String Theory — Influence on Philosophy of Physics & Science (contd.)

0:00 ...that since there's only this one parameter, and there's this kind of feeling that stream theory has a kind of necessity to it, that perhaps there's only sort of one way by necessity that you get, you know, there's sort of one limit that you get, right? If it turns out that it doesn't get leptons right at the end of the day, all the string theorists I can imagine are going to say, well, look, we finally got into the empirical regime we wanted to get. We looked at the evidence and dang, it just didn't work out. So off-coach string theory, what's the next idea we can work with? In other words, they'll return to their empirical, I'm imagining, kind of roots. Once we get out of this regime where at the moment we can only talk about the theoretical consideration we get back to the context of experimental confirmations I mean what what what what my point should make up I'm not sure the straight theory definitely is not a pretty criminal so it is it is not the case that it is not empirically testable of cryptic there are characteristic signatures of string theory which might also already today prove or disprove the string theory conjecture if we would have experiments to do so so for example there is one there is one concept so called an extra dimension concept which brings the scale where we can test these assumptions very close to the scale we can test at present. So it is not the case, so to say, the case for string theory is not empirically hopeless. It is a generally empirically predictive theory, and therefore it is, let's say, the importance of free theory shouldn't be reduced to the question whether it can be reproduced as unabonded

2:30 or not. That's right. Yeah. That's okay. Yeah, the bottom line is that you get something that eventually we can get a handle on in some sort of laboratory center. And then we can see, is it correct or not, is it close or not. So now you're asking what would happen if you would be able to test one level on the other, the theory empirically and we just turned out that it just doesn't work. Well, of course, when the answer would be the consequence would be similar to the consequence in all the scientific concepts, think whether they can, whether they have misunderstood something, whether the experiments are correct, I don't know, or whether they have to choose an entirely different path. So nothing has changed in that respect. But this still leaves open the question how one evaluates the eminence we do have today, which is just a theoretical evidence. Whether it is in some way justified to accept, to give more credit to the theoretical evidence then one would be allowed to in a more traditional scientific context, although well that's not the case. And this is very good. Okay, more David, and then Karl. Okay, and we really have a big example of connection between the relation and the language of people. And the second one is, as you know lately mentioned, So, what's the connection between underdetermination and the use of some of those three parameters? Well, the connection goes by and of course, initially, the statement of how the decimulation tells us if we have a standard model to reproduce our data, we still can expect that there might be a different theory, another theory, but also is able to reproduce.

5:00 Well, if you would imagine that the standard model is a theory without free parameters. This would mean that the standard model is a theory without free parameters in the way I have defined it, which means free parameters for us. So if that would be the case, the standard model would be a unified description of physical phenomena, of all physical phenomena, without any possibility to tune these phenomena. The question is, in this case, if that theory occurred, would it be plausible to expect that there is a new, what, this is basically a problem? This is the answer to the standard argument. I mean, it's supposed to sound a lot about the same industry, for instance, that any embarrassing data we can accommodate five, three, four minutes. They, of course, come from, but that's not true. I mean, we've got way of data to basically know what they're going to do. So it's not the case that... Suppose this animal was beautiful in their respect, and we know all sorts of other problems in it, then we might be fairly happy to say, well, that's about me, but that's our last theity, And we might turn out, and then we might turn out, there's another period of time, that we produce that age equally well. It wouldn't be the same as the parameter thing, because the parameter thing is what they are. It would be a different period. Now, I don't have someone, and I'm not getting why the parameter thing is healthy at all. The other thing is not happening because a different theory in the parameter sense, also the data, it's happening because some theory is not the sort of parameter, but it's a different theory that also is the data. Yes, I mean, of course, it is not, but also in the case of string theory that you, well,

7:30 So, one might add that there may be some argument which make this more questionable than in the startable case, but if we just leave that aside, let's assume that it is not excluded, that there do exist alternatives to string theory which actually do have free parameters. So this is, in this sense, the statement of underdetermination is not affected by assignment. If you go back to the case of the standard model, whether Sutherland has three parameters or not, does not, there's not any implication on the question, at least the way I presented The argument doesn't have any implication on the question whether there do exist other theories, alternative theories, with free parameters. That's correct. So that's why I need the second argument to make it. And I will stop for the question. You seem to be saying that if I have theory with free parameters, it is subject to a certain under-determination effect. but a theory now for parameters is less sensitive, less subject to the background. Within its cluster? Yeah, okay. So I've got two theories. Theory one has been parameter. The theory two is not a reference parameter. Therefore, theory one has an underestimation type which theory two is not a reference. And I don't understand that because it seems to me that data, I'll just say I should do about data, so I've got two or more theories back to the data, and the data tells us the value of the parameter. So the fact that there are all these other theories out there, which differ from our theories theory by chasing the parameters, seems to be irrelevant because we know what the parameters are. Those theories don't be related to what you discovered. Well, there are two reasons to assume that. The first is that a theory that does have free parameters covers a much larger part of the parameter space. So the assumption that theories with free parameters are able to cover the whole parameter space is a more,

