Fleeing earth at the speed of light

Click For Summary

Discussion Overview

The discussion revolves around the feasibility of interstellar travel at speeds approaching that of light, the potential for finding habitable planets outside our solar system, and the implications of relativistic effects on aging and mass during such journeys.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions the closest potentially habitable planet or moon outside our solar system and speculates on the possibility of reaching it at near-light speeds while experiencing time dilation.
  • Another participant emphasizes the lack of information on exoplanets and asserts that the question of habitability remains unanswered, while also stating that mass does not change during high-speed travel.
  • A participant reiterates the focus on whether a journey could take only a few years from the travelers' perspective despite the vast distances involved, suggesting that equipment would be necessary for sustaining life on another planet.
  • One participant proposes that colonizing Mars would be more cost-effective than seeking distant habitable planets, expressing skepticism about finding a nearby habitable world without equipment.
  • Another participant challenges the common assertion that mass increases as speed approaches light, suggesting that this misunderstanding stems from a lack of comprehension of relativity and explaining the differences in perception of acceleration between observers.
  • A later reply confirms the theoretical possibility of aging slowly while traveling near the speed of light, referencing an external resource for further reading.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of interstellar travel, the implications of relativistic physics, and the potential for finding habitable planets. No consensus is reached on these topics.

Contextual Notes

Participants highlight limitations in current knowledge about exoplanets and the complexities of relativistic effects, indicating that assumptions about mass and acceleration may not hold under high-speed conditions.

Pengwuino
Gold Member
Messages
5,112
Reaction score
20
Ok i was wondering something. Whats the closest planet/moon capable (possibly with human interevention) of supporting life that isn't in our solar system? And If you age slowely nearing the speed of life, wouldn't we be able to leave our solar system and reach another planet if we can go near the speed of light (and we'd age much slower so we could actually live out journey)? I know mass has to go incredibly high but its just a mental exercise :)
 
Physics news on Phys.org
We have only begun to find other planetary systems in the last few years. There is virtually NO information about conditions on any of the planets found. So the only answer to your question is "We do not know".

and NO! Your mass would not change if you imbarked on a high speed interstellar journey.
 
Well i meant if we did find one and had to leave Earth and we sent over equipment to sustain life and all that. My main focus on would we make the journey in only a few years of our time even though it might be millions of light years away?

And why does everyone say as your speed -> c, mass - inf.
 
Pengwuino said:
Well i meant if we did find one and had to leave Earth and we sent over equipment to sustain life and all that. My main focus on would we make the journey in only a few years of our time even though it might be millions of light years away?

I think it would be the most cost-effective to colonize Mars. In terms of other habitable planets, however, my guess is that they wouldn't be that far. I would be very surprised, however, if we found one nearby capable of supporting us sans equipment.
 
Pengwuino said:
Well i meant if we did find one and had to leave Earth and we sent over equipment to sustain life and all that. My main focus on would we make the journey in only a few years of our time even though it might be millions of light years away?

And why does everyone say as your speed -> c, mass - inf.
Because they do not understand Relativity?

Suppose you were in a spaceship accelerating away from the Earth with a known constant force applied. To a stationary observer on Earth using the Laws of Newton, the ship's acceleration would appear to be reduced as it neared the speed of light AS IF ITS MASS were increasing. In fact the occupants of the ship may have been on a forced diet and actually lost mass as the journey progressed. The crew of the ship would not experience any reduction in their acceleration nor any change in mass nor would the operation of their lights change. They would note, however, that the Earth was not receding as fast as NEWTON would predict for their rate of acceleration.

The answer is that for relative velocities between 2 objects Newtons laws loose accuracy as you exceed a separation velocity which is a measurable fraction of c. At separation velocities greater then about .1c you must use the Lorentz transforms to correctly surmise the distance traveled.
 
Last edited:
Pengwuino said:
And If you age slowely nearing the speed of life, wouldn't we be able to leave our solar system and reach another planet if we can go near the speed of light (and we'd age much slower so we could actually live out journey)?
Yes, in theory. See http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html .
 
Last edited by a moderator:

Similar threads

  • · Replies 21 ·
Replies
21
Views
5K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
6
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 57 ·
2
Replies
57
Views
4K
  • · Replies 42 ·
2
Replies
42
Views
6K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 30 ·
2
Replies
30
Views
3K
  • · Replies 98 ·
4
Replies
98
Views
10K