Quantum Physics Debunks Materialism

[FrumiousBandersnatch]

So you're saying that if I have two gravity sensors, one a the top of the room and one near the floor, if they both read the same I am on an accelerating spacecraft, and if they read different, I am in a gravitational field?

Yes - the gravitational force decreases with distance from the mass; and, as sjastro pointed out, there will also be tidal variations in a gravitational field.

 

[Kylie]

Yes - the gravitational force decreases with distance from the mass; and, as sjastro pointed out, there will also be tidal variations in a gravitational field.

Of course, since there is no such thing as a truly rigid body, if the spacecraft accelerates, won't there be a greater acceleration at the bottom because it is being pushed by the engine, and the top will have less acceleration because it is being squished a tiny amount?

 

[FrumiousBandersnatch]

Of course, since there is no such thing as a truly rigid body, if the spacecraft accelerates, won't there be a greater acceleration at the bottom because it is being pushed by the engine, and the top will have less acceleration because it is being squished a tiny amount?

Yes, but only in the very brief period until the structure has become uniformly compressed by the acceleration; i.e. not long enough to notice.

 

[sjastro]

Gravity = acceleration?

No.

F=G([m1*m2]/D^2)

I see you have confused yourself by referring to an equation which has a big G in it instead of a little g.
The relevant equation is;

At the Earth's surface g has value of 9.8 m/s² which is in units of acceleration.

 

[Kylie]

Yes, but only in the very brief period until the structure has become uniformly compressed by the acceleration; i.e. not long enough to notice.

But if the rocket is continually firing, won't it be constantly subject to the deformation?

Sorry, I just woke up, and this is half me being silly and half brain addled by lack of coffee.

 

[FrumiousBandersnatch]

But if the rocket is continually firing, won't it be constantly subject to the deformation?

Sure - after a brief interval where the engines are accelerating and the far end of the ship hasn't yet been affected, the entire structure becomes uniformly compressed and then it all accelerates at the same rate.

If this were not the case, e.g. imagine a spaceship made of cheesecake, the crunchy base with the engines on would catch up with the soft pointy end and the spaceship would flatten out until it was uniformly compressed (you'd need a crunchy base much wider than the rest of the spaceship, to hold the flattened front-end, otherwise bits of cheesecake would fall off and get left behind).

Sorry, I just woke up, and this is half me being silly and half brain addled by lack of coffee.

No worries - it's all good practice!

 

[Kylie]

Sure - after a brief interval where the engines are accelerating and the far end of the ship hasn't yet been affected, the entire structure becomes uniformly compressed and then it all accelerates at the same rate.

If this were not the case, e.g. imagine a spaceship made of cheesecake, the crunchy base with the engines on would catch up with the soft pointy end and the spaceship would flatten out until it was uniformly compressed (you'd need a crunchy base much wider than the rest of the spaceship, to hold the flattened front-end, otherwise bits of cheesecake would fall off and get left behind).

So why wouldn't the same thing happen in gravity?

 

[FrumiousBandersnatch]

So why wouldn't the same thing happen in gravity?

The same end result would probably happen in gravity, but because the gravitational attraction reduces towards the pointy end (by the inverse square law), it would weigh less and so collapse more slowly (in principle). IOW, a rock weighs less at the top of Everest than it does at ground level.

 

[Kylie]

The same end result would probably happen in gravity, but because the gravitational attraction reduces towards the pointy end (by the inverse square law), it would weigh less and so collapse more slowly (in principle). IOW, a rock weighs less at the top of Everest than it does at ground level.

And the tip of the rocket, being farther from the engine, would experience the force less as well.

 

[FrumiousBandersnatch]

And the tip of the rocket, being farther from the engine, would experience the force less as well.

No. Once uniformly compressed, all parts of the structure transmit the acceleration uniformly. If that wasn't the case, the engines would eventually catch up with the nose and the spaceship would be squashed flat.

 

[Michael]

Ah, no. The correct logic is that the conservation of energy laws are only applicable where the coefficients of the metric are not time-dependent.

