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How can Space, the volume of the Universe, be bent?


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From t0 Space expands 3D by Time? Must be a spherical shaped entity.

Than the system must be finite at least from the point of spacetime (from t0 to t-now) , energy and matter. Or?

But does space itself can be bent? How? 

Does spacetime has any physical properties can be curved?

Isn’t energy bends under the influence of gravity? Having a slightly curved extend, which is the local space of a physical entity in the moment of observation within the volume of the Universe. 
 

I agree that curved physical entities (waves…everything) can exist within any point of space. 
 

How the elements of a 0 set can be bent?

Edited by Conscious Energy
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1 hour ago, Conscious Energy said:

Isn’t energy bends under the influence of gravity? Having a slightly curved extend, which is the local space of a physical entity in the moment of observation within the volume of the Universe. 

From your somewhat  muddled post, the above needs correcting.Mass/energy curves/bends/warps spacetime. We feel that geometry as gravity.

As John Wheeler said, mass/energy tells spacetime how to curve; spacetime tells matter/energy how to move. [or words to that effect]

 

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30 minutes ago, Conscious Energy said:

What is the physical property of space can be bend by mass/energy? 

We don't know...that's simply how GR models it. A number of us have been arguing with the reality/truth or otherwise of spacetime warpage and gravity. If space, spacetime has a property, it is I suggest expansion and whatever is making that expansion accelerate. But there are others that may like to elaborate.

Edited by beecee
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2 hours ago, Conscious Energy said:

What is the physical property of space can be bend by mass/energy? 

Relationships between events - measurements of space and time differ in the presence of mass-energy, as compared to some far-away reference.

The mathematical object that describes these relationships is called the metric.

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  • 3 weeks later...

Thread,

The OP had some interesting observations.  One was of particular import to me. Any point in space contains everything.  Not sensible at first glance, but if you think about it, information from the furthest galaxies in the observable universe is arriving as we speak to all points of Earth's surface facing in the direction of said shiny body.

Interesting that if you look at a ballgame and I look at a ball game we both see the whole scene, and we are stationed at different points.

Regards, TAR

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10 hours ago, tar said:

Thread,

The OP had some interesting observations.  One was of particular import to me. Any point in space contains everything.  Not sensible at first glance, but if you think about it, information from the furthest galaxies in the observable universe is arriving as we speak to all points of Earth's surface facing in the direction of said shiny body.

Interesting that if you look at a ballgame and I look at a ball game we both see the whole scene, and we are stationed at different points.

Regards, TAR

Relativity deals with this.

Your relative position, speed and distance determines what information you receive and when. If the separate observers are viewing from different reference frames then they may experience different situations to each other, or the same situation at different times etc... There are no fixed times or points in space for any observer, only what they experience relative to something else.

For example; I'm sitting on a moving train reading my book, I'm fixed in position relative to the train and my clock reads a certain time. As we pass a platform a person observes me sitting on the train whizzing by. Relative to that person I'm moving and also our clocks will tick at a slightly different rates (in reality almost negligible since the train will be travelling too slow for our clocks to measure the difference, however lets assume for this analogy the train is travelling fast enough for the clocks to measure the difference) so the observer will experience time slightly differently relatively to me. 

Edited by Intoscience
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I have always found it hard to imagine how either space or time can curve. Instead, I prefer to think of gravity a region of shorter distance and slower time. Distances appear shorter and clocks tick slower in a strong gravitational field than they do in a weak gravitational field. These are the two physical effects of that increase when entering a stronger gravitational field. These effects are invisible but they can be plotted on paper as curved lines so gravity is illustrated as curved spacetime.

On 9/30/2021 at 2:55 AM, Intoscience said:

The OP had some interesting observations.  One was of particular import to me. Any point in space contains everything.  Not sensible at first glance, but if you think about it, information from the furthest galaxies in the observable universe is arriving as we speak to all points of Earth's surface facing in the direction of said shiny body.

 

This is what Einstein called "Mach's Principle". Every point in space is influenced by the combined gravitational effect of every massive body in the universe. This is why a gyroscope orients itself with the distant galaxies rather than the local, and far weaker, sources of gravity such as the Earth or the sun. We tend to ignore the effect of gravity from the trillion or so galaxies because it is equal in all directions but it is the total gravitational field of the universe itself that determines our measurements of space and time.

Ernst Mach explained that when a train stops suddenly the passengers fall forward because their attraction to the distant stars is greater than their attraction to the train.

Edited by bangstrom
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15 hours ago, bangstrom said:

Instead, I prefer to think of gravity a region of shorter distance and slower time.

Actually, distances generally become longer as compared to a far-away reference ruler, though it depends on the type of spacetime you are in.

And this is precisely the physical meaning of mathematical curvature - that relationships between events (ie measurements of space and time) now depend on where and when you make them, relative to a reference point.

Emphasis here being on the word ‘relationships’ - these aren’t effects that locally happen to clocks and rulers; it is how two or more such measurements are related in spacetime, which is why you can only detect them by comparing measurements. Locally all clocks tick at 1 second per second, and all rulers measure 1 meter per meter.

