How about invest in a couple young go-getters named Bill and Steve and their wacky sci-fi "comp-you-toor" gadgets?

I think this greatly depends on what type of time travel we're talking about.

To the past, not the future. But you can come back to current day.

Clearly, bets and stock market. There is no limit to how much money you could make in a short time. (Actually, there is one small wrinkle: the amount of wealth you were dealing with would quickly become so great that it would impact the markets, changing the past. You'd have to play around a little to get this right, but it would still be far, far faster than anything like going into business or investing).

Travel back to 13th-century Poland and assassinate the guy who invented the fork. Then come back to the present time, 'invent' it yourself, and secure a patent for it.

There. Set for life.

Sports betting. It won't affect history the way usurping the real inventors of things or manipulating the stockmarket would. Another great one is to sock away a collectible like a 53 Corvette knowing when you come back it will be worth serious money.

Yeah what Draug says.

Raid Mansa Musa's Mecca pilgrimage procession.

Now this time machine just moves in time, not space, correct? I would presume it would somehow compensate for trajectory (Earth's rotation and orbit and the suns orbit aroind the galactic core and our ever expanding universe) so you would need to keep it to something you could reasonably travel to before or after the trip. Doing a raid on some famous pilgrimage might be difficult.

If it's moving in space enough to account for the earth's orbit, I think it can manage the middle east, Draug.

How much of a stake can I go back with, and what technology can I take with me? Because if I have a decent amount of investment capital, but not the technology to equip mercenaries to be superior to any local force, I'd think buying up the De Beers family farm and the rest of the land surrounding the Kimberley mine before about 1868 or so would be ludicrously profitable. If, on the other hand, I can get some mercenaries with AKs, I'd probably do something like taking over Pizarro's first shipment back to Spain.

OK, I didn't know I ventured into that part of the internet where people argue about technical details of the impossible.

@Draug

Replace "corvette" with "delorean" and you pretty much just summarized the plot of Back to the Future 2.

@Ulytau-

The porn is that way----->

How would it alter the continuum if I went back in time and wrote all of the best songs of the next 20 years well before they were due to be written? Bono might hear one of my songs and have a strange feeling about it. And perhaps I would take the David Bowie/Vanilla Ice riff and use it before either of them.

@abge - The sports betting part, yes, but I was talking about buying a Corvette and putting it in storage (if you couldn't find a way to bring it back) until you returned to 2013.

Yes, you can make yourself rich - one lottery win would do it, but then what? You've got a time machine and more money than you can reasonably spend in your lifetime, so what are you going to do? The temptation to play tricks would be huge. I'd go back to 1400 BC Egypt and have an accurate globe of the Earth made showing the sea bed, the land under the polar icecaps and the tectonic plates, then I'd leave it in the sealed chambers of Tutankhamun's tomb. It would be found when the tomb was opened in 1922.

"And perhaps I would take the David Bowie/Vanilla Ice riff and use it before either of them."
For the record, it was Queen, with David Bowie. And Vanilla Ice doesn't get to be associated with it. /grumpymusicrant

As for the music solution in general, you have no guarantee that the songs will get popular, or even get noticed at all, and it would cause a major impact on history. I'm with Draug on the whole sports betting thing, gambling's probably the only safe way to make money without impacting time too much.

Tricky business, time travel. A lot depends on how reality works. If there is a single stream of reality then you won't be able to change the timeline (assassinate people, invent things early etc). Like walking on the ceiling it will be something you could easily imagine doing and yet a mysterious force would make it impossible. If, however, there are multiple streams of reality you will be able to do whatever you want. However the slightest change would put you on a route to an alternate future. Depending on what you do that alternate future may look near identical to the one you left, but it would not be the reality you left. And the alternate you (if he exists) may not appreciate you turning up.

The best investment is either making sure you find the baseball cards that will be worth lots or buy art from artists such as Picasso. This is unlikely to affect the continuum - the problem with sports betting for example is that you could bankrupt the bookmakers and their business model will fail if they can't set odds correctly.

Btw - if I had a time machine I wouldn't worry about money so much, I'd realise the true potential of such a great invention. Could you imagine your sex life when your chat up line is 'where in time would you like to go tonight?'

The way to do it with the least paradox is to play the lottery-- you don't need to jump more than a day in either direction and the difference between "losing" and "winning" is nothing more than the announcement of whether or not a winning ticket was sold.

You time hop the jackpot once and take the annuity. Every year, when the annuity pays out, you transfer it into cash and bring it back to the day after you won-- and you start a trust fund that pays out to the designee of your choice, investing your "winnings" into a proper investment portfolio. Set yourself up with a new fake identity for every ten years or so, and then as the "current" designee of your trust fund re-assign it to your new identity. Win a lottery jackpot every... twenty or thirty years or so, taking the annuity each time and transferring the cash back in time as early as you can based on the printing dates.

Compound returns for the win.

The problem with sports betting when you know the result is that it's theft. And whilst paying for sex using rides in a time machine as currency would be effective, traditional money would be a lot easier.

Another reason to use the lottery instead-- the lottery people make their money regardless of whether or not you win and every time someone wins one of the major jackpots they make even *more* money. You would essentially be doing them a favor.

@ faerie

You're essentially stealing the money from the chap who would have won it all if you didn't play, and as such changing his life in a really quite massive way.

Besides, a paradox event can't happen. Either whatever you do had already happened that way anyway, or it affects an alternate time line which has no impact on your present. One can't change one's past

Not if you only win the jackpot when there were no other winners-- in that case, you're not stealing it from him any more than you would by winning it normally.

You're simply stealing from the chap who would have won it on the rollover. There's no difference.

No more so than if you'd won it normally.

Erm... if you win it normally it wouldn't be theft. If you win it by using an unfair advantage to know what the numbers are then it is. Surely this is obvious?