Affect of deep space on time dilation

[Jzz]

I have been thinking deeply about the post on ‘TimeSpace’ by Jim Franklin (#4) in the thread ‘Dark Matter Revisited’ in Cosmology. I have been considering whether gravity would really affect matter in such a way as to cause time dilation. After much thought, I have concluded that it is doubtful. It is well established that gravity affects time, as clocks (and everything else) tick slower in strong gravitational fields. But let's consider deep space.

In deep space, far from any significant celestial bodies, a 100 kg object would exert essentially no gravitational pull because there is no nearby mass to interact with gravitationally. This would result in a negligible gravitational force, essentially zero.

Given this, what happens if such a 100 kg body were accelerated to 0.9c? The relativistic mass can be found using the equation:

m_r = m_o/(sqrt{1 – (v^2)/(c^2))

Where:

m_o = 100 kg

c= 3×10^8 m/s

v=0.9 c

Calculating:

m_r = 100/(sqrt(1 – (0.9c^2)/(c^2) (100)/(sqrt(1 - 0.81)) = (100)/( sqrt 0.19)) ≈232 kg

This gives a relativistic mass of about 232 kg, which corresponds to an increase of approximately 132 kg from the rest mass.

With this in mind, would time dilate under these circumstances? It seems there is room for doubt. However, if time dilation is not the cause of cosmic expansion, what then is the explanation? The idea of cosmic expansion might be flawed, especially since the equations used to describe it are not linear. This suggests the data may be skewed to fit certain models."

 

[Gibsense]

Cosmology. I have been considering whether gravity would really affect matter in such a way as to cause time dilation. After much thought, I have concluded that it is doubtful. It is well established that gravity affects time, as clocks (and everything else) tick slower in strong gravitational fields. But let's consider deep space.

We may get a bit confused here. This paragraph appears contradictory. The way in which gravity affects time is called Tume Dilation. Other similar effects result from speed:
Time is observed as slower in the moving object. The distance it moves over is shortened for it. The object's mass is increased (nowadays, it is preferred to say its momentum is increased).

 

[Jzz]

We may get a bit confused here. This paragraph appears contradictory. The way in which gravity affects time is called Tume Dilation. Other similar effects result from speed:
Time is observed as slower in the moving object. The distance it moves over is shortened for it. The object's mass is increased (nowadays, it is preferred to say its momentum is increased).

Thank you for your thoughts. As I mentioned, my intent was to rely as much as possible on proven empirical evidence. It is well-established that clocks slow down in the presence of gravity. The same applies to everything else. But what happens in the absence of gravity? Does time speed up? If you place a clock in a gravity-free environment, it might tick faster than in a strong gravitational field. But how significant would this effect be?

For instance, consider the Voyager spacecraft. They're in a near-gravity-free environment, yet their operations are hardly affected. So, to return to the original point about the "Timespace" theory, which suggests cosmic expansion is due to differences in time experienced in strong gravitational fields (within galaxies) versus weak gravitational fields (in the intergalactic spaces between galaxies), it seems this idea is flawed. The gravitational effects are too small to have any noticeable impact.

An interesting corollary to this, as I calculated, is that the effect of speed is also negligible when gravity is absent. For example, a 100 kg object moving at 0.9c (280,000 km/s) would have a relativistic mass of 232 kg, meaning its relativistic mass is 132 kg greater than its original mass. It turns out that using classical physics gives equally (equivalent ?) results. Using the equation K.E. = 1/2 mv^2, the kinetic energy comes out to 2×10^18 J. Using E=mc^2 to calculate the equivalent mass gives approximately 22.3 kg.

Now, if the 100 kg object is traveling at 0.9c and has a relativistic mass of 232 kg, it means that, in Earth terms, the object is experiencing a force 2.3 times greater than Earth's gravity (2.3 G). This is an interesting point.

There is always the possibility that I am mixing up kinetic energy and rest energy, but the results are still interesting.

I’d be curious to hear your views on this.

 

[billslugg]

Energy has mass just like matter does. Mass is conserved, energy and matter are not.
The additional mass from high speed travel is exerts the same gravitational force as the equivalent rest mass.
The anomalous acceleration seen very far away is due to our local galaxy cluster area being deficient in mass. The gravitational "lines of force" are less in our cosmic zone than the average for far away. Anything there appears to have a fast running clock.

 

[Gibsense]

But what happens in the absence of gravity? Does time speed up? If you place a clock in a gravity-free environment, it might tick faster than in a strong gravitational field. But how significant would this effect be?

Bill said it. Where there is less mass there is 'faster time, comparatively.
It may be better to express this as 'more time' , perhaps. That prompts a thought:

Can the suggestion/fact that time runs faster where mass is less, in a region, be re interpreted as 'density' of mass/space in this respect -

Compared to the size of the universe the mass/enargy was high (dense) when the universe was young (smaller) = Time is slower
Compared to the size of the universe when older, the mass/energy is lower (diluted by expansion) = Time runs faster

NB The speed of light would be unchanged (1 light year = 1 year)

That's a scary Idea - tell me it is wrong please! A second would be the same technical length but would (by secondary measurement) happen faster. Is this where you were headed Jzz? Hopefully Bill will tell us our error, if not we/you identify dark energy (??) and it's on a roll

 

[Gibsense]

If Copilot is sane, it agrees with the above statement. But only after an amount of cajoling because it kept saying 'Yes we could say that as time runs faster the universe expands faster' but with the added caveat that Dark Energy is the main cause.
It seems that the AI suffers from the same problem as old professors can do. It clings to what it has been taught

It said

• As the universe expands, the mass density decreases
• This results in weaker gravitational fields, causing time to run faster

It then went on to say the accelerated expansion of the universe is driven by dark energy
It failed to see the connection

The connection is of course (in case you are Copilot like) :

• The universe as a n-sphere has a radius that matches time (age of the universe)
• Increasing radius = increasing time
• Increasing time = increasing universe volume (sphere circumference)
• Faster time = faster expansion
• Faster expansion = dark energy speculation concept without current explanation til now

 

[Gibsense]

I was tempted to start a new thread called "The Runaway Universe", but I thought it disrespectful to Jzz, who started this thread. So if other ideas could be true (The feeding spinning black hole/white hole scenario) can I appeal to our universe to eat more soon

please: the weeks go by so fast