00:00:00.000 Hello again. So chapter two now from the beginning of infinity it's called
00:00:09.200 closer to reality. It's a much shorter chapter and so that's helpful for me
00:00:14.240 because I don't have as much time today. So we'll read through our parts of it
00:00:19.360 once more and I might make a few comments along the way. It's called
00:00:25.160 closer to reality because David is writing about how it is that we come to
00:00:31.520 understand reality better. In other words come closer to it, closer to our
00:00:36.080 understanding of it. Through our science and technology these things even though
00:00:43.960 they might appear that first glance to put things between us and that
00:00:51.280 reality they're the very things that help bring us closer to the reality and so
00:00:57.400 he makes a very powerful point about that. He begins by providing a personal
00:01:05.200 anecdote and this is where as a graduate student he's talking about how he
00:01:11.360 was working with some fellow students and I'll just read the parts that are
00:01:18.320 relevant to set the scene. He was observing galaxies through microscopes and he
00:01:24.760 continues. That is how astronomers used to use the Palomar Sky Survey, a
00:01:31.200 collection of 1,874 photographic negatives on the sky on glass plates which
00:01:36.960 showed the stars and galaxies are shapes on a white background and so David
00:01:42.560 looked at one of these and he describes how he encountered difficulties so I
00:01:50.120 continue. He continues. One reason is that it is not always obvious which our
00:01:57.560 galaxies and which are merely stars or other foreground objects. Some galaxies
00:02:02.400 are easy to recognize. For instance stars are never spiral or noticeably
00:02:06.960 elliptical but some shapes are so faint that it is hard to tell whether they are
00:02:11.720 sharp. Some galaxies appear small, faint and circular and some are partly obscured by
00:02:17.560 other objects. Nowadays such measurements are made by computers using
00:02:22.040 sophisticated pattern matching algorithms but in those days one just had to
00:02:27.200 examine each object carefully and use clues such as how fuzzy the edges looked.
00:02:31.960 Though there are also fuzzy objects such as supernova remnants in our galaxy
00:02:36.760 one used rules of thumb. How would one test such a rule of thumb? One way is to
00:02:43.720 select a region of the sky at random and then take a photograph of it at
00:02:47.480 higher resolution so that the identification of galaxies is easier. Then one
00:02:51.920 compares those identifications with the ones made using the rule of thumb. If
00:02:56.760 they differ the rule is inaccurate. If they're not differ then one cannot be
00:03:00.600 sure. One can never be sure of course. So it just pours there. He says one
00:03:06.720 can never be sure of course. David says this often all fallibleists do. I often
00:03:15.040 bring it up as well but this idea of being sure or being certain hits are a
00:03:21.560 remarkably pervasive thing that this anti fallibleism. Scientists and
00:03:28.240 philosophers as well as religious dogmatists as well as people who believe in
00:03:33.400 certain kinds of religious certainty are subject to this. I've written a few
00:03:38.560 notes about my thoughts on it. So lots of people seem to want complete or
00:03:45.080 final answers. So people seem to seek final answers in a way. Even at the very
00:03:57.360 beginning of the beginning of infinity David begins chapter one with a
00:04:02.880 quote from John Wheeler made back in 1986 and I'll just read it for you and he
00:04:10.640 writes or John Wheeler said behind it all is surely an idea so simple so
00:04:16.320 beautiful that when we grasp it in a decade a century or a millennium we will
00:04:21.360 all say to each other how could it have been otherwise. So the Wheeler
00:04:26.160 quote I think can be interpreted in one of two ways. Either he's seeking a
00:04:31.800 foundation or perhaps even some kind of certainty or on the other hand he's
00:04:39.120 seeking a fundamental theory and I think he's seeking a fundamental theory but
00:04:44.680 there's a misunderstanding I think at times between what people who are
00:04:51.440 interested in fundamental ideas of doing and what people who are interested in
00:04:55.880 final theories are seeking. There's there's a huge difference. A fundamental
00:05:03.360 theory is a theory that is implicated in many other theories which lies beneath
00:05:08.960 many other theories and so it's fundamental because it's below other things
00:05:17.080 but it's not necessarily foundational so I think there is this difference
00:05:21.440 between fundamental and foundational or even infallibleist but some people
00:05:29.320 might get the sense and that quote that there's something anti-fallibleist
00:05:32.960 going on. The behind it all and so we get to a final theory that is so simple.
