Question: if XY Canis Majoris turned into a supernova would the force reach earth and can black holes be the answer to time travel# plz answer

Katie McDonald answered on 6 Jul 2012:

OK, I didn’t know much about this, so I asked my physicist friend. He says:

“No, it’s too far away – nearly 5000 light-years. Even if it turns into a supernova, it’s nowhere near close enough to be a danger (plus it would take the light 5000 years to get here!). To be a real danger to earth, a supernova would need to be within about 26 light-years; there’s no stars inside that range that are the right size and type to become supernovae though.

Black holes are difficult. We don’t know what happens inside one; it’s totally possible they connect different times and so on. However, we do know what happens *just outside* black holes, and it’s impossible to survive things like the tidal forces (gravity), so what happens inside the black hole itself doesn’t matter, since you can’t get there.” I hope that helps!