Translation: Space expansion/contraction violations conservation of energy laws (just like I said).

In GR, space and time are dynamic, they can change (as is empirically well-established).

Well, the fact that time is dynamic has been well established but the concept that space is dynamic has not been "well established", just "well (constantly) asserted". It certainly hasn't been demonstrated in any sort of controlled experimental way.

But over sufficiently small spatial and temporal scales (i.e. everyday human scales), space & time can be considered to be static and energy conserved; i.e. energy is conserved in the limit.

For all intents and purposes, energy is conserved in GR inside of our solar system, inside of our galaxy, and inside of our galaxy cluster and even our local supercluster. Energy conservation is only violated in GR if one asserts that "space" itself is "dynamic".

Any cosmology model based on GR which does *not* presume that (physically undefined) space changes over time doesn't automatically violate any conservation of energy laws, so GR theory itself cannot be held responsible for cosmology models which evoke space expansion/contraction. Even a concept involving "space time expansion" (object movement) in no way violates conservation of energy laws. It's only by evoking "space expansion" that energy laws are violated.

Of course claiming that dark energy remains constant over multiple exponential increase in volume *also* violates conservation of energy laws, so it's not as though there's just *one* major problem in the LCDM model.

 

[Kylie]

No. Once uniformly compressed, all parts of the structure transmit the acceleration uniformly. If that wasn't the case, the engines would eventually catch up with the nose and the spaceship would be squashed flat.

But once that happens and the rocket is travelling at a steady velocity, it's no longer accelerating. If the rocket then fires again, would the compression increase? Thus, wouldn't the rocket ship continue squishing as the rocket fires?

 

[FrumiousBandersnatch]

Translation: Space expansion/contraction violations conservation of energy laws (just like I said).

No.

 

[FrumiousBandersnatch]

But once that happens and the rocket is travelling at a steady velocity, it's no longer accelerating. If the rocket then fires again, would the compression increase? Thus, wouldn't the rocket ship continue squishing as the rocket fires?

I'm sorry, I was assuming constant acceleration (as under gravity, which was the original comparison).

Clearly, if the rocket stops accelerating, the compression ceases and it will expand a little - assuming perfectly elastic materials, it will return to its pre-acceleration state. But the rocket wouldn't continue squishing when the engines fire again, it would resume squishing, because there is no squishing when the rocket isn't firing

 

[Michael]

No.

A GR based cosmology theory which *does not* rely upon "space expansion" as a cause of redshift doesn't automatically violate any conservation of energy laws. It's therefore not the fault of GR theory that the LCDM violates such laws. Period.

 

[Michael]

But once that happens and the rocket is travelling at a steady velocity, it's no longer accelerating. If the rocket then fires again, would the compression increase? Thus, wouldn't the rocket ship continue squishing as the rocket fires?

Once the rocket stops firing, the original compression will cease. Even if the rocket is not accelerating however, it still has a center of mass and therefore it's outside edges would still tend to "squish" towards that center of mass even while it's coasting at a steady velocity, albeit compressing/squishing very little. Once the rocket fires again, it will tend to compress again.

 

[Halbhh]

This is an awesome presentation, which compiles different experiments in Quantum Physics; as it challenges the way that many see the world.

I could never bring myself to watch more than a minute or two, even though it was kinda ok in the first 2 minutes. Is it about the Von Neumann–Wigner interpretation - Wikipedia ?
Or as in a list here:
Interpretations of quantum mechanics - Wikipedia

That's a fun possibility to entertain of course, but if that was the topic I bet it got some objections!

heh heh

 

[sjastro]

The conservation of energy doesn't even apply to static curved space in general.
The Einstein Field Equations are defined as:

The two important terms for energy conservation (or the lack of it) are the g(uv) and T(uv) terms in the equations.
g(uv) are the coefficients of the metric tensor that define the geometry of spacetime.
For example in the metric that defines flat spacetime ds²=c²dt²- dx²- dy²- dz², the coefficients of g(uv) are g(00)=1, g(11)=g(22)=g(33)=-1

The T(uv) tensor term in the right hand side of the equation defines the energy matter tensor.
If energy is conserved then its partial derivative with respect to time is zero.

