How many observers are needed to calculate the relativistic speed equation?

Click For Summary

Discussion Overview

The discussion revolves around the number of observers required to calculate the relativistic speed equation, exploring the necessity of observers in the context of relative speed calculations in special relativity.

Discussion Character

  • Debate/contested, Conceptual clarification

Main Points Raised

  • One participant suggests that at least two or three observers are needed to calculate the relativistic speed equation.
  • Another participant argues that observers are not necessary for calculations, as the relativistic speed equation can be derived using theoretical methods without actual observation.
  • A further contribution clarifies that two reference frames and one object with a specific velocity are needed to use the relativistic speed equation, regardless of whether the frames are attached to observers.
  • It is noted that if the frames are attached to observers, those observers can be considered as the objects in the calculations.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of observers for calculating the relativistic speed equation, indicating that there is no consensus on this issue.

Contextual Notes

The discussion highlights the dependence on definitions of "observers" and "reference frames," as well as the assumptions regarding the context in which the relativistic speed equation is applied.

Quarlep
Messages
257
Reaction score
4
I am studying the relative speed equations but I confused in one point.
We need (at least) how many observers to calculate relativistic speed equation.
Three or two.
 
Physics news on Phys.org
What do you mean with "relativistic speed equation"?

You do not need observers, you can do this with pen and paper without observing actual experiments at all. It can be useful to imagine what multiple different observers would see, but they are not a necessary part for calculations.
 
I mean let's think there's two observers and nothing else.Can we use relativistic speed equation in these situations.

Relativistic speed equation
2035aab1ba5af2e1ff296512b6a57779.png
 
To use that formula you need two reference frames (with relative velocity u) and one object (with velocity v relative to one frame).

Whether or not any of the frames are attached to an observer is not relevant. But if they are attached to an observer then the observer can certInly be used as the object.
 
Last edited:

Similar threads

  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 87 ·
3
Replies
87
Views
6K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 45 ·
2
Replies
45
Views
5K
  • · Replies 26 ·
Replies
26
Views
1K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K