What is the fabric of spacetime?

[DLeuPel]

The question is in the title. Nothing more to add.

 

[jambaugh]

It is a poetic phrase.

 

[pervect]

The "Fabric" part of the fabric of space-time is just an analogy. Space-time simply says that we have space, where we measure distances with rulers, and time, which we measure with clocks.

Before relativity, we thought space and time were separate phenomenon, but after relativity, it became clear that space and time were closely related and should be regarded as a unified entity.

The "fabric" part of space-time is typically used in other analogies, typically related to cosmology and the expanding universe, which is compared in the analogy to a balloon being inflated.

The mathematical entity that describes space-time is the metric. The metric allows us to calculate lengths and time intervals, as long as we specify a curve along which the appropriate length or time is to be measured.

 

[phinds]

What is the fabric of space-time?

It's a meaningless phrase found in almost all pop-science discussion of space-time. It has no physical reality but as pervect said, it's used in analogies.

 

[PeterDonis]

The OP question has been addressed. Thread closed.