Assuming completely empty space, does a spacecraft traveling at 0.5 C require co

Question

Assuming completely empty space, does a spacecraft traveling at 0.5 C require continuous thrust to avoid deceleration?

If the spacecraft is traveling at 0.5 C, does it's relativistic mass act upon objects that it passes by?

It is understood that space is not truly empty. The question was designed to consider only relativistic effects.

On a continuing thought however, If the spacecraft is traveling at 0.5 C and starts to decelerate, does it need to decelerate it's relativistic mass or it's rest mass?

Explanation / Answer

In completely empty space a spacecraft travelling at any speed does not need thrust to stay at that speed. It only needs thrust to accelerate or decelerate. Space isn't empty, so a spececraft would need a small amount of thrust to maintain it's velocity, but in most circumstances the thrust needed is tiny. This issue was discussed in Would a fast inter-stellar spaceship benefit from an aerodynamic shape?.

No matter how fast a spacecraft travels it doesn't develop a stronger gravitational field. This is because the source of the field is the stress-energy tensor not just the mass. For more discussion of this see reletivistic mass as seen by different observers.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.