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#11
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Descent Thoughts (was - something and nothing)
Hi Panius What you described is why quantum gravity is better than GR
Its a particle attraction Try using curved space in your scenario. Thing is you would get lighter,and lighter as you went deeper and deeper,and you would know you were at the center of the earth when your weight was zero. Quantum gravity,and general relativity are not compatible. I have my own theory of gravity,and it comes out of QM Bert |
#12
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Descent Thoughts (was - something and nothing)
"Odysseus" wrote...
in message ... G=EMC^2 Glazier wrote: Hi Odysseus Just don't want you and Sally stuck between floors in an elevator. I say it will finally come to rest at the center of the earth,and you say it will stop and go,and stop and go forever. Seems the elevator would have a greater force of gravity on its sides than top to bottom? That is another reason for it slowing down,and slowing down is what we are really discussing. I say it will . Bert You're the only one talking about "stopping and starting". As for "a greater force of gravity on its sides" I can't imagine what you mean. The radial components (WRT the 'axis' of the tunnel) of the gravitational forces will cancel each other out; only their axial components need be considered. But if we let reality intrude into this discussion far enough to admit the effects of friction the elevator will certainly make smaller and smaller 'orbits' and eventually stop, in a pattern one might call a 'damped oscillation'; neither Sally nor I have claimed otherwise. --Odysseus Alas! forgotten about again... must be my face... i just have one of those "forgettable" faces. "A greater force of gravity on its sides" indeed does mean what you are calling the radial components. They stretch from the axis of the tunnel out in all 3 dimensional directions toward the Earth's surface. Disregarding the reality check of other frictional effects and just focusing upon these radial components of gravitational force, i do not believe that they will cancel out entirely. If Earth were a sphere whose surface were smooth and whose innards were uniformly and consistently dense, then yes, the radial components would cancel out. Since this is not the case, since the Earth's surface is not perfectly smooth and since its inner volume varies in density, then these radial components would not cancel out and would have an effect on anything that oscillates within the tunnel. The effect would then be a sort of gravitational "friction" that would dampen the oscillations. And this (i realize that i'm being loose with my terminology here) gravitational friction would also affect every cubic cm of material within Earth's surface, wouldn't it? Now let's imagine spreading out from Earth's surface and including the atmosphere as well. Of course, such a mental exercise might be easier to do on a planet such as Jupiter or Saturn, since their "atmospheres" make up the vast majority of their huge volumes. happy days and... starry starry nights! -- Planets, stars and nebulae Hold attention in the sky-- Lay in hay and squint your eye, Lose your youth in moaning sigh & find the truth in every lie! Paine Ellsworth |
#13
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Descent Thoughts (was - something and nothing)
"G=EMC^2 Glazier" wrote in message...
... Hi Panius What you described is why quantum gravity is better than GR Its a particle attraction Try using curved space in your scenario. Thing is you would get lighter,and lighter as you went deeper and deeper,and you would know you were at the center of the earth when your weight was zero. Quantum gravity,and general relativity are not compatible. I have my own theory of gravity,and it comes out of QM Bert I agree. I also think that GR is weak in that it describes an effect rather than a cause. But QG is also weak in that it is so ill-understood. QG is the cause that results in the effects described by GR, but we still don't have much of a handle on either. It is difficult to reconcile observations with reality, probably due, at least in part, to the fact that the very act of observing distorts reality. We try to be a fly on the wall, but we get swatted every time! happy days and... starry starry nights! -- I'm a fool upon a hill, See my planet spinning still? Sun goes down and stars arise Warm and pleasing to my eyes. See my little telescope? People say I'm such a dope; I don't mind because I nurse Secrets of the Universe! Paine Ellsworth |
#14
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Descent Thoughts (was - something and nothing)
Hi Odysseus It is a "given" that the object comes to a complete stop
at each end of the earth(it is going back and forth (yes) There is no air in the tunnel,so I only used "gravity friction" Just a term,and if you would like I'll disregard it. I did not let Sally take away the earth's rotation,for I liked leaving that in to strengthen my side of this discussion. I would like Scott Miller to add his thoughts,for we don't always agree,and that is good. Bert |
#15
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Descent Thoughts (was - something and nothing)
Painius wrote:
"A greater force of gravity on its sides" indeed does mean what you are calling the radial components. They stretch from the axis of the tunnel out in all 3 dimensional directions toward the Earth's surface. Disregarding the reality check of other frictional effects and just focusing upon these radial components of gravitational force, i do not believe that they will cancel out entirely. If Earth were a sphere whose surface were smooth and whose innards were uniformly and consistently dense, then yes, the radial components would cancel out. Since this is not the case, since the Earth's surface is not perfectly smooth and since its inner volume varies in density, then these radial components would not cancel out and would have an effect on anything that oscillates within the tunnel. The effect would then be a sort of gravitational "friction" that would dampen the oscillations. And this (i realize that i'm being loose with my terminology here) gravitational friction would also affect every cubic cm of material within Earth's surface, wouldn't it? I agree with you up to where you say the imbalanced radial forces would cause damping. I think they'd just perturb the 'orbit' a little. If the walls of the tunnel are frictionless and perfectly elastic, even if the car goes 'off course' far enough to collide with them no energy will be lost. Of course if those conditions aren't met there will be a damping effect. Putting it another way, for conservation of mechanical energy to be violated there must be "dissipative" forces at work, and AFAIK gravity is not one of them. --Odysseus |
