I’m going to steal someone’s boarding pass and take two trips: one to the P-Tr Extinction Event (the Great Dying), the other to the K-Pg Extinction Event—two of the greatest game-changers our planet’s biosphere has endured.
Granted, both of these events would most likely already be recorded, as per the parameters of the OP. But, since they were global in affect, I’d like to witness them first hand, from a variety of locations and times of my choosing.
I’m more interested in experiencing the diversity of life prior to the catastrophic events, but concluding the trips with the unfolding catastrophes would add pulse-quickening drama/horror to the ends of the Permian and Cretaceous periods.
It would be a bittersweet experience: bitter because the events closed the door on an incredible variety of life-forms; sweet because they opened new evolutionary doors, eventually leading to us.
The OP doesn’t mention length of stay for the trips, so I’ll stay 6 weeks on each trip and do a lot of zipping around the planet—providing I can survive that long. Not being able to touch, taste or smell anything sounds problematic. Do I have to bring my own food? And, I was hoping to eat a variety of fauna, seeing what tastes like chicken. Then again, having the giant Permian insects unable to touch me is a good thing—big bugs give me the heebie jeebies.
It sounds like I may be protected in the time machine (if I can’t touch the environment, maybe it can’t touch me?). If so, I’d like to journey into the unfolding events themselves. I imagine something along the lines of a Dante’s Inferno experience. If I’m *not *protected, I want to see the approaching catastrophe (asteroid impact, or whatever), then high-tail it out of there just before the point of mortal danger.
If I steal another boarding pass, I’d witness Ben Franklin annoy the heck out of John Adams when they shared a bed in an inn in New Jersey in 1776. I imagine it would be as funny as the bedroom scene in Planes, Trains and Automobiles. “Those aren’t pillows, Mr. Franklin!”