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Old October 10th 18, 04:26 PM posted to sci.astro.amateur
Martin Brown[_3_]
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Posts: 189
Default Neil DeGrasse Tyson headed down same loony road as Carl Sagan?

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.

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 am not so sure about the layer that sits underneath QCD - I never did
like HEP though. I found the arbitrary use of renormalisation to get rid
of unwanted infinities a little bit worrying - it worked OK provided
that you knew what you were doing.

In normal language use, simple implies easy to learn.


That's a very limited use.


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.

--
Regards,
Martin Brown