How is it proved that space-time is curved and not energy impacted by gravity and the path changed?

[Lasse]

Be gentle when you explain. Like you would do it for your granny.

How time can be curved when one second is coming after another and there is no second can be infinite?

Can any observer of or participant in Nature be absolute static?

Edited April 4, 2018 by Lasse

[beecee]

53 minutes ago, Lasse said:

Be gentle when you explain. Like you would do it for your granny.

How time can be curved when one second is coming after another and there is no second can be infinite?

Can any observer of or participant in Nature be absolute static?

Space is what keeps everything from being together: Time is what stops everything from happening together:..Intervals of space and time considered separately are not the same for all observers.

Spacetime can be said to be the multi dimensional framework within which we locate events and describe the relationships between them in terms of space and time. The concept of spacetime follows from the observation that the speed of light is invariant.

The equations of GR describe gravity as simply geometry...the geometry of spacetime as altered in the presence of mass. Spacetime can be warped, twisted [Lense Thirring effect] curved, and even in the form of waves...gravitational waves. We observe distant galaxies and stars lensed by the geometry and curvature of intervening spacetime.

 

How and why isn't really the concern at this time. The fact is that cosmology and GR seem to accurately describe what we observe and is able to make solid verifiable predictions.

53 minutes ago, Lasse said:

How time can be curved when one second is coming after another and there is no second can be infinite?

Example: If you and I were in a  space vehicle, approaching a BH, and you stopped the vehicle at a safe distance away from the BH, while I being the more intrepid explorer, approached the EH of the BH in a shuttle craft,  from my frame of reference, I would approach and cross the EH into oblivion, forever being lost to the rest of the universe. From your perspective though, you would see me approach the EH, and I would be gradually redshifted to beyond your viewing ability...So you grab a powerful infrared telescope and then proceed to watch me again...again, I would continue to be redshifted until beyond the scope's ability to observe. In essence, you would never actually see me cross the EH, just gradually redshifted beyond your view. 

Edited April 4, 2018 by beecee

[Strange]

8 hours ago, Lasse said:

How is it proved that space-time is curved and not energy impacted by gravity and the path changed?

Firstly, science doesn't really work by proving things. Instead what it does is create models (theories) that attempt to describe or explain how things work. Those models are then tested by experiment.

So, we have a model that describes gravity and other effects in terms of the curvature of the geometry of space and time. All the experiments done so far produce results that are in agreement with that theory. So we accept it as a good model.

We have no model that says that energy can be directly affected by gravity (other than through space and time being curved). So there is no evidence for that idea.

8 hours ago, Lasse said:

How time can be curved when one second is coming after another and there is no second can be infinite?

If you are looking for an intuitive way of visualising this, I think you might be out of luck! But we can measure it happening. Clocks at different altitudes run at different speeds because time runs at a different rate depending on their position in the gravitational field.

The easier thing to visualise is special relativity. This doesn't involve curvature. But we do see the clocks of people moving relative to us running slow. One way of visualising this is to think that everything always moves through space-time at the same rate. If something is stationary (relative to you)  then all of that movement is through time. If the object starts moving through space, then this "trades off" some of that movement through time and so their clocks run slow. 

Quote

Can any observer of or participant in Nature be absolute static?

All movement is relative. So something can be static relative to you, but they will be moving relative to something else.

[koti]

I find this video explaining the OP question very clearly. They even constructed a mechanical device visualizing the Lorentz transforms:

 

[Strange]

54 minutes ago, koti said:

I find this video explaining the OP question very clearly. They even constructed a mechanical device visualizing the Lorentz transforms

That is brilliant. I am often sceptical of videos as a means of presenting information but that says everything that needs to be said in a really clear way that makes sense.

(It doesn't quite answer the origin question though, because it doesn't address space-time curvature but it is a good first step along the way.)

[studiot]

Yes it is a good video but I agree with Strange that SR is Euclidian and not about curvature. +1 for finding it though.

