What is Spacetime?

[Super Nova]

Linked is a mind numbing article.

Conclussion- we have no f..ken idea.

When we crack this one... we will see a revolution or our understanding of the universe that may lead to amazing things in communications and travel.

I think it will take hundreds of years.

What Is Spacetime?
Physicists believe that at the tiniest scales, space emerges from quanta. What might these building blocks look like?

People have always taken space for granted. It is just emptiness, after all—a backdrop to everything else. Time, likewise, simply ticks on incessantly. But if physicists have learned anything from the long slog to unify their theories, it is that space and time form a system of such staggering complexity that it may defy our most ardent efforts to understand.
Albert Einstein saw what was coming as early as November 1916. A year earlier he had formulated his general theory of relativity, which postulates that gravity is not a force that propagates through space but a feature of spacetime itself. When you throw a ball high into the air, it arcs back to the ground because Earth distorts the spacetime around it, so that the paths of the ball and the ground intersect again. In a letter to a friend, Einstein contemplated the challenge of merging general relativity with his other brainchild, the nascent theory of quantum mechanics. That would not merely distort space but dismantle it. Mathematically, he hardly knew where to begin. “How much have I already plagued myself in this way!” he wrote.
Einstein never got very far. Even today there are almost as many contending ideas for a quantum theory of gravity as scientists working on the topic. The disputes obscure an important truth: the competing approaches all say space is derived from something deeper—an idea that breaks with 2,500 years of scientific and philosophical understanding.

.............. then heavy read


In physics and, more generally, in the natural sciences, space and time are the foundation of all theories. Yet we never see spacetime directly. Rather we infer its existence from our everyday experience. We assume that the most economical account of the phenomena we see is some mechanism that operates within spacetime. But the bottom-line lesson of quantum gravity is that not all phenomena neatly fit within spacetime. Physicists will need to find some new foundational structure, and when they do, they will have completed the revolution that began just more than a century ago with Einstein.

Link: https://www.scientificamerican.com/arti ... spacetime/

[sprintcyclist]

can you simplify the idea please?

[Super Nova]

can you simplify the idea please?

Sprint, I went back and re-read it.

It is really giving some history to the problem, discussed some ideas but concludes we know SFA.

it ends with.

But the bottom-line lesson of quantum gravity is that not all phenomena neatly fit within spacetime. Physicists will need to find some new foundational structure, and when they do, they will have completed the revolution that began just more than a century ago with Einstein.

They need to start again. We are looking in the wrong places and are way off getting close to understanding space time... at this time, if I can say that... well at this spacetime coordinate we know jack and are no closer to an understanding. back to the drawingboard.

[sprintcyclist]

What is spacetime?

[Super Nova]

What is spacetime?

In classical mechanics, time is separate from space. In special relativity, time and space are fused together into a single 4-dimensional "manifold" called spacetime.
Since spacetime is a smooth manifold, and since the speed of light is great compared to speeds normally accessible to humans, there is little that humans might observe which is noticeably different from what they would observe if the world followed the "geometry of common sense", in which spatial and temporal dimensions are independent.
Things that happen in spacetime are called "events". Events are idealized, four-dimensional points. There is no such thing as an event in motion.
The path of a particle in spacetime traces out a succession of events, which is called the particle's "world line".
In special relativity, to "observe" or "measure" an event means to ascertain its position and time against a hypothetical infinite latticework of synchronized clocks. To "observe" an event is not the same as to "see" an event.

https://en.wikipedia.org/wiki/Spacetime

Also go to youtube... I have watched many over the last few years to try and under it.

https://www.youtube.com/results?search_ ... +explained

However this is the best video..... I have watched it a couple of times. It explains the thinking that led Einstein to develop Special Relativity and then General Relativity.

It is the best to explain spacetime thinking.

[sprintcyclist]

can you explain it in your words?

[Super Nova]

can you explain it in your words?

Oh a test.

I will try from the top of my head no better than this.

https://en.wikipedia.org/wiki/Spacetime ... relativity

But I will try.

Space time is a system where the time is integrated in the co-ordinate system and also allows a unique view of what each observer has of other observers. It preserves that time for an individual will all appear to flow at a set pace but they will appear to move at a different pace through time when observed by someone else, particularly if they are moving at different speeds and direction. Spacetime is the term unsed to connect the 4 co-ordinate systems into one entity, the fourth dimension becasue the speed of light is a univseral constant and if that is constant then only time and space can be flexed. Spacetime is the framework that flexes because the speed of any communciations between things is limited to be always the speed of light.

