3 ms·
From the photon's perspective, the entire universe is compressed to a line of infinitesimal length, from the place it was emitted to the place it is ultimately
by cdelsolar 4y ago
From the photon's perspective, the entire universe is compressed to a line of infinitesimal length, from the place it was emitted to the place it is ultimately absorbed, if any. In its perspective, it takes 0 time to travel through that line (really more of a dot).