00:05:40.040 Now I think that would be misinterpretation but I can understand how someone
00:05:44.040 might read it that way. Whatever the case there is a pervasive meme out there
00:05:53.120 that what we are seeking in science are final answers. It still exists. It's
00:06:01.200 in the vernacular. I think I think it might come from religion and if this is
00:06:06.640 pure speculation and I think that that might come from evolution. What I mean
00:06:13.200 is that parents have almost always until very recently perhaps taught children
00:06:19.920 in this way of don't do it. I'm certain. Are you sure? I said no. You must do this.
00:06:28.680 You have to do this. There is no option so parents tend to speak in these
00:06:33.520 infallibleist ways. These authoritarian infallibleists ways. It's kind of
00:06:38.260 ingrained in the culture. I think that's what might have come first and what's
00:06:42.240 useful first guess for our ancestors who probably got it from evolution. This
00:06:48.840 idea that you simply need to do what you're told because what I've done
00:06:55.680 worked and so what I did is going to work for you. It's the only thing I do know
00:07:00.680 so therefore you better do it or you'll die something like that. And so if
00:07:05.520 this worked for adults to children better than simply allowing
00:07:10.280 children to do absolutely anything they want. In other words rediscovering
00:07:16.520 the entire world themselves without any help which is really the function
00:07:23.040 of parents to help children to understand the world to navigate in ways
00:07:29.360 through the world. The children themselves would appreciate and find fun
00:07:34.520 doing. But before you can have that kind of more nuanced view about children
00:07:41.680 the precursor is do as you're told. So I shouldn't have taught sometimes I
00:07:48.120 think by this anti fallibleism idea. It's ingrained. I think it came first. I
00:07:53.480 think it probably came from evolution. Adults then spoken in fallible
00:07:59.480 ways to each other because that's the way they were taught as children. That evolved
00:08:04.160 probably into some kind of moral laws and about a need for certainty and
00:08:09.240 possibly out of this a metaphysics arose that again was founded on some kind of
00:08:14.120 certainty that the gods absolutely existed and that you had to believe in them
00:08:18.840 because they're definitely there. And so culture is saturated with this and
00:08:23.160 history has been as well. Political movements have been and the key is these
00:08:28.840 things are not extinct because although some of us realize at root there's this
00:08:33.560 poisonous common core to all of this it doesn't mean that everyone is going to
00:08:40.960 be a fallibleist. The default position appears to be in culture now to be
00:08:46.520 anti fallibleists to believe in certainties to believe we can get to some
00:08:50.440 final answer that will be unchanging and it doesn't matter if you are a
00:08:56.960 respected scientist or a philosopher or rationalist. It's quite possible to
00:09:02.520 nevertheless be saturated in anti fallibleism and yet and people are
00:09:08.160 revealed by the ways in which they speak as to whether or not they fundamentally
00:09:13.840 endorse this idea that you can reach final answers in science. You can have
00:09:19.960 complete answers. Let's continue with the beginning of infinity and where David
00:09:25.560 is talking about looking at galaxies through a microscope because they're on
00:09:30.080 photographic plates which is the way it used to be done. He says I was wrong to
00:09:35.320 me impressed by the mere scale of what I was looking at. Some people become
00:09:39.200 depressed at the scale of the universe because it makes them feel insignificant.
00:09:42.200 Other people are relieved to feel insignificant which is even worse but in any
00:09:46.400 case those are mistakes. Feeling insignificant because the universe is large has
00:09:50.480 exactly the same logic as feeling inadequate for not being a cow or a herd of
00:09:54.280 cows. The universe is not there to overwhelm us. It is our home and our resource.