10:00 a less ambitious one, let's say, an assumption that theory without free parameters doesn't. That's one point. And the other point is that actually we know how to construct an awful lot of theories with pre-parameters. And we only know one candidate for a theory that does not have pre-parameters. So on one side, pre-parameters, theory with pre-parameters cover more of the parameters. On the other side, it's obviously much easier to construct that. Therefore, if I look at the whole set of possible theories, the assumption of under-determination is more natural than if I just look at the subset of spectrum unique theories. Again, I can see why... I don't know why not. I don't know if it's the front one, the thing which doesn't have three branches is a great step forward from the theory, which has a few of those smalls and plays. It would be fantastic if we could explain what the charge is going on from the front one. I still don't see how that's connected to the information. Well, I'll do this one. Well, I have a whole lot of questions. One thing I would like to know is, you were mentioning that there was a certain stability that they're not close to . And this was not likely to change . What are the chances it will ever change? What crimes do we have to believe that there will ever be a low mass human information? Well, there are two options how this could change in principle. One way to change it would be that we are at some stage able to test the characteristic scale of the theory. And again, there are two possibilities, either this scale is much lower than we assume to be now, or we find an entirely different type of elementary particle experiment project at some stage,

12:30 we say, test the stream scale, which would be to be now. This is one option, and the second possibility is that we at some stage, I think you're at some stage, all right, to understand the theory is exactly welcome to cover it. So, I mean, let's say option 1A, the option that the 266 gate actually is lower than we saw. This is a great option, though this might, so to say, have plenty of time. We might just run into the spectrum of the interest rate, although that's very likely and the other two questions are very difficult to answer. I mean, let's say at this stage, there are no good arguments. which would suggest that you know, either the string scale experimentally or the low energy scale, however there are no arguments either which to do. So, it's not I'm just curious to know that within the community itself, I mean I recall reading about how we should find during a certain period of maybe conferences on general relativity. This was in a period when general relativity was really almost lost its origins with the experiment. And he was extremely rude and often very obstreperous in these meanings, with certain contributors to the kind of speaks of these meanings, because he felt that they were doing really a new kind of physics which wasn't physics. It was a complete divorce from the experiment. Now, string theory seems to be an even more dramatic case. Are string theorists, I mean you mentioned before that they believe it, well that's in a sense I suppose not entirely surprising because they're doing it. I suppose in a sense what they're surprising is how many of them are in string theory and

15:00 But are they, do they discuss the rather blatant fact that this is a new kind of, in a sense, this is a new kind of physics. It's a physics that's quite a different, I think, in a new sense, it's got whatever. Well, two points first. It's not, I don't think it's clear that people working with people wouldn't believe the subject. I personally was working in the field of physics online where people were working and it did not be . So they just were saying, well, this is a hypothesis, of course, I don't know, but it might be theoretical interest. So I think that the trust of string theorists in their theory distinguishes them considerably from a large number I mean, is there a sense within the field, I mean, within the string theory community, that they really are doing physics of a kind, I mean, it's ironic for us as philosophers that for so long, the criticism of our work was that we had, you know, we were working in a way of dispute. and so on. The metaphysicists seem to have taken on this style with gusto. It is kind of an irony. My impression would be that, of course, there are those arguments. And they are, spring theorists explicitly try to find arguments why they can lead in their theory on a purely theoretical basis. However, I don't think that they would have a very fundamental philosophical perspective on that. They claim to work on a very different theory for different reasons because it is, because it is, because it doesn't have the parameters, because it is overall in my theory, just like that. I don't think that they would like to claim that they are doing physics in a substantially

17:30 different way. So I believe that spring theorists would actually prefer to claim that actually they are physicists like anyone else. in this situation what I do and I'm afraid I think we were I'm going to suggest we stop now there are a couple of people who have questions so thank you very much for your talk