If the Sun exploded, we wouldn't know about it for 8 minutes and 20 seconds. Light and gravity take that long to reach us. Then we would vaporize.
Neil deGrasse TysonFM signals and those of broadcast television...travel out to space at the speed of light. Any eavesdropping alien civilization will know all about our TV programs (probably a bad thing), will hear all our FM music (probably a good thing), and know nothing of the politics of AM talk-show hosts (probably a safe thing).
Neil deGrasse TysonTrillions of years into the future, when all stars are gone...all parts of the cosmos will cool to the same temperature as the ever-cooling background. At that time, space travel will no longer provide refuge because even Hell will have frozen over. We may then declare that the universe has died-not with a bang, but with a whimper.
Neil deGrasse Tyson