Speed of light plus gravity

[thinkandmull]

This thread is for those interested in physics.

As you know traveling at the speed of light slows down time. Gravity also can slow time. I was wondering if something traveling at the speed of light can be affected by gravity and if this would make time slow down even further.
Thanks

 

[Fauken]

This thread is for those interested in physics.

As you know traveling at the speed of light slows down time. Gravity also can slow time. I was wondering if something traveling at the speed of light can be affected by gravity and if this would make time slow down even further.
Thanks

The speed of light is the speed of light is the speed of light; it is constant. Even if a light is shined from a space ship traveling at 0.4c, the light coming out of the flashlight is still traveling 3*10^8 meters per second.

Hope this helps!

 

[thinkandmull]

However, light can be bent by gravity, so can a spaceship traveling that fast be bent by gravity into going slower than can be imagined?

 

[Vico]

This thread is for those interested in physics.

As you know traveling at the speed of light slows down time. Gravity also can slow time. I was wondering if something traveling at the speed of light can be affected by gravity and if this would make time slow down even further.
Thanks

Special Relativity tells us that moving clocks run slower with respect to a stationary observer. This slowing of time becomes more obvious as something approaches the speed of light. Satellites do not travel anywhere near the speed of light, however they are travelling very fast compared to an observer on the ground, so the effect is measurable.

General Relativity says that the closer you are to a heavy mass, such as Earth, the slower time will move for you. This means that a clock on a satellite orbiting the Earth will run faster relative to one on the ground.

GPS satellites travel at approximately 8,700 mph (14,000 km/h) with respect to Earth. This means time runs 7,200 nanoseconds per day slower for a satellite relative to us on Earth as described by Special Relativity.

However, using General Relativity it is possible to calculate that time goes faster for a GPS satellite by 45,900 nanoseconds per day, due to the satellite being 19,000km above the Earth (therefore in weaker gravity). This means overall time runs 38,700 (45,900 – 7,200) nanoseconds faster per day for a GPS satellite relative to us stationary on Earth.

physics.org/article-questions.asp?id=77

 

[Rolltide]

The speed of light is the speed of light is the speed of light; it is constant. Even if a light is shined from a space ship traveling at 0.4c, the light coming out of the flashlight is still traveling 3*10^8 meters per second.

Hope this helps!

The speed of light is a constant… in a vacuum. There are materials known that can slow the speed of light, and there has also been a study that changed the speed of light by altering the shape of photons.

bbc.com/news/uk-scotland-glasgow-west-30944584

 

[thinkandmull]

Can gravity make time stop?

 

[JurisPrudens]

Can gravity make time stop?

Yep. Black hole.

 

[Tomdstone]

As you know traveling at the speed of light slows down time.

These things have to be approached carefully otherwise we can end up in various paradoxes such as the twin paradox with Anne and Bob. Anne and Bob are both 25 years old and Anne stays at home, while Bob goes off on a spaceship to a distant galaxy at a high rate of speed. Bob’s velocity gives him a time dilation factor of 3 so according to Anne, Bob is younger. But with regard to Bob’s reference frame, Anne was moving, so Anne is younger. Now Bob returns to earth. How can Bob be younger than Anne and Anne be younger than Bob at the same time when Bob returns to earth and they are reunited?

 

[Vico]

Can gravity make time stop?

The phenomenon of time is relative not absolute. It may appear to be close to stopped from some relative reference point. One theory of eternal inflation (multiverse theory) says that time itself will end in five billion years.

 

[on_the_hill]

These things have to be approached carefully otherwise we can end up in various paradoxes such as the twin paradox with Anne and Bob. Anne and Bob are both 25 years old and Anne stays at home, while Bob goes off on a spaceship to a distant galaxy at a high rate of speed. Bob’s velocity gives him a time dilation factor of 3 so according to Anne, Bob is younger. But with regard to Bob’s reference frame, Anne was moving, so Anne is younger. Now Bob returns to earth. How can Bob be younger than Anne and Anne be younger than Bob at the same time when Bob returns to earth and they are reunited?

Sometimes the easiest way for me to understand these things is to simply accept them without questioning them. Which I cannot do, since they’re paradoxes that don’t make any sense. Which is a paradox unto itself.