Here lies the problem in 2D flat space (which can be generalised to higher dimensions) using Cartesian coordinates the partial derivative is defined by:

In this case the direction of the projection vector as h approaches zero is unchanging hence we can define the partial derivative.

In curved space however the definition does not work as the projection vector does change direction.
This can be illustrated by the change of a projection vector as it moves along the arcs on the surface of a sphere.

The concept of the derivative in curved space needs to be redefined which factors in the changes in the projection vectors.
In this case we need to calculate the partial derivatives of the metric tensor components which define the geometry of the spacetime in which the projection vectors change.

Without going in specific details which would require a detailed knowledge of tensor analysis the derivative of a tensor known as the covariant derivative is defined as:

The left hand side of the equation is the covariant operator applied to a vector v.
The first term on the right hand side is the normal partial derivative of the vector, the next term contains information how the metric tensor components g(uv) change by calculating their partial derivatives which impacts on changes to the projection vector.

The operator in the second term is known as a Christoffel symbol and is defined as

When the covariant operator is applied to the second rank energy matter tensor T(uv) and assuming the covariant derivative is zero we obtain the following result.

Now we have a “problem”.
As shown previously the conservation law applies when the partial derivative (the first term) equals zero.
This is not an issue with flat static space since all the g(uv) coefficients are constant and their partial derivatives vanish, in which case the second and third terms are zero.
The second and third terms do not vanish for curved spacetime nor for expanding spacetime even when flat since the g(uv) coefficients are now time dependant and have non vanishing terms with respect to the time derivative.

There is a physical reason why conservation of energy is not applicable under these conditions.
Since GR is a non linear theory for gravity unlike Newtonian gravity, not only does mass contribute to gravity but also the gravitational field.
Energy is not conserved as energy can be exchanged between mass and the corresponding gravitational fields.

This was recognized by Einstein and Hilbert well before the advent of expanding cosmologies such as the Big Bang or Steady State.

 

[FrumiousBandersnatch]

A GR based cosmology theory which *does not* rely upon "space expansion" as a cause of redshift doesn't automatically violate any conservation of energy laws. It's therefore not the fault of GR theory that the LCDM violates such laws. Period.

One can hypothesise an infinite number of possible universes... However, the one we observe is expanding:

"The success of Big Bang Nucleosynthesis depends on the fact that we understand how fast the universe was expanding in the first three minutes, which in turn depends on how fast the energy density is changing. And that energy density is almost all radiation, so the fact that energy is not conserved in an expanding universe is absolutely central to getting the predictions of primordial nucleosynthesis correct." - Sean Carroll, among other things, author of Spacetime and Geometry, a graduate-level textbook on general relativity. ​

 

[Michael]

One can hypothesise an infinite number of possible universes... However, the one we observe is expanding:

"The success of Big Bang Nucleosynthesis depends on the fact that we understand how fast the universe was expanding in the first three minutes, which in turn depends on how fast the energy density is changing. And that energy density is almost all radiation, so the fact that energy is not conserved in an expanding universe is absolutely central to getting the predictions of primordial nucleosynthesis correct." - Sean Carroll, among other things, author of Spacetime and Geometry, a graduate-level textbook on general relativity. ​

The fact that a given model *must* violate the laws of physics in order to get it's predictions to be correct only further undermines the validity of the model IMO.

FYI, since the LCDM model predicts a "flat" (rather than a curved) universe, it's not the geometry of the LCMD model that violates conservation of energy laws based on sjastro's argument, it's the "space expansion" process that requires the LCDM model to abandon those laws of physics, along with the postulation of a form of energy (dark energy) that remains constant throughout that expansion process. The LCMD model ultimately violates the conservation laws of energy not once, but *twice* even *before* discussing Guth's so called "free lunch" inflation process.