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节操     例：港大没让我找到饭碗，但加强了我的节操～

Jerry Coyne posted a reader's comment on his blog, Why Evolution Is True , which I read daily. This reader apparently doesn't know the plural of "child", but I digress… Here's the comment:

I will believe in evolution when I listen darwinist tell his fiance or his wife:

"The chemistry of my body make me feel good when I see you. I'm telling this to you because may chemistry is making me tell that, not because I'm free to say this or other thing"

instead of "I love you"

I will believe in evolution when I listen darwinist tell his childrens:

"The chemistry of my body make me feel good when I see you, because the vision results in the possibility that my shelfish genes will survive. I'm telling this to you because may chemistry is making me tell that, not because I'm free to say this or other thing"

instead of "I love you"

This is just garden-variety idiocy you get used to reading Coyne. What is truly remarkable—and lovely—is the comments under Coyne's post in reply to idiocy. Here're the first, the second, and the forth:

1. Doctor Elessar Posted April 3, 2012 at 11:05 am | Permalink
While I have told my children that I love them, I have also talked to them very in depth about the nature of human emotion, neurohormonal interactions and how those things developed through evolution… they and I think that's pretty freaking cool!

2. Mackenzie Posted April 3, 2012 at 11:14 am | Permalink
Well, my husband actually has said that to me before. Not those exact words, mind you, but he often points out the science behind certain feelings. Given that I'm a scientist too, I understand… but sometimes it might be nice just to ignore the science and just say something sweet. :) A girl can dream, right?

4. Jerome Haltom Posted April 3, 2012 at 11:17 am | Permalink
I've said almost exactly that to my fiance. She thought it was cute.

Scroll down and you find more people saying that they told almost exactly the same thing to their loved ones.

Oh my Flying Spaghetti Moster! I wasn't the only person who did that! I finally know, and that's good. Even though in my case the response was not (I recall) exactly enthusiastic, it is still good to know that I was not alone; that I was not the only person who thought it pretty freaking cool that my deepest feelings are basically electric currents, flowing in a network built out of the ashes of stars and shaped by billions of years of blind, purposeless evolution; that I was not, thank FSM, the only person who wanted to share this sense of wonder with my loved one. Why didn't she find it pretty freaking cool too? I sometimes wonder (well, never mind).

To sum it up, and just in case you wonder why I missed comment #3:

3. Greg G Posted April 3, 2012 at 11:15 am | Permalink
Prometheus Retold
Old Song: Updated
You may remember these children’s lyrics:

      Tell me why the stars do shine
      Tell me why the ivy twines
      Tell me why the sky is so blue
      And I will tell you just why I love you
      Because God made the stars to shine
      Because God made the ivy twine
      Because God made the sky's so blue
      Because God made you, that's why I love you.

Someone from MIT rewrote the lyrics.

      Tell me why the stars do shine
      Tell me why the ivy twines
      Tell me why the sky is so blue
      And I will tell you just why I love you
      Nuclear fusion makes stars to shine
      Tropisms make the ivy twine
      Rayleigh scattering makes the sky so blue
      And testicular hormones is why I love you.

180年前的今天（或昨天），小猎犬号上的船员喊船舱里的博物学家，“想看灰海豚不？”

April 1st

All hands employed in making April fools. — at midnight almost nearly all the watch below was called up in their shirts; carpenters for a leak: quarter masters that a mast was sprung. — midshipmen to reef top-sails; All turned in to their hammocks again, some growling some laughing. — The hook was much too easily baited for me not to be caught: Sullivan cried out, “Darwin, did you ever see a Grampus: Bear a hand then”. I accordingly rushed out in a transport of Enthusiasm, & was received by a roar of laughter from the whole watch. —

来源

下面这个据说是象海豹（看不到的请点这里 ）

And yet it's such a beautiful problem.

Imagine an ice cube sitting in a large glass of warm water, left to itself. We all know what will happen. The ice will melt. It will never grow larger. The simple and yet perplexing question is: why?

Fundamental laws of physics do not seem to prohibit the ice cube from growing. Whether a bunch of H2O molecules appear to be water or ice is just a matter of how fast on average they are moving. When slow-moving molecules get together, they freeze. When enough fast-moving molecules mix in, they melt. Now fundamental laws allow both of the following to happen: (1) fast and slow molecules mix well, so the average speed of the whole is somewhere in between—in which case there is a glass of cold water with no ice; (2) fast molecules concentrate in one region and slower ones in another, in which case you have an piece of ice sitting in warm water. But no fundamental law seems to entail that (2) cannot last but must finally become (1). Nor do they seem to entail that (1) will never evolve into (2).

