2
votes
4answers
101 views

How much could one slow down aging using existing spacecraft?

Imagine that I board a spacecraft and head away from the Earth at top speed until I've aged twenty years, then I turn around and come back. How much younger will I be than the unexciting folk who hung ...
0
votes
1answer
73 views

Does speed in space really matter?

This is about validating the science from a science fiction novel. My understanding is that speed is all relative. So while I am in a car on the freeway my speed relative to another passenger is ...
26
votes
1answer
2k views

How long would it take me to travel to a distant star?

Suppose I wanted to travel to one of the recently discovered potentially Earth-like planets such as Kepler 186f that is 490 light years away. Assuming I had a powerful rocket and enough fuel, how long ...
5
votes
1answer
246 views

Travel duration from Earth to a star at 9.8 m/s² acceleration

How much time would it take for a traveler (in traveler's perspective) to reach a star at distance $d$, if it accelerates at 9.8 m/s² (for a comfortable travel)? I understand that $V = V_0 + a\times ...
16
votes
4answers
840 views

How would we see a near-lightspeed object emitting light?

Consider an object travelling near the speed of light relative to us (let it be a spaceship or a star), which is emitting light (consider it monochromatic resulting from a two level electronic ...
0
votes
5answers
1k views

How a spacecraft travelling near light speed avoid asteroids?

How would a spacecraft traveling near light speed avoid a (relatively dense group of) asteroids? Or suppose such spacecraft is designed, how would the physics work for steering it inside such a ...
3
votes
1answer
153 views

What's wrong with this reactionless drive?

I think this is analogues for the Woodward effect, but macroscopic: We assume a spacecraft consisting of a broomstick, a donut and lots of gear for storing and transfering mechanical energy. Take the ...
0
votes
2answers
823 views

If acceleration causes relative time dilation does the eventual deceleration reverse it?

If acceleration causes relative time dilation does the eventual deceleration reverse it? For example: traveling to Alpha Centauri Based on me reading this site: ...
2
votes
2answers
332 views

What equations do I use to do basic time dilation problems?

I understand the concepts of relativity, but I don't know where to go to set up equations to do any actual calculations. For example, what equations would I use to find out the following: A ship ...