Self contained rad-hardened HazMat suit. With filters so you don’t breath in any stuff there, and tests for toxic stuff in the air. Guns and stuff. A place to sleep, also hardened. I’m assuming they can figure out not to transport you into the middle of an ocean.
Besides that, before you leave the best thing to do is to put your head between your legs and kiss your ass goodbye. It doesn’t sound good.
If we assume no vast geoengineering projects by various sorts of intelligences, then in basic outline Earth will be pretty much the same. The continents will still exist, but will have shifted in position. Current mountain ranges will have eroded to stumps, but new ones will have formed. Land bridges will be broken and formed. Shallow seas will uplift to dry land and continental shelves will be flooded.
Climate will be different, but whether it will be hotter, colder, about the same, much hotter or much colder we couldn’t say. Air might be different, more or less oxygen, more or less CO2.
Biologically things will be completely different. 100 million years ago was the Cretaceous era when the only Mammals were tree-shrew type creatures and the world was dominated by dinosaurs, pterodactyls, marine reptiles, and ammonites. 100 million years in the future is far enough that there’s no telling what sorts of plants or animals will be roaming around.
Of course in that time frame we could have experienced a biosphere-decimating mass extinction or two, maybe in 100 million years there won’t be much life left on earth beyond algae and mats of bacteria. If that’s the case don’t expect to be able to breathe the air. Or there might be some new life forms that make the air/water/soil toxic to humans. Breathe in some poison spores, and keel over dead in minutes.
However, I believe the most likely scenario is that the biosphere remains vibrant, and we still have multicellular plants and animals running around, just completely different than what we have today, just as today’s plants and animals are completely different than in the Mesozoic. What sorts of biomes dominate is anyone’s guess, whole new classes of plants could have replaced the dominant ones of today, 100 million years ago there were no grasslands for instance and almost all trees were conifers.
I’d guess it’s pretty likely that you’d be able to breathe the air, and find some plants or animals that are edible. Although walk out into a forest today and try to find some edible plants and unless you know exactly what to look for you’ll have some trouble. Finding edible food 100 million years from now is going to be a nearly impossible task unless you’ve got some sort of testing apparatus or stacks and stacks of rat cages. But then you’ve got to bring food for the rats…
Good idea to ask to be sent back in a boat, because with continental drift you’re likely to end up in the middle of an ocean somewhere. Your call on whether you’d prefer a craft optimized for deep ocean operation, or something amphibious you could use on land. Given that 70% of the Earth’s surface is water, and will likely be the same 100 million years from now, a seaworthy boat is your best choice.
Fully-contained suit with breathing apparatus - absolutely!
24 hours supply of drinking water
Suit must have ability to float
Suit must have ability to withstand extremely high or low temperatures (Earth may have become like the sun or like Neptune, there’s no way to know)
Panic button I could push so the past could pull me out and bring me back home immediately (beam me up, Scotty!)
If there is terra firma and an atmosphere of some type, testing gear for air and water safety
A camera or other image-capturing device
An audio-capturing capability, just in case
A good supply of the meds I was off when I volunteered would be at the top of my list.
I’d grab something that I think might be very rare and valuable in the future. Sell it to future people then bring money ( in whatever form it takes) back and sell it to stupid people who want to own a piece of the future…win.
I’d also take to the future, a real cheeseburger and sell it to someone so they know what one tastes like. Oh I’d also buy a future computer and bring it back with me so I’ll never have to upgrade again.
This is what I was going to say. Modern humans seem to have been around for about 200,000 years. One-fifth of one million years. Humans might be recognisable in a quarter million years. Maybe even a million. A hundred million? If our descendants are still here, we wouldn’t know each other.
Does this time travel device also move through space accurately? Accurately predicting where the earth will be in the universe in 100 million years will be extremely difficult. Orbital models can’t likely predict small fluctuations from deep space objects that will fly in and out of our neighborhood and exert slight gravitational pulls…plus small orbit changes due to asteroid impacts or so forth. Not to mention the general expansion of space itself.
I guess what I’m saying is that landing on the surface of the earth will be tough, since it will be approximately 1.6 quintillion miles away from where it is now in absolute space, and may be impossible to pin down.
A spacecraft might not be a bad idea.
