Could Everything on Earth Float Without Spacetime?

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Discussion Overview

The discussion revolves around hypothetical scenarios involving gravity, spacetime, and wormholes, exploring the implications of removing spacetime from the equation and the nature of gravitational effects. Participants engage in thought experiments and theoretical models related to general relativity and the behavior of objects in extreme conditions.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Mathematical reasoning

Main Points Raised

  • One participant questions whether removing spacetime would result in everything floating in weightlessness, suggesting that gravity is a result of spacetime deformation.
  • Another participant argues that the concept of removing spacetime is not meaningful, as spacetime is integral to the laws of physics.
  • Some participants discuss different models of gravity, noting that describing gravity as a force versus a geometric property of spacetime leads to different interpretations.
  • There is a contention about whether space and time are human inventions or inherent realities, with differing views on their nature.
  • A hypothetical scenario involving wormholes is presented, questioning whether an object would pass through instantly or with a delay, with some participants asserting that wormholes are not factual but theoretically explainable.
  • Participants mention the practical implications of gravitational time dilation in satellite technology, particularly in GPS systems, and the need for corrections due to relativistic effects.
  • There are discussions about the validity of various models and the importance of accurate timekeeping in physics, with references to gravitational lensing and radar-ranging as confirmations of Einstein's theories.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of spacetime, gravity, and the implications of hypothetical scenarios. The discussion remains unresolved, with no consensus on the interpretations of spacetime and gravity.

Contextual Notes

Some participants highlight the limitations of thought experiments that remove spacetime, noting that such scenarios may not align with established physical laws. There are also unresolved questions about the nature of wormholes and their implications for instantaneous travel.

  • #31
George Akba said:
If we go by special relativity and assume that: "the curvature of spacetime due to gravity is negligible" we are left with matter.

I don't understand what you mean by this, or by the post it's quoted from. SR is only valid in the absence of gravity; it is not a competitor theory to GR, which includes gravity. It's a special case of GR.
 
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  • #32
Peter quotes are from Wikipedia this article: https://en.wikipedia.org/wiki/Special_relativity fourth paragraph.

I don't mean that SR(Special Relativity) is a competitor theory to GR(General Relativity). What I am trying to show is that with both SR and GR perspective we can see a proportional relationship between Curvature - Geodesic Projection and a Matter.

"Einstein discovered the field equations of general relativity, which relate the presence of matter and the curvature of spacetime and are named after him. The Einstein field equations are a set of 10 simultaneous,non-linear, differential equations. The solutions of the field equations are the components of the metric tensor of spacetime. A metric tensor describes a geometry of spacetime. The geodesic paths for a spacetime are calculated from the metric tensor."
https://en.wikipedia.org/wiki/Gravity

Again what I am trying to simply say is that Matter - is proportional to Gravity. Matter is directly related to Gravity. If you agree this is correct. I will have a question for you.

Thanks for reply
 
  • #33
George Akba said:
What I am trying to show is that with both SR and GR perspective we can see a proportional relationship between Curvature - Geodesic Projection and a Matter.

GR certainly includes such a relationship, but SR does not; SR assumes flat spacetime, and cannot handle any spacetime curvature.

George Akba said:
what I am trying to simply say is that Matter - is proportional to Gravity. Matter is directly related to Gravity.

First, "gravity" does not necessarily mean "spacetime curvature". The precise way to say it would be that tidal gravity means spacetime curvature. "Gravity" can mean other things besides tidal gravity.

Second, I would say that the Einstein Field Equation tells us how matter produces spacetime curvature; it does not say the two are the same thing.
 
  • #34
>...if we take Spacetime out of equation

Returning to the original question. If momentum and mass can exist outside of space-time then in your thought experiment everything would drift away or together depending on the momentum and any charges there might be.

Anthony
 
  • #35
_Anthony_ said:
>...if we take Spacetime out of equation

Returning to the original question. If momentum and mass can exist outside of space-time then in your thought experiment everything would drift away or together depending on the momentum and any charges there might be.

Anthony
How can you possibly know that? You have suspended the laws of physics but assumed that some of the laws of physics still apply. I don't think that can be a valid assumption.
 
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  • #36
phinds,

Thanks for quoting my post and questioning my reasoning. Once the laws of physics are redefined anything is possible but beyond that considered Thompson's raisin in pudding model of the atom, completely wrong yet it does a passable job. I interpreted the question as lay person would, "What if all the laws of physics still worked but gravity was gone?" You showed that the question makes no real sense based on the current understanding of physics.
 
  • #37
The center of the universe is back in time at the big bang. Everything in the universe today is at the edge of the expanding universe.
 
  • #38
MidiMagic said:
The center of the universe is back in time at the big bang. Everything in the universe today is at the edge of the expanding universe.
"center" is a word in English that normally refers to spatial positioning, not temporal positioning, so no, it isn't in the normal English meaning of that sentence. Yes, it is the "edge" of temporal expansion but that's not common terminology and is confusing with being explicit that you are talking about temporal coordinates, not spatial coordinates.
 
  • #39
_Anthony_ said:
phinds,

Thanks for quoting my post and questioning my reasoning. Once the laws of physics are redefined anything is possible but beyond that considered Thompson's raisin in pudding model of the atom, completely wrong yet it does a passable job. I interpreted the question as lay person would, "What if all the laws of physics still worked but gravity was gone?" You showed that the question makes no real sense based on the current understanding of physics.
Yeah, we get that a lot here. Basically people never tire of asking questions that can really only be rephrased as "if the laws of physics did not apply, what would the laws of physics say about <insert nonsense of your choice>". So you are hardly alone in thinking that way, but it's good to move away from it, as you clearly are.
 
  • #40
_Anthony_ said:
If momentum and mass can exist outside of space-time then [...]

You need space and time to define momentum, and depending on the way you do it, mass too.

But I can't imagine a scenario with mass and no space or time. It just doesn't make any sense for reasons that were explained earlier in this thread.
 
  • #41
_Anthony_ said:
phinds, Once the laws of physics are redefined anything is possible but beyond that considered Thompson's raisin in pudding model of the atom, completely wrong yet it does a passable job.

But that was a model. Models can and do rewrite the laws of physics. And it's also possible, by the way, to rewrite the laws of physics without a model.

But you are doing none of that. You don't have a model. You don't have laws. Laws and models are generalizations from observations. You don't have any observations, either.

What you are doing has already been pointed out to you to be a wrong way. You are taking the laws of physics and you are imagining what they mean. You are then proposing rearrangements of those meanings.

To understand what the laws of physics mean you need to look at the observations that they are generalizations of. Physics is more about the phenomenology than the philosophy. You are attempting to focus on the latter while ignoring the former. Moreover, your attempts at focusing on the latter are failing because you are ignoring the former.

Physics is an attempt to understand how things behave. And those things are naturally-occurring phenomena, not human-invented properties like mass and momentum.
 
  • #42
Mister T said:
... space and time are human inventions. Creations of the mind.
Mister T said:
What makes you think that being an invention and existing are mutually exclusive?
I explained that I made no error.
Mister T, space and time were around long before mankind. Indeed, they were around for quite some time before the Solar System formed.

Let that be the end of this spiral into madness.
 
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  • #43
Thread closed for moderation.

Edit: the thread will remain closed.
 
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