Reference Frames: Can an Observer Know He is Accelerating?

In summary, the conversation discusses the ability of an observer in an accelerating reference frame to deduce their acceleration without any outside contact. It is mentioned that this concept is discussed in General Relativity theory, where one can distinguish between inertial and non-inertial reference frames through experimental effects. It is also mentioned that in non-inertial frames, there are certain forces that are present. The conversation concludes by mentioning that part of the foundation of general relativity is the idea that an observer in an accelerating reference frame cannot distinguish between acceleration and an external gravitational field.
  • #1
tardon007
4
0
hi folks!

I have a question which had been haunting me for quite some time...

can an observer sitting in a accelerating reference frame deduce that he is accelerating without establishing any contact with the outside world( i am alluding to outside the frame ambience)?
 
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  • #2
Please be more specific of what you are asking. Are you saying that a person is moving through space, but he has no other landmarks to see that he is moving?

Paden Roder
 
  • #3
I think surely he can.

In fact, this was discussed in the General Relativity theory. One can distinguish between inertial and non inertial reference frames, by means of experimental effects. One of them is the property of weighting bodies to remain in their original status. If you are pushed or accelerated forward, your body will tend to remain at rest. In particular, your body or any weighting body will experiment a reaction rearward -m*a.

Imagine you are traveling by train, without windows. You could hang your umbrella on some cross bar. Then you will see the umbrella turning a little angle rearward while the train is accelerating. This effect is enough clear to state you are really accelerating forward.

On the same way, you can state the Earth is turning around Sun and not the contrary, by means of the centrifugal force.

In non-inertial reference frames there are certain forces that are present only at this type of frames.
 
  • #4
A typical 2-D "accelerometer" consists of 4 springs of equal, unstretched length the one ends of which are attached to the middle point of the sides of a square "box", whereas their other ends are attached to a ball (or something) sitting in the middle of the square box.
If the box is stationary with respect to a noninertial frame, the ball will no longer remain in the middle of box.
 
  • #5
Part of the foundation of general relativity is the idea that an observer sitting in a accelerating reference frame can deduce that he is not in an inertial frame but cannot distinguish between the effects of acceleration and that of an external gravitational field.
 

1. What is a reference frame and why is it important?

A reference frame is a coordinate system that is used to describe the position, motion, and other physical properties of objects. It is important because it allows us to measure and understand the behavior of objects in a consistent and standardized manner.

2. How does an observer know if they are in an accelerating reference frame?

An observer can detect acceleration by feeling a force acting on them or by observing the motion of objects in their surroundings. If they feel a force pushing them in a certain direction or if objects around them appear to be moving, then they are likely in an accelerating reference frame.

3. Can an observer determine their exact acceleration in a non-inertial reference frame?

No, an observer cannot determine their exact acceleration in a non-inertial reference frame. This is because the laws of physics, such as Newton's laws, do not hold true in non-inertial reference frames.

4. How do reference frames affect the perception of time and space?

Reference frames can affect the perception of time and space because the measurement of these quantities can vary depending on the observer's frame of reference. For example, time can appear to pass slower for an observer in an accelerating frame compared to an observer in an inertial frame.

5. Can an observer in a non-inertial reference frame still make accurate measurements?

An observer in a non-inertial reference frame can still make accurate measurements, but they must take into account the effects of acceleration on their measurements. This can be done by using the appropriate equations and taking into account factors such as gravitational forces or fictitious forces.

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