[fisherman]

The water over marianas trench has limited significance to the overall mass beneath that part of Earth

Iceman, this seems like the type of question you would know the answer to...would tidal forces, both ocean and land cause the weight distribution of the earth to be constantly shifting?

[Iceman]

I'm by no means an expert on tidal forces outside a couple physics and planetary astronomy courses.

The short answer is yes. But the more specific answer is that it's probably negligible in the grand scheme of things.

When it's high tide in the middle of the ocean, that only an extra <1m of water masses there. You get higher tides along the coasts, but the famously high tides like in the Bay of Fundy only occur because you have such a restricted basin geometry, so water 'piles up' in that funnel shaped basin to rise 8 m or so. Very impressive sight and causes some spectacular geomorphology, but it's really  not a huge deal as far as adding and removing mass in the context of the earth, since theres still ~5600 km of rock beneath it.

With GRACE data, I would bet that the local mass change due to tides would be enough to be measurable - but again, would be small.  For instance, GRACE data, though coarse resolution (around 200 x 200 km depending on the specific region) has measured changes in gravitational pull measured in areas of extreme groundwater extraction, around the Great Lakes as water levels have risen in the last 8-10 years, and it can measure seasonal changes due to ice and snow melt in some regions.

But again, these changes are (probably) like measuring increased mass added to a pool when someone pees in it.

Edit: should add that the weight distribution on the surface of the earth is obviously unequal, but much of it is 'cosmetic' in nature. The real difference makers are tectonic systems like subduction zones, mountain belts, hot spots, where dense crust (not just near surface rock units) is thickened by a more significant amount (several to tens of km!).

[stevecanuck]

My overall point is that the earth is not symmetrical in terms of weight distribution. I'm sure the side of the flat earth on which the Pacific Ocean resides is heavier that the other side. I suspect the difference is significant enough to cause UA to push the lighter side up relative to the other and cause a flip. Again, think of a beer tray.

[Tom Bishop]

When you put a disk on the water and try to stand on it, get back to me.

You keep making this analogy but what I posted about larger ships being more stable is apt. In your scenerio it would be more like a bacterium trying to tip over a floating circular beer tray.

[stevecanuck]

When you put a disk on the water and try to stand on it, get back to me.

You keep making this analogy but what I posted about larger ships being more stable is apt. In your scenerio it would be more like a bacterium trying to tip over a floating circular beer tray.

Nope. Boats aren't flat. They are designed to float and follow obvious physical laws. Anything flat that's being pushed at an acceleration equal to 1g has to be perfectly balanced. And you know it.

[Tom Bishop]

When you put a disk on the water and try to stand on it, get back to me.

You keep making this analogy but what I posted about larger ships being more stable is apt. In your scenerio it would be more like a bacterium trying to tip over a floating circular beer tray.

Nope. Boats aren't flat. They are designed to float and follow obvious physical laws. Anything flat that's being pushed at an acceleration equal to 1g has to be perfectly balanced. And you know it.

Incorrect. It is not only boats that float. Many different types of masses can float, including masses that are non-symmetrical. They float without flopping around willy-nilly like in your imagination. Gravity being physically equivalent to upwards acceleration shows that a floating object can be continuously accelerated upwards without flopping around.

It is clear that larger floating objects are more stable. It is also clear that if a bacterium can't tip over a floating circular beer tray that we would also have difficulty tipping over something with a similar size ratio.

[stevecanuck]

When you put a disk on the water and try to stand on it, get back to me.

You keep making this analogy but what I posted about larger ships being more stable is apt. In your scenerio it would be more like a bacterium trying to tip over a floating circular beer tray.

Nope. Boats aren't flat. They are designed to float and follow obvious physical laws. Anything flat that's being pushed at an acceleration equal to 1g has to be perfectly balanced. And you know it.

Incorrect. It is not only boats that float. Many different types of masses can float, including masses that are non-symmetrical. They float without flopping around willy-nilly like in your imagination. Gravity being physically equivalent to upwards acceleration shows that a floating object can be continuously accelerated upwards without flopping around.

