For Book: How to Tell What Eon You're In

[TromboneAl]

Well, the bluff near our house erodes back, on average, a foot per year:

So, in 65 million years, that's ... carry the one ... a lot!

 

[M Paquette]

Time traveling over millions of years? Don't forget to allow for the rise and subsidence of land, continental drift (*SPLASH*) and such.

Oh, and if your time travel machine doesn't have some means of adjusting it's position in space, a good spacesuit and supplies might be handy, just in case you come out where the Earth isn't. (Orbital motion of the Earth, movement of the Solar System through the galaxy, motion of the entire galaxy, cosmological inflation, etc)

 

[braumeister]

if your time travel machine doesn't have some means of adjusting its position in space, a good spacesuit and supplies might be handy, just in case you come out where the Earth isn't.

One of the principal reasons I refuse to read anything involving time travel.

Almost exactly 100 years ago, Einstein knocked over that particular applecart by explaining that time only exists as part of the composite entity "spacetime" but that insight is still disregarded by most. Understandably, since the math is so fiendishly hard, but still ...