Quasars as crypto key

In cryptography, it's important to have a key that's uncrackable. Any simple pattern can be cracked - simple monoalphabetic cyphers (one-for-one substitution, such as A=B, B=Q, C=F, etc.) are even used as puzzles in some newspapers, in which the reader is tasked with "translating" a quote from a famous book into normal English (anyone remember the name of these types of puzzles?). A polyalphabetic cypher (A=B if even, A=G if odd, etc.) can also be cracked. More complex patterns as well - other systems use matrix multiplication, large prime numbers, or computer-generated "random numbers." The problem with the latter is that the numbers are never truly random, so after enough digits in the message, it can be cracked.

But apparently quasars have unpredictable variabilities in (radio) brightness, and therefore could be ideal keys. If, of course, the person at the other end knew which quasar you were using, what time you started looking at it, and had a decent radio telescope...

Archbishop of Cantebury: "billions will die from global warming"

It's nice to see that not all Protestants are whack jobs.

[Archbishop of Canterbury Dr. Rowan Williams] said the public had a moral responsibility to change lifestyles.

The consequences if they did not, the Archbishop warned, would be the deaths of billions of people worldwide from the effects of extreme climate change.

He said the Bible made it clear that God would not forgive people who had been warned they were doing wrong. And he said US President George W Bush's stance of refusing to cut emissions because it might compromise American jobs was not compatible with a Christian point of view.

"I think if we look at the language of the Bible we very often come across situations where people are judged for not responding to warnings," he told BBC.


--Roger Harrabin, BBC

In sum, global warming is happening, it's a sign from God, God will punish us if we don't heed His warning, and He'll start out with Dubya, who isn't even a real Christian. Sweet!

Horizon Problem

I've been talking lately with Jethereal about a cosmology conundrum. The universe is roughly 13.7 billion years old. Due to the speed of light, this means that we cannot see objects further away than 13.7 billion light years. The universe is actually larger than that 13.7 Glyr due to inflation, but we just can't see those parts because there hasn't been enough time for the light to get to us yet. Let's assume there's a quasar located, oh, 15 Glyr away from us. It's moving away from us true, but at a slower speed than that of light. We'll assume that it's actually 15 Glyr away when the Universe hits 15 Gyr old, and our horizon hits the quasar.

The question is as follows: What do we see when the horizon gets to the quasar? Jethereal proposed that it springs into our view fully formed. I countered that the quasar had to form at some point in time, so where did the light from its formation go? I proposed that the light from formation gets to us when the horizon hits the quasar.

Neither of us are actually cosmologists, so we're not sure of the answer. Anyone else want to weigh in?

x-posted

Buying the Sun

Well, time on Sun computer systems. Seems anyone with a credit card can buy time on supercomputers to process data. The US worries that this includes terrorists trying to design better nuclear bombs, but c'mon, you'd think credit card companies would screen them out! Or maybe not. But anyways, I don't get why you'd wanna buy time, when you could just build a SETI@home knock off and convince a bunch of people to run it. ;)

Hard Bloggin' Scientist

Think it applies to me?

Composting Credit offers

If you've ever tossed a credit card application in the trash, even after tearing it up, read this (it's 3 pages long), and be scared. I shred, and then toss the shreds in my worm bin.

Crossposted to my blog. Found by Xtina.

Sleep's essential

Sorry for the scanty posts recently - I was away on Spring Break for the last week, and now I'm trying to get a refund for the flight that never got there. "Long story too short to tell."

Just saw a brief blog post on sleep deprivation - just like talking on the cellphone, it's as damaging to your driving reflexes as driving drunk! (Not that my students believe it.)

If you have been up for more than 20 hours, your reflexes are roughly comparable to those of someone with a blood-alcohol level of 0.08, which in many states is enough to be considered legally drunk. You should not drive, and you most certainly should not fly a plane, in that condition. Moreover, the effects add up. Sleeping only six hours a night for a week makes you as tired on the seventh night as if you had had no sleep at all.

--Dr. Sanjay Gupta, CNN Medical Correspondent

*Gulp* I think I'd been up 18 hours when I got home last night. And to think I won't drive for an hour after drinking, more if I've any passengers! I should make personal rules like that for sleep. It was either that though or drive two hours in rushhour at 7am this morning...