Can you tell us about the string theory and what it tells us about other dimensions?
Yes, so string theory is I would say an example of speculative physics where it's not based
on experiments that people are doing but rather people trying to come up with just using pure
math to find out if there are other ways to come up with physical theory that we know in
order to solve certain problems.
In some ways string theory is not yet even really a theory.
It's a set of efforts to think about how we might be able to come up with another theory.
At its basic level the idea of the strings is just to say instead of thinking of point
particle interactions and thinking of particles as little single points, to think of them
as interactions along lines and so the lines are like strings.
Probably the original interest in this is just to solve some of the problems of quantum mechanics
that we don't really understand.
One of the things that goes on in quantum field theory is that when you do certain calculations
you get infinity as an answer and usually we don't like that in physics.
We don't like what we call singularities.
Things where at certain points you would calculate just that you get infinity and in the present
standard way that we approach that we'll just make cutoffs and say well instead of putting
it infinity we'll just put it at some finite but very large value and make a cutoff and it
seems somewhat arbitrary.
String theory at one level is just an attempt to solve some of those inconsistencies in the
known quantum mechanics that we have.
At another level it's an attempt I would say in some cases to get rid of fine tuning.
At this meeting there's been a lot of discussion about fine tuning.
Some proposals for the string theory is to say well if we do physics right then we'll
be able to explain everything in terms of just geometry and we won't have to invoke these
fine tuning constants.
It's very speculative because they haven't done this and yet that is sort of one of the attempts
that they would like to do.
And another thing they would like to be able to do with it is to be able to say there are
these many worlds or parallel universes to say there is one large super universe and
then our universe is like a subset or a bubble inside of this larger universe.
So I guess I would say string theory is interesting but it's really at this point what I would call
speculative mathematics of trying to come up with alternate ways of defining physics.
Now the dimensionality part of it is interesting because that is actually not especially controversial
in physics.
When Einstein came along with general relativity he treated time like a dimension.
So we have three dimensions you know length, height and depth and so we were used to three
spatial dimensions.
Einstein came along and said well there is a fourth dimension of time and then we can talk
about curvature of space and things like that.
Well once we started to add these extra dimensions for general relativity then people said well why
do we need to stop with just four.
We could go on and add extra dimensions.
And so that by itself is probably not especially controversial in physics but again it's speculation
at this point of can we do the math that would make it work out to actually see something
sensible if we have these other dimensions.
I think to me it sounds like a sort of a back door for materialism or atheism.
Do you think so?
I would say a lot of people who are pursuing string theory are indeed pursuing it out of
a theological desire to have a consistent atheism.
In general in physics there's two ways that theories have advanced and actually both often
work.
One would be out of just experiments where people have data that they don't understand and they
adjust and come up with new theories to explain that data.
So we could call that data driven science.
But there's another side to science which you could call aesthetically driven science.
Where someone says well this theory just doesn't look very pretty.
And I want to come up with a prettier looking theory.
And actually that has also been very successful.
So for example we were talking before about anti-matter.
The anti-matter theory was proposed by Dirac before there was ever any observations of anti-matter.
But the equations would look very nice and symmetric if there was such a thing as anti-matter.
And so because the equations sort of look nice then people went looking for anti-matter.
And you can go back to a number of other theories even Einstein's theory of relativity.
For many people it seemed much more aesthetically pleasing than other alternatives.
And so there's been this back and forth between data driven science and you could say philosophical
or aesthetical type science.
And so then it gets into well what is aesthetically pleasing?
That is actually something that we should find.
And that of course very much depends on your theology, on your philosophy and so on.
And so for example some people would say it would be very aesthetically pleasing to
have a universe which exists forever and never changes and has no beginning.
But the data says otherwise.
The data says that we have a beginning.
And so while at one point people would have tried to create a theory that was an infinite
and eternal universe it simply doesn't agree with the data.
So sometimes we have to put our aesthetic desires aside and say well the data tells us something
different.
Yeah in the case of string theory at least some of the people who are doing it are doing
it out of a desire to recover the eternal universe.
To say well we have a beginning of this particular universe but there are many other universes that
are out there.
And so really it's one much much larger eternal universe.
And then we have these small universes that keep popping up inside of that.
And so in many ways it really is being driven by aesthetic considerations of wanting something
which is eternal.
So what is the purpose of science to you then?
I mean it should be aesthetical or it should be pragmatical or?
I actually think that the beauty of modern science is bringing both of them together.
That when you are only being data driven and practical and sort of saying let's fit this.
Sometimes you can miss some of the underlying beauty that's in the laws of physics.
So I think that actually God made the laws of physics in a beautiful way.
The problem is that when we try to impose our own view of beauty in advance and say it must
be the way that I think is beautiful we often go very far wrong.
And so back in the middle ages and even ancient times people came up with very aesthetically
appealing theories only five elements you know air, fire, water, earth and so on.
And that had sort of an appeal to it but it turned out to be wrong.
And so the data kind of overturned that as people started to do chemistry and so on.
But on the other hand as I look at the history of physics I would say it's been back and forth
that sometimes you don't have any advance until you get new data and new experiments.
On the other hand sometimes you can be sitting and looking at the experiments for a long time
and not getting very far and then somebody comes up with a beautiful idea and that beautiful
idea actually unifies a lot of things and makes it easier to understand the data.
So actually you know Einstein is a very famous saying of his that you know one of the most
incomprehensible things about the universe is why it is so comprehensible.
It's not at all obvious that our theories should match reality.
You know why should it be that actually beautiful theories tend to be true about the universe.
It turns out that actually the aesthetic sense often times drives us to a good theory.
And I would say as a Christian that's because in fact God made the universe beautiful and
he used very nice laws.
But we can go wrong if we insist it has to be beautiful the way I want it to be beautiful.
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.
So would you say that being just objective or following the creation would be much more logical and beneficial for today's science?
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.
And I would say most people these days in philosophy and in science would agree with that.
That scientists very much passionately want the answer to come out a certain way.
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.
And so often times people find surprises things that are not the way they expect things to be and they're honest about that.
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.
So this idea of sort of the neutral scientist who has no opinions no desires is not accurate.
We all want it to come out a certain way and I do think that we talked before about string theory.
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.
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.
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.