[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.83,0:00:04.27,Default,,0000,0000,0000,,Every day we face issues like climate change
Dialogue: 0,0:00:04.27,0:00:05.71,Default,,0000,0000,0000,,or the safety of vaccines
Dialogue: 0,0:00:05.71,0:00:08.35,Default,,0000,0000,0000,,where we have to answer questions whose answers
Dialogue: 0,0:00:08.35,0:00:11.66,Default,,0000,0000,0000,,rely heavily on scientific information.
Dialogue: 0,0:00:11.66,0:00:15.33,Default,,0000,0000,0000,,Scientists tell us that the world is warming.
Dialogue: 0,0:00:15.33,0:00:17.28,Default,,0000,0000,0000,,Scientists tell us that vaccines are safe.
Dialogue: 0,0:00:17.28,0:00:19.46,Default,,0000,0000,0000,,But how do we know if they are right?
Dialogue: 0,0:00:19.46,0:00:21.57,Default,,0000,0000,0000,,Why should be believe the science?
Dialogue: 0,0:00:21.57,0:00:24.90,Default,,0000,0000,0000,,The fact is, many of us actually\Ndon't believe the science.
Dialogue: 0,0:00:24.90,0:00:27.31,Default,,0000,0000,0000,,Public opinion polls consistently show
Dialogue: 0,0:00:27.31,0:00:29.63,Default,,0000,0000,0000,,that significant proportions of the American people
Dialogue: 0,0:00:29.63,0:00:33.22,Default,,0000,0000,0000,,don't believe the climate is\Nwarming due to human activities,
Dialogue: 0,0:00:33.22,0:00:36.72,Default,,0000,0000,0000,,don't think that there is\Nevolution by natural selection,
Dialogue: 0,0:00:36.72,0:00:40.80,Default,,0000,0000,0000,,and aren't persuaded by the safety of vaccines.
Dialogue: 0,0:00:40.80,0:00:44.32,Default,,0000,0000,0000,,So why should we believe the science?
Dialogue: 0,0:00:44.32,0:00:47.96,Default,,0000,0000,0000,,Well, scientists don't like talking about \Nscience as a matter of belief.
Dialogue: 0,0:00:47.96,0:00:50.44,Default,,0000,0000,0000,,In fact, they would contract science with faith,
Dialogue: 0,0:00:50.44,0:00:53.68,Default,,0000,0000,0000,,and they would say belief is the domain of faith.
Dialogue: 0,0:00:53.68,0:00:57.24,Default,,0000,0000,0000,,And faith is a separate thing\Napart and distinct from science.
Dialogue: 0,0:00:57.24,0:00:59.79,Default,,0000,0000,0000,,Indeed they would say religion is based on faith
Dialogue: 0,0:00:59.79,0:01:04.25,Default,,0000,0000,0000,,or maybe the calculous of Pascal's wager.
Dialogue: 0,0:01:04.25,0:01:07.11,Default,,0000,0000,0000,,Blaise Pascal was a 17th century mathematician
Dialogue: 0,0:01:07.11,0:01:09.63,Default,,0000,0000,0000,,who tried to bring scientific\Nreasoning to the question of
Dialogue: 0,0:01:09.63,0:01:11.54,Default,,0000,0000,0000,,whether or not he should believe in God,
Dialogue: 0,0:01:11.54,0:01:13.62,Default,,0000,0000,0000,,and his wager went like this:
Dialogue: 0,0:01:13.62,0:01:15.94,Default,,0000,0000,0000,,well, if God doesn't exist
Dialogue: 0,0:01:15.94,0:01:18.08,Default,,0000,0000,0000,,but I decide to believe in him
Dialogue: 0,0:01:18.08,0:01:20.54,Default,,0000,0000,0000,,nothing much is really lost.
Dialogue: 0,0:01:20.54,0:01:22.45,Default,,0000,0000,0000,,Maybe a few hours on Sunday.
Dialogue: 0,0:01:22.45,0:01:23.23,Default,,0000,0000,0000,,[Laughter]
Dialogue: 0,0:01:23.23,0:01:26.38,Default,,0000,0000,0000,,But if he does exist and I don't believe in him,
Dialogue: 0,0:01:26.38,0:01:28.52,Default,,0000,0000,0000,,then I'm in deep trouble.
Dialogue: 0,0:01:28.52,0:01:31.58,Default,,0000,0000,0000,,And so Pascal said, we'd better believe in God.
Dialogue: 0,0:01:31.58,0:01:33.61,Default,,0000,0000,0000,,Or as one of my college professors said,
Dialogue: 0,0:01:33.61,0:01:36.11,Default,,0000,0000,0000,,"He clutched for the handmill of faith."
Dialogue: 0,0:01:36.11,0:01:37.77,Default,,0000,0000,0000,,He made that leap of faith
Dialogue: 0,0:01:37.77,0:01:41.90,Default,,0000,0000,0000,,leaving science and rationalism behind.
Dialogue: 0,0:01:41.90,0:01:45.39,Default,,0000,0000,0000,,Now the fact is though, for most of us,
Dialogue: 0,0:01:45.39,0:01:48.18,Default,,0000,0000,0000,,most scientific claims are a leap of faith.
Dialogue: 0,0:01:48.18,0:01:52.94,Default,,0000,0000,0000,,We can't really judge scientific\Nclaims for ourselves in most cases.
Dialogue: 0,0:01:52.94,0:01:55.70,Default,,0000,0000,0000,,And indeed this is actually\Ntrue for most scientists as well
Dialogue: 0,0:01:55.70,0:01:57.85,Default,,0000,0000,0000,,outside of their own specialties.
Dialogue: 0,0:01:57.85,0:02:00.49,Default,,0000,0000,0000,,So if you think about it, a geologist can't tell you
Dialogue: 0,0:02:00.49,0:02:02.25,Default,,0000,0000,0000,,whether a vaccine is safe.
Dialogue: 0,0:02:02.25,0:02:05.24,Default,,0000,0000,0000,,Most chemists are not experts in evolutionary theory.
Dialogue: 0,0:02:05.24,0:02:07.05,Default,,0000,0000,0000,,A physicist cannot tell you,
Dialogue: 0,0:02:07.05,0:02:08.97,Default,,0000,0000,0000,,despite the claims of some of them,
Dialogue: 0,0:02:08.97,0:02:12.32,Default,,0000,0000,0000,,whether or not tobacco causes cancer.
Dialogue: 0,0:02:12.32,0:02:14.49,Default,,0000,0000,0000,,So, if even scientists themselves
Dialogue: 0,0:02:14.49,0:02:16.22,Default,,0000,0000,0000,,have to make a leap of faith
Dialogue: 0,0:02:16.22,0:02:17.90,Default,,0000,0000,0000,,outside their own fields,
Dialogue: 0,0:02:17.90,0:02:21.98,Default,,0000,0000,0000,,then why do they accept the\Nclaims of other scientists?
Dialogue: 0,0:02:21.98,0:02:24.23,Default,,0000,0000,0000,,Why do they believe each other's claims?
Dialogue: 0,0:02:24.23,0:02:27.11,Default,,0000,0000,0000,,And should we believe those claims?
Dialogue: 0,0:02:27.11,0:02:30.17,Default,,0000,0000,0000,,So what I'd like to argue is yes, we should,
Dialogue: 0,0:02:30.17,0:02:33.05,Default,,0000,0000,0000,,but not for the reason that most of us think.
