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  • Now, people have a lot of misconceptions about science --

  • about how it works and what it is.

  • A big one is that science is just a big old pile of facts.

  • But that's not true -- that's not even the goal of science.

  • Science is a process.

  • It's a way of thinking.

  • Gathering facts is just a piece of it, but it's not the goal.

  • The ultimate goal of science is to understand objective reality

  • the best way we know how,

  • and that's based on evidence.

  • The problem here is that people are flawed.

  • We can be fooled --

  • we're really good at fooling ourselves.

  • And so baked into this process is a way of minimizing our own bias.

  • So sort of boiled down more than is probably useful,

  • here's how this works.

  • If you want to do some science,

  • what you want to do is you want to observe something ...

  • say, \"The sky is blue. Hey, I wonder why?\"

  • You question it.

  • The next thing you do is you come up with an idea that may explain it:

  • a hypothesis.

  • Well, you know what? Oceans are blue.

  • Maybe the sky is reflecting the colors from the ocean.

  • Great, but now you have to test it

  • so you predict what that might mean.

  • Your prediction would be,

  • \"Well, if the sky is reflecting the ocean color,

  • it will be bluer on the coasts

  • than it will be in the middle of the country.\"

  • OK, that's fair enough,

  • but you've got to test that prediction

  • so you get on a plane, you leave Denver on a nice gray day,

  • you fly to LA, you look up and the sky is gloriously blue.

  • Hooray, your thesis is proven.

  • But is it really? No.

  • You've made one observation.

  • You need to think about your hypothesis, think about how to test it

  • and do more than just one.

  • Maybe you could go to a different part of the country

  • or a different part of the year

  • and see what the weather's like then.

  • Another good idea is to talk to other people.

  • They have different ideas, different perspectives,

  • and they can help you.

  • This is what we call peer review.

  • And in fact that will probably also save you a lot of money and a lot of time,

  • flying coast-to-coast just to check the weather.

  • Now, what happens if your hypothesis does a decent job but not a perfect job?

  • Well, that's OK,

  • because what you can do is you can modify it a little bit

  • and then go through this whole process again --

  • make predictions, test them --

  • and as you do that over and over again, you will hone this idea.

  • And if it gets good enough,

  • it may be accepted by the scientific community,

  • at least provisionally,

  • as a good explanation of what's going on,

  • at least until a better idea

  • or some contradictory evidence comes along.

  • Now, part of this process is admitting when you're wrong.

  • And that can be really, really hard.

  • Science has its strengths and weaknesses

  • and they depend on this.

  • One of the strengths of science is that it's done by people,

  • and it's proven itself to do a really good job.

  • We understand the universe pretty well because of science.

  • One of science's weaknesses is that it's done by people,

  • and we bring a lot of baggage along with us when we investigate things.

  • We are egotistical,

  • we are stubborn, we're superstitious,

  • we're tribal, we're humans --

  • these are all human traits and scientists are humans.

  • And so we have to be aware of that when we're studying science

  • and when we're trying to develop our theses.

  • But part of this whole thing,

  • part of this scientific process,

  • part of the scientific method,

  • is admitting when you're wrong.

  • I know, I've been there.

  • Many years ago I was working on Hubble Space Telescope,

  • and a scientist I worked with came to me with some data,

  • and he said, \"I think there may be a picture

  • of a planet orbiting another star in this data.\"

  • We had not had any pictures taken of planets orbiting other stars yet,

  • so if this were true,

  • then this would be the first one

  • and we would be the ones who found it.

  • That's a big deal.

  • I was very excited,

  • so I just dug right into this data.

  • I spent a long time trying to figure out if this thing were a planet or not.

  • The problem is planets are faint and stars are bright,

  • so trying to get the signal out of this data

  • was like trying to hear a whisper in a heavy metal concert --

  • it was really hard.

  • I tried everything I could,

  • but after a month of working on this,

  • I came to a realization ... couldn't do it.

  • I had to give up.

  • And I had to tell this other scientist,

  • \"The data's too messy.

  • We can't say whether this is a planet or not.\"

  • And that was hard.

  • Then later on we got follow-up observations with Hubble,

  • and it showed that it wasn't a planet.

  • It was a background star or galaxy, something like that.

  • Well, not to get too technical, but that sucked.

  • (Laughter)

  • I was really unhappy about this.

  • But that's part of it.

  • You have to say, \"Look, you know, we can't do this with the data we have.\"

  • And then I had to face up to the fact

  • that even the follow-up data showed we were wrong.

  • Emotionally I was pretty unhappy.

  • But if a scientist is doing their job correctly,

  • being wrong is not so bad

  • because that means there's still more stuff out there --

  • more things to figure out.

  • Scientists don't love being wrong but we love puzzles,

  • and the universe is the biggest puzzle of them all.

  • Now having said that,

  • if you have a piece and it doesn't fit no matter how you move it,

  • jamming it in harder isn't going to help.

