Does the spacetime curvature according to Einstein really exist?

[tmdarkmatter]

If time goes by slower close to a black hole, this graph is completely altered. the distances between the times should increase until reaching an infinite distance. If the time units for the falling observer start being longer than the time units for the faraway observer, both observers will get to the same curve. So at time 15, one t of the falling observer corresponds to an infinite amount of ts of the faraway observer. In both cases the falling observer never reaches the event horizon.

I think you just have two different times in the same graph.

[Genady]

27 minutes ago, tmdarkmatter said:

If time goes by slower close to a black hole, this graph is completely altered. the distances between the times should increase until reaching an infinite distance. If the time units for the falling observer start being longer than the time units for the faraway observer, both observers will get to the same curve. So at time 15, one t of the falling observer corresponds to an infinite amount of ts of the faraway observer. In both cases the falling observer never reaches the event horizon.

I think you just have two different times in the same graph.

Yes, this is two graphs shown together. One is in the frame of the falling observer. In this graph, "time" is the falling observer's proper time:

The falling observer reaches the horizon and the singularity in a finite time.

The other is in the frame of the distant observer. In this graph, "time" is the Schwartzschild time of that observer:

In this frame, the falling observer never reaches the horizon.

[mistermack]

4 hours ago, tmdarkmatter said:

It takes a force to compress air, so gravity must also be a force, not a mathematical wonder.

Not true. The force comes from below, via the surface of the Earth acting on the gas, and is constantly accelerating the gas relative to the inertial frame that it's in. 

[swansont]

4 hours ago, tmdarkmatter said:

Several km is pretty thin, but still very far away from a thin line.

Since you never defined “thin” this is a pretty lame objection. A couple parts in a thousand is pretty thin.

You’ve given no rigorous analysis as to why it should be any thinner.

4 hours ago, tmdarkmatter said:

You might think how I would incorporate time in my idea. Well, I think that time should somehow have to be related to the amount of radiation coming from all directions.

You still have not quantified these radiation levels or presented any sort of model.

 

4 hours ago, tmdarkmatter said:

 

So when there is a gravitational shadow or when the object is moving at fast speeds, it is being hit by less radiation or radiation only coming from a certain angle.

Fast relative to what?

If the radiation is coming from all directions shouldn’t this increase the rate from the direction of motion?

(doesn’t apply to EM radiation, of course, since that always moves at c relative to the observer)

 

Do you have any independent evidence that radiation affects time? That time passes faster in daytime than nighttime, for example?

3 hours ago, tmdarkmatter said:

But of course I am only supposing and guessing, so this topic will be closed soon anyway.

!

Moderator Note

Yes, since you have presented nothing that passes as science. Soapboxing is against the rules, and we don’t have a “supposing and guessing” section.

 

[Phi for All]

3 hours ago, tmdarkmatter said:

But of course I am only supposing and guessing, so this topic will be closed soon anyway.

And if that happens, hopefully you'll understand that it was because your concepts were shown to be wrong because they disagree with what we observe, and not because we're trying to preserve the memory of Einstein.

[Genady]

12 hours ago, mistermack said:

I can give a couple of links that can answer that better than I could : 

https://arxiv.org/abs/gr-qc/0411060  

I've looked through the paper. It appears that the "space-river model" is not, and it does not intend to be an interpretation of GR. It rather

Quote

offers a mental picture ... that can be understood by non-experts (at least in the spherical case) without the benefit of mathematics.

It applies only to a limited set of reference frames / observers, in a limited set of space-time geometries, e.g.,

Quote

It is generally assumed that the fluid, or river, analogy applies to a limited class of general relativistic spacetimes, those in which the metric can be expressed up to an overall factor (a “conformal” factor) in terms of a shift vector (the velocity of the river) on an otherwise flat background space.

