These astrophysics always amuse me. I am a great physics fan and I find reading these posts very interesting. But btw ,light does not necessarily travel in straight lines. For example black holes, it's gravitational power is so huge that it even sucks in light towards it. The masses in the space bends the space time fabric and creates a cavity. If the cavity is too huge, even light cannot pass in straight lines and has to bend a little... So, light does not travel in straight line, it only travels in the lines what it thinks is straight....
This is a great post altogether.. I myself have posted an article about dark matter. As a physics enthusiast,i would request you to go through it by clicking the link below
https://steemit.com/science/@aman.shady/is-the-human-soul-actually-a-dark-matter
Thanks for your comment.
You are right. The curvature of the universe (originating from the masses in it) defines what a straight line is. Geodesics would be the right word to use.
Yes.. that's the word... Keep posting mate .
Don't worry, I will ;)
Good to know mate. ;-) ;-)