It is clear that larger floating objects are more stable. It is also clear that if a bacterium can't tip over a floating circular beer tray that we would also have difficulty tipping over something with a similar size ratio.

Full circle. You can continue to deny because there's no way to prove it either way.

[fisherman]

Tom, I am curious as to what you think causes time dilation, if not spacetime warp.  Even gravitational time dilation is based it.  The closer you are to massive objects and the more massive the objects, the more spacetime is warped resulting in stronger gravity.  It’s odd, to say the least that you think that GTD somehow supports UA.  It's in direct contradiction to it.

Also, still waiting for an answer to my question on how mass can be effected by and/or resist a non-force.

[Tom Bishop]

Tom, I am curious as to what you think causes time dilation, if not spacetime warp.  Even gravitational time dilation is based it.  The closer you are to massive objects and the more massive the objects, the more spacetime is warped resulting in stronger gravity.  It’s odd, to say the least that you think that GTD somehow supports UA.  It's in direct contradiction to it.

Also, still waiting for an answer to my question on how mass can be effected by and/or resist a non-force.

This was already discussed in the rocket analogy that was discussed, as well as the water droplet analogy. When you accelerate into photons you perceive their sequence of events quicker. The spacetime warp is not needed.

[fisherman]

This was already discussed in the rocket analogy that was discussed, as well as the water droplet analogy. When you accelerate into photons you perceive their sequence of events quicker. The spacetime warp is not needed.

If spacetime warp is not needed,why do you perceive events quicker? 


Maybe this will help.

Imagine that the vertical rod is 186,000 miles long and there is a light signal bouncing off a mirror at each end.  So each round trip from bottom to top and back to bottom is 2 seconds. Why does the moving clock click at exactly half the speed of the stationary clock?  The light is bouncing back and forth between the mirrors at the same rate, but the stationary clock makes two round trips and the moving clock only makes one.




So motion changes how time elapses.  It condenses the passage of time.  And what is another word for condensing something?  If I take a sheet regular size notebook paper and condense it, what do I have to do it? What is the difference between the space the light is moving through on the stationary clock and the space the light is moving through on the moving clock?

And you still didn't answer my question about how a non-force effects the motion of mass.

[stevecanuck]

Many different types of masses can float, including masses that are non-symmetrical. They float without flopping around willy-nilly like in your imagination.

You are right, to a certain extent. Let me back off from my assertion that non-symmetrical. flat objects will flip. I agree they will not necessarily flip. They would have to be asymmetrical beyond a certain point for that to happen.

What WILL happen, even if they still float, is that they will list. Any object that has a flat "top side", but is not perfectly weight-distributed, will sit in the water at an angle relative to the flat surface. I don't see any way to deny that.

[Tom Bishop]

This was already discussed in the rocket analogy that was discussed, as well as the water droplet analogy. When you accelerate into photons you perceive their sequence of events quicker. The spacetime warp is not needed.

If spacetime warp is not needed,why do you perceive events quicker? 

Because the clock is basically broadcasting the equivalent of a series of photographs of the clock face into space towards you with changes at one second intervals which reads 00:01 00:02 00:03 00:04 00:05.

If you accelerate into those photons you will perceive the change of 00:01 to 00:05 in a quicker amount of time than you would if you were not accelerating and they were hitting you at one second intervals. You perceive them to move quicker when accelerating toward them much like fast forwarding a VHS tape speeds up the sequence of images on a television, or if you were to flip the pictures in a flip book a little faster.

Time isn't really speeding up or slowing down for anything. You are just perceiving the sequence of images faster because you are accelerating into the sets of photons that are traveling towards you through space, 'fast forwarding' the 'video' sequence of image that was broadcasted towards you.

Obviously this perception explanation is a simpler and clearer explanation than "the fabric of time bent!"

Maybe this will help.

Imagine that the vertical rod is 186,000 miles long and there is a light signal bouncing off a mirror at each end.  So each round trip from bottom to top and back to bottom is 2 seconds. Why does the moving clock click at exactly half the speed of the stationary clock?  The light is bouncing back and forth between the mirrors at the same rate, but the stationary clock makes two round trips and the moving clock only makes one.