If you consider what happens when you imagine travelling at near the speed of light and you turn on your torch light. You may expect the light from the torch to be seen to be going at your speed plsu the speed of the light coming from your torch. But no, it is still the normal speed of light from your perspective. So how can this be explained. The explaination is your time has slowed down relative to a stationary obverser. As stationary observer would se the light fro mthe torch trvel as the speed of light but would see a wavelngth difference only. They would also see you appear longer than they woudl observe you if you were stationary next to them.

So we all have a different view of of what is happenign in the universe. Thing don't happen at the same time for anything, the speed of ligh is the limit and a constant. So only space and time parameters are let to change. The joining of 3 D space with time providign the construct because your velocity in space changes the perspection of time when seen by an external observer. So it is all relative... my spacetime is different to your and your perseption of my space time is different to what I observer.

Anyway, that was shit....... and you better off readign about it. The linked video above on Einstein is perfect for the explaination.

[Super Nova]

This is a better explaination.

[sprintcyclist]

can you explain it in your words?

Oh a test.

I will try from the top of my head no better than this.

https://en.wikipedia.org/wiki/Spacetime ... relativity

But I will try.

Space time is a system where the time is integrated in the co-ordinate system and also allows a unique view of what each observer has of other observers. It preserves that time for an individual will all appear to flow at a set pace but they will appear to move at a different pace through time when observed by someone else, particularly if they are moving at different speeds and direction. Spacetime is the term unsed to connect the 4 co-ordinate systems into one entity, the fourth dimension becasue the speed of light is a univseral constant and if that is constant then only time and space can be flexed. Spacetime is the framework that flexes because the speed of any communciations between things is limited to be always the speed of light.

If you consider what happens when you imagine travelling at near the speed of light and you turn on your torch light. You may expect the light from the torch to be seen to be going at your speed plsu the speed of the light coming from your torch. But no, it is still the normal speed of light from your perspective. So how can this be explained. The explaination is your time has slowed down relative to a stationary obverser. As stationary observer would se the light fro mthe torch trvel as the speed of light but would see a wavelngth difference only. They would also see you appear longer than they woudl observe you if you were stationary next to them.

So we all have a different view of of what is happenign in the universe. Thing don't happen at the same time for anything, the speed of ligh is the limit and a constant. So only space and time parameters are let to change. The joining of 3 D space with time providign the construct because your velocity in space changes the perspection of time when seen by an external observer. So it is all relative... my spacetime is different to your and your perseption of my space time is different to what I observer.

Anyway, that was shit....... and you better off readign about it. The linked video above on Einstein is perfect for the explaination.

So, that is not your words ?

[Super Nova]

can you explain it in your words?

Oh a test.

I will try from the top of my head no better than this.

https://en.wikipedia.org/wiki/Spacetime ... relativity

But I will try.

Space time is a system where the time is integrated in the co-ordinate system and also allows a unique view of what each observer has of other observers. It preserves that time for an individual will all appear to flow at a set pace but they will appear to move at a different pace through time when observed by someone else, particularly if they are moving at different speeds and direction. Spacetime is the term unsed to connect the 4 co-ordinate systems into one entity, the fourth dimension becasue the speed of light is a univseral constant and if that is constant then only time and space can be flexed. Spacetime is the framework that flexes because the speed of any communciations between things is limited to be always the speed of light.

If you consider what happens when you imagine travelling at near the speed of light and you turn on your torch light. You may expect the light from the torch to be seen to be going at your speed plsu the speed of the light coming from your torch. But no, it is still the normal speed of light from your perspective. So how can this be explained. The explaination is your time has slowed down relative to a stationary obverser. As stationary observer would se the light fro mthe torch trvel as the speed of light but would see a wavelngth difference only. They would also see you appear longer than they woudl observe you if you were stationary next to them.

So we all have a different view of of what is happenign in the universe. Thing don't happen at the same time for anything, the speed of ligh is the limit and a constant. So only space and time parameters are let to change. The joining of 3 D space with time providign the construct because your velocity in space changes the perspection of time when seen by an external observer. So it is all relative... my spacetime is different to your and your perseption of my space time is different to what I observer.

Anyway, that was shit....... and you better off readign about it. The linked video above on Einstein is perfect for the explaination.

So, that is not your words ?

yes it was, off the top of my head.