 

[tmdarkmatter]

18 hours ago, Phi for All said:

concepts were shown to be wrong because they disagree with what we observe

Why would my concepts disagree with what we observe? I think it is rather that we cannot confirm if this concept is true because we cannot measure all the radiation hitting us and calculate its force nor can we confirm that spacetime curvature exists. There are no proofs. It is just that we are conformists. If spacetime curvature can only be confirmed by gravity and gravity can only be confirmed by spacetime curvature, than this is not science. And even if you melt both ideas and say that spacetime curvature is gravity, we can still remove the spacetime curvature and say that there is only gravity and nothing else. So we are still in the times of Newton, we just have to optimize our understanding of gravity taking into account that protons themselves are being bent by gravitation and that they are also redshifted. Spacetime curvature is nonsense. It is just "an idea quickly accepted by the world of scientists without any proofs" that made Einstein rich and famous and with it the western world became the winners of sime kind of "cold war of science" (just check the amount of nobel prizes by country to see what I mean). Unfortunately, it converted physics into some kind of religion and now it is impossible to propose new ideas without being classified as flat earther.  The first condition necessary to be a scientist is not special skills or intelligence. The first conditions are being modest, being able to observe the world/universe, being able to listen to others and having good intentions for humanity. And your goal should not be to become rich and famous nor to treat others as flat earthers, just because they say something different to your unconfirmed theory. I know that you will now show me that the theory was confirmed several times, but if you really take your time and analyze the situation, you will always arrive at the same sentences I mentioned at the beginning.

Edited April 21, 2023 by tmdarkmatter

[exchemist]

44 minutes ago, tmdarkmatter said:

Why would my concepts disagree with what we observe? I think it is rather that we cannot confirm if this concept is true because we cannot measure all the radiation hitting us and calculate its force nor can we confirm that spacetime curvature exists. There are no proofs. It is just that we are conformists. If spacetime curvature can only be confirmed by gravity and gravity can only be confirmed by spacetime curvature, than this is not science. And even if you melt both ideas and say that spacetime curvature is gravity, we can still remove the spacetime curvature and say that there is only gravity and nothing else. So we are still in the times of Newton, we just have to optimize our understanding of gravity taking into account that protons themselves are being bent by gravitation and that they are also redshifted. Spacetime curvature is nonsense. It is just "an idea quickly accepted by the world of scientists without any proofs" that made Einstein rich and famous and with it the western world became the winners of sime kind of "cold war of science" (just check the amount of nobel prizes by country to see what I mean). Unfortunately, it converted physics into some kind of religion and now it is impossible to propose new ideas without being classified as flat earther.  The first condition necessary to be a scientist is not special skills or intelligence. The first conditions are being modest, being able to observe the world/universe, being able to listen to others and having good intentions for humanity. And your goal should not be to become rich and famous nor to treat others as flat earthers, just because they say something different to your unconfirmed theory. I know that you will now show me that the theory was confirmed several times, but if you really take your time and analyze the situation, you will always arrive at the same sentences I mentioned at the beginning.

I have a couple of questions:

- How does your radiation concept account for the time dilation we observe in communications satellites, which is accurately predicted by relativity?

- Are you an electrical engineer, by any chance? 

Edited April 21, 2023 by exchemist

[Eise]

54 minutes ago, tmdarkmatter said:

If spacetime curvature can only be confirmed by gravity and gravity can only be confirmed by spacetime curvature, than this is not science.

It is a fact, that with a description in terms of spacetime curvature, we can make better descriptions, more encompassing, about gravity than with Newtonian gravity. That doesn't necessarily mean that spacetime 'really' is curved. It only means that with this model we can make more and better predictions, and a deeper understanding of phenomena in the 'strong gravity' regime, and on modelling the universe and its history. So why shouldn't we use GR instead of Newtonian gravity?

It might also be interesting for you to know, that a formulation of GR without curved spacetime is possible, but then you should accept as a fact that gravity slows down time, and changes lengths of objects in gravitation fields, relative to observers that are far away from any gravitational field. According Kip Thorne (Black Holes and Time Warps) some calculations even become easier, than using the mathematical description with curved spacetime.

And do not forget: if you think you have an alternative, you must show, mathematically, that you can describe everything that is already correctly described by GR.

[Markus Hanke]

1 hour ago, tmdarkmatter said:

Why would my concepts disagree with what we observe?

1. When you place an accelerometer into free fall, it will measure exactly zero at all times, irrespective of how it falls. Therefore, no forces act on it. Ergo, gravity isn’t a force of any kind.

