29 March 2006

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!

25 March 2006

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?


23 March 2006

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. ;)

22 March 2006

Hard Bloggin' Scientist

Think it applies to me?

I am a hard bloggin' scientist. Read the Manifesto.

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.

20 March 2006

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...

Dinosaur extinction could have seeded Titan

Sclerotic-rings pointed out a BBC article stating that the asteroid that caused the dinosaurs' mass extinction could've blasted rocks into space that could've eventually hit both Titan and Europa.

Asked after his presentation by one scientist whether he thought microbes would be able to survive Titan's freezing temperatures, Dr Gladman answered: "That's for you people to decide, I'm just the pizza delivery boy."

Gladman also checked landing velocities to determine theoretical heating: the <100 rocks to Europa hit too fast, while the <20 rocks to Titan might've made it. The one thing BBC didn't note was that Gladman's talk was submitted, not peer reviewed, but it took some digging for me to find.

Debunking: Library Book Donations to NOLA

Because I love debunking urban myths. Yes, public libraries in New Orleans are accepting book donations post-Katrina. No, that's not really the best use of your time and money. Many donated books turn out to not be usable, mailing books may result in multiple duplications, and they're too short-staffed to be able to process the book donations anyway. Instead of spending five bucks on book rate, donate that five bucks directly to the libraries.

Source: Snopes.com
More Info: NOLA Library Donations FAQ

15 March 2006

Google Mars

Google has rolled out another entertaining map service: Google Mars. Three views are available: elevation, visible, and IR, and you can click to turn on markers for things like crater names, landing sites, and news articles. And you can search for terms like "Olympus Mons" or "Spirit" - differrent color icons indicate landmarks (red), other points of interest (green), and spacecraft (yellow). It's pretty neat! You don't get green cheese when you zoom in all the way though, like you did with Google Moon. ;)

14 March 2006

Statement as of 4:55 PM MST on March 14, 2006

For Phoenix, AZ:

Statement as of 4:55 PM MST on March 14, 2006

... Spring or Vernal equinox is Monday March 20th at 1126 am MST...

The sun will be directly over the Equator at 1126 am MST Monday
March 20th... as it Marks the Halfway Point of its six-month journey
northward. This Crossing of the sun directly over the Equator is
known as the Vernal equinox. The sun will continue its northward
journey until the Summer solstice on June 21st.

This is the time of year when days and nights are near equal length.
This is also the time of year when the sun rises directly in the east
and sets directly in the west. Thus... you may find yourself looking
directly into the sun while driving east just after sunrise (around
637 am MST in phoenix) or driving west just before sunset (around
637 PM MST in phoenix). So... please be extra cautious while driving.


Hee, I love everyday astronomy. :)

06 March 2006

Press Release Science: Do's

Press release: a comparatively short news blurb about ongoing science. Results are typically released without being checked by other scientists in the field, or have been checked but are based only on a single study, so they are preliminary results and should be taken with a grain of salt. However, they are written in Common English, rather than Science English, and so are more comprehensible to the general public. Additionally, press releases typically come out much sooner than peer reviewed research.

I have seen my very first example of a good press release. The Boston Globe article (first part) tells how one group found that exercising pregnant mice resulted in larger brains in the offspring, but the most impressive part to the whole article is the three paragraphs after the press release, warning the reader that the results are preliminary!

The two other following blurbs do the same thing. I'm not sure when the Globe decided to do it in this manner, but I think I'm going to have to write them a letter of thanks.


I just got my 2006 phone book, and you know what that means: I get to shred the old one and feed it to my worm bin! *grin*

05 March 2006


A comment from Chestocrates reminded me of recent discussions I had about species-like definitions. It's amazing to me just how many words there are with similar meanings but some subtle differences. My understanding is as follows.

  • Species: unique things (animal or plant) that do not breed breed with each other. Of course there's more to that when the species does not have sexual reproduction.

  • Subspecies: a subdivision of species that can reproduce with each other, but may not due to either geographic or behavioral differences.

  • Breed: a man-made subdivision of animal species that typically can and do reproduce with each other unless humans prevent it.

  • Cultivar: a man-made subdivision of plant species that do not reproduce with each other. Often, cultivars are unable to reproduce without human intervention. An example is that broccoli and cabbage are cultivars of the same species of plant (brassica oleracea).

  • Morph: a subspecies of animal that do not interbreed due to behavior.

  • Strain: in microbiology, a subspecies of bacteria or virus with unique characteristics, such as the H5N1 strain of avian influenza; in animals, especially lab rats, a subspeces specifically bred with certain traits, such as diabetes.

Feel free to correct me if I'm wrong, and I'll update the original post.

02 March 2006

Godless mathematics

And to think I was just asking a friend about Diff EQ's this afternoon. Whew, I'm glad I've seen the light!

01 March 2006

Creationists still at it

In Utah, Mormon fundie central, legislators tried to pass a law requiring teachers to state that "evolution is not a fact and the state doesn't endorse the theory." (CNN/AP) Fortunately, the state House voted it down 2-1, but the Senate had approved it!

"I don't believe that anybody in there really wants their kids to be taught that their great-grandfather was an ape," [bill sponsor, Republican Senator Chris] Buttars said.

Well of course not! It was something like thousands or millions of generations ago, and they weren't apes, they were homo erectus! Duh.