Wednesday, April 16, 2008

Wednesday Math, Vol. 20: three million is greater than six thousand.

This is an picture of the Andromeda galaxy, the thing that is the farthest away from us and still visible by the naked eye in the night sky by many accounts. The more scientific name for this is M 31, where M stands for Messier, a French astronomer of the 18th Century who cataloged about 100 comet-like looking things in the night sky. The galaxy, a large smudge that seems to us on earth to be stuck in the sky somewhere over the North Pole, was one of the things Messier put on his list, and it is included in sky maps from astronomers of 1,000 years gone by. Some can see M 33 with the naked eye, which is farther away still. Me, I'm too old.

Some like to think that science is common sense, but that isn't the case. It is only for the past few centuries that we understood that light has a speed, and the idea that the speed is constant is credited to the Michelson Morley experiment, so it is now celebrating its 120th birthday. The upshot of all of this is that when we look at things that are astronomical distances away, we are looking at the past. The light from the moon is about a second old when we see it, the light from the sun is a snapshot from eight minutes ago. Really close stars are light years away, and the closest, the Alpha Centauri and Proxima Centauri stars, are showing us now what they were like less than 5 years ago. The Andromeda galaxy we see is actually its state from about 2.9 million years ago. These measurements are done by measuring parallax, which deals with angles and sides of a triangle, and by the red shift, a brilliant idea of Einstein's that says that while light moves at a constant speed, it does bend perceptibly when it hits a large enough gravity field.

There are deep philosophical implications to the simple scientific statement "Light has a speed." We know sound is not instantaneous if we sit in the cheap seats at a ball game. We see the swing of the bat and the ball starting to fly and only then do we hear the loud CRACK of the contact. (If you are 400 feet away in the bleachers of a stadium at sea level like the ballparks in Oakland and San Francisco, the delay is about 1/3 of a second.) The light gets to our eyes before the sound gets to our ears, because light is so much faster than sound, we can experience this. But nothing we can perceive is faster than light, so nothing in our physical experience can make clear that we do not look at a true instantaneous snapshot when we look at the night sky, but a glimpse a many different objects at many different moments in the past.

One of the implications is disturbing to some. Those who deny evolution, who lump together their hodgepodge criticisms under the heading "intelligent design", do not all believe the same thing, but many are bound together by a desire to believe a literal interpretation of the biblical account of Genesis. The most literal of these people hold to the Young Earth hypothesis, that by doin' the math of all the "begats", we can date the start of creation at about 6,000 years ago. It's a problem for them that the most mathematical of the sciences, physics as applied to astronomy, lets us do the math and show beyond serious debate that some parts of God's creation visible to us for centuries had to exist for at least 2,900,000 years, and 2,900,000 > 6,000. Moreover, we have really cool telescopes now, and we can see that in terms of the universe, M 31 is a close neighbor and there are things in the universe that are really far away.

I was at work a few days back and talking to another math teacher about M 31. I asked if he knew how far away it was, and he guessed. It was a bad guess, because he thought it might be hundreds of billions of light years away. I'm used to students guessing badly, I don't think less of them for it. It shows they are willing to learn. His guess was bad because the accepted age of the universe is around 13.5 billion years, so there's no way that we could see anything older than that. He nodded his head at his mistake, and I added that this sighting with the naked eye puts the lie to the Young Earth hypothesis in much the same way photography from outer space makes it clear the Flat Earth hypothesis isn't correct.

His next statement, a statement from a math teacher, was that when dealing with the maker of all things, our ideas of time and space have no relevance, since the wisdom of the Great Maker is infinitely greater than our own. I was looking for common ground with this person, so I said that he was taking the ideas of "days" as they were defined in Genesis metaphorically and he agreed.

In fact, I was being kind. He was not being metaphorical at all, but reflexively defensive. I cannot give his exact quote, but I am paraphrasing him correctly when he said our ideas have no meaning when we discuss the Creation. In other words, when it comes to God, any crap bullshit believed by a large enough number of people should be given equal weight with the best efforts done by people doing serious and brilliant work trying to discover without prejudice the way the universe works.