(Ok, the second law of thermodynamics does say that (1) will never evolve into (2). But this law is not fundamental—it just summarizes the result of what happens at a more fundamental level, the level of (say) molecular motion. The question is still: why are molecules so careful not to break the second law, a law which they seem able to break?)

At some point in their career, Maxwell and Boltzmann (somewhat independently) hit upon the following answer. Say the ice-in-water system has n billions of H2O molecules in it. Let's map every micro arrangement of the entire system, with the position and velocity of every molecule specified, onto a unique point in a space—although this space is in fact 6n billion-dimensional, we can pretend it is two-dimensional, like the carpet on your floor. The evolution of the entire system is then representable as movement from one point to another on the carpet.

Now—and this is a mathematical truth—there are vastly more points on the carpet that correspond to cold water and no ice than there are points that correspond to ice in warm water. The reason is basically highschool combinatorics. If you have 20 balls labeled "Fast" and 20 labelled "Slow" to put into two boxes, you have only 2 ways of putting all Fast balls in one box and all Slow balls in another, but 369512 ways to divide them evenly between two boxes. And the number of molecules in a glass of water is on the order of, I'm not sure, about 10^24. So almost the entire carpet is occupied by cold-water arrangements and only a tiny, almost non-existent fraction is occupied by ice-in-warm-water arrangements. Now given any particular ice-in-warm-water, we do not know exactly where it is on the carpet except that it is in that tiny region. But even without knowing that, we can be quite sure that when this point moves, it is overwhelming likely to move into the vast cold-water-and-no-ice region and wander in there forever, never back again. That's why ice always melts and never spontaneously grow.

M&B’s math was correct. But there is an striking objection (first made by Zermelo, the guy who axiomatized set theory). Suppose there are two glasses of warm water on the table, each with an ice cube sitting in it. They are otherwise identical except that for every H2O molecule in glass A, there is a molecule in the corresponding position in glass B that is moving at the same speed but in the opposite direction. And vice versa for every molecule in glass B. Now ask: what will the two glasses become ten minutes later? M&B say: they will both contain cold water with no ice. But, the objection says, since every molecule in B is moving toward where the corresponding molecule in A came from, the trajectory of the point on the carpet representing B in the next ten minutes will coincide with the trajectory of the point representing A in the past ten minutes, just pointing to the opposite direction—so B's future is, literally, A's past. If M&B have correctly explained why the ice sitting in glass A will melt in the future, then they also predict that the ice sitting in glass B was melt in the past and has since spontaneously grown to its current size. Worse yet, M&B's explanation applies to B (explaining why it will melt), too, which generates a similar prediction about A (that it was melt but has grown ).

And we don't really need two glasses. Take any ice-in-warmer-water system in the world, we can just imagine its molecule-for-molecule velocity reversal and apply the same reasoning. So the M&B answer, if correct, predicts of every ice-in-warm-water system in the world not only that the ice will melt, but that it was melt too, and that the currect state is the ice's least melt state. All this is quite crazy.

Not just that. There are vastly many more ways for the entire universe to be in a soup of total equilibrium than for it to contain people, rocks, cats, or anything that is in any way distinguishable from anything else. We are certainly moving toward that equilibrium state. But if the M&B line is correct, it is overwhelmingly probable that we were in that state too just a second ago, and further into the past; it is overwhelmingly probable that our current state is the most non-equilibrium state that ever existed.

It is true that we appear to have evidence for a non-equilibrium past, like photos, fossils, etc. But these things are almost certainly fake if M&B are right. The reason is that systems at equilibrium can sometimes fluctuate away from equilibrium with a certain probability; but the probability is lower the farther away the fluctuation. It is surely very unlikely that a universe at equilibrium should fluctuate into the current state we are in, complete with fake photos and fossils, but it is even more unlikely hat it should fluctuate into the state of the universe 100 years ago (say), whose total entropy (the number of micro states compatible with the macro state of the system) is even lower. The most probable and economic hypothesis that explains the current state is therefore that the universe only fluctuated just far eough to give us the current state, but not far enough to give us what we believe to be the past as well.

Boltzmann ended up positing (half-heartedly) what has become known as the "past hypothesis" in order to save his theory, and still later he became not quite sure just what his theory was. But anyway, the past hypothesis basically says that it is a brute fact that the past is what we think it is. And this is obviously unsatisfactory. So we have yet to explain why ice melts.

After a great victory . —What is best about a great victory is that it liberates the victor from the fear of defeat. "Why not be defeated some time, too?" he says to himself; "Now I am rich enough for that."