Spinning at the speed of light?

Click For Summary
SUMMARY

Objects cannot rotate at the speed of light due to the requirement of infinite energy to accelerate any massive object to the speed of light (c). While special particles known as "tachyons" are theorized to exist and could travel faster than light, there is no empirical evidence supporting their existence. Furthermore, the implications of faster-than-light travel could violate causality, as it may allow for backward time signaling, conflicting with the principles of Special Relativity (SR).

PREREQUISITES
  • Understanding of Special Relativity (SR)
  • Familiarity with the concept of massless particles
  • Knowledge of energy-mass equivalence
  • Basic grasp of causality in physics
NEXT STEPS
  • Research the properties and implications of tachyons in theoretical physics
  • Study the principles of Special Relativity and its impact on mass and energy
  • Explore the concept of causality and its relevance to faster-than-light travel
  • Investigate the relationship between rotational motion and relativistic effects
USEFUL FOR

Physics students, theoretical physicists, and anyone interested in the implications of Special Relativity and faster-than-light concepts.

RunSwimSurf
Gold Member
Messages
23
Reaction score
0
Actually I have a couple of questions. First of all, I'm new here so hello to everyone.

1) Is it possible for an object or something to rotate at the speed of light? For example, with a special record player, can a record spin at or near the speed of light or does c only refer to a straight path? Also, do the same rules apply meaning an infinite amount of energy is needed to accelerate the record to c?

2) Let's say that it is possible for a record to spin at light speed. If the inside and the outside of the record are traveling at the speed of light, but the outside of the record must travel a greater distance, then wouldn't the outside of the record be traveling faster than the speed of light? (I vaguely remember seeing this problem in a Calvin and Hobbes comic strip)

3) Since it's impossible to accelerate an object to the speed of light, is it possible for an object to exist which has always been faster than light? Another massless particle of some sort? Or does SR forbid this?

Thanks.
 
Physics news on Phys.org
RunSwimSurf said:
1) Is it possible for an object or something to rotate at the speed of light? For example, with a special record player, can a record spin at or near the speed of light or does c only refer to a straight path? Also, do the same rules apply meaning an infinite amount of energy is needed to accelerate the record to c?
Yeah, it's impossible because it takes an infinite amount of energy to accelerate any massive object to c.
RunSwimSurf said:
3) Since it's impossible to accelerate an object to the speed of light, is it possible for an object to exist which has always been faster than light? Another massless particle of some sort? Or does SR forbid this?
SR doesn't really forbid it, such hypothetical particles are called "tachyons", see this article. But there's no evidence they exist, and if SR is correct any faster-than-light signalling would also open up the possibility of sending signals backwards in time for reasons relating to the relativity of simultaneity, so they'd cause problems with causality.
 

Similar threads

High School Max Speed of Molecules: 1 Electron Stripped?
  • · Replies 9 ·
Replies
9
Views
2K
High School Light Speed In Forward and Backward Directions
  • · Replies 51 ·
2
Replies
51
Views
5K
Undergrad Light Speed in Dense Medium: Explained
  • · Replies 1 ·
Replies
1
Views
2K
High School Let me ask a thing about the Speed of Light
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Can Propeller Speeds and Wave Breaks Challenge the Speed of Light?
  • · Replies 13 ·
Replies
13
Views
2K
Graduate 1-Way Speed of Light
  • · Replies 42 ·
2
Replies
42
Views
3K
Undergrad One-Way Speed of Light: Is it Possible?
  • · Replies 53 ·
2
Replies
53
Views
7K
Undergrad Is Measuring the One-Way Speed of Light Possible Near a Black Hole?
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Why do we still say “the speed of light” instead of “c”?
  • · Replies 12 ·
Replies
12
Views
2K
Undergrad Light speed independent of source
  • · Replies 22 ·
Replies
22
Views
2K