Physics, Astronomy & Cosmology / Re: If a BH singularity defies our mathematics does it also defy our physics?« on: Yesterday at 21:59:53 »
When you mention "gravitational lensing", does this have to be a proof of Einstein's Relativity Theory?Notwithstanding the fact that this message shouldn't have been posted, it's easy enough to answer.
Couldn't it be explained by optical effects, resulting from the passage of light through the interstellar gas which surrounds a massive object, such as a distant star or galaxy.
The interstellar gas may be very thin. But it exists, and so may be supposed to influence the light passing through it.
So inducing refractive effects, just like a glass lens does, in the form of a terrestrial "magnifying glass".
Obviously no-one claims that the magnifying effects of glass lenses prove Relativity, so why claim it for Interstellar gas?
Yes there's a little gas in the way of the light from distant stars.
Yes, it will (very slightly) alter the path of that light.
But here's the interesting bit; it will alter the path of blue light more than it will alter the path of red light.
So, if the effect were significant the stars would all be spread out into spectra- like tiny rainbows.
And they aren't so we know the effect is too small to observe in most cases..
Also, gravitational lensing doesn't have this effect- all colours are bent equally.
And that's what we see when we look at lensed objects- they aren't spread out into spectra like they would be if it was simply refraction.