So motion changes how time elapses.  It condenses the passage of time.  And what is another word for condensing something?  If I take a sheet regular size notebook paper and condense it, what do I have to do it? What is the difference between the space the light is moving through on the stationary clock and the space the light is moving through on the moving clock?

In your animation there the photon making the diagonal path takes longer to bounce between the mirrors when motion occurs because the light travels at a set speed and the particular diagonal path it has to make to bounce between the mirrors when in motion requires greater amount of space to complete the mirror circuit, as compared to simply bouncing up and down in the scenario where the mirrors are stationary.

Spacetime bending isn't required to do that. You can see its physical path and why it takes longer in the animation. That would also occur if it were a bouncy ball moving at a set speed through space doing that in those situations instead of a photon. The ball that has to move on the diagonal path at a set speed would also bounce between the mirrors slower. No spacetime bending required.

And you still didn't answer my question about how a non-force effects the motion of mass.

Please rephrase your question. Why should a non-force affect the motion of mass?

[fisherman]

In your animation there the photon making the diagonal path takes longer to bounce between the mirrors when motion occurs because the light travels at a set speed and the particular diagonal path it has to make to bounce between the mirrors when in motion requires greater amount of space to complete the mirror circuit than simply bouncing up and down in the scenario where the mirrors are stationary.

Spacetime bending isn't required to do that. You can see its physical path and why it takes longer in the animation. That would also occur if it were a bouncy ball moving at a set speed through space doing that in those situations instead of a photon. The ball that has to move on the diagonal path would also bounce between the mirrors slower. No spacetime bending required.

You’re getting there, but you’re still not connecting the dots. The diagonal that the light signal must travel along...the bend in space time.  The physical space between the two ends of the moving clock is warped relative to the space between the two ends of the stationary clock.  In the animation the moving clock is ticking at half the rate as the stationary clock.  How would that diagonal chance if the moving clock were ticking at a quarter of the rate of the stationary clock?

If that’s not intuitive enough for you...Imagine a really, really tall building.  We will call it “space”.  As the top of space moves faster through time (because we know that a clock runs faster at the top of a building), than the bottom of “space” what happens to  space (building)?  It starts to tip, or bend or warp, whatever you want to call it.  The point is that because time is moving at a higher rate at the top than at the bottom, the shape of space changes as it moves through time.

Or how about this analogy...imagine two kayaks floating side by side going down a river and joined at the middle by pole.  The river is time and the kayaks are space.  The left bank of the river is straight and the right side is curvy.  The current in the stream is 186,000 mph, but because the kayak on right must navigate the curves, it is moving slower than the kayak on the left.  What happens?  Our “space” will twist as the kayak on the left moves faster than the kayak on right.

This one should be the most intuitive at all.  Imagine points A and B on either side of a mountain. Points A and B are the two ends of the light clock.  One car goes a steady 186,000 mph straight through a tunnel from point A to point B.  A second car goes a steady 186,000 mph around and over the mountain on a twisty road.  Obviously it takes the second car longer because the road is “warped”.  The more warped the road is the longer it will take to get from point A to point B.

So if it takes one light signal longer to go from point A to point B, than another light signal to get from point A to B when they are both moving at the same speed, what can we conclude?  Spacetime (like the road in the analogy) between points A and B is curvier for one light signal. The only reason it would take one light signal longer to move from point A to point B when it is moving the same speed as another light signal is because it must navigate more twists and turns. That's what causes Gravitational time dilation.  The deeper in the gravity field, the more warped spacetime is and the slower clocks will run because it has to navigate more twists and turns.  I’m running out of ways to explain it.

Please rephrase your question. Why should a non-force affect the motion of mass?

Not sure there is simpler way to rephrase it.  That is what I am asking you why should a non-force affect the motion of mass? You seem to think that gravity somehow effects the motion of "gravitational mass" differently than it does "inertial mass".