100 million years ago human beings were tree shrews. If there are any organisms descended from humans 100 million years in the future they will be nothing like modern humans. They might not even be recognizable as primates. 100 million years ago the ancestors of whales, elephants, porcupines, rhinoceroses, grizzly bears, bats, gorillas, moles, anteaters, zebras, giraffes, antelope, pigs, mice, pangolins, hyenas, raccoons, rabbits, seals, dolphins, cheetahs, otters, capybaras, wolves, and sloths all pretty much looked like a tree shrew. Or to put in another way, all placental mammal species alive today are descended from ONE nondescript mammal species that lived 100 million years ago.
There will be no human beings 100 million years in the future. Maybe there will be intelligent life forms, and it might be some of those life forms were descended from humans. But they won’t be human or anything close to human.
It’s likely that, whatever animals exist, it will be possible to identify their ancestry somewhat. Some might be obviously a kind of reptile, or bird, or mammal, or arthropod, or fish. But a person looking around at the animals of the middle cretaceous and then traveling forward 100 million years to the present is going to wonder what happened to all the dinosaurs. Only really really small ones are left, and only the flying ones. Search the oceans and you’ll only find a few shell-less remnants of the once dominant ammonites. And some water shrews have grown bigger than any dinosaur, only they eat plankton now. And a peculiar little plant called “grass” has taken over vast swathes of the planet surface.
Hasn’t human evolution slowed down for humans since being the strongest, quickest, and resistant to sickness are no longer (more or less) necessary to survive in this world?
Basically, thanks to modern technology, the weaker human genes that would normally get weeded out, are getting passed down the line.
I’m starting to think your username isn’t just for japes.
Maybe we’ll all evolve back into mindless dinosaur-like beasts.
Thanks all for the interesting replies. Especially Lemur866… great points and write-ups.
And the video Gordon Urquhart linked to is fascinating. There’s something vaguely creepy about the 100 MY projection, too.
I’m a teacher and I can confirm that a hundred million years is many orders of magnitude too high a timeframe for this.
I’m a parent and I essentially agree.
Pretend it’s accurately locked onto the same lat/longitudinal coordinates as to where you are now, based off of Earth’s rotational axis.
As far as altitude, thankfully, the scientists have figured out a way to at least pin the portal to the surface (wherever that may end up being), so you don’t end up thousands of feet above/below land or water, or end up embedded in a mountain.
Maybe not a spacecraft, but some sort of air-locked, amphibious, all-terrain vehicle.
Missed the edit window…
You can have your choice of lat/long coordinates. Doesn’t have to be exactly where you are now. But pick carefully.
Also, you can stay as long as you want, but it has to be a minimum of 2 hours, as that’s how long it takes to reverse the portal for extraction.
There is no apparent rush or time element that this needs to be done. They need to continue their research before sending a human. If it didn’t work with animals, it won’t work with humans.
It’s no fun if you fight the hypothetical. 
But if you insist, let’s just say it’s a political snag: No animals are allowed to be sent across, only a human volunteer is acceptable.
There’s a Harlan Ellison short story where someone gets himself transported back in time 100,000,000 years (or so), believing he was going to an epoch of non-meat-eating dinosaurs, and promptly gets masticated by a bronto (or whatever) for looking like an interesting new plant. So keep that in mind.
Wear a space suit.
There won’t be any humans, so don’t worry about that, but the environment may be very bad for you. 100 million years ago, the amount of oxygen in the air would have made you sick, and who knows how you might react to the pollen of the plants of 100,002,015 AD? They could be poisonous.
You have no idea what the terrain or climate you’re appearing in will be like. You may materialize over water, but let’s hope that won’t happen, but still - it could be freezing cold or ferociously hot. So wear the suit.
OK, putting aside this obvious risk and no immediate need to even so this…
Arrive in the best space suit or larger capsule if available fully equipped with a comfortable environment for air, water and food enough to last a couple of weeks in case there are problems. The technology would be fully equipped with audio/video recording equipment which would record the entire event to return with. Once there, I’d use whatever known forms of radio communications we have to be used to attempt to make contact with anyone if possible. I would also want to be equipped with recording equipment that would capture all the possible video and audio transmissions that might be there.
Considering the span of time, I’m not expecting any of this to bring back much useful information, because someone from the 1800s coming to 2015 might want to look for some signals because it was a form of communications, where in 2015 we don’t use them any longer. So whatever media we use now is going to be replaced with someone else not yet conceived. I think the best we can expect to bring back would be data of the atmosphere and a visual and audio record of what is outside the space suit or capsule. If possible I’d want to leave behind a time capsule from 2015.