Stephen Hawking has suggested that the absence of tourists from the future is an argument against the existence of time travel: this is a variant of the Fermi paradox.
This is a variant of the Fermi paradox. Stephen Hawking has suggested that the absence of tourists from the future is an argument against the existence of time travel.
Stephen Hawking has suggested that the absence of tourists from the future is an argument against the existence of time travel. This is a variant of the Fermi paradox.
Stephen Hawking has suggested that the absence of tourists from the future is an argument against the existence of time travel. This is a variant of the Fermi paradox.