Dialogue: 0,0:02:33.05,0:02:35.20,Default,,0000,0000,0000,,Most of us were taught in school\Nthat the reason we should
Dialogue: 0,0:02:35.20,0:02:38.83,Default,,0000,0000,0000,,believe in science is because of the scientific method.
Dialogue: 0,0:02:38.83,0:02:41.21,Default,,0000,0000,0000,,We were taught that scientists follow a method
Dialogue: 0,0:02:41.21,0:02:43.82,Default,,0000,0000,0000,,and that this method guarantees
Dialogue: 0,0:02:43.82,0:02:46.20,Default,,0000,0000,0000,,the truth of their claims.
Dialogue: 0,0:02:46.20,0:02:48.72,Default,,0000,0000,0000,,The method that most of us were taught in school,
Dialogue: 0,0:02:48.72,0:02:51.30,Default,,0000,0000,0000,,we can call it the text book method,
Dialogue: 0,0:02:51.30,0:02:54.06,Default,,0000,0000,0000,,is the hypothetical deductive method.
Dialogue: 0,0:02:54.06,0:02:56.92,Default,,0000,0000,0000,,According to the standard\Nmodel, the textbook model,
Dialogue: 0,0:02:56.92,0:02:59.60,Default,,0000,0000,0000,,scientists develop hypotheses, they deduce
Dialogue: 0,0:02:59.60,0:03:02.12,Default,,0000,0000,0000,,the consequences for those hypotheses,
Dialogue: 0,0:03:02.12,0:03:03.84,Default,,0000,0000,0000,,and then they go out into the world and they say,
Dialogue: 0,0:03:03.84,0:03:06.72,Default,,0000,0000,0000,,"Okay, well are those consequences true?"
Dialogue: 0,0:03:06.72,0:03:09.43,Default,,0000,0000,0000,,Can we observe them taking\Nplace in the natural world?
Dialogue: 0,0:03:09.43,0:03:12.23,Default,,0000,0000,0000,,And if they are true, then the scientists say,
Dialogue: 0,0:03:12.23,0:03:15.43,Default,,0000,0000,0000,,"Great, we know the hypothesis is correct."
Dialogue: 0,0:03:15.43,0:03:17.31,Default,,0000,0000,0000,,So there are many famous examples in the history
Dialogue: 0,0:03:17.31,0:03:20.47,Default,,0000,0000,0000,,of science of scientists doing exactly this.
Dialogue: 0,0:03:20.47,0:03:22.10,Default,,0000,0000,0000,,One of the most famous examples
Dialogue: 0,0:03:22.10,0:03:24.59,Default,,0000,0000,0000,,comes from the work of Albert Einstein.
Dialogue: 0,0:03:24.59,0:03:26.98,Default,,0000,0000,0000,,When Einstein developed the\Ntheory of general relativity,
Dialogue: 0,0:03:26.98,0:03:29.20,Default,,0000,0000,0000,,one of the consequences of his theory
Dialogue: 0,0:03:29.20,0:03:32.10,Default,,0000,0000,0000,,was that space time wasn't just an empty void
Dialogue: 0,0:03:32.10,0:03:34.21,Default,,0000,0000,0000,,but that it actually had a fabric.
Dialogue: 0,0:03:34.21,0:03:36.03,Default,,0000,0000,0000,,And that that fabric was bent
Dialogue: 0,0:03:36.03,0:03:39.06,Default,,0000,0000,0000,,in the presence of massive objects like the sun.
Dialogue: 0,0:03:39.06,0:03:41.93,Default,,0000,0000,0000,,So if this theory were true then it meant that light
Dialogue: 0,0:03:41.93,0:03:43.46,Default,,0000,0000,0000,,as it passed the sun
Dialogue: 0,0:03:43.46,0:03:45.78,Default,,0000,0000,0000,,should actually be bent around it.
Dialogue: 0,0:03:45.78,0:03:47.98,Default,,0000,0000,0000,,That was a pretty startling prediction
Dialogue: 0,0:03:47.98,0:03:49.87,Default,,0000,0000,0000,,and it took a few years before scientists
Dialogue: 0,0:03:49.87,0:03:51.28,Default,,0000,0000,0000,,were able to test it.
Dialogue: 0,0:03:51.28,0:03:53.52,Default,,0000,0000,0000,,But they did test it in 1919,
Dialogue: 0,0:03:53.52,0:03:55.97,Default,,0000,0000,0000,,and lo and behold it turned out to be true.
Dialogue: 0,0:03:55.97,0:03:59.38,Default,,0000,0000,0000,,Starlight actually does bend\Nas it travels around the sun.
Dialogue: 0,0:03:59.38,0:04:01.76,Default,,0000,0000,0000,,This was a huge confirmation of the theory.
Dialogue: 0,0:04:01.76,0:04:03.42,Default,,0000,0000,0000,,It was considered proof of the truth
Dialogue: 0,0:04:03.42,0:04:05.07,Default,,0000,0000,0000,,of this radical new idea,
Dialogue: 0,0:04:05.07,0:04:06.68,Default,,0000,0000,0000,,and it was written up in many newspapers
Dialogue: 0,0:04:06.68,0:04:09.10,Default,,0000,0000,0000,,around the globe.
Dialogue: 0,0:04:09.10,0:04:11.85,Default,,0000,0000,0000,,Now sometimes this theory or this model
Dialogue: 0,0:04:11.85,0:04:14.87,Default,,0000,0000,0000,,is referred to as the deductive-nomological model.
Dialogue: 0,0:04:14.87,0:04:18.38,Default,,0000,0000,0000,,Meaning those academics\Nlike to make things complicated.
Dialogue: 0,0:04:18.38,0:04:23.74,Default,,0000,0000,0000,,But also because in the ideal case, it's about laws.
Dialogue: 0,0:04:23.74,0:04:26.37,Default,,0000,0000,0000,,So nomological means having to do with laws.
Dialogue: 0,0:04:26.37,0:04:29.60,Default,,0000,0000,0000,,And in the ideal case, the hypothesis isn't just an idea:
Dialogue: 0,0:04:29.60,0:04:31.81,Default,,0000,0000,0000,,ideally, it is a law of nature.
Dialogue: 0,0:04:31.81,0:04:34.15,Default,,0000,0000,0000,,Why does it matter that it is a law of nature?
Dialogue: 0,0:04:34.15,0:04:36.92,Default,,0000,0000,0000,,Because if it is a law, it can't be broken.
Dialogue: 0,0:04:36.92,0:04:38.96,Default,,0000,0000,0000,,If it's a law then it will always be true
Dialogue: 0,0:04:38.96,0:04:40.51,Default,,0000,0000,0000,,in all times and all places
Dialogue: 0,0:04:40.51,0:04:42.68,Default,,0000,0000,0000,,no matter what the circumstances are.
Dialogue: 0,0:04:42.68,0:04:45.89,Default,,0000,0000,0000,,And all of you know at least\None example of a famous law:
Dialogue: 0,0:04:45.89,0:04:49.27,Default,,0000,0000,0000,,Einstein's famous equation, E=MC2,
Dialogue: 0,0:04:49.27,0:04:51.19,Default,,0000,0000,0000,,which tells us what the relationship is
Dialogue: 0,0:04:51.19,0:04:53.70,Default,,0000,0000,0000,,between energy and mass.