00:09:58.800 The bigger the better. Again here's one of those ways in which David provides a
00:10:06.120 subtle introduction or preview for things to come and this is a powerful
00:10:14.080 point and it's one of the ones that is most swiftly rejected in my experience
00:10:18.920 when they encounter these ideas. This idea that the universe is our home. If we
00:10:24.400 take that seriously that it's not merely our own residence or even our
00:10:29.480 planet, even our solar system but the universe is our home. It contains our
00:10:34.000 resources. It is a hostile environment but home nonetheless. It's not out to
00:10:40.080 kill us but it's also not out to sustain us. We and the knowledge that we produce
00:10:46.480 is the thing that enables us to control the implacably vast and hostile
00:10:51.440 universe and so we need to work with the universe. It's not against us but it's
00:10:59.440 not going to go out of its way to help us either. It's not a thinking thing.
00:11:04.160 And he says the bigger the better and then as far as we know it seems as though
00:11:09.040 the physical universe is infinite. He continues. But then there is the
00:11:15.760 philosophical magnitude of a cluster of galaxies. As I move the crosshairs to
00:11:20.560 one nondescript galaxy after another, checking it what I guess to be the
00:11:24.520 center of each. Some whimsical thoughts occurred to me. I wondered whether I
00:11:29.440 would be the first and last human being ever to pay conscious attention to a
00:11:34.760 particular galaxy. I was looking at the blurry object for only a few seconds.
00:11:38.840 Yet it might be laden with meaning for all I knew.
00:11:43.640 Okay, so this is where I'll try and summarise the remainder of what he says
00:11:48.160 there but I would urge everyone to read it because his summary is far more
00:11:51.560 eloquent than his actual words are going to be far more eloquent than my
00:11:55.840 summary. But essentially he says that this process is error prone in a sort of
00:12:02.640 humorous way because as a non-expert looking at these galaxies he's prone to the
00:12:09.680 kind of errors that someone who is prone more frequently to the kind of
00:12:14.080 errors that someone who is expert in this might not be. And so as he's thinking
00:12:19.640 about whether or not a particular galaxy that he's looking at is one that no
00:12:27.200 person on Earth will ever look at again nor has ever looked at. He thinks perhaps
00:12:32.480 there are planets orbiting stars in that galaxy that he's looking at and on
00:12:38.800 those planets are civilisations and those civilisations have long histories
00:12:44.160 and culture and he's thinking all this and he's mind is kind of expanding to
00:12:50.440 the realisation that there could be so much meaning embedded in that
00:12:57.440 picture and that image that well at least embedded philosophically in that
00:13:04.280 image that what is behind those pixels on that photographic plate what is
00:13:11.240 behind those little smudges on the photographic plate is a huge amount of
00:13:16.840 meaning or what he does actually say. He asks the person that he was
00:13:26.280 he asked the person that he was working with he says is that a galaxy or a star
00:13:30.720 neither was the reply that is just a defect in the photographic emulsion the
00:13:35.960 drastic mental gear change made me laugh my grandiose speculations about the
00:13:39.880 deep meaning of what I was seeing had turned out to be in regard to this
00:13:43.240 particular object nothing at all suddenly there were no people in that that
00:13:48.040 image there were there was no culture there was no history and it all just
00:13:53.400 vanished really quickly so he made a mistake and then he goes on to say but
00:14:02.520 wait was I ever looking at a galaxy all the other blobs were in fact
00:14:06.920 microscopic smudges of silver too if I misclassified the cause of all of
00:14:12.120 them because it looked too much like the others why was that such a big era he
00:14:19.120 says because an area in experimental science is a mistake about the cause of
00:14:23.000 something like an accurate observation it is a matter of theory very little in
00:14:27.760 nature is detectable by unaided human senses most of what happens is too fast
00:14:32.680 too slow too big or too small to remote or too hidden behind opaque barriers or
00:14:37.280 operate on principles too different from anything that influenced our
00:14:40.760 evolution but in some cases we can arrange for such phenomena to become
00:14:44.720 perceptible via scientific instruments we experience such instruments is
00:14:50.520 bringing us closer to reality just as I felt while looking at that galactic
00:14:55.240 cluster but in purely physical terms they only have a separate us further
00:14:59.160 from it I could have looked up the night sky in the direction of that cluster
