in the universe is moving at the speed of light. This covers travelling through all 4 dimension (Length, Height, Depth and TIME).

Therefore, if you are standing still you are not moving through the 3 spatial dimensions (well actually you are since the Earth is moving and rotating, but ignoring this..) so you are only moving through the time dimension at the speed of light.

If however you were in an aircraft flying in a straight line then some of you motion would be through the spatial dimension, therefore subtracting you speed of travel through the time dimension.

Its all a balancing act. the faster you move in the spatial dimensions the slower you move through the time dimension.

If you were ever able to move at the speed of light then time would stop.

Photons have zero mass and therefore can move at the speed of light and gravity (or any other force) cannot change their speed.

Hope this covers what you wish to know

Answer 4

Albert Einstein Quote:

"Sitting next to a pretty girl for an hour feels like a minute, placing one's hand on a hot stove for a minute feels like an hour".

"This is intended to introduce the listener to the concept of the interval between two events being perceived differently by different observers."

Thought this was quite a good view on it, as if you look at a fly, who see's time slower than us, they have more time to react to an incoming swatting hand, and thus can avoid it.
So i guess its each persons perspective.

Answer 5

Too technical for me but im sure the black hole has the effects on time and photons

Answer 6

Neither.

Answer 7

ha.. ha..ha ....good question