Proof: FAQ is contradictory concerning the matter of gravity

  • 7 Replies
  • 2544 Views
find the following excerpt of the FAQ:

Quote

Q: "What about gravity?"

A1: The Earth is accelerating upwards at 1g (9.8m/s-2) along with every star, sun and moon in the universe. This produces the same effect as gravity.

...

Q: "Doesn't this mean we'd be travelling faster than the speed of light, which is impossible?"

A: From any relative frame of reference in the universe, the Earth is travelling below the speed of light.

The theory of relativitity states that no observer in an inertial reference frame will ever measure the speed of a massive body to be greater than or equal to that of light."

Q: "If the world was really flat, what would happen if you jump off the disc's edge?"

A: You would enter an inertial reference frame, moving at a constant velocity in the direction the Earth was moving before you jumped. The Earth would continue accelerating upwards past you at a rate of 1g, so it would appear to you that you were falling into space.


The last answer says:
Quote
The Earth would continue accelerating upwards past you at a rate of 1g


which contradicts with the answer directly preceeding it:
Quote

A: From any relative frame of reference in the universe, the Earth is travelling below the speed of light.



So, this answer is somehow misleading. Required here is an explanation on the matter of time dilatation that an observer that falls over the edge experiences. The hint on the "inertial reference frame" which such an observer enters is not clear enough from my point of view.
ife is great!

?

joffenz

  • The Elder Ones
  • 1272
Proof: FAQ is contradictory concerning the matter of gravity
« Reply #1 on: June 06, 2006, 06:10:05 AM »
There is no contradiction. One answer is describing a theoretical situation, the other describing the current situation.

Proof: FAQ is contradictory concerning the matter of gravity
« Reply #2 on: June 06, 2006, 07:48:10 AM »
When I understand you correct, you say that the theoretical situation is not applicable to the actual situation. Therefore you have just agreed that FE theory is wrong. Is that what you wanted to say?
ife is great!

?

Sas

  • 101
Proof: FAQ is contradictory concerning the matter of gravity
« Reply #3 on: June 06, 2006, 08:30:31 AM »
I agree strongly with Deadlock, and your saying essentially "oh no it doesn't" is typical, and embarrassing to the species.
elling people in africa not to use condoms if a crime against humanity. I believe there's a God I just don't believe he is out to make our lives miserable.

Proof: FAQ is contradictory concerning the matter of gravity
« Reply #4 on: June 06, 2006, 11:01:58 AM »
There is no contradiction. The answer states that "no observer in an inertial reference frame will ever measure the speed of a massive body to be greater than or equal to that of light."

The speed of light is a barrier restricting the exchange of information, not velocity. Relative to the person we will be traveling in excess of the speed of light, but neither of us will ever know it.

Here is my understanding of what the observer would experience upon stepping off the edge:

He would enter an inertial reference frame, as the FAQ says, and would be travelling at the same speed as the earth was just before he stepped off; 0 m/s. The earth would accelerate away from him at G for a while, but after it reached some significant fraction of C in relation to the observer, it would appear to start to slow down. Relative to the observe, the earth's acceleration would be decreasing, and the earths mass would be increasing.

For us on earth, however, no such phenomenon occurs; since our velocity is still 0, our mass stays constant, so the force required to accelerate us stays constant, so our acceleration stays constant. The body of the observer, which has been accelerating away from us at 1g for some time, would eventually appear to become more massive and would experience decreasing acceleration.

Proof: FAQ is contradictory concerning the matter of gravity
« Reply #5 on: June 06, 2006, 11:14:54 AM »
So we are pretty aligned this time: The effect you descibed is what I have referenced using the term "time dilatation".
ife is great!

Proof: FAQ is contradictory concerning the matter of gravity
« Reply #6 on: June 06, 2006, 11:20:10 AM »
Oh, I thought that, since you were asking a question, you did not already know the answer.

Yes, that is the effect that allows a constant local acceleration of 1g without ever violating the information-exchange barrier defined by the speed of light. If your point was that something should be included in the FAQ about this, then you're right.

?

Erasmus

  • The Elder Ones
  • 4242
Proof: FAQ is contradictory concerning the matter of gravity
« Reply #7 on: June 06, 2006, 01:10:35 PM »
I disagree that the details of the effects of special relativity need to be explained in our FAQ.  Maybe a link to the relevant Wikipedia article, nothing more.
Why did the chicken cross the Möbius strip?