Dialogue: 0,0:04:53.70,0:04:57.38,Default,,0000,0000,0000,,And that relationship is true no matter what.
Dialogue: 0,0:04:57.38,0:05:01.07,Default,,0000,0000,0000,,Now, it turns out though that there are \Nseveral problems with this model.
Dialogue: 0,0:05:01.07,0:05:04.42,Default,,0000,0000,0000,,The main problem is that it's wrong.
Dialogue: 0,0:05:04.42,0:05:08.24,Default,,0000,0000,0000,,It's just not true. [Laughter]
Dialogue: 0,0:05:08.24,0:05:11.25,Default,,0000,0000,0000,,And I'm going to talk about\Nthree reasons why it's wrong.
Dialogue: 0,0:05:11.25,0:05:13.43,Default,,0000,0000,0000,,So the first reason is a logical reason.
Dialogue: 0,0:05:13.43,0:05:17.54,Default,,0000,0000,0000,,It's the problem of the fallacy\Nof affirming the consequent.
Dialogue: 0,0:05:17.54,0:05:19.83,Default,,0000,0000,0000,,So that's another fancy academic way of saying
Dialogue: 0,0:05:19.83,0:05:22.85,Default,,0000,0000,0000,,that false theories can make true predictions.
Dialogue: 0,0:05:22.85,0:05:24.40,Default,,0000,0000,0000,,So just because the prediction comes true
Dialogue: 0,0:05:24.40,0:05:27.79,Default,,0000,0000,0000,,doesn't actually logically\Nprove that the theory is correct.
Dialogue: 0,0:05:27.79,0:05:31.82,Default,,0000,0000,0000,,And I have a good example of that too, \Nagain from the history of science.
Dialogue: 0,0:05:31.82,0:05:34.39,Default,,0000,0000,0000,,This is a picture of the Ptolemaic universe
Dialogue: 0,0:05:34.39,0:05:36.50,Default,,0000,0000,0000,,with the Earth at the center of the universe
Dialogue: 0,0:05:36.50,0:05:39.08,Default,,0000,0000,0000,,and The Sun and the planets going around it.
Dialogue: 0,0:05:39.08,0:05:41.10,Default,,0000,0000,0000,,The Ptolemaic model was believed
Dialogue: 0,0:05:41.10,0:05:44.39,Default,,0000,0000,0000,,by many very smart people for many centuries.
Dialogue: 0,0:05:44.39,0:05:46.13,Default,,0000,0000,0000,,Well, why?
Dialogue: 0,0:05:46.13,0:05:49.50,Default,,0000,0000,0000,,Well the answer is because it made \Nlots of predictions that came true.
Dialogue: 0,0:05:49.50,0:05:51.51,Default,,0000,0000,0000,,The Ptolemaic system enabled astronomers
Dialogue: 0,0:05:51.51,0:05:54.35,Default,,0000,0000,0000,,to make accurate predictions\Nof the motions of the planet,
Dialogue: 0,0:05:54.35,0:05:56.81,Default,,0000,0000,0000,,in fact more accurate predictions at first
Dialogue: 0,0:05:56.81,0:06:01.28,Default,,0000,0000,0000,,than the Copernican theory\Nwhich we now would say is true.
Dialogue: 0,0:06:01.28,0:06:03.87,Default,,0000,0000,0000,,So that's one problem with the textbook model.
Dialogue: 0,0:06:03.87,0:06:06.35,Default,,0000,0000,0000,,A second problem is a practical problem,
Dialogue: 0,0:06:06.35,0:06:09.52,Default,,0000,0000,0000,,and it's the problem of auxiliary hypotheses.
Dialogue: 0,0:06:09.52,0:06:12.36,Default,,0000,0000,0000,,Auxiliary hypotheses are assumptions
Dialogue: 0,0:06:12.36,0:06:14.15,Default,,0000,0000,0000,,that scientists are making
Dialogue: 0,0:06:14.15,0:06:17.74,Default,,0000,0000,0000,,that they may or may not even\Nbe aware that they're making.
Dialogue: 0,0:06:17.74,0:06:19.77,Default,,0000,0000,0000,,So an important example of this
Dialogue: 0,0:06:19.77,0:06:22.18,Default,,0000,0000,0000,,comes from the Copernican model,
Dialogue: 0,0:06:22.18,0:06:25.18,Default,,0000,0000,0000,,which ultimately replaced the Ptolemaic system.
Dialogue: 0,0:06:25.18,0:06:27.18,Default,,0000,0000,0000,,So when Nicolaus Copernicus said,
Dialogue: 0,0:06:27.18,0:06:29.74,Default,,0000,0000,0000,,actually the Earth is not the center of the universe,
Dialogue: 0,0:06:29.74,0:06:31.86,Default,,0000,0000,0000,,the sun is the center of the solar system,
Dialogue: 0,0:06:31.86,0:06:33.59,Default,,0000,0000,0000,,the Earth moves around the sun.
Dialogue: 0,0:06:33.59,0:06:36.82,Default,,0000,0000,0000,,Scientists said, well okay, Nicolaus, if that's true
Dialogue: 0,0:06:36.82,0:06:38.58,Default,,0000,0000,0000,,we ought to be able to detect the motion
Dialogue: 0,0:06:38.58,0:06:40.67,Default,,0000,0000,0000,,of the Earth around the sun.
Dialogue: 0,0:06:40.67,0:06:42.80,Default,,0000,0000,0000,,And so this slide here illustrates a concept
Dialogue: 0,0:06:42.80,0:06:44.73,Default,,0000,0000,0000,,known as stellar parallax.
Dialogue: 0,0:06:44.73,0:06:48.39,Default,,0000,0000,0000,,And astronomers said, if the Earth is moving
Dialogue: 0,0:06:48.39,0:06:51.76,Default,,0000,0000,0000,,and we look at a prominent star, let's say, Sirius
Dialogue: 0,0:06:51.76,0:06:53.75,Default,,0000,0000,0000,,—well I know I'm in Manhattan\Nso you guys can't see the stars,
Dialogue: 0,0:06:53.75,0:06:57.22,Default,,0000,0000,0000,,but imagine you're out in the country, \Nimagine you chose that rural life—
Dialogue: 0,0:06:57.22,0:07:00.52,Default,,0000,0000,0000,,and we look at a star in December, we see that star
Dialogue: 0,0:07:00.52,0:07:03.61,Default,,0000,0000,0000,,against the backdrop of distant stars.
Dialogue: 0,0:07:03.61,0:07:06.47,Default,,0000,0000,0000,,If we now make the same observation six months later
Dialogue: 0,0:07:06.47,0:07:09.99,Default,,0000,0000,0000,,when the Earth has moved to this position in June,
Dialogue: 0,0:07:09.99,0:07:14.28,Default,,0000,0000,0000,,we look at that same star and we see it against a different backdrop.
Dialogue: 0,0:07:14.28,0:07:18.67,Default,,0000,0000,0000,,That difference, that angular\Ndifference, is the stellar parallax.
Dialogue: 0,0:07:18.67,0:07:21.29,Default,,0000,0000,0000,,So this is the prediction that\Nthe Copernican model makes.
Dialogue: 0,0:07:21.29,0:07:23.37,Default,,0000,0000,0000,,Astronomers looked for the stellar parallax
Dialogue: 0,0:07:23.37,0:07:29.16,Default,,0000,0000,0000,,and they found nothing, nothing at all.