 

[koti]

3 minutes ago, Strange said:

That is brilliant. I am often sceptical of videos as a means of presenting information but that says everything that needs to be said in a really clear way that makes sense.

(It doesn't quite answer the origin question though, because it doesn't address space-time curvature but it is a good first step along the way.)

Glad you like it, I love how they modify the axises in post production to show spacetime stretching and keeping c constant. After watching this I was looking at buying their „time globe” but it seems its just a one off device. Its a pitty that laughable products are being offered to schools and something like this isn’t abailable (its fairly simple to make) 

[Strange]

1 minute ago, koti said:

and something like this isn’t abailable (its fairly simple to make) 

Business opportunity?

 

[koti]

8 minutes ago, Strange said:

(It doesn't quite answer the origin question though, because it doesn't address space-time curvature but it is a good first step along the way.)

 

3 minutes ago, studiot said:

Yes it is a good video but I agree with Strange that SR is Euclidian and not about curvature. +1 for finding it though.

 

I agree. I just couldn’t resist posting it though because the video shows in wonderful clarity how/why the Lotentz transform works.

1 minute ago, Strange said:

Business opportunity?

 

I don’t see how to scale it...a few dozen universities would buy it and then the market is saturated. Regular non-physics-geek people wouldn’t buy it. 

[interested]

9 hours ago, Strange said:

 

Edited April 5, 2018 by interested
posted on wrong thread

[studiot]

Quote

How is it proved that space-time is curved and not energy impacted by gravity and the path changed?

 

17 hours ago, Lasse said:

Be gentle when you explain. Like you would do it for your granny.

How time can be curved when one second is coming after another and there is no second can be infinite?

Can any observer of or participant in Nature be absolute static?

Your questions and opening post are a bit jumbled so before going into detail let us get straight exactly what you are asking.

 

Lorentz and Fitzgerald had some experimental results so they developed mathematical formulae that fitted these results, but they had no idea why in terms of the science of Mechanics of the day.

Einstein came along with a theoretical hypothesis, based on new thinking he called "The principle of relativity", which produced the same formulae (and others besides as it included electromagnetic phenomena as well as mechanical ones.) This was in 1905 and the new theory was called Special Relativity. It did not involve curved space.

So they then had experimental evidence/verification of this theory.

In 1915 Einstein produced a paper  with a wider ranging subject matter he called General Relativity.
This paper did indeed incorporate curved space.

Furthermore Einstein again offered the possibility (he did not conduct the experiments himself) experimental verification, but this was much more difficult and could only be achieved over astronomical distances.

This was his first paper on the subject and introduced another new principle of Physics.

 

So when you say 'proove the curvature' are you interested in

a) Understanding what is meant by this curvature?

b) the theoretical development that leads to the conclusion that curvature exists?
This is pretty difficult.

c) Or are you interested in the experimental evidence that supports this conclusion (which is easier)?

[Lasse]

17 hours ago, beecee said:

Time is what stops everything from happening together:.

But with everything seems to happen something...in other words every physical entity seems to be impacted by time i.e. with everything happening something and no second can be infinite i.e it could be exactly the same. What can be absolute static? Space? Does space moves? Does it have any velocity? Or it is absolutely static?

Thanks for the interesting reflections.  I will try to answer as soon as I can! It will take a bit more time because I have classes.

By then every thought is welcome of course

[mistermack]

On 4/5/2018 at 6:23 PM, Lasse said:

 What can be absolute static? Space? Does space moves? Does it have any velocity? Or it is absolutely static?

You might like to read a bit about the river model.

My thread in speculations had some interesting relevant thoughts and links on that subject. 

I'm not pushing "my own hypothesis", it's just easier to link it than bulk post a load of stuff from it:

https://www.scienceforums.net/topic/110805-gravity-please-knock-this-down/  

 

[Scott of the Antares]

On 05/04/2018 at 9:27 AM, koti said:

I find this video explaining the OP question very clearly. They even constructed a mechanical device visualizing the Lorentz transforms:

 

Thanks for posting that video Koti; it was amazing! Such a good example:)