This is what I thought - I just wanted to make sure I hadn’t failed to consider something obvious. Am meeting up with some old friends who are science geeks next month and wanted to throw out the line “for all we know, the center of the galaxy exploded 25,999.9 years ago and we could all die tomorrow” and I didn’t want anyone coming back with “well actually…we would have detected that by now thanks to technology xyz that was in ivented in 20XX”.