 

[Tom Bishop]

You’re getting there, but you’re still not connecting the dots. The diagonal that the light signal must travel along...the bend in space time.  The physical space between the two ends of the moving clock is warped relative to the space between the two ends of the stationary clock.  In the animation the moving clock is ticking at half the rate as the stationary clock.  How would that diagonal chance if the moving clock were ticking at a quarter of the rate of the stationary clock?

The animation that you posted gives a physical depiction of how it works without spacetime bending. Light travels at a set finite speed. It is clear that the path is longer when traveling diagonally than when travelling up and down. It is also clear that a bouncy ball with a set speed moving on a diagonal path like the diagonal photon would also take longer to bounce between the two surfaces.

Some of these analogies for "spacetime" are actually demonstrations on how it works without needing the spacetime.

Other analogies like

'if we imagine spacetime as a piece of paper that we crumple'...

'if we imagine spacetime like a car driving up a mountain'...

'if we imagine spacetime like a canoe on water'...

are not actually physical demonstrations on how spacetime works to do those things, but are imaginative analogies that we can relate with on a propositional basis. We can't directly manipulate this hidden layer of reality, spacetime, to confirm that. Spacetime is not necessarily like any of those things. There is no reason for why we should imagine that it is, when the discussed effects from movement and acceleration can be explained elsewise without such assumptions.

[fisherman]

The animation that you posted gives a physical depiction of how it works without spacetime bending. Light travels at a set finite speed. It is clear that the path is longer when traveling diagonally than when travelling up and down. It is also clear that a bouncy ball with a set speed moving on a diagonal path like the diagonal photon would also take longer to bounce between the two surfaces

It shows exactly a bend is space time.  You said yourself, the light on the moving clock moves through diagonal space.  The light on the stationary clock moves through vertical space.  Bend something vertical and it becomes horizontal.

There is no reason for the light signal moving between the top and the bottom of the clock to tick at different rates except that there is a difference in the shape of  the spacetime through which the light signal moves. I don’t see how you can disagree with that (but I’m sure you’ll find a way). The shape of the space is different and accounts for the differing rate of ticks.  From that we can conclude that motion (specifically acceleration) creates a warp in space time.

How?

If two objects are moving along the same straight line at the same speed they are not in motion relative to one another. There will be no difference in the rate a light clock ticks for each object. When one of the objects changes its direction and/or speed (accelerates)  relative to the other the two objects are now in relative motion.  Motion now exists where previously there had been no motion. 

Now that the objects are in relative motion to one another, light clocks traveling with each object will tick at different rates.  And as I stated above, the only reason the light clocks would click at different rates is because the shape of the spacetime through which the light travels has changed. 

In short,
No motion=no difference in tick rate
No difference in tick rate=no difference shape of spacetime
No motion=no difference is shape of spacetime

As opposed to
Motion (resulting from acceleration)=difference in tick rate
Difference in tick rate=difference is shape of spacetime
Motion (resulting from acceleration)=difference in shape of spacetime.[/i]

Motion resulting from acceleration warps space time.

Now that we’ve taken the long way around(pun intended) to back where we started, I ask again

If acceleration produces a warp in spacetime and acceleration and gravity are equivalent, then why shouldn’t we conclude that a warp in spacetime is what we experience as gravity as opposed to some unknown mysterious force pushing the earth up?

We can't directly manipulate this hidden layer of reality, spacetime, to confirm that. Spacetime is not necessarily like any of those things.

You struggle with the concept that spacetime is an actual material thing, which is understandable.  Its whole other rabbit hole to go down, but if the equivalence principle is to hold up, then spacetime must be material.

[Tom Bishop]

It shows exactly a bend is space time.  You said yourself, the light on the moving clock moves through diagonal space.  The light on the stationary clock moves through vertical space.  Bend something vertical and it becomes horizontal.

Since we know that light can travel diagonally in normal Newtonian space to do this, why do we need to modify and bend that situation for your spacetime explanation?

There is no reason for the light signal moving between the top and the bottom of the clock to tick at different rates except that there is a difference in the shape of  the spacetime through which the light signal moves.

Yes, there is a reason. It takes longer for an object traveling at a set speed to travel on the diagonal route in the animation. Just look at the animation you provided. It shows how it would work in normal Newtonian space.

