Question about travelling faster than light.

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Discussion Overview

The discussion revolves around the concept of traveling faster than light and its implications on time, particularly whether such travel could result in moving backwards in time. Participants explore theoretical scenarios, the nature of time dilation, and the limitations imposed by current understanding of physics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants propose that if an object with mass could reach or exceed the speed of light, time would behave differently, potentially leading to backward time travel.
  • Others argue that this notion is flawed, emphasizing that time dilation does not imply time can reverse and that the concept of imaginary time is often misunderstood.
  • A few participants mention tachyons as hypothetical faster-than-light particles, suggesting they have interesting properties but caution against oversimplified interpretations.
  • Some express skepticism about the feasibility of time travel, stating it is impossible under current physical laws.
  • There is a discussion about the confusion between imaginary time and negative time, with some asserting that this confusion contributes to misconceptions about faster-than-light travel equating to time travel.
  • Participants highlight the importance of distinguishing between theoretical discussions and practical realities, noting that many claims about time travel stem from misunderstandings of relativity.

Areas of Agreement / Disagreement

Participants generally do not reach consensus, with multiple competing views on the implications of traveling faster than light and whether it could lead to time travel. Disagreements persist regarding the interpretations of time dilation and the nature of time itself.

Contextual Notes

Limitations include the speculative nature of the discussion, reliance on hypothetical scenarios, and varying interpretations of theoretical physics concepts. The conversation reflects a mix of technical reasoning and imaginative speculation.

  • #61
Tachyons are theoretical particles or waves that travel faster than the speed of light. Tachyons exist in a theoretical world where objects have negative mass. Negative mass is most easily define as a volume of negative density; i.e. -mass = volume * -density. Ergo negative mass density. This is preferable to calculations using invariant mass that involve the square root of a negative number, i.e., imaginary.
 
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  • #62
SJBauer said:
Tachyons are theoretical particles or waves that travel faster than the speed of light. Tachyons exist in a theoretical world where objects have negative mass. Negative mass is most easily define as a volume of negative density; i.e. -mass = volume * -density. Ergo negative mass density. This is preferable to calculations using invariant mass that involve the square root of a negative number, i.e., imaginary.

Repeating a wrong doesn't make it right. There is no accepted definition of mass or energy for tachyons that comes out negative. Total energy and KE for a tachyon are positive. Mass (rest, invariant) is imaginary. Please do not repeat again a false statement.
 

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