Dialogue: 0,0:07:29.16,0:07:32.78,Default,,0000,0000,0000,,And many people argued that this proved \Nthat the Copernican model was false.
Dialogue: 0,0:07:32.78,0:07:34.51,Default,,0000,0000,0000,,So what happened?
Dialogue: 0,0:07:34.51,0:07:37.10,Default,,0000,0000,0000,,Well in hindsight we can say that astronomers were making
Dialogue: 0,0:07:37.10,0:07:39.43,Default,,0000,0000,0000,,two auxiliary hypotheses, both of which
Dialogue: 0,0:07:39.43,0:07:42.07,Default,,0000,0000,0000,,we would now say were incorrect.
Dialogue: 0,0:07:42.07,0:07:45.64,Default,,0000,0000,0000,,The first was an assumption about the size of the Earth's orbit.
Dialogue: 0,0:07:45.64,0:07:48.69,Default,,0000,0000,0000,,Astronomers were assuming that the Earth's orbit was large
Dialogue: 0,0:07:48.69,0:07:51.26,Default,,0000,0000,0000,,relative to the distance of the stars.
Dialogue: 0,0:07:51.26,0:07:53.72,Default,,0000,0000,0000,,Today we would draw the picture more like this,
Dialogue: 0,0:07:53.72,0:07:55.26,Default,,0000,0000,0000,,this comes from NASA,
Dialogue: 0,0:07:55.26,0:07:57.56,Default,,0000,0000,0000,,and you see the Earth's orbit is actually quite small.
Dialogue: 0,0:07:57.56,0:08:00.60,Default,,0000,0000,0000,,In fact, it's actually much\Nsmaller even than shown here.
Dialogue: 0,0:08:00.60,0:08:01.93,Default,,0000,0000,0000,,The stellar parallax therefore,
Dialogue: 0,0:08:01.93,0:08:05.64,Default,,0000,0000,0000,,is very small and actually very hard to detect.
Dialogue: 0,0:08:05.64,0:08:07.42,Default,,0000,0000,0000,,And that leads to the second reason
Dialogue: 0,0:08:07.42,0:08:09.09,Default,,0000,0000,0000,,why the prediction didn't work,
Dialogue: 0,0:08:09.09,0:08:11.32,Default,,0000,0000,0000,,because scientists were also assuming
Dialogue: 0,0:08:11.32,0:08:14.36,Default,,0000,0000,0000,,that the telescopes they had were sensitive enough
Dialogue: 0,0:08:14.36,0:08:16.24,Default,,0000,0000,0000,,to detect the parallax.
Dialogue: 0,0:08:16.24,0:08:18.41,Default,,0000,0000,0000,,And that turned out not to be true.
Dialogue: 0,0:08:18.41,0:08:20.38,Default,,0000,0000,0000,,It wasn't until the 19th century
Dialogue: 0,0:08:20.38,0:08:22.05,Default,,0000,0000,0000,,that scientists were able to detect
Dialogue: 0,0:08:22.05,0:08:24.16,Default,,0000,0000,0000,,the stellar parallax.
Dialogue: 0,0:08:24.16,0:08:26.79,Default,,0000,0000,0000,,So, there's a third problem as well.
Dialogue: 0,0:08:26.79,0:08:29.06,Default,,0000,0000,0000,,The third problem is simply a factual problem,
Dialogue: 0,0:08:29.06,0:08:31.98,Default,,0000,0000,0000,,that a lot of science doesn't fit the textbook model.
Dialogue: 0,0:08:31.98,0:08:34.33,Default,,0000,0000,0000,,A lot of science isn't deductive at all,
Dialogue: 0,0:08:34.33,0:08:36.22,Default,,0000,0000,0000,,it's actually inductive.
Dialogue: 0,0:08:36.22,0:08:38.51,Default,,0000,0000,0000,,And by that we mean that scientists don't necessarily
Dialogue: 0,0:08:38.51,0:08:41.35,Default,,0000,0000,0000,,start with theories and hypotheses, often they just
Dialogue: 0,0:08:41.35,0:08:44.99,Default,,0000,0000,0000,,start with observations of stuff going on in the world.
Dialogue: 0,0:08:44.99,0:08:47.60,Default,,0000,0000,0000,,And the most famous example\Nof that is one of the most
Dialogue: 0,0:08:47.60,0:08:50.77,Default,,0000,0000,0000,,famous scientists who ever lived, Charles Darwin.
Dialogue: 0,0:08:50.77,0:08:53.76,Default,,0000,0000,0000,,When Darwin went out as a young \Nman on the voyage of the Beagle,
Dialogue: 0,0:08:53.76,0:08:57.43,Default,,0000,0000,0000,,he didn't have a hypothesis, he didn't have a theory.
Dialogue: 0,0:08:57.43,0:09:00.69,Default,,0000,0000,0000,,He just knew that he wanted\Nto have a career as a scientist
Dialogue: 0,0:09:00.69,0:09:02.74,Default,,0000,0000,0000,,and he started to collect data.
Dialogue: 0,0:09:02.74,0:09:04.70,Default,,0000,0000,0000,,Mainly he knew that he hated medicine
Dialogue: 0,0:09:04.70,0:09:06.99,Default,,0000,0000,0000,,because the sight of blood made him sick so
Dialogue: 0,0:09:06.99,0:09:09.40,Default,,0000,0000,0000,,he had to have an alternative career path.
Dialogue: 0,0:09:09.40,0:09:11.50,Default,,0000,0000,0000,,So he started collecting data.
Dialogue: 0,0:09:11.50,0:09:14.64,Default,,0000,0000,0000,,And he collected many things including his famous finches.
Dialogue: 0,0:09:14.64,0:09:16.92,Default,,0000,0000,0000,,When he collected these finches,\Nhe threw them in a bag
Dialogue: 0,0:09:16.92,0:09:19.52,Default,,0000,0000,0000,,and he had no idea what they meant.
Dialogue: 0,0:09:19.52,0:09:21.41,Default,,0000,0000,0000,,Many years later back in London,
Dialogue: 0,0:09:21.41,0:09:23.62,Default,,0000,0000,0000,,Darwin looked at his data again and began
Dialogue: 0,0:09:23.62,0:09:26.11,Default,,0000,0000,0000,,to develop an explanation,
Dialogue: 0,0:09:26.11,0:09:29.56,Default,,0000,0000,0000,,and that explanation was the\Ntheory of natural selection.
Dialogue: 0,0:09:29.56,0:09:31.39,Default,,0000,0000,0000,,Besides inductive science,
Dialogue: 0,0:09:31.39,0:09:34.58,Default,,0000,0000,0000,,scientists also often participate in modeling.
Dialogue: 0,0:09:34.58,0:09:36.87,Default,,0000,0000,0000,,One of the things scientists want to do in life
Dialogue: 0,0:09:36.87,0:09:39.06,Default,,0000,0000,0000,,is to explain the causes of things.
Dialogue: 0,0:09:39.06,0:09:40.85,Default,,0000,0000,0000,,And how do we do that?
Dialogue: 0,0:09:40.85,0:09:43.07,Default,,0000,0000,0000,,Well, one way you can do it is to build a model
Dialogue: 0,0:09:43.07,0:09:44.87,Default,,0000,0000,0000,,that tests an idea.