2. You can place (electrically neutral) test particles behind appropriate shielding that blocks out all (or at the very least most of) the ambient radiation hitting it. This has demonstrably no effect at all on how they behave gravitationally. Ergo, gravity has nothing to do with ambient radiation pressure differentials.

3. Newtonian radiation fields (ie vector fields) of binary sources are dipole in nature, and thus their polarisation states differ by 90 degrees. Real-world gravitational radiation on the other hand is quadrupole radiation, with polarisation states inclined by 45 degrees. Ergo, gravity isn’t a Newtonian force field.

4. Ambient radiation (being mostly photons) cannot and does not couple to rotational angular momentum of a near-by central body. In the real world though, angular momentum does very much have specific gravitational effects. Ergo, gravity has nothing to do with ambient radiation.

5. Real-world gravity distorts shape and volume of freely falling test bodies, which ambient radiation differentials cannot do. Ergo, gravity is not radiation differentials.

6. Ambient radiation does not dilate the relative rates between clocks, as real-world gravity does. For example, electrically neutral unstable elementary particles such as the Z-boson do not couple to the photon field, and yet their lifetimes are dilated in the same way as any other clock under the influence of real-world gravity. Thus, gravity isn’t just radiation pressure.

And many more…

1 hour ago, tmdarkmatter said:

we cannot measure all the radiation hitting us

This is nonsense - “radiation” in this context is just electromagnetic fields, which can be measured to extraordinarily high precision. Using SQUIDs, you can (e.g.) measure magnetic flux densities on the order of 10^-18T. So we have a really good idea about ambient radiation environments. And by shielding it - which is simple enough to do - you can check whether this has any effect on gravity, which it evidently doesn’t.

Furthermore, we can directly measure the gravitational effect of small-ish everyday objects on each other just fine, even using simple table-top setups like the Cavendish apparatus (we did this as a project when I was in high school). You can buy DIY kits for this and try it out yourself at home, in fact I would very much encourage you to do so. You can also place that same setup into a vacuum chamber surrounded by appropriate shielding, and find that the gravitational effects do not change at all.

In fact, even just wrapping 2-3 layers of standard kitchen aluminium foil tightly all around the Cavendish apparatus in a way that leaves no gaps and no conducting paths will reduce the internal ambient EM flux densities by roughly a factor of 10,000 (~80dB of shielding or so), and thus any gravitational effects should reduce accordingly. You can (at least in principle) try this at home, and what you will find is that that is not what happens - there will be no changes at all in gravitational attraction. Thus, the notion that gravity is just ambient radiation pressure is a very bad model, since it bears no resemblance whatsoever to what we actually observe in the real world.

1 hour ago, tmdarkmatter said:

If spacetime curvature can only be confirmed by gravity and gravity can only be confirmed by spacetime curvature, than this is not science.

Spacetime is a model - we take the description of some real-world scenario (like e.g. two bodies beginning a free-fall toward one another), put it into the model, do the maths, and out comes a prediction of how this system will evolve. We can then check this prediction by comparing it with what actually happens in the real world, and it will either turn out to be correct, or not. This is very much in accord with the scientific method - if the predictions are correct, the model is good; if not, it needs to be amended or discarded. A model in physics does not in general make any claims about ontological truths; it claims only that its predictions accord with real-world observations, and thus that it is valid in that specific sense. In the case of GR, the claim is that the mathematical entity of a semi-Riemannian manifold with curvature that is constraint by a specific relationship between metric and energy-momentum distribution shares the same dynamics as those observed for real-world test particles under the influence of gravity - there is a specific mapping between these two, but not necessarily an ontological identity. There might well be an identity, but that isn’t the a priori claim here, and in any case largely a philosophical question.

You on the other hand don’t have anything at all - it seems you don’t even have a mathematical framework that allows specific numerical predictions to be made, and thus you don’t have anything that can be subjected to the scientific method in the first place. So you aren’t doing science, you are just wildly guessing - and it appears you are doing this solely based on your personal dislike of GR, which, in my humble opinion, is a really bad reason. We want to move forward with better models, not regress back to LeSage et al, which we already know cannot work for fundamental reasons.

