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Now we are coming to the nub of the matter. You claim that the acceleration due to a rocket is “different” from the acceleration due to gravity. How could this be?
When an object is experiencing acceleration it doesn’t matter what kind of force is giving rise to that acceleration or what machine is responsible for it. If an acceleration is present it should have some effect on the spaceship and on its passengers also.
In the space station the astronauts are under the influence of a constant acceleration of around 8.4m/s2 why should you claim that this does not affect the astronauts?
In effect what you are saying, namely that there is a difference in acceleration due to gravity and that due to a rocket engine
is a complete right about turn to what the equivalence principle states, namely that there is no difference between the force caused by gravitation and that caused by an acceleration.
In my example, in a space craft far from anywhere else, the passengers are weightless, they are free falling around space, so the application of an acceleration would have no effect on them. As long as they are weightless, acceleration should not affect them.
Or can you claim that these astronauts have weight?
In my example, in a space craft far from anywhere else, the passengers are weightless, they are free falling around space
so the application of an acceleration would have no effect on them.
Halc: Einstein would claim they're not accelerating, but tracing a straight worldline. Only in a non-local coordinate system (that of Earth instead of the space station) is the space station accelerating. This may be difficult to visualize if you cannot conceive of 4 dimensional coordinates, let alone non-euclidean 4 dimensional coordinates.
Halc: Either will cause my coffee to stay in its cup.
Halc: Yes, there is very much a difference, since there is a trivial local test to distinguish one from the other.
Yes of course they would. They could stand on a bathroom scale (a weight scale, not a mass scale) and it would read their weight. A weight scale measures force. A mass (balance) scale measures mass, a very different thing.
Kryptid: Of course it would affect them. The difference is that, unlike the case of free fall in a gravitational field, the spacecraft and the astronauts are not accelerating at the same rate. The engines accelerate the rocket, which pushes the floor of the ship up against the feet of the astronauts. The ship's floor "feels" the acceleration before the astronauts' feet do, and their feet feel it before their heads do. This is because force propagates through material objects at a finite speed.
My point is that astronauts in my example (i.e., in a spaceship far from any gravitational influences), would also be weightless and in free fall and hence the force of acceleration exerted on the ship would not affect them. Ergo, Einstein’s equivalence principle is wrong.
How can the acceleration due to gravity differ from the acceleration from a rocket.
In the space station, the astronauts are not affected by the acceleration because they are in free fall and weightless. My contention is that exactly the same reasoning would apply to weightless astronauts in a rocket propelled ship far from any source of gravity.
According to what you state , moving at this speed the astronauts should be plastered to one side of the walls of the space station. Unable to move.
I will have to rethink my position.
Bored Chemist:How conceited are you? I mean, I'm pretty self assured but even I would draw the line at that sort of thing.