Dialogue: 0,0:09:44.87,0:09:46.66,Default,,0000,0000,0000,,So this is a picture of Henry Cadell,
Dialogue: 0,0:09:46.66,0:09:49.12,Default,,0000,0000,0000,,who was a Scottish geologist in the 19th century.
Dialogue: 0,0:09:49.12,0:09:50.91,Default,,0000,0000,0000,,You can tell he's Scottish because he's wearing
Dialogue: 0,0:09:50.91,0:09:53.06,Default,,0000,0000,0000,,a deerstalker cap and Wellington boots.
Dialogue: 0,0:09:53.06,0:09:55.30,Default,,0000,0000,0000,,[Laughter]
Dialogue: 0,0:09:55.30,0:09:57.06,Default,,0000,0000,0000,,And Cadell wanted to answer the question,
Dialogue: 0,0:09:57.06,0:09:58.75,Default,,0000,0000,0000,,how are mountains formed?
Dialogue: 0,0:09:58.75,0:10:00.24,Default,,0000,0000,0000,,And one of the things he had observed
Dialogue: 0,0:10:00.24,0:10:02.91,Default,,0000,0000,0000,,is that if you look at mountains\Nlike the Appalachians,
Dialogue: 0,0:10:02.91,0:10:04.74,Default,,0000,0000,0000,,you often find that the rocks in them
Dialogue: 0,0:10:04.74,0:10:06.06,Default,,0000,0000,0000,,are folded,
Dialogue: 0,0:10:06.06,0:10:07.64,Default,,0000,0000,0000,,and they're folded in a particular way,
Dialogue: 0,0:10:07.64,0:10:09.02,Default,,0000,0000,0000,,which suggested to him
Dialogue: 0,0:10:09.02,0:10:11.97,Default,,0000,0000,0000,,that they were actually being\Ncompressed from the side.
Dialogue: 0,0:10:11.97,0:10:14.16,Default,,0000,0000,0000,,And this idea would later play a major role
Dialogue: 0,0:10:14.16,0:10:16.50,Default,,0000,0000,0000,,in discussions of continental drift.
Dialogue: 0,0:10:16.50,0:10:18.96,Default,,0000,0000,0000,,So he built this model, this crazy contraption
Dialogue: 0,0:10:18.96,0:10:21.27,Default,,0000,0000,0000,,with levers and wood and here's his wheelbarrow,
Dialogue: 0,0:10:21.27,0:10:23.04,Default,,0000,0000,0000,,buckets, a big sledgehammer.
Dialogue: 0,0:10:23.04,0:10:25.39,Default,,0000,0000,0000,,I don't know why he's got the Wellington boots.
Dialogue: 0,0:10:25.39,0:10:27.16,Default,,0000,0000,0000,,Maybe it's going to rain.
Dialogue: 0,0:10:27.16,0:10:30.01,Default,,0000,0000,0000,,And he created this physical model in order
Dialogue: 0,0:10:30.01,0:10:34.52,Default,,0000,0000,0000,,to demonstrate that you could in fact create
Dialogue: 0,0:10:34.52,0:10:37.14,Default,,0000,0000,0000,,patterns in rocks, or at least in this case in mud,
Dialogue: 0,0:10:37.14,0:10:39.28,Default,,0000,0000,0000,,that looked a lot like mountains
Dialogue: 0,0:10:39.28,0:10:41.11,Default,,0000,0000,0000,,if you compressed them from the side.
Dialogue: 0,0:10:41.11,0:10:44.48,Default,,0000,0000,0000,,So it was an argument about\Nthe cause of mountains.
Dialogue: 0,0:10:44.48,0:10:47.44,Default,,0000,0000,0000,,Nowadays, most scientists prefer to work inside,
Dialogue: 0,0:10:47.44,0:10:50.04,Default,,0000,0000,0000,,so they don't build physical models so much
Dialogue: 0,0:10:50.04,0:10:52.37,Default,,0000,0000,0000,,as to make computer simulations.
Dialogue: 0,0:10:52.37,0:10:55.10,Default,,0000,0000,0000,,But a computer simulation is a kind of a model.
Dialogue: 0,0:10:55.10,0:10:57.24,Default,,0000,0000,0000,,It's a model that's made with mathematics,
Dialogue: 0,0:10:57.24,0:10:59.88,Default,,0000,0000,0000,,and like the physical models of the 19th century,
Dialogue: 0,0:10:59.88,0:11:03.97,Default,,0000,0000,0000,,it's very important for thinking about causes.
Dialogue: 0,0:11:03.97,0:11:06.51,Default,,0000,0000,0000,,So one of the big questions\Nto do with climate change,
Dialogue: 0,0:11:06.51,0:11:08.37,Default,,0000,0000,0000,,we have tremendous amounts of evidence
Dialogue: 0,0:11:08.37,0:11:10.41,Default,,0000,0000,0000,,that the earth is warming up.
Dialogue: 0,0:11:10.41,0:11:12.64,Default,,0000,0000,0000,,This slide here, the black line shows
Dialogue: 0,0:11:12.64,0:11:14.76,Default,,0000,0000,0000,,the measurements that scientists have taken
Dialogue: 0,0:11:14.76,0:11:16.90,Default,,0000,0000,0000,,for the last 150 years
Dialogue: 0,0:11:16.90,0:11:18.30,Default,,0000,0000,0000,,showing that the earth's temperature
Dialogue: 0,0:11:18.30,0:11:19.92,Default,,0000,0000,0000,,has steadily increased,
Dialogue: 0,0:11:19.92,0:11:22.83,Default,,0000,0000,0000,,and you can see in particular\Nthat in the last 50 years
Dialogue: 0,0:11:22.83,0:11:24.68,Default,,0000,0000,0000,,there's been this dramatic increase
Dialogue: 0,0:11:24.68,0:11:26.84,Default,,0000,0000,0000,,of nearly one degree Centigrade,
Dialogue: 0,0:11:26.84,0:11:29.19,Default,,0000,0000,0000,,or almost two degrees Fahrenheit.
Dialogue: 0,0:11:29.19,0:11:31.84,Default,,0000,0000,0000,,So what, though, is driving that change?
Dialogue: 0,0:11:31.84,0:11:34.05,Default,,0000,0000,0000,,How can we know what's causing
Dialogue: 0,0:11:34.05,0:11:35.76,Default,,0000,0000,0000,,the observed warming?
Dialogue: 0,0:11:35.76,0:11:37.30,Default,,0000,0000,0000,,Well, scientists can model it
Dialogue: 0,0:11:37.30,0:11:39.43,Default,,0000,0000,0000,,using a computer simulation.
Dialogue: 0,0:11:39.43,0:11:42.38,Default,,0000,0000,0000,,So this diagram illustrates a computer simulation
Dialogue: 0,0:11:42.38,0:11:44.49,Default,,0000,0000,0000,,that has looked at all the different factors
Dialogue: 0,0:11:44.49,0:11:46.76,Default,,0000,0000,0000,,that we know can influence the earth's climate,
Dialogue: 0,0:11:46.76,0:11:49.67,Default,,0000,0000,0000,,so sulfate particles from air pollution,
Dialogue: 0,0:11:49.67,0:11:53.19,Default,,0000,0000,0000,,volcanic dust from volcanic eruptions,
Dialogue: 0,0:11:53.19,0:11:54.93,Default,,0000,0000,0000,,changes in solar radiation,
Dialogue: 0,0:11:54.93,0:11:57.59,Default,,0000,0000,0000,,and, of course, greenhouse gases.
