Tronic

Supernovae might show up in worm holes like a ticking clock?

I'd like to jump in and say time-travel however possible would be the easy part in achieving the desired effect ie going to watch an old concert. The harder parts would be ending up at the right location, problem lies with all reference points moving at different speeds in different directions forever changing like the weather. A mis-calculation of smallest degree would throw the traveller out in outer space. A different kind of anchor point could help.. stuck to earth like a magnet, always present throughout the entire time period as a marker for landing. The sub-space warp would need it's own time-machine inside the worm-hole to act like a regulator, otherwise what's to stop you taking a million years to get through when your desired trip was 5 minutes, even if the worm holes were side by side for testing? Could get lucky. Might be a practical speed woven into them already such as instantaneous but then you'd have problem of tearing while being half in half out. A snapshot/teleportation device would be needed at each end, like an airlock.