00:15:02.480 and there would have been nothing between it in my eye but a few grams of air but
00:15:06.440 I would have seen nothing at all I could have interposed a telescope and I
00:15:12.240 might have seen it in the event I was interposing a telescope a camera a
00:15:16.800 photographic developmental laboratory another camera to make copies of the
00:15:20.080 plates a truck to bring the plates to my university and a microscope I could
00:15:24.440 see the cluster far better with all that equipment in the way this is
00:15:30.560 profound this idea that the technology that human beings have created because of
00:15:38.560 our scientific knowledge then is the very thing which allows us to get
00:15:44.000 closer to reality but in a sense it puts physical barriers between us and that
00:15:49.960 reality but the reason that we do that is in order to help us correct our
00:15:55.200 areas to constrain what we know I had a similar experience when I although I
00:16:03.800 studied astronomy at university I didn't tend to look through telescopes very
00:16:08.440 often at all what I did do was use computers so we had the Swinburn University
00:16:13.960 supercomputer which is basically just a whole bunch of normal computers but
00:16:19.200 all working in parallel together a room full of normal computers working in
00:16:22.040 parallel and they call it a supercomputer and what we used to do were galaxy
00:16:26.520 simulations we used to collide galaxies together and in particular I looked at
00:16:30.800 one called up 271 and this was a pair of spiral galaxies that is in the
00:16:36.280 process of colliding of course all you see all that is seen by astronomers when
00:16:42.360 it looks through telescopes at a galaxy like that is a static picture the
00:16:49.440 motion of the stars let alone the two galaxies is occurring on scales of millions
00:16:57.200 and hundreds of millions of years it is reasonable to presume that no one
00:17:05.160 alive today is going to see much in the way of motion of those two galaxies in
00:17:12.000 reality we do not see them moving but we know they are at least we do not see
00:17:17.760 them moving with our naked eye we know they are because we can detect when we
00:17:23.320 look more closely the red shift of the stars the the the the spectra of star
00:17:28.680 reveals the direction in which parts of those galaxies are moving and so we
00:17:33.480 can see that they're actually moving together we can also determine by the
00:17:39.480 same methods how massive the galaxies are because with spiral galaxies they
00:17:44.000 are literally spinning and the faster they're spinning the more massive the
00:17:48.280 galaxies are so you can have an estimate for the mass of the galaxy so you can
00:17:51.760 find an estimate for the velocity and you can find an estimate for the mass then
00:17:56.680 what you can do is you can put some of this data into a supercomputer and
00:18:01.720 then what you can do is you can try to guess what's going to happen next to the
00:18:07.720 galaxies during the collision and after the collision will they merge together
00:18:12.120 will they pass through one another it's actually possible for spiral galaxies
00:18:15.960 that collide to pass through one another not unaffected but they will pass
00:18:20.080 through and keep going they're kind of like clouds it's very unusual
00:18:24.720 highly unlikely for stars themselves to collide even though the galaxies
00:18:31.640 have because there's so much empty space in between the stars and so we will
00:18:39.000 never see this galaxy pair actually colliding we will never see by which I
00:18:47.320 mean able to observe the consequences of the predictions that we make unless
00:18:54.440 we're still around in a long time had some hundreds of millions of years what I
00:18:59.280 predicted would happen is that they would indeed combine into one single galaxy
00:19:04.080 but that's based on the output of a supercomputer and it's based on a very low
00:19:11.720 resolution prediction by which I mean not only do we make assumptions which are
00:19:18.880 very aeroprene about the masses of these two galaxies and the velocities of
00:19:24.120 these two galaxies we cannot possibly with our current technology with our
00:19:29.480 supercomputer technology simulate the collision of two bodies each of which
00:19:36.920 contains some hundreds of billions of stars if you want to find out what
00:19:43.160 happens when a couple of hundred objects over here combine with a couple of
00:19:48.600 hundred objects over there this is the famous n-body problem and that quickly
00:19:54.760 becomes intractable it's very difficult to try and figure out what all those
00:19:59.200 particles are doing in response to each other so what you do is instead of
00:20:04.240 assuming that you've got some hundreds of billions here and some hundreds of