Dialogue: 0,0:11:57.59,0:11:59.15,Default,,0000,0000,0000,,And they asked the question,
Dialogue: 0,0:11:59.15,0:12:02.60,Default,,0000,0000,0000,,what set of variables put into a model
Dialogue: 0,0:12:02.60,0:12:06.08,Default,,0000,0000,0000,,will reproduce what we actually see in real life?
Dialogue: 0,0:12:06.08,0:12:08.18,Default,,0000,0000,0000,,So here is the real life in black.
Dialogue: 0,0:12:08.18,0:12:10.29,Default,,0000,0000,0000,,Here's the model in this light grey,
Dialogue: 0,0:12:10.29,0:12:12.01,Default,,0000,0000,0000,,and the answer is
Dialogue: 0,0:12:12.01,0:12:16.29,Default,,0000,0000,0000,,a model that includes, it's the answer E on that SAT,
Dialogue: 0,0:12:16.29,0:12:18.55,Default,,0000,0000,0000,,all of the above.
Dialogue: 0,0:12:18.55,0:12:20.16,Default,,0000,0000,0000,,The only way you can reproduce
Dialogue: 0,0:12:20.16,0:12:21.81,Default,,0000,0000,0000,,the observed temperature measurements
Dialogue: 0,0:12:21.81,0:12:23.90,Default,,0000,0000,0000,,is with all of these things put together,
Dialogue: 0,0:12:23.90,0:12:25.98,Default,,0000,0000,0000,,including greenhouse gases,
Dialogue: 0,0:12:25.98,0:12:28.06,Default,,0000,0000,0000,,and in particular you can see that the increase
Dialogue: 0,0:12:28.06,0:12:29.96,Default,,0000,0000,0000,,in greenhouse gases tracks
Dialogue: 0,0:12:29.96,0:12:32.08,Default,,0000,0000,0000,,this very dramatic increase in temperature
Dialogue: 0,0:12:32.08,0:12:34.02,Default,,0000,0000,0000,,over the last 50 years.
Dialogue: 0,0:12:34.02,0:12:36.48,Default,,0000,0000,0000,,And so this is why climate scientists say
Dialogue: 0,0:12:36.48,0:12:39.33,Default,,0000,0000,0000,,it's not just that we know that\Nclimate change is happening,
Dialogue: 0,0:12:39.33,0:12:42.22,Default,,0000,0000,0000,,we know that greenhouse gases are a major part
Dialogue: 0,0:12:42.22,0:12:45.07,Default,,0000,0000,0000,,of the reason why.
Dialogue: 0,0:12:45.07,0:12:47.23,Default,,0000,0000,0000,,So now because there all these different things
Dialogue: 0,0:12:47.23,0:12:48.85,Default,,0000,0000,0000,,that scientists do,
Dialogue: 0,0:12:48.85,0:12:51.82,Default,,0000,0000,0000,,the philosopher Paul Feyerabend famously said,
Dialogue: 0,0:12:51.82,0:12:53.80,Default,,0000,0000,0000,,"The only principle in science
Dialogue: 0,0:12:53.80,0:12:57.100,Default,,0000,0000,0000,,that doesn't inhibit progress is: anything goes."
Dialogue: 0,0:12:57.100,0:13:00.65,Default,,0000,0000,0000,,Now this quotation has often\Nbeen taken out of context,
Dialogue: 0,0:13:00.65,0:13:02.74,Default,,0000,0000,0000,,because Feyerabend was not actually saying
Dialogue: 0,0:13:02.74,0:13:04.34,Default,,0000,0000,0000,,that in science anything goes.
Dialogue: 0,0:13:04.34,0:13:06.13,Default,,0000,0000,0000,,What he was saying was,
Dialogue: 0,0:13:06.13,0:13:08.01,Default,,0000,0000,0000,,actually the full quotation is,
Dialogue: 0,0:13:08.01,0:13:10.02,Default,,0000,0000,0000,,"If you press me to say
Dialogue: 0,0:13:10.02,0:13:11.77,Default,,0000,0000,0000,,what is the method of science,
Dialogue: 0,0:13:11.77,0:13:15.46,Default,,0000,0000,0000,,I would have to say: anything goes."
Dialogue: 0,0:13:15.46,0:13:16.70,Default,,0000,0000,0000,,What he was trying to say
Dialogue: 0,0:13:16.70,0:13:19.04,Default,,0000,0000,0000,,is that scientists do a lot of different things.
Dialogue: 0,0:13:19.04,0:13:21.48,Default,,0000,0000,0000,,Scientists are creative.
Dialogue: 0,0:13:21.48,0:13:23.76,Default,,0000,0000,0000,,But then this pushes the question back:
Dialogue: 0,0:13:23.76,0:13:26.60,Default,,0000,0000,0000,,if scientists don't use a single method,
Dialogue: 0,0:13:26.60,0:13:28.76,Default,,0000,0000,0000,,then how do they decide
Dialogue: 0,0:13:28.76,0:13:30.41,Default,,0000,0000,0000,,what's right and what's wrong?
Dialogue: 0,0:13:30.41,0:13:32.10,Default,,0000,0000,0000,,And who judges?
Dialogue: 0,0:13:32.10,0:13:34.08,Default,,0000,0000,0000,,And the answer is, scientists judge,
Dialogue: 0,0:13:34.08,0:13:37.30,Default,,0000,0000,0000,,and they judge by judging evidence.
Dialogue: 0,0:13:37.30,0:13:40.30,Default,,0000,0000,0000,,Scientists collect evidence in many different ways,
Dialogue: 0,0:13:40.30,0:13:42.37,Default,,0000,0000,0000,,but however they collect it,
Dialogue: 0,0:13:42.37,0:13:44.92,Default,,0000,0000,0000,,they have to subject it to scrutiny.
Dialogue: 0,0:13:44.92,0:13:47.23,Default,,0000,0000,0000,,And this led to sociologist Robert Merton
Dialogue: 0,0:13:47.23,0:13:49.55,Default,,0000,0000,0000,,to focus on this question of how scientists
Dialogue: 0,0:13:49.55,0:13:51.39,Default,,0000,0000,0000,,scrutinize data and evidence,
Dialogue: 0,0:13:51.39,0:13:53.80,Default,,0000,0000,0000,,and he said they do it in a way he called
Dialogue: 0,0:13:53.80,0:13:55.97,Default,,0000,0000,0000,,"organized skepticism."
Dialogue: 0,0:13:55.97,0:13:57.80,Default,,0000,0000,0000,,And by that he meant it's organized
Dialogue: 0,0:13:57.80,0:13:59.52,Default,,0000,0000,0000,,because they do it collectively,
Dialogue: 0,0:13:59.52,0:14:01.24,Default,,0000,0000,0000,,they do it as a group,
Dialogue: 0,0:14:01.24,0:14:03.77,Default,,0000,0000,0000,,and skepticism, because they do it from a position
Dialogue: 0,0:14:03.77,0:14:05.32,Default,,0000,0000,0000,,of distrust.
Dialogue: 0,0:14:05.32,0:14:07.04,Default,,0000,0000,0000,,That is to say, the burden of proof
Dialogue: 0,0:14:07.04,0:14:09.70,Default,,0000,0000,0000,,is on the person with a novel claim.