I'm not trying to pick a fight with the faithful, at least not the faithful who hang around here. I know Padre Mickey believes that devout Christians do not have to accept Iron Age creation myths to accept the love of God. I don't think I've made any statements that will upset FranIAm or others. But to those Americans who make the Young Earth part of their view of the universe, let me say it's time to sit down and shut up. You hurt our country by forcing us to fight again these already decided battles, and countries where the insane do not get an important voice in politics are going to continue to kick our ass in science and technology, and soon enough our status as the World's Only Superpower will be as quaint as the idea that Nobody Fucks With The Spanish Armada.

Here endeth the lesson.

(Major errors corrected by Ken, freelance fact checker who works for beer when I see him, and lives hundreds of miles away. Such a deal!)

(Yet another error corrected by my good old pal Alan. Dammit, Jim, I'm a mathematician, not a scientist!)


dguzman said...

And what a lesson! Beautiful post, sir, eloquently stated. I keep thinking about a video that Padre Mickey posted, about some crazy tour group that takes kids into museums and teaches them that any of the information about the dinos and the history of Earth is merely "theory" or "opinion," not fact. That video was incredibly frightening.

Anonymous said...

YAY dinasaurs! That was as usual another great post Matty Boy.

ken said...

OK, here in my role as fact checker to the financial adviser to the stars....
1. It's a photo, not an artist's rendition,
2. The Messier list is of things that look kinda like comets, but aren't. They're in no particular order, just the order he happened to write them down in.
3. M33 is a bit farther away, and is, I'm told, visible to the keen naked eye at very dark sites. I've never seen it without a telescope, personally.
4. By "the Centauri stars", i think you mean just the Alpha Centauri system. Other stars in Centaurus are much farther away. (being "in" a constellation really just means being in a defined area of the sky, at any distance.)
5. The age of the universe is 13.73+/-0.12 billion years. 3.5 was probably just a typo. The Earth is about 4.5 billion years old.

OK, with all that out of the way, it's a great post.

- ken

PS start checking your facts yourself, or I'm gonna have to start charging you. Maybe a beer next time I see you...

Matty Boy said...

Yow! My ass done been kick-ified!

You're right, Ken. The first two rounds are on me next time around.

I'll start making the necessary corrections.

Distributorcap said...


i dont suppose i can get beamed up to Andromeda...... (tho in one episode they did escape the milky way)

astronomy and cosmology are some of my favorite topics

Matty Boy said...

Hey, DCap! I'm enough of a nerd to know you are talking the episode you are talking about! Superior aliens defeated by alcohol and Kirk's ability to make the sweet, sweet luuuuuuuuv!

They still write sci-fi, but they don't write it like that anymore.

FranIAm said...

Outstanding post.

As for my faithful self- I stand with el Padrecito de Panama. That whole 6,000 year ago thing just doesn't work for me and God as I understand Him/Her is much more vast and as a result does not require pat answers and a neat timeline.

The only thing I might prefer to a Fran Matty blogger meet up is one that also included, possibly simultaneously, Padre and Dcap.

Ed said...

Greetings! I keep finding references to you on other blogs that I like and I finally got off my lazy virtual butt, stopped by for a look-see and liked what I saw. Excellent post, but I'm sure that those "intelligent" design folks (not to be confused with rational, intelligent christians like Franiam) will find some way to explain that you're wrong and a god-hatin', terrorist sympathizin' heathen on top of it. Keep it up!

Yer ol' buddy Al said...

Hey Matty,
Just a minor info correction on the matter of credit for determining the constant value of the speed of light. Philosophers argued about whether or not light had a fixed or infinite speed as far back as the 11th century. Attempts to measure the speed of light by astronomers goes back into the 17th century. It was theoretically derived as a constant value by James Clerk Maxwell around the mid 19th century. Actually he was expressing the velocity of a propagating wave of electromagnetic energy through what was then considered to be the "aether". His suggestion that light could be a wave of constant speed was correct. It was later verified (indirectly) by the Michelson-Morley experiment that demonstrated that light did not move relative to the motion of the earth. One of the basic tenets of Einstein's Theory of Relativity was that light speed was a fixed constant, but, in the tradition of all great scientists, his work is based on the work of all those astute minds that preceded him.

Matty Boy said...

Thanks to Ed for stopping by, and to my old buddy Alan for correcting the science. I'm more math-y than science-y, and I'm glad to get the refinements of the 'splainin'.