Can special relativity be violated by an electron in a television tube?

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Discussion Overview

The discussion centers on the possibility of an electron in a television tube traveling faster than the speed of light and how this relates to special relativity. Participants explore the implications of this scenario, including the nature of the motion observed in television tubes and the distinction between actual particle speed and perceived motion.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that electrons in a television tube can travel faster than light, questioning how special relativity accounts for this.
  • Others argue that nothing is actually traveling at superluminal speeds, referencing external sources for clarification.
  • One participant emphasizes that the glowing dot seen on the screen can appear to move faster than light due to the timing of different electrons hitting the phosphor screen, but this does not involve actual faster-than-light travel.
  • It is proposed that the apparent motion of the glowing dot is an optical illusion, as it does not carry information faster than light, thus not violating special relativity.
  • Several methods of creating images that seem to move faster than light are mentioned, but the distinction between perceived motion and actual information transfer is highlighted.

Areas of Agreement / Disagreement

Participants express disagreement regarding the interpretation of electron speeds and the implications for special relativity. While some clarify that the glowing dot's motion does not violate special relativity, others maintain that the initial claim about electrons traveling faster than light needs further examination.

Contextual Notes

There are unresolved assumptions about the definitions of speed and motion in the context of the discussion, particularly regarding the distinction between actual particle speeds and perceived motion on the screen.

abbeynewton
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Now i heard it is possible for an electron in the tube of a television tube to travel across the tube at a speed faster than the speed of light. How can special relativity explain this?
 
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What is a "television tube"?
 
Bill_K said:
What is a "television tube"?
:smile:
 
abbeyNewton said:
Now i heard it is possible for an electron in the tube of a television tube to travel across the tube at a speed faster than the speed of light. How can special relativity explain this?
What you heard was wrong. An electron can't travel faster than the speed of light.
What you probably heard was that the image of a glowing dot on the picture tube can travel faster than the speed of light. An electron beam that intersects the phosphor screen is changing direction. Different electrons are hitting the phosphor screen at different times, creating a glowing dot that moves across the screen faster than light.
The glowing dot is an image which doesn't carry information. The glowing dot is not a real object. The FTL motion is an illusion created by many electrons that are synchronized to hit the screen at different times.
The glowing dot does not carry information faster than the speed of light in a vacuum. Therefore, the apparent motion of the glowing dot can move faster than light without violating special relativity. Faster than light motion only violates special relativity if information is traveling faster than light.
There are several ways of making an image that moves faster than light. However, the image does not carry information faster than light. Therefore, the image can be considered analogous to an "optical illusion".
 

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