Dialogue: 0,0:14:09.70,0:14:12.91,Default,,0000,0000,0000,,And in this sense, science\Nis intrinsically conservative.
Dialogue: 0,0:14:12.91,0:14:15.41,Default,,0000,0000,0000,,It's quite hard to persuade the scientific community
Dialogue: 0,0:14:15.41,0:14:19.19,Default,,0000,0000,0000,,to say, "Yes, we know something, this is true."
Dialogue: 0,0:14:19.19,0:14:21.44,Default,,0000,0000,0000,,So despite the popularity of the concept
Dialogue: 0,0:14:21.44,0:14:23.09,Default,,0000,0000,0000,,of paradigm shifts,
Dialogue: 0,0:14:23.09,0:14:24.45,Default,,0000,0000,0000,,what we find is that actually,
Dialogue: 0,0:14:24.45,0:14:26.70,Default,,0000,0000,0000,,really major changes in scientific thinking
Dialogue: 0,0:14:26.70,0:14:31.12,Default,,0000,0000,0000,,are relatively rare in the history of science.
Dialogue: 0,0:14:31.12,0:14:34.64,Default,,0000,0000,0000,,So finally that brings us to one more idea:
Dialogue: 0,0:14:34.64,0:14:38.46,Default,,0000,0000,0000,,if scientists judge evidence collectively,
Dialogue: 0,0:14:38.46,0:14:40.97,Default,,0000,0000,0000,,this has led historians to focus on the question
Dialogue: 0,0:14:40.97,0:14:42.46,Default,,0000,0000,0000,,of consensus,
Dialogue: 0,0:14:42.46,0:14:44.23,Default,,0000,0000,0000,,and to say that at the end of the day,
Dialogue: 0,0:14:44.23,0:14:46.06,Default,,0000,0000,0000,,what science is,
Dialogue: 0,0:14:46.06,0:14:47.82,Default,,0000,0000,0000,,what scientific knowledge is,
Dialogue: 0,0:14:47.82,0:14:51.12,Default,,0000,0000,0000,,is the consensus of the scientific experts
Dialogue: 0,0:14:51.12,0:14:53.47,Default,,0000,0000,0000,,who through this process of organized scrutiny,
Dialogue: 0,0:14:53.47,0:14:55.21,Default,,0000,0000,0000,,collective scrutiny,
Dialogue: 0,0:14:55.21,0:14:56.97,Default,,0000,0000,0000,,have judged the evidence
Dialogue: 0,0:14:56.97,0:14:59.58,Default,,0000,0000,0000,,and come to a conclusion about it,
Dialogue: 0,0:14:59.58,0:15:02.23,Default,,0000,0000,0000,,either yea or nay.
Dialogue: 0,0:15:02.23,0:15:03.86,Default,,0000,0000,0000,,So we can think of scientific knowledge
Dialogue: 0,0:15:03.86,0:15:05.89,Default,,0000,0000,0000,,as a consensus of experts.
Dialogue: 0,0:15:05.89,0:15:07.48,Default,,0000,0000,0000,,We can also think of science as being
Dialogue: 0,0:15:07.48,0:15:09.29,Default,,0000,0000,0000,,a kind of a jury,
Dialogue: 0,0:15:09.29,0:15:11.71,Default,,0000,0000,0000,,except it's a very special kind of jury.
Dialogue: 0,0:15:11.71,0:15:13.62,Default,,0000,0000,0000,,It's not a jury of your peers,
Dialogue: 0,0:15:13.62,0:15:16.18,Default,,0000,0000,0000,,it's a jury of geeks.
Dialogue: 0,0:15:16.18,0:15:19.54,Default,,0000,0000,0000,,It's a jury of men and women with Ph.Ds,
Dialogue: 0,0:15:19.54,0:15:21.73,Default,,0000,0000,0000,,and unlike a conventional jury,
Dialogue: 0,0:15:21.73,0:15:23.54,Default,,0000,0000,0000,,which has only two choices,
Dialogue: 0,0:15:23.54,0:15:25.90,Default,,0000,0000,0000,,guilty or not guilty,
Dialogue: 0,0:15:25.90,0:15:29.47,Default,,0000,0000,0000,,the scientific jury actually has a number of choices.
Dialogue: 0,0:15:29.47,0:15:32.10,Default,,0000,0000,0000,,Scientists can say yes, something's true.
Dialogue: 0,0:15:32.10,0:15:35.08,Default,,0000,0000,0000,,Scientists can say no, it's false.
Dialogue: 0,0:15:35.08,0:15:37.31,Default,,0000,0000,0000,,Or, they can say, well it might be true
Dialogue: 0,0:15:37.31,0:15:40.32,Default,,0000,0000,0000,,but we need to work more\Nand collect more evidence.
Dialogue: 0,0:15:40.32,0:15:42.01,Default,,0000,0000,0000,,Or, they can say it might be true,
Dialogue: 0,0:15:42.01,0:15:43.65,Default,,0000,0000,0000,,but we don't know how to answer the question
Dialogue: 0,0:15:43.65,0:15:45.03,Default,,0000,0000,0000,,and we're going to put it aside
Dialogue: 0,0:15:45.03,0:15:47.88,Default,,0000,0000,0000,,and maybe we'll come back to it later.
Dialogue: 0,0:15:47.88,0:15:51.92,Default,,0000,0000,0000,,That's what scientists call "intractable."
Dialogue: 0,0:15:51.92,0:15:54.81,Default,,0000,0000,0000,,But this leads us to one final problem:
Dialogue: 0,0:15:54.81,0:15:57.30,Default,,0000,0000,0000,,if science is what scientists say it is,
Dialogue: 0,0:15:57.30,0:16:00.08,Default,,0000,0000,0000,,then isn't that just an appeal to authority?
Dialogue: 0,0:16:00.08,0:16:01.35,Default,,0000,0000,0000,,And weren't we all taught in school
Dialogue: 0,0:16:01.35,0:16:04.46,Default,,0000,0000,0000,,that the appeal to authority is a logical fallacy?
Dialogue: 0,0:16:04.46,0:16:07.37,Default,,0000,0000,0000,,Well, here's the paradox of modern science,
Dialogue: 0,0:16:07.37,0:16:09.60,Default,,0000,0000,0000,,the paradox of the conclusions I think historians
Dialogue: 0,0:16:09.60,0:16:12.48,Default,,0000,0000,0000,,and philosophers and sociologists have come to,
Dialogue: 0,0:16:12.48,0:16:15.68,Default,,0000,0000,0000,,that actually science is the appeal to authority,
Dialogue: 0,0:16:15.68,0:16:19.51,Default,,0000,0000,0000,,but it's not the authority of the individual,
Dialogue: 0,0:16:19.51,0:16:21.92,Default,,0000,0000,0000,,no matter how smart that individual is,
Dialogue: 0,0:16:21.92,0:16:25.66,Default,,0000,0000,0000,,like Plato or Socrates or Einstein.
Dialogue: 0,0:16:25.66,0:16:28.66,Default,,0000,0000,0000,,It's the authority of the collective community.
Dialogue: 0,0:16:28.66,0:16:31.84,Default,,0000,0000,0000,,You can think of it is a kind of wisdom of the crowd,
Dialogue: 0,0:16:31.84,0:16:35.29,Default,,0000,0000,0000,,but a very special kind of crowd.
