Simultaneity

[mmcirvin]

Measured in the heliocentric frame, the time to the Galileo probe's destruction is now less than the light-speed travel time between Earth and Jupiter. What that implies is that, according to special relativity, there are some inertial rest frames (corresponding to motion at a large fraction of the speed of light in the direction of Jupiter) in which Galileo is already gone as I write this, and others in which it still exists.

Comments

[mmcirvin.livejournal.com]

And so that I can sound even more insane by following up to myself repeatedly: NASA's Galileo impact page used UTC. If I recall correctly, this has surfaces of simultaneity defined in a nonrotating geocentric frame, though the lengths of the seconds are such that they correspond to seconds in a frame moving with the surface of the Earth as it rotates.

It probably doesn't make a great deal of difference, but my guess is that they're making the reasonable extension to Jupiter via taking half the round-trip light travel interval.