Edited April 21, 2023 by Markus Hanke

[tmdarkmatter]

2 hours ago, Markus Hanke said:

You can place (electrically neutral) test particles behind appropriate shielding that blocks out all (or at the very least most of) the ambient radiation hitting it.

First of I all, I want to thank you for your very detailed reply to my questions. I will go through all the elements and issues you mentioned once again during the weekend when I have more time and even during the following weeks or months, because I am very interested in all these things. This information is very useful for me. The same applies to all other valuable replies I have received here. Thank you all very much!

But what I want to ask you at first is how good can "appropriate shielding" be that blocks out "all" ambient radiation. We are saying that neutrinos go through the entire planet due to their very little interaction with matter, while the radiation we so far detected is "almost immediately" being blocked by the surface of our planet, the atmosphere, or the "shielding" you are mentioning. But what if gravity is being caused by radiation with features that are just in between these two extreme situations. In that case, only very big objects like the moon would be able to "effectively block" this radiation in order to make this gravitational shadow be detectable for our instruments. Single atoms might also block this radiation but the effect observed would be completely negligible for us and it would not be possible to measure this effect. Just compare the diameter of earth with the diameter of a single atom to see the magnitude by which the gravitational effect should be negligible and undetectable. I think that this kind of "gravitational radiation" (if it exists) would mostly pass through an atom, because it is very improbable that it just hits the pinhead in a soccer field in the first try and gets absorved or reflected. This radiation with ultra high frequency should have to pass through billions of atoms to finally get absorbed or reflected in a way we can detect and is not being blocked by a sheet of aluminium foil. Lets say that if I want to block this radiation, I would need at least big asteroids or several (maybe hundreds) of kilometers of matter with a thickness of billions and billions of atoms, so i can observe an effect. Only if I put a huge object of this size in front of you, I would be able to show you a change in gravity, as it happens when the moon passes by, pulling our oceans. We say that gravity is a weak force, it is indeed a very very very weak force.

So where should we begin to try to find this kind of radiation? I think we have to go below earth as much as possible to see what components of the ambient radiation are still present down there. You might say that there isn´t any radiation down there. Well, neutrinos are there and there might be more, much more radiation with a very low interaction with matter. Of course this radiation has to be negligible/undetectable at first, if we need an object of the size of earth to create enough gravitational force for an acceleration of only 9,81 ms2. Just compare your aluminium sheet with earth. You might say that you cannot create gravitational force in a lab, that´s because you cannot move planets and position them according to your needs. Whenever you see a gravitational effect, it´s because you are using objects of the right size and shielding. We define this shielding as mass.

Shouldn´t mountains pull us? Well if we compare the thickness of a mountain (maybe 1000 m) with the thickness of earth, the effect of the mountain should still be negligible compared to the gravity of earth, so we do not notice it.

Edited April 21, 2023 by tmdarkmatter

[swansont]

3 hours ago, tmdarkmatter said:

Why would my concepts disagree with what we observe? I think it is rather that we cannot confirm if this concept is true because we cannot measure all the radiation hitting us and calculate its force

If you are positing some new radiation we can’t measure, then we aren’t observing it. But you need some independent confirmation of this. This is science, not science fiction.

 

10 minutes ago, tmdarkmatter said:

But what I want to ask you at first is how good can "appropriate shielding" be that blocks out "all" ambient radiation. We are saying that neutrinos go through the entire planet due to their very little interaction with matter, while the radiation we so far detected is "almost immediately" being blocked by the surface of our planet, the atmosphere, or the "shielding" you are mentioning. But what if gravity is being caused by radiation with features that are just in between these two extreme situations. In that case, only very big objects like the moon would be able to "effectively block" this radiation in order to make this gravitational shadow be detectable for our instruments. Single atoms might also block this radiation but the effect observed would be completely negligible for us and it would not be possible to measure this effect.

We can detect neutrinos, though, so something that interacts more readily should be more easily detected. Saying it’s not possible to measure them is inconsistent.

And if it’s responsible for gravity, that would tell us how readily such radiation interacts. If one were to quantify the effects, which is why we do such things in science, and why hand-wavy claims such as yours carry almost no weight. It’s a teaser, but very quickly one asks where the meat of the claim is.

