Special relativity and Earth in context to a stationary point

Click For Summary

Discussion Overview

The discussion revolves around the implications of special relativity, particularly focusing on time dilation as experienced by individuals on Earth compared to a hypothetical twin in a different frame of reference. Participants explore the effects of Earth's velocity in space and the conceptual understanding of time dilation in various scenarios, including the twin paradox.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions the significance of time dilation due to Earth's velocity, suggesting that at 1,750,204 mph, the effects must be considerable.
  • Another participant clarifies that Earth's actual orbital speed is about 64,000 mph, which results in a negligible time dilation factor.
  • A participant proposes a hypothetical scenario where one twin remains on Earth while the other is at a point of absolute zero, inquiring about the relative aging of the twins after 10 years.
  • Concerns are raised about the concept of absolute velocity in the context of special relativity, emphasizing that all velocities are relative and lack intrinsic significance.
  • Some participants express curiosity about the potential for future technological advancements to alter our understanding of time dilation and its implications.
  • There is a discussion about whether time dilation increases uniformly with velocity or at an exponential rate as one approaches the speed of light.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the implications of Earth's velocity on time dilation, and multiple competing views remain regarding the significance of time dilation in various scenarios.

Contextual Notes

Participants acknowledge the limitations of their assumptions and the complexities of defining inertial frames in the context of spacetime curvature.

Who May Find This Useful

Individuals interested in the concepts of relativity, time dilation, and the philosophical implications of velocity and reference frames in physics.

gray1985
Messages
2
Reaction score
0
Special relativity and Earth in context to a stationary point.

Could anyone please help me (I have a keen interest in relativity, but I am not an academic in the subject)

If Earth is traveling around at around 1,750,204 mph then surely the time dilation caused must be significant!

Lets take the twin paradox if we could take a set of new twins, leave one on Earth (child A) and managed to put the other (child B) at a point of absolute zero (hypothetically assuming that there was a point of absolute zero). What would be the relative time dilation on the twins if after 10 years from child A’s perspective had passed. Basically how much older would we (along with Child A) consider child B?

Like I say I’m interested in the time dilation we on Earth go through every day and just accept as the norm!

Also does time dilation have uniform increase with velocity or does it happen at an exponential rate towards c?
 
Physics news on Phys.org
Time dilation with respect to what?

Also note that the velocity you quoted is about 0.26% of the speed of light. The time dilation factor [itex]\gamma[/itex] only differs from unity by about 3 x 10-6 for those speeds, which is completely negligible for almost all practical purposes.
 
Welcome to PF!

Hi gray1985! Welcome to PF! :smile:
gray1985 said:
If Earth is traveling around at around 1,750,204 mph then surely the time dilation caused must be significant!

Nooo … the Earth orbits the Sun at about 18 miles per second (about 64,000 mph), which is about 1/10,000 of the speed of light.

Time dilation would be about 1 - 1/200,000,000.
Also does time dilation have uniform increase with velocity or does it happen at an exponential rate towards c?

https://www.physicsforums.com/library.php?do=view_item&itemid=166"is √(1 - v2/c2), which is approximately 1 - (1/2)(v/c)2 if v is small, and approximately √(1 - v/c)(1 + v/c) ~ √2(1 - v/c) if v is nearly c. :wink:
 
Last edited by a moderator:
First things first, Thanks guys for taking the time to answer

That figure 1,750,204 mph was trying to factor in all things, i.e Earth spinning, Earth orbiting round the sun, sun round our galaxy and the galaxy being hurtled through the universe. (I naively assume that all these will factor and dilate time in our particular frame of reference.

Allow me to try and illustrate my problem a little better.
(I would be very pleased if someone could correct my thinking,)

if we could hypothetically exist at a point in the universe where our velocity through said universe was essentially zero and compared it to say the total sum of all contributing factors that make up the figure I stated (1750,204), would child B be notably older that twin A (lets say we could compare them biologically for aging)?

Like I say I’m not an academic on relativity (so please allow for my poor use of terminologies and what I’m sure are wild amateurish statements). Relativity fascinates me and I genuinely believe (and brace yourself for a wild statement) that time dilation is in essence a form of time travel. And although I’m aware mass can never attain light speed so that time travel in practicality is far fetched, but I believe that maybe 500, 1000 10,000 years from now, breakthroughs and discoveries may open doors that we perceive as closed.

So I guess ultimately what I’m asking, if child B (space kid) has aged more over the 10 years given his frame of reference in comparison to child A on earth, then surly in a rather rudimentary fashion, the time dilatation that has occurred to child A on Earth has caused it to travel further into the ‘future’ in comparison to its twin (twin B).

(note when I use the term traveled into the future I mean it solely with respect to his twin i.e twin B).

I think I’m genuinely curios as to what our given speed through the universe is doing to our frame of reference.

Many thanks
 
gray1985 said:
if we could hypothetically exist at a point in the universe where our velocity through said universe was essentially zero and compared it to say the total sum of all contributing factors that make up the figure I stated (1750,204), would child B be notably older that twin A (lets say we could compare them biologically for aging)?
That was answered in post #2: no.

Becareful saying things like "our velocity through said universe", though - special relativity throws out the concept of absolute velocity, so this velocity you have chosen is quite arbitrary. It doesn't hold any real physical significance.

Also be careful with 'anything is possibe with technology' type statements: technology is limited by the laws of physics and as a result, some things really are not possible.
 
As russ said, all velocity is relative in relativity, and so is time dilation. If we ignore spacetime curvature (which makes it impossible to define an inertial reference frame over a large region of spacetime), there is some inertial frame where we are traveling at 0.99c, another where we're traveling at 0.6c, another where we're at rest, etc...and all inertial frames are treated as equally valid in special relativity.
 

Similar threads

  • · Replies 79 ·
3
Replies
79
Views
6K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 54 ·
2
Replies
54
Views
4K
  • · Replies 20 ·
Replies
20
Views
4K
  • · Replies 57 ·
2
Replies
57
Views
4K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 35 ·
2
Replies
35
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 37 ·
2
Replies
37
Views
5K
  • · Replies 31 ·
2
Replies
31
Views
4K