หนังสือแนะนำ (อีกแล้ว): ฟิสิกส์ 6 บทสุดง่าย

เป็นหนังสือที่แปลมาจาก Six Easy Pieces ของ Richard P. Feynman นะครับ ราคา 190 บาทเท่านั้น

ใครก็ตามที่สนใจว่าธรรมชาติทำงานอย่างไรควรจะอ่านเล่มนี้ก่อนครับ ความจริงทุกคนที่เรียนวิทยาศาสตร์ควรจะอ่านก่อน ไม่งั้นจะสับสนว่าเรียนวิทยาศาสตร์ไปทำโจทย์หรือไปสอบเท่านั้นหรือ หนังสือมีหกบทที่คัดเลือกมาจากบทบรรยายของ Richard Feynman ที่สอนนักเรียนฟิสิกส์เมื่อนานมาแล้ว เนื้อหายังดีมากอยู่ครับไม่ล้าสมัย

A Good Essay From The Past

I first read the essay by Danny Hillis about Richard Feynman and the Connection Machine about two decades ago and by chance read it again today. I still like it very much.

An Excerpt:

...For Richard, figuring out these problems was a kind of a game. He always started by asking very basic questions like, "What is the simplest example?" or "How can you tell if the answer is right?" He asked questions until he reduced the problem to some essential puzzle that he thought he would be able to solve. Then he would set to work, scribbling on a pad of paper and staring at the results. While he was in the middle of this kind of puzzle solving he was impossible to interrupt. "Don't bug me. I'm busy," he would say without even looking up. Eventually he would either decide the problem was too hard (in which case he lost interest), or he would find a solution (in which case he spent the next day or two explaining it to anyone who listened). In this way he worked on problems in database searches, geophysical modeling, protein folding, analyzing images, and reading insurance forms...

If you like science, or want to have a glimpse of how one of the finest minds of our species operated, you might want to check it out.

Another Great Physicist Passed Away

John Archibald Wheeler passed away today.

He was a living legend, had many fantastical ideas, taught and inspired generations of physicists including Richard Feynman and Kip Thorne.

I only knew him from his General Relativity book and his lectures about It-from-Bit.

 

For an example of the kind of things he imagined, check this passage from his wikipedia page:  ...theorizes experiments utilizing photons from distant locations in the universe, imaged using galaxy clusters as lenses, but which are detected using apparatus for quantum entanglement, thereby influencing history billions of years in the past.

There is also a heartfelt essay by one of his former students here.

The Best Comic Ever!

It combines so many things I like: Ninja, Science, Mythbusters, Zombie, and Feynman!

It also has a message: "Ideas are tested by experiment." That is the core of science. Everything else is bookkeeping.

A Genius' Quotes

Richard Feynman is my scientific hero. I decided to get real science education after reading the first few chapters from these books by him. I found these quotes when I'm ordering another of his books:
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Perhaps the best example of Feynman's self-understanding lies in his attitude toward money. After some happy years at Cornell, Feynman is lured to Caltech, where he is even happier. But one day the University of Chicago offers him "a tremendous amount of money, three or four times what I was making." He writes back:

"After reading the salary, I've decided that I must refuse. The reasons I have to refuse a salary like that is I would be able to do what I've always wanted to do -- get a wonderful mistress, put her up in an apartment, buy her nice things. . . . With the salary you have offered, I could actually do that, and I know what would happen to me. I'd worry about her, what she's doing; I'd get into arguments when I come home, and so on. All this bother would make me uncomfortable and unhappy. I wouldn't be able to do physics well, and it would be a big mess. What I've always wanted to do would be bad for me, so I've decided that I can't accept your offer."

More choice quotes:

"I learned from her [his mother] that the highest forms of understanding we can achieve are laughter and human compassion."

"That's the way the world was: You worked long hours and got nothing for it, every day."

"Have no respect whatsoever for authority; forget who said it and instead look at what he starts with, where he ends up, and ask yourself, 'Is it reasonable?' "

"Our responsibility is to do what we can, learn what we can, improve the solutions, and pass them on. It is our responsibility to leave the people of the future a free hand. . . . If we suppress all discussion, all criticism, proclaiming 'This is the answer, my friends; man is saved!' we will doom humanity for a long time to the chains of authority, confined to the limits of our present imagination. It has been done so many times before."

Understanding Something Is More Than Just Knowing Fancy Words

An anecdote by Richard Feynman:

For example, there was a book that started out with four pictures: first there was a windup toy; then there was an automobile; then there was a boy riding a bicycle; then there was something else. And underneath each picture it said, "What makes it go?"

I thought, "I know what it is: They're going to talk about mechanics, how the springs work inside the toy; about chemistry, how the engine of the automobile works; and biology, about how the muscles work."

It was the kind of thing my father would have talked about: "What makes it go? Everything goes because the sun is shining." And then we would have fun discussing it:

"No, the toy goes because the spring is wound up," I would say. "How did the spring get wound up?" he would ask.