00:20:07.160 billions here you can just use some millions here and some millions here and so
00:20:12.560 you've only got some very very tiny fraction of the actual number of objects
00:20:17.680 here and here and then assuming that when they collide it is similar to what
00:20:22.240 happens when you've actually got the hundreds of billions where there are not
00:20:26.600 that's true we'll be sorted out in use to come as the computers get more
00:20:33.680 powerful and we can see whether or not we're converging on the same answer but
00:20:38.440 all this is to say that all of this technology supercomputers and the
00:20:43.400 software that runs on them and the observations that we make using
00:20:47.400 telescopes enable us to see into the distant future it's a blurry image but
00:20:54.000 it's better than a random guess and the better our technology becomes the more
00:20:59.600 resolution we have about the future about predicting the future and this is a
00:21:04.560 this is a genuine kind of prediction I'm fond of talking about prophecies
00:21:09.920 where people have really unconstrained ideas about the function of knowledge
00:21:15.400 but unless we have a particular interest or some people have a particular
00:21:19.560 interest somewhere in doing something with up to 7.1 I think it's fair to say
00:21:26.760 that given the sheer number of galaxies and stars in the universe it'll be
00:21:32.640 some hundreds of millions of years before anyone's interested in going to
00:21:35.920 up to 7.1 trying to I don't know use the resources there okay so that was a
00:21:42.960 a long diversion let me go back to the beginning of infinity okay and I'll
00:21:50.080 just I'm jumping around a little bit here but this is another interesting part
00:21:54.080 a few pages back where he says the computers nowadays do the catalog of
00:22:00.960 galaxies rather than having graduate students look at photographic plates and
00:22:04.760 he says the computers that nowadays catalog galaxies may or may not do it
00:22:09.560 better than the graduate students used to but they certainly did not experience
00:22:13.000 such reflections as David had as a result I mentioned this because I often
00:22:17.320 hear scientific research described in a rather bleak way suggesting that it
00:22:21.640 is mostly mindless toil the inventor Thomas Edison once said none of my
00:22:26.920 inventions came by accident I see a worthwhile need to be met and I make trial
00:22:32.040 after trial until it comes what it boils down to is 1% inspiration and 99%
00:22:39.200 perspiration some people say the same about theoretical research where the
00:22:44.880 perspiration phase is supposedly uncreative intellectual work such as doing
00:22:48.320 algebra or translating algorithms into computer programs but the fact that a
00:22:52.120 computer or robot can perform a task mindlessly there's not implied that it
00:22:55.560 is a mindless task when scientists do it after all computers play chess
00:23:00.400 mindlessly by exhaustively searching the consequences of all possible
00:23:04.520 moves by humans achieve a similar looking functionality in a completely
00:23:07.880 different way by creative and enjoyable thought perhaps those galaxy
00:23:12.400 cataloging computer programs were written by those same graduates some of
00:23:16.200 those same graduate students distilling what they had learned into reproducible
00:23:19.880 algorithms which means that they must have learned something while performing a
00:23:24.720 task that a computer performs without learning anything but more profoundly I
00:23:28.680 expect that Edison was misinterpreting his own experience a trial that fails is
00:23:34.160 still fun a repetitive experiment is not repetitive if one is thinking
00:23:37.800 about the ideas that it is testing and the reality that is investigating that
00:23:43.440 galaxy project was intended to discover with a dark matter see the next
00:23:47.600 chapter really exists and it succeeded if Edison or those graduate students or
00:23:53.280 any scientific researcher engaged upon the perspiration phase of discovery had
00:23:58.280 really been doing it mindlessly they would be missing most of the fun which is
00:24:02.920 also what largely powers that 1% inspiration so this is important and this is
00:24:10.200 a theme that we will come back to that what people are has different to any
00:24:18.720 other entity in the universe that we know of we are creative and so even if
00:24:23.400 we're going through a an uncreative perspiration phase apparently we're doing
00:24:29.880 something very different than if an automated machine was taking that task
00:24:36.080 for us we are able to think about each of the steps we're able to think about
00:24:41.080 other things while we're doing it and so we are necessarily creative at all
00:24:45.640 points so now what's the purpose of scientific instruments I prefaced this at
