Faster Than Light

WBahn

Joined Mar 31, 2012
32,874
To paraphrase the definition, if you start going you keep going unless something stops you. Gee, thanks for that glimmer of pure genius! I would have never known that unless i had seen it written in a textbook, thanks so much, how on earth do i thank thee (ha ha).
Yet, this was a very novel and revolutionary concept at one time. So was the notion that two objects, sans air resistance, fall at the same rate regardless of mass. The effect of air resistance on a feather verses a rock creates the preconception that heavy objects accelerate more than lighter objects. This was simply accepted, with philosophical explanations backing it up, despite all of the opportunities available in everyday life that largely refute it, even with the effect of air resistance. It wasn't until the advent of experimental physics that these notions began to give way -- but not without a fight.

There is one theory though that i think may not hold anymore, as it depends on all the mass in the universe and how it affects every single object in the universe. I have trouble with this because the speed of gravitational waves has been verified to be at the speed of light. That means that things that are light years away would have a hard time influencing my straw hat.
This is no different than someone claiming that an earthquake hundreds or even thousands of miles away can't affect their straw hat because of the finite speed at which they travel.

Or claiming that the sun has no effect on your straw hat because it takes about eight minutes for those waves to get to it.

The effect those distance stars have on your straw hat are not due to where the star is this moment, but where it was at the time the gravitational waves started their journey toward you (which also happens to be where it appears, to you, to be right now as opposed to where it actually is).
 

MrAl

Joined Jun 17, 2014
13,708
Yet, this was a very novel and revolutionary concept at one time. So was the notion that two objects, sans air resistance, fall at the same rate regardless of mass. The effect of air resistance on a feather verses a rock creates the preconception that heavy objects accelerate more than lighter objects. This was simply accepted, with philosophical explanations backing it up, despite all of the opportunities available in everyday life that largely refute it, even with the effect of air resistance. It wasn't until the advent of experimental physics that these notions began to give way -- but not without a fight.



This is no different than someone claiming that an earthquake hundreds or even thousands of miles away can't affect their straw hat because of the finite speed at which they travel.

Or claiming that the sun has no effect on your straw hat because it takes about eight minutes for those waves to get to it.

The effect those distance stars have on your straw hat are not due to where the star is this moment, but where it was at the time the gravitational waves started their journey toward you (which also happens to be where it appears, to you, to be right now as opposed to where it actually is).
Hi,

As to the revolutionary concept, yes that is an interesting part of history and a steppingstone to more robust ideas. I guess we cannot expect to get a full theory right from the start it takes time to reason out these things and make measurements and do experiments. I wonder what Newton would say if he could see the LHC super collider today and read about Einstein. "Hey guys, it's just gravity, get over it".

Yes, i believe that is a reasonable argument about the gravity waves and inertia. The fact that they cannot influence an object on the fly though may be what allows objects to move. The distant objects can only hold objects in place due to the past influence. It might be interesting to think about what would happen in a million years or maybe a billion or more years if the object was not affected by any other deliberate external force. Would the distant objects be able to stop the moving object, slowing it down a little at a time. Maybe some calculations would be in order here. If the object gets closer to some distant objects out in front but gets farther from distant objects in back, maybe it will actually keep moving forever like the 'theory' states now about inertia. Is it even possible that the moving object speeds up. I can imagine this might be like some object floating in space between the moon and the earth, where it starts out very close to that zero gravity region, then starts to slowly drift toward either the moon or the earth. We know it will speed up as time progresses due to it getting closer and closer to the mass it is heading towards. Thus, maybe inertia is not the idea that a mass will keep moving at a constant speed in the same direction, but will gradually speed up, and if the masses it is heading towards are not distributed in some uniform way, may even change direction to favor the larger bulk of mass in that region.
 
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