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On 9/30/2021 at 3:55 AM, Intoscience said:

Relativity deals with this.

Your relative position, speed and distance determines what information you receive and when. If the separate observers are viewing from different reference frames then they may experience different situations to each other, or the same situation at different times etc... There are no fixed times or points in space for any observer, only what they experience relative to something else.

For example; I'm sitting on a moving train reading my book, I'm fixed in position relative to the train and my clock reads a certain time. As we pass a platform a person observes me sitting on the train whizzing by. Relative to that person I'm moving and also our clocks will tick at a slightly different rates (in reality almost negligible since the train will be travelling too slow for our clocks to measure the difference, however lets assume for this analogy the train is travelling fast enough for the clocks to measure the difference) so the observer will experience time slightly differently relatively to me. 

I have read Einstein's train thing and the idea of Simultaneity needs to be agreed upon in order to make any sense of anything.  I think you have to consider

I have been suspended from Twitter, shadow banned on Gab and now a watcher or bot deleting my sentences as I write.

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On 9/30/2021 at 3:55 AM, Intoscience said:

Relativity deals with this.

Your relative position, speed and distance determines what information you receive and when. If the separate observers are viewing from different reference frames then they may experience different situations to each other, or the same situation at different times etc... There are no fixed times or points in space for any observer, only what they experience relative to something else.

For example; I'm sitting on a moving train reading my book, I'm fixed in position relative to the train and my clock reads a certain time. As we pass a platform a person observes me sitting on the train whizzing by. Relative to that person I'm moving and also our clocks will tick at a slightly different rates (in reality almost negligible since the train will be travelling too slow for our clocks to measure the difference, however lets assume for this analogy the train is travelling fast enough for the clocks to measure the difference) so the observer will experience time slightly differently relatively to me. 

except, Einstein assumes an observer that views both the stationary observer and the moving observer at the same time, in order to compare what they each observe at each moment.   This makes the comparison mute as the third observer, that compares the two, has his or her own reference frame and can therefore NOT guarantee anything is happening at the same time.

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1 hour ago, tar said:

except, Einstein assumes an observer that views both the stationary observer and the moving observer at the same time, in order to compare what they each observe at each moment.   This makes the comparison mute as the third observer, that compares the two, has his or her own reference frame and can therefore NOT guarantee anything is happening at the same time.

Relativity of simultaneity, I think covers that.

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22 hours ago, StringJunky said:

Relativity of simultaneity, I think covers that.

StringJunky,

That is what I am looking to discuss.  Einstein talks about a lightning strike as a device to establish simultaneity, but does not account for the distance of each observer from the strike

there are a number of inconsistencies and impossibilities that arise using relativity equations.  One such hard to square issue is that of the speed of light being constant and defined as a travel time over a certain distance.   How can you use this as a standard when both time and distance are warped with high velocities and large gravitational fields?

the difficulty is an imagination can place two observers at two different points at the same time, but since they are in actuality separated by a distance, NOTHING can happen at the same time in both places

only an event that happened half way between would be noticed by both observers at the same time

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On 9/13/2021 at 8:12 PM, Conscious Energy said:

But does space itself can be bent? How?

it seems to me that space and space time are being spoken of as the same thing here. Einstein used the concept of curved space time. Not curved space. It's questionable whether space time exists. Does the future exist, or the past? Maybe that's a philosophical question. Does something exist, if it's inevitable? Because that's all the future is. Something that doesn't exist, but certainly will. 

That's spacetime really. It maps the past and the future. Space isn't noticably curved in the present, but it is, if you add the past and the future. 

I found this online, from the University of Austin. Don't know if you will find it relevant :

https://stardate.org/astro-guide/faqs/what-do-scientists-mean-when-they-say-space-curved   

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This is simply a case of Conscious Energy ( and Tar ? ) mistaking the 'model' of space-time for space-time itself.
The model assigns a co-ordinate system to space-time, and the visible 'curvature' of that co-ordinate system effectively reproduces the effects of gravity. IOW, the model has curvature', space-time ... not necessarily.

Actually, before Markus yells at me, GR, the model, actually uses relationships between events in space-time, as defined by a metric.
( I only used a co-ordinate system because it, and its curvature, are easier to visualize than changing separations in 4 dimensions )

Edited by MigL
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7 hours ago, tar said:

One such hard to square issue is that of the speed of light being constant and defined as a travel time over a certain distance. 

It is not constant, it is invariant. That’s a really important difference!

The other thing is that this invariance is a local statement. If you send EM radiation through a larger region of curved spacetime, and you naively calculate the speed using your own clocks and rulers, you will come out with a smaller value - this is called Shapiro delay, and is one of the classic tests of GR. Nonetheless, the speed remains at exactly c at each point of the trajectory taken. That’s because what changes is the relationship between events in spacetime - not Maxwell’s equations.

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2 hours ago, Markus Hanke said:

It is not constant, it is invariant. That’s a really important difference!

Thanks... and a mistake I pesonally make many times. I have learnt something.  

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