A valuable service

I have been ruminating on the perils of time travel. One of my favorite little stories is here. It's basically a wikipedia chat history outlining newbie time travelers continually trying to kill Hitler, and the weary veterans who go back and preserve the timeline. If it was a book, I would have bought copies for everyone I knew.

I've been toying with a time travel story myself, and one of the little nuggets I've come back to is a strange piece of advice I had got from an economics teacher back in junior high school. I don't remember much from his lessons, but once he did explain how compound interest works - how at a decent interest rate your money will double every 7 years at 10% interest. So his advice to us was (REALLY) if you ever got a time machine, you should go back about 70 years, drop a thousand in a bank, and come back to find you'd doubled ten times ($1000->$2000->$4000->$8000->$16000->$32000->$64000->$128000->$256000->$512000->ONE MILLION DOLLARS) To turn a grand into a cool million just sitting in a vault somewhere... wow.

I'd be lying if I said I hadn't daydreamed that scenario quite a few times. Take a grand, step into the time machine, come back, and withdraw a Million. Of course to a 12 year old, the concept of $1000 is pretty high too. But now I'm a man, and as time has gone by, I've come up with several... issues... with this get rich quick scheme. (And hey, let's not rain on the dream: Time travel is the EASY part.)

Ten percent interest was pretty normal in the early 1980s. Nowadays, you try to find a bank that gives more than 3% on interest. At that rate, your 70 year investment of $1000 is only worth about $8000. Hardly enough to buy your unstable isotopes for the time journey. You need to go to the stock market for an over time performance of higher than 5%. And that takes some active management. Definitely not set-and-forget. There's talk about going back and buying 1000 shares of GE or Xerox at IPO and letting is grow and split... but you just know that some time in there, someone would be wondering "who the heck owns 12% of this company? Let's do a proxy, and do a shares exchange for new stock, and if those old missing shares don't turn up, they're worthless..." It's just too risky. I'll at least assume that you would do your homework and pick a bank that you know won't go out of business before you'd withdraw your money.

Plus, really, how do you get that first thousand? Go back to 1930 with a handful of 2010 minted $20 bills? Ha. So you need to buy 1929 issue bills, which in good condition go for about $100 per. So you're paying $5000 for that first $1000. Ok, but we're talking a Million, so maybe that's not so bad. Still, if the interest rate is down to 3%, You're paying $5000 for $8000. Not the best deal.

Gold is always an option, of course. The problem there is that an ounce of gold in 1930 is worth $20. Today an ounce of gold is worth over $1000. So your $1000 in gold to deposit in 1930 will cost you $50,000 in gold to bring back. Again, if you can get your 10%, no worries... but at 5% you're losing money, bro.

Now I know what you're thinking now: You'll just withdraw that $50,000 from the bank - the same bank that you went back and deposited that gold into those years ago. SORRY - that one is going to be a causality paradox... This is the equivalent of you going back in time to give yourself the plans to build a time machine in the first place: The money has to have come from someplace outside of the causal loop, just like you actually need to invent the time machine in the first place. And don't even THINK of funding your time machine development with the funds you've grown by using the time machine. Do not mess with causality. I can't be certain, but I'm pretty sure that once you cross a causal line, the whole timeline you just set up winks out of existence, and you're right back at the moment before the time machine entered your life.

I guess my point in all of this is that even WITH a time machine, it's going to be pretty hard to follow my economics teacher's advice.

I think a potentially good business idea would be to open a time traveler's bank: We'd accept payment in commodities, things that have a somewhat constant value over time, but are perhaps less inflated than gold... or heck we'd take gold too, because who is to say they haven't figured out a way to make cheaply it in the future... though at that point you need to wonder what a time traveler would want with a compound interest bank account when gold can be made at will. In the interest of timeline preservation, we'd need to make sure that none of our deposits are alloys or isotopes that are impossible to create in our current timeframe, and no technology trades of course (unless they want to bring next year's iPad... I'd violate causality for one of those).

Anyway, we would provide a certain level of stewardship for the assets - we'd manage a conservative stock portfolio for a 7% return. We'd also be prepared to cash out based on a certain code word and document combination, with no troublesome need to pretend to be your own great great grandson.

Naturally, we would make targeted investments based on our client's requests, and we may just make some minor piggyback investments of our own (not big enough to create attention) so we could take advantage of the information we have...

The only problem is that if the time traveler does violate causality by dipping into those funds before the time they had left to come back and deposit them (and I could see that happening a lot with the human resistance, trying to stock up BEFORE the robots take over), then the whole time loop would collapse. For all I know I've already had dozens of clients, and each one tripped up causality and I've reset to 2011 each time.

It's possible.