1 00:00:00,000 --> 00:00:14,000 Can you tell us about the string theory and what it tells us about other dimensions? 2 00:00:14,000 --> 00:00:21,500 Yes, so string theory is I would say an example of speculative physics where it's not based 3 00:00:21,500 --> 00:00:27,300 on experiments that people are doing but rather people trying to come up with just using pure 4 00:00:27,300 --> 00:00:34,180 math to find out if there are other ways to come up with physical theory that we know in 5 00:00:34,180 --> 00:00:38,120 order to solve certain problems. 6 00:00:38,120 --> 00:00:41,760 In some ways string theory is not yet even really a theory. 7 00:00:41,760 --> 00:00:48,980 It's a set of efforts to think about how we might be able to come up with another theory. 8 00:00:48,980 --> 00:00:56,360 At its basic level the idea of the strings is just to say instead of thinking of point 9 00:00:56,360 --> 00:01:01,220 particle interactions and thinking of particles as little single points, to think of them 10 00:01:01,220 --> 00:01:09,080 as interactions along lines and so the lines are like strings. 11 00:01:09,080 --> 00:01:13,280 Probably the original interest in this is just to solve some of the problems of quantum mechanics 12 00:01:13,280 --> 00:01:15,760 that we don't really understand. 13 00:01:15,760 --> 00:01:20,880 One of the things that goes on in quantum field theory is that when you do certain calculations 14 00:01:20,880 --> 00:01:26,060 you get infinity as an answer and usually we don't like that in physics. 15 00:01:26,060 --> 00:01:28,660 We don't like what we call singularities. 16 00:01:28,660 --> 00:01:35,840 Things where at certain points you would calculate just that you get infinity and in the present 17 00:01:35,840 --> 00:01:42,120 standard way that we approach that we'll just make cutoffs and say well instead of putting 18 00:01:42,120 --> 00:01:48,200 it infinity we'll just put it at some finite but very large value and make a cutoff and it 19 00:01:48,200 --> 00:01:50,480 seems somewhat arbitrary. 20 00:01:50,480 --> 00:01:56,160 String theory at one level is just an attempt to solve some of those inconsistencies in the 21 00:01:56,160 --> 00:01:59,820 known quantum mechanics that we have. 22 00:01:59,820 --> 00:02:08,780 At another level it's an attempt I would say in some cases to get rid of fine tuning. 23 00:02:08,780 --> 00:02:12,860 At this meeting there's been a lot of discussion about fine tuning. 24 00:02:12,860 --> 00:02:18,280 Some proposals for the string theory is to say well if we do physics right then we'll 25 00:02:18,280 --> 00:02:24,680 be able to explain everything in terms of just geometry and we won't have to invoke these 26 00:02:24,680 --> 00:02:26,760 fine tuning constants. 27 00:02:26,760 --> 00:02:31,580 It's very speculative because they haven't done this and yet that is sort of one of the attempts 28 00:02:31,580 --> 00:02:32,980 that they would like to do. 29 00:02:32,980 --> 00:02:36,980 And another thing they would like to be able to do with it is to be able to say there are 30 00:02:36,980 --> 00:02:42,300 these many worlds or parallel universes to say there is one large super universe and 31 00:02:42,300 --> 00:02:48,140 then our universe is like a subset or a bubble inside of this larger universe. 32 00:02:48,140 --> 00:02:53,620 So I guess I would say string theory is interesting but it's really at this point what I would call 33 00:02:53,620 --> 00:03:00,400 speculative mathematics of trying to come up with alternate ways of defining physics. 34 00:03:00,400 --> 00:03:06,320 Now the dimensionality part of it is interesting because that is actually not especially controversial 35 00:03:06,320 --> 00:03:08,280 in physics. 36 00:03:08,280 --> 00:03:13,060 When Einstein came along with general relativity he treated time like a dimension. 37 00:03:13,060 --> 00:03:18,560 So we have three dimensions you know length, height and depth and so we were used to three 38 00:03:18,560 --> 00:03:20,220 spatial dimensions. 39 00:03:20,220 --> 00:03:25,360 Einstein came along and said well there is a fourth dimension of time and then we can talk 40 00:03:25,360 --> 00:03:27,500 about curvature of space and things like that. 41 00:03:27,500 --> 00:03:33,280 Well once we started to add these extra dimensions for general relativity then people said well why 42 00:03:33,280 --> 00:03:36,240 do we need to stop with just four. 43 00:03:36,240 --> 00:03:38,600 We could go on and add extra dimensions. 