Teaching as if the student had a mind
|February 28, 2011||Posted by O'Leary under Cosmology|
Contrary to the spirit of this catalogue of bitches against critical thinking in the school system, I offered to answer a schoolkid’s questions. I do write children’s science sometimes, but am sure glad I don’t teach for a living. Doubtless there’s some state somewhere in the US where I’d get fired for saying this, below, contrary to state regulations:
How do you believe the Earth was created?
[From Denyse: I typically accept NASA’s explanations in a broad sense. Many things can be inferred from the known laws of physics and chemistry since the Big Bang, and they help us predict certain events. For example, the elements of nature (hydrogen, helium, oxygen, etc.) must do certain things. They do not change their minds or go on strike. Of course, there is constant controversy about the details, but that is true of most fields. one needs an enquiring mind and critical thinking skills to sort out the controversies that arise.
Do you think there is anything significant about Earth?
[Well, given that we both live here and can’t move, I’d give that one ten out of ten. But now, seriously, I think what you mean is, is Earth an unusual planet? I think it certainly is. While it is possible that there are other planets in our Milky Way galaxy that are like Earth, from all I have seen in the astronomy news, they wouldn’t be very common or easy to reach. Although we often hear news about an “Earth-like” planet, when you read the story closely, you will find that the researchers simply mean that the planet is of similar size to Earth or in a similar place orbiting a star. But so is Venus, which is not considered friendly to life. Mars may once have had life but it almost certainly doesn’t now. It would be prudent to assume that, in terms of life, Earth is significant.]
Do you think there is any living beings in the universe? (aside from us)
[Hard to say. If we mean simple life forms, I wouldn’t be surprised if some are discovered in my lifetime. I also wouldn’t be surprised if some of them came from Earth. In the early days when the planets were forming, they traded rocks much more readily than any would today. And simple life forms can survive an astonishing amount of punishment. Nematode worms survived the Columbia space shuttle blowup in 2003.
But if we are talking about the SETI space aliens and such, I honestly think that that is a myth of popular culture. I enjoy the myth as much as anyone, but get nervous when people insist that it “must be” true. Why?
First, even if there have been or will be cultures like ours, we are probably separated from them by vast expanses of space and time.
Second, there may be no overlap between their communication and ours. For most of recorded human history, people did not know that bats use echolocation. We only realized that when we started using it ourselves (radar). Until we knew about the Van der Waals force, who realized that geckos use the Van der Waals force to climb up glass columns? So there could be practical limitations on what we and the aliens could discover about each other because we have not even reckoned the possibilities. Perhaps we would not even regard the intelligent aliens as living, so different might they be from us.]
Are we just another planet?
[I know of no reason to think so. Let me put it this way: Suppose we discovered a donut-shaped planet. Now, very specific conditions would be required to create such a structure and keep it in place. Someone might say, “Well, we know of 1800 planets now and this one is donut-shaped, which means that if there are 18 trillion planets, a billion must be shaped like donuts.” Hey, wait a minute. That depends on the assumption that the donut-producing conditions have ever occurred anywhere else at any time. If we found independent evidence that those conditions occur from time to time in various places, we might reasonably infer that there are indeed other donut-shaped planets. But apart from discovering such evidence, we can’t use probability at all. Some things only ever do happen once, and when our sample is one, we may be looking at just such an event.
In the same way, we can’t use the sheer numbers of planets to determine whether Earth is unusual. ]
Why would the universe be so big if we were the only living beings in it?
[Well, first we haven’t established that we are the only living beings. I was providing reasons for caution about assuming that life forms in other parts of the galaxy would be like the space aliens of popular literature.
About the size of the Universe, remember that it is assumed to be spreading out from a point of infinite density, on a regular schedule. So whatever the size is, that is the size it must be. It would probably be that size whether we or any other living beings existed or not. Think of it like blowing up a balloon, using an automated pump. ]
What makes the Earth so significant compared to other planets?
[Well, if we are the ones ascribing the significance, then it is significant because we say so. It signifies something to us. Now, if you believe in God, you probably believe that God considers Earth significant because we live here. God may know of other intelligent beings in other parts of the universe whom he also considers significant.]