Relative Velocity: How Newton & Einstein Used Light Speed

In summary, the conversation discusses the concept of relative velocity and the limitations of using light as a reference in measuring it. It also touches on the differences between Newton's and Einstein's approach to relative velocity and the use of different transformations in special relativity. The speaker suggests reading existing threads on the subject and gaining a better understanding of the Galilean and Lorentz transformations.
  • #1
bodhi
23
0
i constantly feel that Newton was right in measuring the relative velocity.einstein makes use of light which has a limitation of 300000 km/s .It seems as if because light cannot travel more than 300000 km/s we we see the other object moving at lesser speed.
to confirm that in relative velocity equation we divide(u+v)by only such a factor dependent on product of 2 velocities i.e u*v / product of light velocity i.e c^2.

so everything is measured with respect to "c" which itselves has a limitation. can anyone help me out with this.
 
Physics news on Phys.org
  • #2
Bodhi, can I make a suggestion for you? This is the second thread you have started without a clear question. Instead of starting new threads, why don't you just read existing threads that deal with the subjects you are concerned with? That's what I did for a year before I ever made my first post and I think that is what most people do before they even log on. You can learn a lot that way and it's much quicker because you won't have to wait for any responses.
 
  • #3
bodhi said:
i constantly feel that Newton was right in measuring the relative velocity.einstein makes use of light which has a limitation of 300000 km/s. It seems as if because light cannot travel more than 300000 km/s we we see the other object moving at lesser speed.[..]

You start with a wrong suggestion, perhaps that's the cause of your problem? Einstein handled relative velocity exactly as Newton did, and light itself isn't important.

However, Newton assumed that a measurement system isn't affected by a change in velocity, while according to Einstein it is affected by it - for example, it needs a resynchronization of clocks. As a consequence, SR and classical mechanics use different transformations between reference systems that are in relative motion.
to confirm that in relative velocity equation we divide(u+v)by only such a factor dependent on product of 2 velocities i.e u*v / product of light velocity i.e c^2.
Those are system transformation equations: SR uses the Lorentz transformation instead of the Galilean transformation.
Do you really know and understand the Galilean transformation? If so, please explain the difference between the relative speed of two things as measured with a reference system, and a system transformation.


Harald
 

1. What is relative velocity?

Relative velocity is the measurement of the velocity (speed and direction) of an object in relation to another object.

2. How did Newton use relative velocity in his laws of motion?

Newton's laws of motion state that an object will remain in a state of rest or constant velocity unless acted upon by an external force. Relative velocity is used to calculate the motion of objects when they are in relation to one another, allowing us to understand how forces act on an object to change its velocity.

3. How did Einstein use relative velocity in his theory of relativity?

In Einstein's theory of relativity, he introduced the concept that the laws of physics are the same for all observers, regardless of their relative velocities. This means that the laws of physics must hold true even when objects are moving at high speeds, and relative velocity plays a crucial role in understanding this concept.

4. How is light speed related to relative velocity?

In Einstein's theory of relativity, the speed of light is considered to be the ultimate speed limit in the universe. The concept of relative velocity is used to understand how the speed of an object changes in relation to the speed of light, as well as how time and space are affected at high velocities.

5. How is relative velocity used in real-world applications?

Relative velocity is used in many real-world applications, such as space travel, navigation, and sports. In space travel, it is crucial to understand relative velocity in order to accurately reach and dock with other spacecraft. In navigation, relative velocity is used to calculate the movement of ships and airplanes in relation to each other. In sports, it is used to analyze the performance of athletes and their movements in relation to their opponents.

Similar threads

  • Special and General Relativity
2
Replies
57
Views
4K
  • Special and General Relativity
Replies
33
Views
2K
  • Special and General Relativity
Replies
28
Views
1K
  • Special and General Relativity
Replies
20
Views
747
  • Special and General Relativity
Replies
3
Views
821
  • Special and General Relativity
Replies
12
Views
2K
  • Special and General Relativity
2
Replies
38
Views
3K
  • Special and General Relativity
2
Replies
35
Views
2K
  • Special and General Relativity
Replies
21
Views
519
Back
Top