Is Spacetime Real?
forbes.com
Is Spacetime Real?
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Re: Is Spacetime Real?
#2Define "real"
Re: Is Spacetime Real?
#3Define "real"
define "define"
Re: Is Spacetime Real?
#4TLDR: Article ends with
> whether it’s “real” or not — that’s not a question that science has yet discovered the answer to.
Re: Is Spacetime Real?
#5“What exactly is spacetime? Is it a real thing like an atom, or just a mathematical construct that is used to describe how mass 'generates' gravity?”
This is a false dichotomy. Atoms too are "just" a mathematical construct used to describe how certain observable, physical systems behave. It's even called the atomic _theory_, and like all other good theories it knows its limits. At low enough energies, it's too fine and at high enough energies it's too coarse a model. Spacetime is exactly as real as any other current model of observable physical phenomena that physics can offer.
Re: Is Spacetime Real?
#6“What exactly is spacetime? Is it a real thing like an atom, or just a mathematical construct that is used to describe how mass 'generates' gravity?” This is a false dichotomy. Atoms too are "just" a mathematical construct used to describe how certain observable, physical systems behave. It's even called the atomic _theory_, and like all other good theories it knows its limits. At low enough energies, it's too fine a…
While not a perfect definition of "real", don't we already have images of atoms?
Re: Is Spacetime Real?
#7The question is meaningless.
Re: Is Spacetime Real?
#8“What exactly is spacetime? Is it a real thing like an atom, or just a mathematical construct that is used to describe how mass 'generates' gravity?” This is a false dichotomy. Atoms too are "just" a mathematical construct used to describe how certain observable, physical systems behave. It's even called the atomic _theory_, and like all other good theories it knows its limits. At low enough energies, it's too fine a…
While not a perfect definition of "real", don't we already have images of atoms?
We do. Thinking a bit about what that means, we have photographs showing how the physical entity we model as atoms interact with light, and can confirm that the theory lines up with experiment.
If we adopt that same definition for spacetime, we also have photographs of it, e.g. https://en.wikipedia.org/wiki/Solar_eclipse_of_May_29,_1919#... and https://en.wikipedia.org/wiki/Gravitational_lens#Gallery.
Re: Is Spacetime Real?
#9Define "real"
If you're talking about what you can feel, what you can smell, what you can taste and see, then real is simply electrical signals interpreted by your brain.
- Morpheus
Re: Is Spacetime Real?
#10“What exactly is spacetime? Is it a real thing like an atom, or just a mathematical construct that is used to describe how mass 'generates' gravity?” This is a false dichotomy. Atoms too are "just" a mathematical construct used to describe how certain observable, physical systems behave. It's even called the atomic _theory_, and like all other good theories it knows its limits. At low enough energies, it's too fine a…
I dont agree its a false dichotomy.
Yes every theory is just a model to fit observations etc etc. But Atoms are conceivable - they work as a model, but we can also imagine how to fit into the reality that we experience. We can 'see' them to an extent with special instruments. And their abilities/behaviours are evident in all the physical world of compounds and elements around us. You can disolve salt in water, you can light up a neon sign.
Quantum Mechanics is a model that fits experiment results very well, but is very hard to conceive of. Wave function collapse has no obvious analogue in the world as we experience it. Thats the point of schrodingers cat. You either have to go for the many worlds interpretation, or get into spooky stuff about observers.
Spacetime/relativity is similar, we can do stuff like fly a clock around the world in an airplane, or observe mercury transitioning past the sun, but its much less conceivable based on our everyday world. So spacetime might just be a constuct, like wave function collapse, that doesnt map easily onto our experience of the world. Certainly its a question worth asking.