Dialogue: 0,0:16:35.29,0:16:37.65,Default,,0000,0000,0000,,Science does appeal to authority,
Dialogue: 0,0:16:37.65,0:16:40.19,Default,,0000,0000,0000,,but it's not based on any individual,
Dialogue: 0,0:16:40.19,0:16:42.55,Default,,0000,0000,0000,,no matter how smart that individual may be.
Dialogue: 0,0:16:42.55,0:16:44.53,Default,,0000,0000,0000,,It's based on the collective wisdom,
Dialogue: 0,0:16:44.53,0:16:47.04,Default,,0000,0000,0000,,the collective knowledge, the collective work,
Dialogue: 0,0:16:47.04,0:16:48.77,Default,,0000,0000,0000,,of all of the scientists who have worked
Dialogue: 0,0:16:48.77,0:16:51.60,Default,,0000,0000,0000,,on a particular problem.
Dialogue: 0,0:16:51.60,0:16:54.57,Default,,0000,0000,0000,,Scientists have a kind of culture of collective distrust,
Dialogue: 0,0:16:54.57,0:16:56.33,Default,,0000,0000,0000,,this "show me" culture,
Dialogue: 0,0:16:56.33,0:16:58.33,Default,,0000,0000,0000,,illustrated by this nice woman here
Dialogue: 0,0:16:58.33,0:17:01.28,Default,,0000,0000,0000,,showing her colleagues her evidence.
Dialogue: 0,0:17:01.28,0:17:03.51,Default,,0000,0000,0000,,Of course, these people don't\Nreally look like scientists,
Dialogue: 0,0:17:03.51,0:17:05.75,Default,,0000,0000,0000,,because they're much too happy.
Dialogue: 0,0:17:05.75,0:17:09.62,Default,,0000,0000,0000,,[Laughter]
Dialogue: 0,0:17:09.62,0:17:13.07,Default,,0000,0000,0000,,Okay, so that brings me to my final point.
Dialogue: 0,0:17:13.07,0:17:16.34,Default,,0000,0000,0000,,Most of us get up in the morning.
Dialogue: 0,0:17:16.34,0:17:17.98,Default,,0000,0000,0000,,Most of us trust our cars.
Dialogue: 0,0:17:17.98,0:17:19.45,Default,,0000,0000,0000,,Well, see, now I'm thinking, I'm in Manhattan,
Dialogue: 0,0:17:19.45,0:17:20.83,Default,,0000,0000,0000,,this is a bad analogy,
Dialogue: 0,0:17:20.83,0:17:23.54,Default,,0000,0000,0000,,but most Americans who don't live in Manhattan
Dialogue: 0,0:17:23.54,0:17:25.09,Default,,0000,0000,0000,,get up in the morning and get in their cars
Dialogue: 0,0:17:25.09,0:17:27.69,Default,,0000,0000,0000,,and turn on that ignition, and their cars work,
Dialogue: 0,0:17:27.69,0:17:29.60,Default,,0000,0000,0000,,and they work incredibly well.
Dialogue: 0,0:17:29.60,0:17:32.48,Default,,0000,0000,0000,,The modern automobile hardly ever breaks down.
Dialogue: 0,0:17:32.48,0:17:35.36,Default,,0000,0000,0000,,So why is that? Why do cars work so well?
Dialogue: 0,0:17:35.36,0:17:37.45,Default,,0000,0000,0000,,It's not because of the genius of Henry Ford
Dialogue: 0,0:17:37.45,0:17:41.11,Default,,0000,0000,0000,,or Carl Benz or even Elon Musk.
Dialogue: 0,0:17:41.11,0:17:42.90,Default,,0000,0000,0000,,It's because the modern automobile
Dialogue: 0,0:17:42.90,0:17:47.94,Default,,0000,0000,0000,,is the product of more than 100 years of work
Dialogue: 0,0:17:47.94,0:17:49.67,Default,,0000,0000,0000,,by hundreds and thousands
Dialogue: 0,0:17:49.67,0:17:51.14,Default,,0000,0000,0000,,and tens of thousands of people.
Dialogue: 0,0:17:51.14,0:17:53.23,Default,,0000,0000,0000,,The modern automobile is the product
Dialogue: 0,0:17:53.23,0:17:55.62,Default,,0000,0000,0000,,of the collected work and wisdom and experience
Dialogue: 0,0:17:55.62,0:17:58.21,Default,,0000,0000,0000,,of every man and woman who has ever worked
Dialogue: 0,0:17:58.21,0:17:59.95,Default,,0000,0000,0000,,on a car,
Dialogue: 0,0:17:59.95,0:18:02.64,Default,,0000,0000,0000,,and the reliability of the technology is the result
Dialogue: 0,0:18:02.64,0:18:05.44,Default,,0000,0000,0000,,of that accumulated effort.
Dialogue: 0,0:18:05.44,0:18:08.16,Default,,0000,0000,0000,,We benefit not just from the genius of Benz
Dialogue: 0,0:18:08.16,0:18:09.55,Default,,0000,0000,0000,,and Ford and Musk
Dialogue: 0,0:18:09.55,0:18:12.14,Default,,0000,0000,0000,,but from the collective intelligence and hard work
Dialogue: 0,0:18:12.14,0:18:14.06,Default,,0000,0000,0000,,of all of the people who have worked
Dialogue: 0,0:18:14.06,0:18:16.04,Default,,0000,0000,0000,,on the modern car.
Dialogue: 0,0:18:16.04,0:18:18.18,Default,,0000,0000,0000,,And the same is true of science,
Dialogue: 0,0:18:18.18,0:18:20.74,Default,,0000,0000,0000,,only science is even older.
Dialogue: 0,0:18:20.74,0:18:23.53,Default,,0000,0000,0000,,Our basis for trust in science is actually the same
Dialogue: 0,0:18:23.53,0:18:26.16,Default,,0000,0000,0000,,as our basis in trust in technology,
Dialogue: 0,0:18:26.16,0:18:29.93,Default,,0000,0000,0000,,and the same as our basis for trust in anything,
Dialogue: 0,0:18:29.93,0:18:32.45,Default,,0000,0000,0000,,namely, experience.
Dialogue: 0,0:18:32.45,0:18:34.25,Default,,0000,0000,0000,,But it shouldn't be blind trust
Dialogue: 0,0:18:34.25,0:18:37.30,Default,,0000,0000,0000,,any more than we would have blind trust in anything.
Dialogue: 0,0:18:37.30,0:18:39.61,Default,,0000,0000,0000,,Our trust in science, like science itself,
Dialogue: 0,0:18:39.61,0:18:41.66,Default,,0000,0000,0000,,should be based on evidence,
Dialogue: 0,0:18:41.66,0:18:43.20,Default,,0000,0000,0000,,and that means that scientists
Dialogue: 0,0:18:43.20,0:18:45.14,Default,,0000,0000,0000,,have to become better communicators.
Dialogue: 0,0:18:45.14,0:18:47.98,Default,,0000,0000,0000,,They have to explain to us not just what they know
Dialogue: 0,0:18:47.98,0:18:50.12,Default,,0000,0000,0000,,but how they know it,
Dialogue: 0,0:18:50.12,0:18:53.61,Default,,0000,0000,0000,,and it means that we have\Nto become better listeners.
Dialogue: 0,0:18:53.61,0:18:55.44,Default,,0000,0000,0000,,Thank you very much.
Dialogue: 0,0:18:55.44,0:18:57.45,Default,,0000,0000,0000,,(Applause)