the MARTINI SHAKER

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Making People Smarter

I spoke to Merlin Mann on the phone the other day. We had a great conversation, and he ended it with an interesting question:

“How do we make people smarter?”

I have a couple of ideas….
(more…)

SXSW 2010: I’m done stewing. Here’s the poop.

My very first SXSW experience is now in the history books. I had an amazing time, but the sheer volume of experiences and information that was crammed into 5 days was a little overwhelming. I needed a little time to …
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TweetStar

One of the refreshingly inspiring panels that I attended at SXSWi this year was about people who engage in “Slow Twitter.” These people take their time to craft most of their tweets for maximum entertainment value. Most of the time, …
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Spring Break for nerds.

Tomorrow morning, I’m headed on a plane to beautiful Austin, TX for the South By Southwest Interactive Conference, also known to some as Spring Break for nerds.

This is my first trip to SXSWi, and I couldn’t be any more excited. …
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A conversation that made me cry.

Nathan wanted to go on a car ride with me last night. In addition to being in the “me too” phase, he’s started his “Why?” stage early, so of course he wanted to know why we were taking an …
(more…)

The squashed bug.

Shaken for you: August 3, 2009

So, while I was in the shower this morning (somehow this blog is turning into a log of morning shower thoughts) I got to thinking about time travel.

Specifically, I thought of the rules about the causality of affecting the future by taking care not to influence or change the past. I’m sure you’ve heard the old yarn about not even harming a fly in the past for fear of setting off a chain of events that completely reshapes the future.

Taking this into account, if that is truly the case, then time travel is not even advisable. Because when you travel through time, you have to land somewhere. And when you land your time machine, chances are good that you are going to land on some sort of ant, caterpillar, or other little insect. Even if you travel through time without a machine in this sort of “Quantum Leap”-ish machineless style, there’s still a chance you’re going to step on something you’re not supposed to.

Even then, have you ever thought of all the bugs you inadvertently step on every day? I really hadn’t until this morning, but I bet each of us squashes our fair share of critters every time we walk down the street.

So, time travel’s out. Or is it?

All this thinking got me curious, so I looked up a little bit about time travel on Wikipedia and found an interesting tidbit about the Novikov self-consistency principle. In summary:

…the Novikov consistency principle asserts that if an event exists that would give rise to a paradox, or to any “change” to the past whatsoever, then the probability of that event is zero.

The example they use to support this revolves around autoinfanticide. That is to say, you can’t travel to the past and kill your baby self, because if your baby self is killed in the past, then you obviously can’t come back from the future to commit the deed. I think the same applies to squashing bugs. Obviously, if your time machine lands on a bug, then whatever events that causes can’t necessarily be catastrophic because you’re arriving from a future that is most likely pretty OK… unless you’re coming back from a future that is embattled by an insect uprising.

But that’s a whole other deal.

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  • Ovidio
    So if the probability of changing the past and rise a paradox when you travel is p=1 then your chances of traveling are q <= 1-p = 0
    :)
  • I think that's the most serious comment/answer to a post that anyone's ever written on this site.
  • andrewstrader
    What can I say? I have thought about time travel a lot, for some reason.
  • andrewstrader
    Very interesting. The alternative theory, of course, is that if you travel to the past, any influence you have will inexorably alter the course of events, so that you could never return to the future you once knew. Even disrupting a single atom can kill Schroedinger's cat. But the consistency problem is more likely to be resolved by the fact that real time travel would involve first travelling through space so fast and so far that you exit your own "light cone". Then any influence you have on "past" events wouldn't manifest themselves in your original light cone until after the space-time point that you left, thus preserving causality. For example, if you left Earth in the year 2000 and travelled to the year 1500, then you would have to end up in some location that was more than 500 light-years away from Earth. Even if you fired lasers at Earth from your new location, it would take them 500 years to get there, thus preventing any paradox such as you killing yourself with a laser two seconds before you departed in your time-travelling vehicle. This is in keeping with the apparent restriction of having to use black holes for time travel. You'd actually have to use two very large black holes (large enough that tidal forces wouldn't atomize you -- galactic nexi are good candidates). You would fly into the gravitational field of one black hole, accelerate beneath its event horizon, and sling shot yourself through hyperspace. Of course you'd have to aim directly for the event horizon of another, distant black hole, so you could slow yourself back down. Otherwise, you'd be trapped in the wrong inertial frame, unable to return to your own familiar space-time continuum. If you're lucky, you might permanently slingshot yourself into a parallel dimension, where events had taken a course more to your liking, even if they would have been paradoxical within your home matter-energy matrix. Oh, and did I mentioned that your space ship might have to be made of dark matter? Improbability engines would help with navigation too, but I don't know how those would work.
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