I don’t see how you can disagree with that (but I’m sure you’ll find a way). The shape of the space is different and accounts for the differing rate of ticks.  From that we can conclude that motion (specifically acceleration) creates a warp in space time.

How?

No. The light traveled diagonally as the mirrors moved, just like in the animation you provided. Nothing about "spacetime" is required to make this work.

No motion=no difference in tick rate
No difference in tick rate=no difference shape of spacetime
No motion=no difference is shape of spacetime

Motion resulting from acceleration warps space time.

These are just statements.

Now that we’ve taken the long way around(pun intended) to back where we started, I ask again

If acceleration produces a warp in spacetime and acceleration and gravity are equivalent, then why shouldn’t we conclude that a warp in spacetime is what we experience as gravity as opposed to some unknown mysterious force pushing the earth up?

Acceleration does not necessarily produce a 'warp in spacetime'. We have seen that the effects can be explained elsewise. It is clear to me that 'spacetime' is just nonsense that you were hoodwinked into believing because they needed to explain the horizontally motionless earth experiments like Michelson-Morley, from which they came up with these overelaborate explanations for reality. This is the basis for this.

You struggle with the concept that spacetime is an actual material thing, which is understandable.  Its whole other rabbit hole to go down, but if the equivalence principle is to hold up, then spacetime must be material.

Nothing you have shown in regards to the speeding up or slowing down of events requires bending spacetime. You are proposing a fanciful explanation for something which does not need to be fancifully explained.

[Tom Bishop]

Many different types of masses can float, including masses that are non-symmetrical. They float without flopping around willy-nilly like in your imagination.

You are right, to a certain extent. Let me back off from my assertion that non-symmetrical. flat objects will flip. I agree they will not necessarily flip. They would have to be asymmetrical beyond a certain point for that to happen.

What WILL happen, even if they still float, is that they will list. Any object that has a flat "top side", but is not perfectly weight-distributed, will sit in the water at an angle relative to the flat surface. I don't see any way to deny that.

And what makes you think that the center of mass of the Earth is perfectly centered and weight distributed?

A crooked cup on a crooked ship will still have level water in it.

And if we allow the surface structures like the 'cup' to melt and erode over eons, and allow for new mountain creation, etc., the new features and prominent peaks of the Earth would point vertically in relation to the water surface instead of remaining crooked.

[stevecanuck]

Many different types of masses can float, including masses that are non-symmetrical. They float without flopping around willy-nilly like in your imagination.

You are right, to a certain extent. Let me back off from my assertion that non-symmetrical. flat objects will flip. I agree they will not necessarily flip. They would have to be asymmetrical beyond a certain point for that to happen.

What WILL happen, even if they still float, is that they will list. Any object that has a flat "top side", but is not perfectly weight-distributed, will sit in the water at an angle relative to the flat surface. I don't see any way to deny that.

And what makes you think that the center of mass of the Earth is perfectly centered and weight distributed?

I have to admit I'm a little disappointed with your efforts. I never said it was. I said it would HAVE TO BE perfectly weight balanced. And not just on top, but the entire disk. Is it? Has the site ever addressed the topic?

A crooked cup on a crooked ship will still have level water in it.

It's like you're not even trying. YES, it will have level water in it, BUT most of it would be on one side of the cup. The earth equivalent of that would see the oceans spilling over one side of your "cup", ie: the "ice wall", and into space.

And we allow the surface structure of the 'cup' to melt and erode over eons, and allow for new mountain creation, etc., the new prominent peaks of the Earth would point vertically in relation to the water surface instead of remaining crooked.

It sounds like you made all that up as you were typing. Congratulations you have just invented a brand new branch of geology on the fly.

[fisherman]

Nothing you have shown in regards to the speeding up or slowing down of events requires bending spacetime.

Can time slow down for a light clock that is not moving through horizontal space?  If not, then yes, space must change shape for time to slow down.

Acceleration does not necessarily produce a 'warp in spacetime'. We have seen that the effects can be explained elsewise.

What is the elsewise? 

