Stephen Hawking Service: Possibility of Time Travellers 'Can't Be Excluded' (bbc.com)
Organisers of Prof Stephen Hawking's memorial service have seemingly left the door open for time travellers to attend. From a report: Those wishing to honour the theoretical physicist, who died in March aged 76, can apply via a public ballot. Applicants need to give their birth date - which can be any day up to 31 December 2038. Prof Hawking's foundation said the possibility of time travel had not been disproven and could not be excluded. It was London travel blogger IanVisits who noticed that those born from 2019 to 2038 were theoretically permitted to attend the service at Westminster Abbey. He said: "Professor Hawking once threw a party for time travellers, to see if any would turn up if he posted the invite after the party. None did, but it seems perfect that the memorial website allows people born in the future to attend the service. Look out for time travellers at the Abbey."
Yeah, but that's the 19th of January. Maybe if you attempted to enter a date after that, it would revert to 1970....
09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
There is a universal clock. It's the speed of light.
That is not a clock.
The speed of light in vacuum is 299,792,458 m/s for all reference frames, but that's a ratio. As distance (m) shortens, time (s) contracts so the ratio remains the same. But time changes.
If you travel at 99.5% of light speed, you might insist that you travelled one light year in a little over a year, yet someone watching your travel from the sideline might say you travelled ten light years in over ten years. Both of you are correct, because both distance and time changes depending on viewpoint.