 

[Vera_Ljuba]

These things have to be approached carefully otherwise we can end up in various paradoxes such as the twin paradox with Anne and Bob. Anne and Bob are both 25 years old and Anne stays at home, while Bob goes off on a spaceship to a distant galaxy at a high rate of speed. Bob’s velocity gives him a time dilation factor of 3 so according to Anne, Bob is younger. But with regard to Bob’s reference frame, Anne was moving, so Anne is younger. Now Bob returns to earth. How can Bob be younger than Anne and Anne be younger than Bob at the same time when Bob returns to earth and they are reunited?

That is not a paradox. The equivalence of coordinate systems ONLY applies to “stationary systems”, which include those systems which move with a “constant speed on a straight line”. Bob undergoes a period of acceleration and deceleration, so the basic setup of the “special relativity” does not apply.

 

[thinkandmull]

The phenomenon of time is relative not absolute. It may appear to be close to stopped from some relative reference point. One theory of eternal inflation (multiverse theory) says that time itself will end in five billion years.

Isn’t this Kant’s position?

 

[Vico]

Isn’t this Kant’s position?

The answer is dependent on what is called perception. Kant rejected the transcendental realism of both Leibniz and Newton. He made the distinction between sensation and intuition and held to non-empirical intuition, rejecting Berkeley’s empirical intuition (who also rejected the transcendental realism).

So to say yes it is relative has different meanings.

 

[thinkandmull]

What’s the difference between empirical intuition and transcendental realism? Modern physics says that time is something empirical, so if Kant was correct his “time” would be superimposed on what physicists speak of now

 

[Vico]

What’s the difference between empirical intuition and transcendental realism? Modern physics says that time is something empirical, so if Kant was correct his “time” would be superimposed on what physicists speak of now

Kant, transcendental realism: that view “which regards space and time as something given in themselves (independent of our sensibility)”.

Pure intuition: pure intuitions are concepts of space and time applied to every perception. Pure intuitions of space and time can be exercised independent of experience, so they can serve as the basis of math and geometry.

Empirical intuition: Once pure intuitions are applied to sensations they become empirical, which means,* sensations* that exist in space and time.

 

[thinkandmull]

How can perceptions of “space and time as something given in themselves” be perceived except empirically?

 

[Vico]

How can perceptions of “space and time as something given in themselves” be perceived except empirically?

Sensations when combined with pure intuition make empirical intuitions.

The faculty of sensibility applies pure intuitions to give form to the sensations.

 

[thinkandmull]

Now bringing up empirical intuitions? It doesn’t answer how Liebniz’s view differed from Berkeley

 

[Sacred_Heart_1]

This thread is for those interested in physics.

As you know traveling at the speed of light slows down time. Gravity also can slow time. I was wondering if something traveling at the speed of light can be affected by gravity and if this would make time slow down even further.
Thanks

The speed of light traveled is all relative to time outside the speed of light. It’s continuous. Time inside and outside the speed of light is the same. If light belongs to the same space/time continuum then there is no difference.

Time slowing down is just a theory. It cannot be proven or disproven at this time. Yea the physics add up but common sense says that it cannot be true; for if it was true Space within this continuum would be ripped apart by time. Even in a black hole this is true, yet, I think its gamma radiation that escapes violently from black holes.

Look a human being cannot survive the speed of light nor the ripping of black holes. If we look from an outside perspective we can see that it all happens within time. The passage of time is a constant it doesn’t change no matter what physical reality works upon it. Perhaps, the perception of time passing plays tricks.

Let’s say we have a photon that has to go hundred meters. When the photon hits the hundred meter mark it has done so through the same passage of time whether within the speed of light or without the speed of light. We can perceive this to be true in either perspective; otherwise it becomes paradoxical because even though the photon hit the hundred meter mark, in your theory it would still be travelling to hit the mark because time slows. Time relates to time inside and outside of the speed of light. its all the same.

 

[Vico]

Now bringing up empirical intuitions? It doesn’t answer how Liebniz’s view differed from Berkeley

You asked “How can perceptions of “space and time as something given in themselves” be perceived except empirically?” not how the two views of Liebniz and Berkeley differed.