#16
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Descent Thoughts (was - something and nothing)
If you introduce factors into our thought experiment that are known to
produce friction and dissipate energy then, lo and behold, there will be friction and the oscillations will get smaller. Sally "G=EMC^2 Glazier" wrote in message ... Hi Odysseus Reaching the earth's center might not be its center of gravity? The tunnel might be curved this way and that.The reason is all the earth's particles would have to be perfectly homogenized for the tunnel,and the object in it to go north and south in a straight line. The earth does wobble. The 8 thousand mile distance would make this effect noticeable. Like I've stated a tunnel going through the earth in not an isolate system. Lots of stuff to take energy away,even with out air friction. Bert |
#17
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Descent Thoughts (was - something and nothing)
Hi Sally Seems energies can't be destroyed but they can be
transferred.and most end up as heat created by friction. Throw a rock in the pond,and its energy creates an up and down wave that moves towards the shore line,and it ends up rippling against the sandy shore and that causes friction,and this up down wave action ends up as heat. Sally I hope you did not think I was Cheating? The pond wave did not lose its energy by air friction. The rock hitting the water proved that water is non-compressible.. Bert |
#18
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Descent Thoughts (was - something and nothing)
You are quite right about the rock and its energy transfer into waves.
Similarly, if our falling/rising elevator undergoes massive acceleration due to the G field then it may radiate gravity waves and therefore lose some energy. This is analogous to accelerating charged particles transferring some energy into/from electromagnetic radiation. However I said, right at the start, that I was assuming a none-relativistic scenario. If you want to modify the experiment so that the elevator is falling into a black hole then I will agree that it may radiate some energy by various means, especially as it nears the event horizon. In the original Newtonian experiment we could construct a blockage in the shaft and the elevator will then crash into it. Much of the energy will then be converted to heat while some will be transferred into shock waves which will radiate from the crash scene...just like the water waves. However, you have now added extra features to the experiment and I will readily agree that in this case the elevator will certainly slow down :-) Look at masses in elliptical orbits. They are constantly moving through gravity fields of changing intensity. Yet the only orbital decay is due to frictional interactions with their environment, either directly or via tidal forces. Yes, I do know about Mercury and its orbital discrepancies which were seen as confirmation of the theory of General Relativity. (Or was it Special Relativity? I've forgotten...) Sally "G=EMC^2 Glazier" wrote in message ... Hi Sally Seems energies can't be destroyed but they can be transferred.and most end up as heat created by friction. Throw a rock in the pond,and its energy creates an up and down wave that moves towards the shore line,and it ends up rippling against the sandy shore and that causes friction,and this up down wave action ends up as heat. Sally I hope you did not think I was Cheating? The pond wave did not lose its energy by air friction. The rock hitting the water proved that water is non-compressible.. Bert |
#19
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Descent Thoughts (was - something and nothing)
Hi Sally You mentioned "massive acceleration" Gravity is not a
constant. You enter the elevator,and it has a rate of fall indicator. What would be your rate of fall at the 2,000 mile depth? That is half way to the earth's center.(gravity is a particle attraction) Would your rate of fall always be a positive 32 ft per second per second passing though the earth's center? Now going up hill you decelerating and again you have the same problem. Falling to the earth,or falling towards a blackhole are different,for you don't have particles(gravity) trying to pull in the opposite direction. Falling through a tunnel going through the earth this is a continual problem. Walking between two mountains their particle attraction is trying to pull you towards them,but it is to weak to effect you. This is not the case deep inside the earth (like 2,000 miles down) Sally this is why a pendulum slows down even in a vacuum. Rotation is a lot better than stop and go. We have a metal disc floating on top of a magnetic field spinning in a vacuum,and its been spinning for 75 years. Bert |
#20
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Descent Thoughts (was - something and nothing)
What if the universe needs two separate laws? QM for the micro
universe,and GR for the macro universe. In the micro universe we use Planck scales for measurements and to give you an idea these scales are smaller than atoms by just as much as atoms are smaller than stars.. Now I've mentioned micro blackholes and macro blackholes,and I think they will link the micro universe with the macro universe. There has to be a link with the singularity in the core of every blackhole,and the time before the big bang. Einstein's GR predicted blackholes,and QM is needed to explain their singularity,and this will unite the two. Blackholes are their common denominator. Its gravity all the way down. Bert |
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