Philosophy Now Forum

Philosophy Explorer wrote: ↑Tue Apr 10, 2018 11:50 pm Based on this article, I don't see why there's such a strong desire to separate math from physics:

https://en.m.wikipedia.org/wiki/Relatio ... nd_physics

What do you make of the discovery of non-Euclidean geometry in the 1840's? Either the world is Euclidean or it's not. Yet each geometry is internally consistent. Math gives no clue as to which is true of the world. In fact that was the moment that people realized that math only tells you what's logically consistent; and can never tell you what's true.

You can't get your entire worldview from extremely naive and unsophisticated articles such as the one you just linked.

Philosophy Explorer wrote:I expect to find a dimensionless point. ...

Oh dear oh dear, and there was me really hoping this was just all a good wind-up.

Try thinking about the words 'dimensionless point', how do you think we could find such 'thing'? Not least because if you use it to mean an actual thing then you are uttering a logical contradiction and that is always false.

And some links do show they're real. ...

No they really don't.

The article that says that lines always have a midpoint implies that the line (it doesn't matter if they're straight or curved) is made up of an infinity of dimensionless points (by logic) and has no gaps. ...

There are no real lines in reality they, like your 'dimensionless point', are mathematical constructs not real things.

So where's your proof?

The proof is in the logic, i.e. a 'dimensionless point' is a contradiction of terms if you use it to mean a real object. Try thinking about it, it's like a 'square circle', a 'round cube', etc, etc.

Philosophy Explorer wrote:Based on this article, I don't see why there's such a strong desire to separate math from physics: ...

It's not a 'desire'. It's because Mathematics whilst brilliant at generating possible models cannot tell us what is true about reality, for this you need Physics and in Physics there are a bunch of super specialised mathematicians called theoretical physicists who works on just that, generating models but they need the experimental physicists to confirm whether what they propose is actually true. Now you could say ah! but just because the experimenters can't prove it doesn't mean it's not true and there is a truth there but you are now into the realm of Philosophy, specifically metaphysic and epistemology, and Philosophy tells us that the world is over-determined by theories and that Physics so far appears to be hands-down the best approach to discovering how things work in the world.
p.s
By 'true' in the above I do not mean absolute truth but true in that the model or theory meets the observational data as confirmed by experimentation.

The last time I checked, Euclidean geometry was regarded as the best model for our universe which suggests it is the best candidate for reality. So do you propose to divorce Euclidean geometry from physics or wed it? Or do you have a better model?

PhilX

OMG! Do you not read anything said to you?

Is it that you are just incapable of thinking philosophically about your thoughts?

Arising_uk wrote: ↑Wed Apr 11, 2018 1:19 am OMG! Do you not read anything said to you?

Is it that you are just incapable of thinking philosophically about your thoughts?

Irrelevant

PhilX

This on a philosophy forum. Still, I think that is all the explanation me and wtf need about you.

Arising_uk wrote: ↑Wed Apr 11, 2018 1:32 am This on a philosophy forum. Still, I think that is all the explanation me and wtf need about you.

Still irrelevant.

PhilX

Philosophy Explorer wrote: ↑Wed Apr 11, 2018 1:11 am The last time I checked, Euclidean geometry was regarded as the best model for our universe which suggests it is the best candidate for reality. So do you propose to divorce Euclidean geometry from physics or wed it? Or do you have a better model?

So you agree that geometry is a model of the world and not the world itself. Progress!!

Regarding Euclidean geometry, did you miss the Einsteinian revolution last century?

wtf wrote: ↑Wed Apr 11, 2018 2:15 am

Philosophy Explorer wrote: ↑Wed Apr 11, 2018 1:11 am The last time I checked, Euclidean geometry was regarded as the best model for our universe which suggests it is the best candidate for reality. So do you propose to divorce Euclidean geometry from physics or wed it? Or do you have a better model?

So you agree that geometry is a model of the world and not the world itself. Progress!!

Regarding Euclidean geometry, did you miss the Einsteinian revolution last century?

As far as the model goes, it appears that the best model of the universe is Euclidean since no curvature has been observed in space. The question now is since geometric models aren't real, then how do we know that any of them apply to space?

PhilX

Philosophy Explorer wrote: ↑Wed Apr 11, 2018 2:45 am As far as the model goes, it appears that the best model of the universe is Euclidean since no curvature has been observed in space. The question now is since geometric models aren't real, then how do we know that any of them apply to space?

We don't. That's the problem. We used to think that math was the way to discover the truth about the universe. Then in the 1840's we discovered that math is a toolkit for building models, but it doesn't give you any way to know which model is true. Math is agnostic to physical truth. You can use math to build mutually inconsistent theories.

At first non-Euclidean geometry was regarded as just a curiosity. Then Einstein showed his crazy new ideas to his mathematician friend Minkowski; and Minkowski said, "Hey, math has got just the thing to express your ideas." And that thing was differential geometry, the study of curved surfaces and spaces. Riemann's non-Euclidean manifolds turned out to be just what Einstein needed to make sense of his theory.

But now there was a huge societal downside. Math used to be about certainty. And now it turned out to be nothing more than a tool for building models. So what could we count on? First we found out that we could not depend for the truth on the Church, and that reason in the form of math was the way to the truth about the world. And in the beginning of the twentieth century, the certainty of math failed. Morris Kline wrote a book called Mathematics: The Loss of Certainty about all this. It's not too farfetched to trace the development of cultural relativism and the contemporary doubt about rationality itself; to the moment in the 1840's when people discovered that math is not the truth.