You can go back in time to any year on earth. What year would you choose and what would you do there?

I'd go back a few million years whenever fish decided to crawl onto land and yeet them back into the ocean.
- If you just wait long enough those fish turn into mammals and go back in the water on their own.
- Turn the fuck back around!

I'd definitely pull a Biff Tannen

Is it one way? If so, I will pass.
If not, I would take my kid to see some of the big steam engines of the past that we can't anymore, take a ride on an established safe train/route. (Or maybe buy some old Lego to take home)
- I’d do something g similar except ride all the electric interurban trains that no longer exist.

Depends on the rules.
Round trip to a 'read only' version of the past? I'd like to see the dinosaurs.
Round trip that can make changes? Probably a few hundred or even thousand years ago, so I could give them modern technology, information about climate change, try to educate people on social issues, etc. I'd create detailed instructions and try to make a religion out of it. There's no guarantee it would work, but I'd hopefully return to a solarpunk utopia. Honestly not sure if I would try this, as it would basically overwrite everything I've ever known.
One way trip? I'd probably pass, unless I can de-age. I would definitely want to go back to being a child with all my current knowledge.
- Round trip that can make changes? Probably a few hundred or even thousand years ago, so I could give them modern technology, information about climate change, try to educate people on social issues, etc
  What tech would you take back if you could though?
  
  I haven't really thought through the details.
  It would probably take decades to prepare, and to figure out what the best approach would be.
  It also depends on how much I could bring back.
  If it's just me and what I can carry, I think I would just bring a few things to demonstrate the tech. Maybe a high power flashlight and solar charger. The important part would be a detailed guide on how to re-enginer everything we have today, as well as the science behind it. Really, I think scientific knowledge would be the most impactful.
  If this was a huge operation with near infinite resources, I would send back a giant self sustaining compound with a general purpose factory. I think it would probably be possible to sustain a roughly 60s level of technology indefinitely on a small scale until the rest of the world caught up
- You could visit late 1700s or early 1800s and start a company that makes renewable energy. Maybe something like wind power, wave power etc, should be achievable with the technology available at the time. If your company becomes successful enough, you could compete fossil fuels out of the market. Then, invest that money into developing energy storage technologies to outcompete the internal combustion engine.
  
  That’s a good idea, and it could make a one way trip worth it if it meant becoming super powerful. I’d also focus on medical technology, and maybe computing.
  Although I’m a bit unsure of whether I could really create enough broad social change just from that. My goal would be liberation for people of all races, genders, and sexual orientations, the dismantling of capitalism and power structures, etc.
  The other option would be to do far back enough so that I could be some sort of god king, which would be a lot more work technologically, but might be easier to create a religion that would canonize my instructions.

I probably go back to when I was a kid and my mom kidnapped me and since I look so much like my dad kick in the door and raise myself as my own father.
Use my knowledge of the future too make myself incredibly rich and give my younger self all of the advantages and opportunities of life.

I'd probably go back to around 2000 and tell myself that my stupid decisions were going to catch up to me in about 24 years, and they will definitely cost me the relationship I have with only person in this world who had ever genuinely loved me, and that it will drive her mad and she will react in a most brutal and callous way.
I would remind myself that the way I think other people are feeling is almost always wrong, to some degree, and that i should listen better to her about her feelings while I still have a chance to salvage what was once true love.
I would explain that, if I'm not careful, I will misinterpret everything she says about her feelings, and i will lose all my friends and hobbies, one by one, trying to be someone for her that she doesn't even want.
I would describe the way it feels to be with her, then illustrate the way it will feel when she starts dating other guys while you beg her to please work with you on your relationship, and that it would already be too late no matter how much you want it to work.
I would suggest that, if I decide to proceed while ignoring all my other advice, then I should at least not buy a house with her in 2023 when she is so insistent. Just hold out for one more year before making that mistake.
She wanted to be my forever person, and i didn't know how to deserve that. We were fucking teenagers when we got together, and neither of us knew how to be. We were just spitballing.
And I'm a fucken dumdum.
I probably wouldn't listen to me anyway

Big pass on a one-way ticket. I'd quite like to see a dinosaur though....
- It should be a very short glance though...
  Time Traveler Causes of Death

1988 and see the Berlin Wall (from the west obviously), travel through ghost metro stations
- I was in West Berlin in 1981, we had a picnic by the wall and rode the metro through the ghost stations. Which were a bit meh to be honest. You had to change a certain amount of currency to visit the east and we couldn't afford it, so we just stayed in the train and went back again.
  We hitched to Berlin, and the freakiest part was driving through the corridor that linked West Berlin to West Germany.
  