[Genady]

5 minutes ago, tmdarkmatter said:

Shouldn´t mountains pull us? Well if we compare the thickness of a mountain (maybe 1000 m) with the thickness of earth, the effect of the mountain should still be negligible compared to the gravity of earth, so we do not notice it.

We do notice it. See here (Gravity of Earth - Wikipedia😞

Quote

Local differences in topography (such as the presence of mountains), geology (such as the density of rocks in the vicinity), and deeper tectonic structure cause local and regional differences in the Earth's gravitational field, known as gravitational anomalies.^[16] Some of these anomalies can be very extensive, resulting in bulges in sea level, and throwing pendulum clocks out of synchronisation.

The study of these anomalies forms the basis of gravitational geophysics. The fluctuations are measured with highly sensitive gravimeters, the effect of topography and other known factors is subtracted, and from the resulting data conclusions are drawn. Such techniques are now used by prospectors to find oil and mineral deposits. Denser rocks (often containing mineral ores) cause higher than normal local gravitational fields on the Earth's surface. Less dense sedimentary rocks cause the opposite.

 

[tmdarkmatter]

6 minutes ago, Genady said:

We do notice it. See here

Yes, thank you! Of course with the right instruments and knowledge you can detect this effect. I just wanted to say that you are not going to be pulled to the montain when walking next to it in way we can easily see.

[swansont]

14 minutes ago, tmdarkmatter said:

This radiation with ultra high frequency should have to pass through billions of atoms to finally get absorbed or reflected in a way we can detect and is not being blocked by a sheet of aluminium foil. Lets say that if I want to block this radiation, I would need at least big asteroids or several (maybe hundreds) of kilometers of matter with a thickness of billions and billions of atoms, so i can observe an effect. Only if I put a huge object of this size in front of you, I would be able to show you a change in gravity, as it happens when the moon passes by, pulling our oceans. We say that gravity is a weak force, it is indeed a very very very weak force.

We detect actual gravitational radiation in LIGO, which is exceedingly weak, and this shielding you propose should be proportional.

It’s one thing to say it’s responsible for gravity and another to say it’s too weak to measure. You can’t have it both ways.

 

[tmdarkmatter]

14 minutes ago, swansont said:

If you are positing some new radiation we can’t measure, then we aren’t observing it. But you need some independent confirmation of this. This is science, not science fiction.

Ok, maybe this model is still "science fiction".

[Markus Hanke]

38 minutes ago, tmdarkmatter said:

But what I want to ask you at first is how good can "appropriate shielding" be that blocks out "all" ambient radiation.

It doesn’t have to block out all radiation, just a noticeable portion of it - all you want to check for is whether the gravitational interaction between two neighbouring bodies reduces once you introduce shielding. In my last post I have already suggested an experiment that you can - in principle at least - do at home: get a Cavandish apparatus, and place it into some kind of Faraday cage, such as a few layers of tinfoil. So long as there are no gaps or conducting paths, this provides a good ~70-80dB worth of shielding. That’s more than enough for you to be able to tell whether there’s a change in the value of G due to shielding, or not.

38 minutes ago, tmdarkmatter said:

But what if gravity is being caused by radiation with features that are just in between these two extreme situations.

You said before that the radiation in question is electromagnetic (photons). If instead you need to introduce new, hitherto unknown entities in order to make your idea work, then you are better off just sticking with spacetime.

38 minutes ago, tmdarkmatter said:

We define this shielding as mass.

All forms of energy-momentum are a source of gravity, not just mass. This also includes stress, strain, pressure, electromagnetic fields, energy density, momentum density, and also the gravitational field itself. For example, the region in and around a Schwarzschild black hole is completely empty - there is no “mass” located anywhere (\(T_{\mu \nu}=0\) everywhere in that spacetime). The entirety of that gravitational environment is made up of gravitational self-interaction alone. 

Edited April 21, 2023 by Markus Hanke

[swansont]

1 hour ago, tmdarkmatter said:

Ok, maybe this model is still "science fiction".

Then we’re done here