  • There's going to be a time when you have to let go of your idea

  • if you want to understand the bigger picture.

  • The price of doing science is admitting when you're wrong,

  • but the payoff is the best there is:

  • knowledge and understanding.

  • And I can give you a thousand examples of this in science,

  • but there's one I really like.

  • It has to do with astronomy,

  • and it was a question that had been plaguing astronomers

  • literally for centuries.

  • When you look at the Sun, it seems special.

  • It is the brightest object in the sky,

  • but having studied astronomy, physics, chemistry, thermodynamics for centuries,

  • we learned something very important about it.

  • It's not that special.

  • It's a star just like millions of other stars.

  • But that raises an interesting question.

  • If the Sun is a star

  • and the Sun has planets,

  • do these other stars have planets?

  • Well, like I said with my own failure in the \"planet\" I was looking for,

  • finding them is super hard,

  • but scientists tend to be pretty clever people

  • and they used a lot of different techniques

  • and started observing stars.

  • And over the decades

  • they started finding some things that were pretty interesting,

  • right on the thin, hairy edge of what they were able to detect.

  • But time and again, it was shown to be wrong.

  • That all changed in 1991.

  • A couple of astronomers --

  • Alexander Lyne -- Andrew Lyne, pardon me --

  • and Matthew Bailes,

  • had a huge announcement.

  • They had found a planet orbiting another star.

  • And not just any star, but a pulsar,

  • and this is the remnant of a star that has previously exploded.

  • It's blasting out radiation.

  • This is the last place in the universe you would expect to find a planet,

  • but they had very methodically looked at this pulsar,

  • and they detected the gravitational tug of this planet as it orbited the pulsar.

  • It looked really good.

  • The first planet orbiting another star had been found ...

  • except not so much.

  • (Laughter)

  • After they made the announcement,

  • a bunch of other astronomers commented on it,

  • and so they went back and looked at their data

  • and realized they had made a very embarrassing mistake.

  • They had not accounted for some very subtle characteristics

  • of the Earth's motion around the Sun,

  • which affected how they measured this planet going around the pulsar.

  • And it turns out that when they did account for it correctly,

  • poof -- their planet disappeared.

  • It wasn't real.

  • So Andrew Lyne had a very formidable task.

  • He had to admit this.

  • So in 1992 at the American Astronomical Society meeting,

  • which is one of the largest gatherings of astronomers on the planet,

  • he stood up and announced that he had made a mistake

  • and that the planet did not exist.

  • And what happened next --

  • oh, I love this --

  • what happened next was wonderful.

  • He got an ovation.

  • The astronomers weren't angry at him;

  • they didn't want to chastise him.

  • They praised him for his honesty and his integrity.

  • I love that!

  • Scientists are people.

  • (Laughter)

  • And it gets better!

  • (Laughter)

  • Lyne steps off the podium.

  • The next guy to come up is a man named Aleksander Wolszczan

  • He takes the microphone and says,

  • \"Yeah, so Lyne's team didn't find a pulsar planet,

  • but my team found not just one

  • but two planets orbiting a different pulsar.

  • We knew about the problem that Lyne had,

  • we checked for it, and yeah, ours are real.\"

  • And it turns out he was right.

  • And in fact, a few months later,

  • they found a third planet orbiting this pulsar

  • and it was the first exoplanet system ever found --

  • what we call alien worlds -- exoplanets.

  • That to me is just wonderful.

  • At that point the floodgates were opened.

  • In 1995 a planet was found around a star more like the Sun,

  • and then we found another and another.

  • This is an image of an actual planet orbiting an actual star.

  • We kept getting better at it.

  • We started finding them by the bucketload.

  • We started finding thousands of them.

  • We built observatories specifically designed to look for them.

  • And now we know of thousands of them.

  • We even know of planetary systems.

  • That is actual data, animated, showing four planets orbiting another star.

  • This is incredible. Think about that.

  • For all of human history,

  • you could count all the known planets in the universe on two hands --

  • nine -- eight?

  • Nine? Eight -- eight.

  • (Laughter)

  • Eh.

  • (Laughter)

  • But now we know they're everywhere.

  • Every star --

  • for every star you see in the sky there could be three, five, ten planets.

  • The sky is filled with them.

  • We think that planets may outnumber stars in the galaxy.

  • This is a profound statement,

  • and it was made because of science.

  • And it wasn't made just because of science and the observatories and the data;

  • it was made because of the scientists who built the observatories,

  • who took the data,

  • who made the mistakes and admitted them

  • and then let other scientists build on their mistakes

  • so that they could do what they do

  • and figure out where our place is in the universe.

  • That is how you find the truth.

  • Science is at its best when it dares to be human.

  • Thank you.

  • (Applause and cheers)

Now, people have a lot of misconceptions about science --

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【TED】The secret to scientific discoveries? Making mistakes | Phil Plait

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    林宜悉   に公開 2019 年 04 月 11 日
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