  I was born after the Berlin Wall fell, but have read a lot about it, that is why I find it so fascinating.
- (from the west obviously)
  Big fan of the Kentler Project?
- why would you want to hang out on the nazi side?

I wouldn't go anywhen. My dissatisfaction is intrinsic and the year is irrelevant.
- Please fuck me
  
  Not even with someone else's dick.

2500 BC. Egypt. Just sit and look at those aliens build the pyramids.
- Someone's gonna be disappointed
  
  Are you implying that the big triangles were made only by the giants without alien intervention?

As a woman I'd rather not go into any distant path.
So i choose last year and slap myself before I do an especially stupid thing that caused me near financial ruin and drained what little savings I had.
- That is the way to go. Any point in time in the past is generally worse than the present. So just go back enough to fix something in our own life'and maybe play the lottery or some stock trading to get set for life.

If I get to go with a Tardis, language barrier won’t be a problem. If not, medieval Europe will be out of the question, since languages have changed so much during the past few centuries.
If you travel back even further to see mammoths or even dinosaurs, languages won’t be an issue. Who knows what the ancient microbes will do to your immune system, so there are some serious risks.
I guess the past 200 years might be the most reasonable ones to choose from. I think I might want to meet James Prescott Joule (1818-1889), the inventor of the correct unit of energy.
James Watt (1736-1819) would be pretty interesting too, so I hope English hasn’t changed too much. Would be pretty annoying if we can’t communicate properly.

I would go back to my teen years just to relive it again. Assuming I could repeat the process when I read this post I would do it over and over again. I wouldn't change anything, I would just enjoy the ride.

Definitely need to go back a few years for some stock trades ........

Trans and disabled, so that limits my options a bit.
I think I’d just go back to 2011 and just vibe.

I'd go back 9 months prior to June 14th, 1946 and yell "Wait! For the love of God, use a condom!"
- For anyone wondering, yes this is the birthdate of the detestable newspaper tycoon Ralph McAllister Ingersol II
- Just kick him in the balls before he climaxes

August of '69. The first Woodstock.

I would go back to the inception of Bitcoin start some kind of shop, maybe pizza ice cream and donuts and offer products for Bitcoin. Any profits I Madoff non-Bitcoin sales I would sink directly into getting people to give me more Bitcoin.
- Would be funny if you caused an early blitz that petered out, and then the coin never became the number one coin.
  
  You're right you'd probably have to be careful. Might need to balance the purchasing with mining.

Fun in this thread to identify who is a white man by whether they'd even consider being safe visiting the past

Was there every a better moment to see if you can ride a T-rex? See the dinosaurs walk the earth, experience the wild nature that must have been around back then. I bet we don't know about a lot of the amazing things from that time.
Of course you would have a hard time trying to survive, but it would be cool. Dangerous, but cool.
- Are we assuming we can go back? Or are you just stuck with dinos as your friends now?
  
  Well, that is one of the typical things I would start thinking about when I am there... If I could go back it would be epic to do this. If not, I'll skip, thank you very much.
  
  You can go back, but not forwards /s

2016 and you know why
- Hell yea, punch that kid before he can derail the timeline

20,000 bce. tell the first person to come up with social hierarchy to fuck off

I'll go back to the golden years of life before everything became political and people visited one another and knee how to speak their minds.

- You know you could have just downvoted and moved on. Instead you chose to suck the fun out. You're a fun-sucker.
  Every party needs a pooper and I guess that poopers you. Party pooper
  
  In my family we call that the fun sponge.
  
  The word you're looking for is "curmudgeon".
  What I was actually trying to do is encourage a discourse that furthered society, rather than rehash a trope such as the one found at the source of this thread.
  I'm not confident that this will actually eventuate here, but I'm hopeful that someone will pleasantly surprise me.
- Seriously, this is a question that's essentially "What if?" which has been debated by philosophers, argued by historians, fantasized and written about in countless books and displayed in libraries and museums around the planet.
  so therefore no one should ever be interested in the topic ever again lmao what. Take a breath dawg, chill, it's ok for people to converse on the internet
- okay so sounds like it's a pretty popular ponderance
  maybe chill the fuck out? since it's so normal?
- I'd go back 30 seconds before you hit submit on this question and take your keyboard away from you.
  Seriously, this is a comment that's essentially "waaa I didn't like this" which has been posted by toddlers, argued by narcissists, fantasized and written about in countless comments and displayed in posts and videos around the planet.
  What on earth did you think this comment would add to the fabric of society?