"I wound it up."

"And how did you get moving?"

"From eating."

"And food grows only because the sun is shining. So it's because the sun is shining that all these things are moving." That would get the concept across that motion is simply the transformation of the sun's power.

I turned the page. The answer was, for the wind-up toy, "Energy makes it go." And for the boy on the bicycle, "Energy makes it go." For everything, "Energy makes it go."

Now that doesn't mean anything. Suppose it's "Wakalixes." That's the general principle: "Wakalixes makes it go." There's no knowledge coming in. The child doesn't learn anything; it's just a word!

What they should have done is to look at the wind-up toy, see that there are springs inside, learn about springs, learn about wheels, and never mind "energy." Later on, when the children know something about how the toy actually works, they can discuss the more general principles of energy.

So, when you try to understand how something works or comes to be, and some authority say to you it's because of X, you better know how X operates.

If you haven't read a book called "Surely You're Joking, Mr. Feynman", you should really read it at least once in your life. It contains a lot of fun adventures by the great scientist Richard Feynman.

Evidences For Life's Common Ancestors & The Tree Of Life

A good friend of mine asked me what evidences I have for my belief in the idea that all living things on earth have common ancestors. This is an excellent question since it's very important to base our judgement about reality on good evidences, or we can easily be led astray by our commonsense, biases, and other extremely appealing ideas that don't match reality.*

My specific belief is this: All living things on Earth descend from one or small number of groups of ancestors. (I would like to say one group, but I'm open to the possibility that there are unknown life forms that have independent ancestors, distinct from our group.)

For this particular belief, a very good summary of evidences can be be found here (29+ Evidences for Macroevolution: The Scientific Case for Common Descent.)

Also, a very informative depiction of known life on Earth can be found at the Tree of Life Web Project. Make sure that you read this page about the interpretation of the image.

An implication of the belief is that I am a (mostly distant) relative of bacteria, mushrooms, blue-green algae, jasmine rice, earth worms, monitor lizards, cows, starfish, mangoes, octopuses, fire ants, bees, dogs, monkeys, gorillas, parrots, sharks, triceratops, T-Rexes, the slaves that built the pyramids, Ghenghis Khan, and you, the reader.

Another implication that if there are extra-terrestrial beings (which I really hope there are, although I don't have any evidence for that yet) it's very unlikely for them to look very similar to us. Even if we and ET have the same common ancestors, that ancestors must have come to earth billions of years ago and will have enough time to evolve into us and myriads forms of animals and plants. Similarly, the ET would descend from the common ancestors over the similarly long time period. So, Captain Kirk in Star Trek should not be able to mate with those ET chicks if he is not really, really into inter-planetary bestiality. (Same reasoning applies to Superman and Lois Lane.**)

Yet another implication is that human is not the apex of evolution. There will be other lifeforms in the billions of years ahead if we don't destroy all life first. We are the first Earth lifeform that can destroy all life on Earth using our technology, but we are not necessarily the best lifeform. To think that we are the peak of all possible lifeforms is just extremely arrogant.

Finally, my body is made of atoms from things (living/dead, never-alive) from the past. Therefore, I also believe that when I die, some atoms that used to be me will be recycled into other living things in the future but the atoms won't carry any of my memory there, since my memory is not stored in specific atoms, but in the patterns of how atoms are arranged. This is supported by the fact that, atoms inside my bodies are very likely to have been in bodies of people of the past, yet I don't share their memory. Conversely, with very high probability, atoms that are in my body now weren't the same atoms that were in my body when I was a child, yet I still remember many things from my childhood. This gives me a hope that, in principle, human can preserve identity/memory by capturing the memory patterns and upload them to more permanent substrate and become relatively immortal.

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* The great Richard Feynman summed it up (in this book) thus: "... there are many reasons why you might not understand [an explanation of a scientific theory] ... Finally, there is this possibility: after I tell you something, you just can't believe it. You can't accept it. You don't like it. A little screen comes down and you don't listen anymore. I'm going to describe to you how Nature is - and if you don't like it, that's going to get in the way of your understanding it. It's a problem that [scientists] have learned to deal with: They've learned to realize that whether they like a theory or they don't like a theory is not the essential question. Rather, it is whether or not the theory gives predictions that agree with experiment. It is not a question of whether a theory is philosophically delightful, or easy to understand, or perfectly reasonable from the point of view of common sense. [A scientific theory] describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you can accept Nature as She is - absurd.

I'm going to have fun telling you about this absurdity, because I find it delightful. Please don't turn yourself off because you can't believe Nature is so strange. Just hear me all out, and I hope you'll be as delighted as I am when we're through."


**Larry Niven wrote a very funny essay called "Man of Steel,Woman of Kleenex" on the problems involved when Superman and Lois Lane try to mate.