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Old October 10th 18, 05:06 PM posted to sci.astro.amateur
Chris L Peterson
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Default Neil DeGrasse Tyson headed down same loony road as Carl Sagan?

On Wed, 10 Oct 2018 16:26:47 +0100, Martin Brown
wrote:

On 10/10/2018 14:19, Chris L Peterson wrote:
On Wed, 10 Oct 2018 08:34:40 +0200, Paul Schlyter
wrote:

I have not argued anywhere that it is simple to find any answers.

You have a quite unusual definition of simple if you think e.g.
tensor calculus is simple. Yes, the GR theory
uses tensor calculus as an essential part.


Well, in truth, tensor calculus IS simple. That is, it requires
nothing more than following a set of rules. That's why problems are
readily solved by computers.


You have a *very* strange definition of simple. Most postgraduate
mathematics students struggle to visualise the true meaning of covariant
and contravariant derivative tensors in a curved metric space.

Even Newtonian dynamics quickly becomes computational solutions only for
the three body problem unless you have a very rare stable closed form.


I would describe as "simple" in the context I'm talking about here
anything which has a computational solution.

But that's irrelevant to my point. The laws of nature are simple. GR
is simple. That doesn't require that everyone somehow has the ability
to utilize the tools used to solve problems.


The inverse square laws for gravity and electromagnetism are relatively
simple but the dynamics of objects moving under them is not even for
three self gravitating bodies.


I didn't say that behavior is simple. I said that the rules are
simple. Simple rules can certainly lead to complex behavior, which may
be difficult or even impossible to predict.


You can describe GR in a simple way as matter curving straight lines in
spacetime but to use it in anger requires very high level mathematics
that is typically not taught at undergraduate level except at a handful
of institutions. By any reasonable definition that makes it not simple.


I disagree. It is simple by virtue of the fact that it is subject to
known rules that can be reliably and consistently applied to describe
the behavior of nature. The nature of the math is irrelevant.