Yes, there is a reason. It takes longer for an object traveling at a set speed to travel on the diagonal route in the animation. Just look at the animation you provided. It shows how it would work in normal Newtonian space.

Of course it would be the same in Newtonian space.  The nature of spacetime didn’t change between Newton and Einstein, just our understanding of it did.  Newton just didn’t recognize the significance of the fact and how it related to gravity.

You are proposing a fanciful explanation for something which does not need to be fancifully explained. 

As opposed to the unfanciful explanation of some force that accelerates the earth up, without any explanation how it works or where it comes from.

These are just statements.

Statements that logically follow. You obviously disagree but don’t explain why.

[Tom Bishop]

I've explained why these things would work without relativity quite clearly. You can stop pretending to be confused and refer back to those posts.

Relativity is not needed for Time Dilation. Time Dilation was predicted before the advent of relativity by physicist Joseph Larmor, showing that it does not need relativity to work. He also discovered the Lorentz transformations some years before both Lorentz and Einstein. Larmor held the Lucasian Chair, the same chair held by Isaac Newton, George Airy, and Stephen Hawking.

In fact, Larmor disagreed with Einstein's approach of taking the time dilation equations to use with "spacetime".

https://en.wikipedia.org/wiki/Joseph_Larmor

"In his book Aether and Matter (1900), [Larmor] again presented the Lorentz transformations, time dilation and length contraction (treating these as dynamic rather than kinematic effects). Larmor was opposed to the spacetime interpretation of the Lorentz transformation in special relativity because he continued to believe in an absolute aether. He was also critical of the curvature of space of general relativity, to the extent that he claimed that an absolute time was essential to astronomy (Larmor 1924, 1927)."

In the following paper physicist Joseph Levy shows how aether theory explains time dilation without spacetime:

Bio - http://wiki.naturalphilosophy.org/index.php?title=Joseph_Levy

Paper - https://arxiv.org/ftp/physics/papers/0611/0611077.pdf

Aether Theory Clock Retardation vs. Special Relativity Time Dilation
Joseph Levy

Abstract:

"Assuming a model of aether non-entrained by the motion of celestial bodies, one can provide a rational explanation of the experimental processes affecting the measurement of time when clocks are in motion. Contrary to special relativity, aether theory does not assume that the time itself is affected by motion; the reading displayed by the moving clocks results from two facts: 1/ Due to their movement through the aether, they tick at a slower rate than in the aether frame. 2/ The usual synchronization procedures generate a synchronism discrepancy effect. These facts give rise to an alteration of the measurement of time which, as we shall show, exactly explains the experimental results. In particular, they enable to solve an apparent paradox that special relativity cannot explain (see chapter 4). When the measurement distortions are corrected, the time proves to be the same in all co-ordinate systems moving away from one another with rectilinear uniform motion. These considerations strongly support the existence of a privileged aether frame. The consequences concern special relativity (SR) as well as general relativity (GR) which is an extension of SR. We should note that Einstein himself became conscious of the necessity of the aether from 1916, in contrast with conventional relativity."

I have to admit I'm a little disappointed with your efforts. I never said it was. I said it would HAVE TO BE perfectly weight balanced. And not just on top, but the entire disk. Is it? Has the site ever addressed the topic?

It's like you're not even trying. YES, it will have level water in it, BUT most of it would be on one side of the cup. The earth equivalent of that would see the oceans spilling over one side of your "cup", ie: the "ice wall", and into space.

It sounds like you made all that up as you were typing. Congratulations you have just invented a brand new branch of geology on the fly.

If you have the crooked deck of a crooked ship and pour a bucket of sand onto the crooked deck, the peak of the sand will be pointing straight up, and not be crooked with the ship's deck.

If we have two mounds of sand on the crooked deck of a ship, and push them together, it will create a bigger mound, also pointing straight up, and not aligned with the crooked deck of the ship.

It is clear that erosion and new hill and mountain creation would cause the formations to align with the vertical and not with the slope of the surface.

Your idea of water 'falling off' assumes a lot. Since those areas are far from the Sun it would most likely freeze and create a container for itself than fall off.