44 00:03:38,600 --> 00:03:46,120 And so that by itself is probably not especially controversial in physics but again it's speculation 45 00:03:46,120 --> 00:03:50,760 at this point of can we do the math that would make it work out to actually see something 46 00:03:50,760 --> 00:03:53,020 sensible if we have these other dimensions. 47 00:03:53,020 --> 00:04:01,240 I think to me it sounds like a sort of a back door for materialism or atheism. 48 00:04:01,240 --> 00:04:03,200 Do you think so? 49 00:04:03,200 --> 00:04:08,280 I would say a lot of people who are pursuing string theory are indeed pursuing it out of 50 00:04:08,280 --> 00:04:14,100 a theological desire to have a consistent atheism. 51 00:04:14,100 --> 00:04:20,480 In general in physics there's two ways that theories have advanced and actually both often 52 00:04:20,480 --> 00:04:21,860 work. 53 00:04:21,860 --> 00:04:28,080 One would be out of just experiments where people have data that they don't understand and they 54 00:04:28,080 --> 00:04:31,040 adjust and come up with new theories to explain that data. 55 00:04:31,040 --> 00:04:34,320 So we could call that data driven science. 56 00:04:34,320 --> 00:04:38,760 But there's another side to science which you could call aesthetically driven science. 57 00:04:38,760 --> 00:04:42,800 Where someone says well this theory just doesn't look very pretty. 58 00:04:42,800 --> 00:04:46,360 And I want to come up with a prettier looking theory. 59 00:04:46,360 --> 00:04:48,800 And actually that has also been very successful. 60 00:04:48,800 --> 00:04:54,220 So for example we were talking before about anti-matter. 61 00:04:54,220 --> 00:05:01,320 The anti-matter theory was proposed by Dirac before there was ever any observations of anti-matter. 62 00:05:01,320 --> 00:05:07,640 But the equations would look very nice and symmetric if there was such a thing as anti-matter. 63 00:05:07,640 --> 00:05:13,960 And so because the equations sort of look nice then people went looking for anti-matter. 64 00:05:13,960 --> 00:05:19,320 And you can go back to a number of other theories even Einstein's theory of relativity. 65 00:05:19,320 --> 00:05:26,480 For many people it seemed much more aesthetically pleasing than other alternatives. 66 00:05:26,480 --> 00:05:32,040 And so there's been this back and forth between data driven science and you could say philosophical 67 00:05:32,040 --> 00:05:35,800 or aesthetical type science. 68 00:05:35,800 --> 00:05:40,440 And so then it gets into well what is aesthetically pleasing? 69 00:05:40,440 --> 00:05:43,160 That is actually something that we should find. 70 00:05:43,160 --> 00:05:48,560 And that of course very much depends on your theology, on your philosophy and so on. 71 00:05:48,560 --> 00:05:52,640 And so for example some people would say it would be very aesthetically pleasing to 72 00:05:52,640 --> 00:05:57,860 have a universe which exists forever and never changes and has no beginning. 73 00:05:57,860 --> 00:05:59,540 But the data says otherwise. 74 00:05:59,540 --> 00:06:01,760 The data says that we have a beginning. 75 00:06:01,760 --> 00:06:06,060 And so while at one point people would have tried to create a theory that was an infinite 76 00:06:06,060 --> 00:06:08,640 and eternal universe it simply doesn't agree with the data. 77 00:06:08,640 --> 00:06:14,880 So sometimes we have to put our aesthetic desires aside and say well the data tells us something 78 00:06:14,880 --> 00:06:17,280 different. 79 00:06:17,280 --> 00:06:22,640 Yeah in the case of string theory at least some of the people who are doing it are doing 80 00:06:22,640 --> 00:06:26,360 it out of a desire to recover the eternal universe. 81 00:06:26,360 --> 00:06:32,680 To say well we have a beginning of this particular universe but there are many other universes that 82 00:06:32,680 --> 00:06:33,880 are out there. 83 00:06:33,880 --> 00:06:37,640 And so really it's one much much larger eternal universe. 84 00:06:37,640 --> 00:06:42,480 And then we have these small universes that keep popping up inside of that. 85 00:06:42,480 --> 00:06:47,820 And so in many ways it really is being driven by aesthetic considerations of wanting something 86 00:06:47,820 --> 00:06:48,820 which is eternal. 87 00:06:48,820 --> 00:06:51,120 So what is the purpose of science to you then? 88 00:06:51,120 --> 00:06:55,600 I mean it should be aesthetical or it should be pragmatical or? 89 00:06:55,600 --> 00:07:01,660 I actually think that the beauty of modern science is bringing both of them together. 90 00:07:01,660 --> 00:07:08,320 That when you are only being data driven and practical and sort of saying let's fit this. 91 00:07:08,320 --> 00:07:11,900 Sometimes you can miss some of the underlying beauty that's in the laws of physics. 