00:24:52.600 the beginning of the video so let me return to the text now the primary
00:24:59.360 function of the telescopes optics is to reduce the illusion that the stars are
00:25:03.120 few faint twinkling and moving the same is true of every feature of the
00:25:07.560 telescope and of all other scientific instruments each layer of indirectness
00:25:12.160 through its associated theory corrects errors illusions misleading
00:25:16.320 perspectives and gaps perhaps it is the mistaken empiricist idea of pure
00:25:21.320 theory-free observation that makes it seem odd that truly accurate observation is
00:25:27.760 always so hugely indirect but the fact is that progress requires the application
00:25:34.240 of ever more knowledge in advance of our observations and so he says even
00:25:39.280 though he was mistaken in one case when he was looking at one of the smudges on
00:25:45.520 the photographic plates misinterpreting that smudge as galaxy when it just
00:25:52.400 turned out to be a fingerprint that concern that the rest of the images
00:26:01.080 that he was looking at were similarly just smudges or weren't galaxies for some
00:26:04.640 other reason can't be true because the point is that our knowledge and our
00:26:13.640 technology corrects errors like that he didn't have the knowledge at
00:26:18.880 a particular point but the other expert did and so he says so I was indeed
00:26:23.160 looking at galaxies observing a galaxy via specs of silver is no different in
00:26:26.960 that regard from observing a garden via via images on the retina okay so I'm
00:26:32.200 going to the conclusion now so it's a fast chapter it's a good chapter and so
00:26:39.360 he continues explanatory theories tell us how to build and operate
00:26:42.680 instruments in exactly the right way to work this miracle like
00:26:46.480 conjuring tricks and reverse such instruments fool our senses into seeing what
00:26:50.480 is really there our minds through the methodological criterion that I'm
00:26:54.000 mentioning chapter one conclude that a particular thing is real if and only if
00:26:58.360 it figures in our best explanation of something physically all that has
00:27:02.040 happened is that human beings on earth have dug up raw materials such as iron
00:27:05.720 or and sand and have rearranged them still on earth into complex objects such
00:27:10.080 as radio telescopes computers and display screens and now instead of looking at
00:27:13.600 the sky they look at those objects they're focusing their eyes on human
00:27:18.160 artifacts that are close enough to touch but their minds are focused on alien
00:27:22.880 entities and processes light years away sometimes they are looking at glowing
00:27:27.880 dots just as their ancestors did but on computer monitors instead of the sky
00:27:32.440 sometimes they are looking at numbers or graphs but in all cases they are
00:27:36.880 inspecting local phenomena pixels on a screen ink on paper and so on these
00:27:41.880 things are physically very unlike stars they are much smaller they are not
00:27:46.200 dominated by nuclear forces and gravity they are not capable of transmutating
00:27:49.960 elements or creating life they have not been there for billions of years but
00:27:54.760 when astronomers look at them they see stars so this is profound and this is
00:27:59.920 the idea that we do not experience reality directly and even if we would take
00:28:07.760 away all of that instrumentation and technology and we were to lay on our
00:28:13.680 backs and look up to night sky and see a star what's actually going on as David
00:28:19.240 mentions in his TED talk and I think he talks about this in chapter 1 I didn't
00:28:23.360 mention it is light photons are striking the back of the retina eventually once
00:28:30.640 they get through the cornea and causing electrical signals to be sent via the
00:28:37.120 optic nerve back to the brain and in the brains and neurons are crackling
00:28:42.440 away they're communicating with another and that's what we are okay so we we
00:28:47.400 are a mind that's inside of that brain and however the mind works it depends at
00:28:51.840 least in part for now on how the neurons transmit electricity to one another
00:28:59.560 that's what we are everything else is interpretation our brain has to interpret
00:29:04.880 the signals coming from the optic nerve the optic nerve is only sending
00:29:09.320 signals because light has been detected at the retina and that light has only
00:29:16.000 been detected at the retina because it's somehow made its way through the
00:29:19.360 atmosphere from the star so this process of seeing stars or seeing anything is
00:29:25.240 an extremely complex phenomena where there are many layers of interpretation
00:29:29.280 between your mind and the reality out there so that's chapter 2 I'm not
00:29:35.360 sure when I'll get to chapter 3 we'll say it could be some weeks but this is