- #1
weezy
- 92
- 5
This is a basic assumption that's made during the derivation of results of special theory of relativity is that space is homogeneous i.e. space intervals shouldn't be given preference based on our choice of origin. However I want to understand more about this assumption and its importance.
Let's imagine an alternate universe where people have gained access to and they travel there and initially find out all laws of physics are just the same as it was in our home universe. They go on to assume that the smallest possible unit of space is a cube of size h^3 where h is Planck length. We also assume astronomers on that universe have found a way to measure distance to stars without analysing their luminosity.
But the observers on that universe find that small stars that should be low mass and consequently low volume and are very far away appear as huge spheres in the night sky. In other words all of their observations point to the fact that the faraway stars who's properties like temperature and radiation tell us it's not big but they appear bigger than their size for some reason. Same applies for other objects too like faraway galaxies appear way bigger than the average in their neighbourhood. And to add to their mystery this only happens when they look at the north sky. The south sky shows objects that appear smaller in size than expected.
They conclude that the quanta or smallest unit of space varies in length/size compared to theirs as you move vast distances from south to north (with respect to the plane of orbit of their planet) for some unknown reason. That is you cannot have a unit of space smaller than the size of, say your planet, once you reach a certain distance x away from your current location in the northern sky where x is a big number of lightyears. If you were to travel lightyears away into the northern sky the size of your particles and your measuring devices will get bigger in proportion so that you don't notice anything out of the ordinary but you see your home planet shorter than it should be.
Now my question is that are we completely sure that space is homogeneous i.e. do we observe any properties in stars and galaxies that could tell us that there's some discrepancy in sizes our theories predict and what is observed?
What are the changes that one would need to observe to develop a theory such as relativity then? For one homogeneity of space assumption must be discarded because it doesn't work on this universe. It does matter what your origin is. Also one has to find a non linear distance formula between two points. Should they experimentally find out the geometry of the universe and necessary distance formulas relative to their choice of origin, do the nonlinear distance formulas have any other effects that aren't simply obvious? What are your thoughts?
Let's imagine an alternate universe where people have gained access to and they travel there and initially find out all laws of physics are just the same as it was in our home universe. They go on to assume that the smallest possible unit of space is a cube of size h^3 where h is Planck length. We also assume astronomers on that universe have found a way to measure distance to stars without analysing their luminosity.
But the observers on that universe find that small stars that should be low mass and consequently low volume and are very far away appear as huge spheres in the night sky. In other words all of their observations point to the fact that the faraway stars who's properties like temperature and radiation tell us it's not big but they appear bigger than their size for some reason. Same applies for other objects too like faraway galaxies appear way bigger than the average in their neighbourhood. And to add to their mystery this only happens when they look at the north sky. The south sky shows objects that appear smaller in size than expected.
They conclude that the quanta or smallest unit of space varies in length/size compared to theirs as you move vast distances from south to north (with respect to the plane of orbit of their planet) for some unknown reason. That is you cannot have a unit of space smaller than the size of, say your planet, once you reach a certain distance x away from your current location in the northern sky where x is a big number of lightyears. If you were to travel lightyears away into the northern sky the size of your particles and your measuring devices will get bigger in proportion so that you don't notice anything out of the ordinary but you see your home planet shorter than it should be.
Now my question is that are we completely sure that space is homogeneous i.e. do we observe any properties in stars and galaxies that could tell us that there's some discrepancy in sizes our theories predict and what is observed?
What are the changes that one would need to observe to develop a theory such as relativity then? For one homogeneity of space assumption must be discarded because it doesn't work on this universe. It does matter what your origin is. Also one has to find a non linear distance formula between two points. Should they experimentally find out the geometry of the universe and necessary distance formulas relative to their choice of origin, do the nonlinear distance formulas have any other effects that aren't simply obvious? What are your thoughts?
