So I was reading up about gravity and how objects with a bigger mass actually “bend” the fabric of space which is often called space-time. But what is it exactly?
Can we see space-time? Does it actually exist or is it just a concept/hypothetical?
Also, an article mentioned that that we need to be in the 5th dimension to actually see space-time. So, does that prove higher dimensions do in fact exist and are having an impact on our 3D world?
In: Planetary Science
>But what is it exactly?
A set of mathematical equations which are often oversimplified to a rubber sheet.
>Can we see space-time?
Yes.
Not with our eyes, but if you shine a laser down two really long tunnels at the same time (using a special type of mirror called a beam splitter) and then recombine and “overlap” the two beams, you can see one tunnel becoming a teeny tiny bit longer than the other whenever something with mass moves past – whether that’s a car driving on the road outside or a pair of black holes merging millions of lightyears away/millions of years ago.
>Does it actually exist or is it just a concept/hypothetical?
We can also use it to see neutron stars falling into black holes and then – since waves in space-time travel slightly faster than light through the imperfect vacuum of intergalactic space – point normal telescopes at where it happened and see it happen “for real” (by which I mean using light).
>Also, an article mentioned that that we need to be in the 5th dimension to actually see space-time. So, does that prove higher dimensions do in fact exist and are having an impact on our 3D world?
On the contrary, the waves we’ve been able to see have allowed us to rule out higher dimensions existing and having an impact on our 3D world in specific ways.
Edit to clarify: higher dimensions can still exist and have impacts in various other ways. We have no evidence to say they do, but also no evidence to say they can’t.
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