92 00:07:11,900 --> 00:07:17,920 So I think that actually God made the laws of physics in a beautiful way. 93 00:07:17,920 --> 00:07:23,900 The problem is that when we try to impose our own view of beauty in advance and say it must 94 00:07:23,900 --> 00:07:28,960 be the way that I think is beautiful we often go very far wrong. 95 00:07:28,960 --> 00:07:34,880 And so back in the middle ages and even ancient times people came up with very aesthetically 96 00:07:34,880 --> 00:07:40,480 appealing theories only five elements you know air, fire, water, earth and so on. 97 00:07:40,480 --> 00:07:44,640 And that had sort of an appeal to it but it turned out to be wrong. 98 00:07:44,640 --> 00:07:49,920 And so the data kind of overturned that as people started to do chemistry and so on. 99 00:07:49,920 --> 00:07:56,880 But on the other hand as I look at the history of physics I would say it's been back and forth 100 00:07:56,880 --> 00:08:03,140 that sometimes you don't have any advance until you get new data and new experiments. 101 00:08:03,140 --> 00:08:07,580 On the other hand sometimes you can be sitting and looking at the experiments for a long time 102 00:08:07,580 --> 00:08:13,740 and not getting very far and then somebody comes up with a beautiful idea and that beautiful 103 00:08:13,740 --> 00:08:18,380 idea actually unifies a lot of things and makes it easier to understand the data. 104 00:08:18,380 --> 00:08:24,900 So actually you know Einstein is a very famous saying of his that you know one of the most 105 00:08:24,900 --> 00:08:30,340 incomprehensible things about the universe is why it is so comprehensible. 106 00:08:30,340 --> 00:08:35,740 It's not at all obvious that our theories should match reality. 107 00:08:35,740 --> 00:08:42,140 You know why should it be that actually beautiful theories tend to be true about the universe. 108 00:08:42,140 --> 00:08:48,880 It turns out that actually the aesthetic sense often times drives us to a good theory. 109 00:08:48,880 --> 00:08:53,200 And I would say as a Christian that's because in fact God made the universe beautiful and 110 00:08:53,200 --> 00:08:55,260 he used very nice laws. 111 00:08:55,260 --> 00:09:01,140 But we can go wrong if we insist it has to be beautiful the way I want it to be beautiful. 112 00:09:01,140 --> 00:09:16,140 I think some scientists are very obsessed to prove their ideology and it sometimes seems like the scientific world is losing a lot of time and finance. 113 00:09:16,140 --> 00:09:29,140 So would you say that being just objective or following the creation would be much more logical and beneficial for today's science? 114 00:09:29,140 --> 00:09:39,880 Yeah I would certainly say that the idea of a dispassionate scientist who is just seeking the truth no matter where it is is kind of a myth. 115 00:09:39,880 --> 00:09:45,880 And I would say most people these days in philosophy and in science would agree with that. 116 00:09:45,880 --> 00:09:50,880 That scientists very much passionately want the answer to come out a certain way. 117 00:09:50,880 --> 00:10:00,620 Now that doesn't always mean they do bad science because even if you want the answer to come out a certain way you can still be honest when it doesn't come out the way you want. 118 00:10:00,620 --> 00:10:07,620 And so often times people find surprises things that are not the way they expect things to be and they're honest about that. 119 00:10:07,620 --> 00:10:18,360 So for instance the Big Bang Theory is an example where lots of scientists did not want the Big Bang to be true but they were honest enough when the data was overwhelming to say yes there is a Big Bang. 120 00:10:18,360 --> 00:10:25,360 So this idea of sort of the neutral scientist who has no opinions no desires is not accurate. 121 00:10:25,360 --> 00:10:32,360 We all want it to come out a certain way and I do think that we talked before about string theory. 122 00:10:32,360 --> 00:10:51,400 I would say string theory is an interesting effort but I would say the amount of effort invested in it is probably far more than it deserves because people see this as a way of explaining away all the fine tuning that seems to point to God. 123 00:10:52,260 --> 00:11:00,740 And so even I would say if that was not true string theory would still be sort of an interesting thing to pursue just to see if you can make it work. 124 00:11:00,740 --> 00:11:09,600 But my impression is the amount of effort put into it is very much driven by a desire to come up with a way of explaining the universe without any need for God.