Sunday, June 19, 2005

I love you, BBC.

Oh, those crazy Nepalese! The Maoist council said "Our party has issued special instructions to all cadres, the People's Liberation Army and other units not to carry out physical attacks on any unarmed person until another decision." Why does that take a special decision? How is that not just good policy? Ack. Anyway, the quote is taken from this BBC article about the aftermath of a landmine explosion that killed 38 innocents.
This is also a nice article from BBC about using seismic "geophones" to listen for elephants. Though admittedly impractical, it sounds really cool.
A story I like about how ancient Egypt rocked...
But this is my favorite. Using quantum mechanics, in such basic terms, to allow time travel. Quantum behaviour is governed by probabilities. Before something has actually been observed, there are a number of possibilities regarding its state. But once its state has been measured those possibilities shrink to one - uncertainty is eliminated.
So, if you know the present, you cannot change it. If, for example, you know your father is alive today, the laws of the quantum universe state that there is no possibility of him being killed in the past.
It is as if, in some strange way, the present takes account of all the possible routes back into the past and, because your father is certainly alive, none of the routes back can possibly lead to his death.
I love you, BBC.

1 comment:

Anonymous said...

The somewhat inconsistent part about that quantum model for time travel is that it states that you can go back in time and observe things, as long as you don't change them...but making observations does induce a change—a collapse in the state (like the kind that would prevent one from killing one's predecessors). And if you go back in time with knowledge of the state as it was originally, then you eliminate that part of the equation and force the state back into one of uncertainty! Of course, this all involves applying quantum mechanics to non-quantum systems...but it's certainly (heh) fun to think about.