On 22/06/15 09:44, Col wrote:
"RedAcer" wrote in message
...
On 21/06/15 15:02, Col wrote:
Dawlish wrote:
There's no 'right' and no wrong in science, as I've attested to on
here any times.there is no proof, though deniers want there to be.
The best you'll get is a consensus amongst scientists. In this case,
the consensus is huge, at 99.9% in the latest literature survey. What
does that suggest about CO2 being the major cause of global warming.

A good analogy is gravity. The theory of gravity is not proven and
never will be. However, if I was stood under a falling piano, I'd be
inclined to do my best to get out of the way. A denier, however would
be still telling anyone in hearing distance that the theory is a
bunch of crap. Right up to the end. ??

In the instance of gravity, how much proof do you want??

We know how it works,

Do we?

Yes.
We can throw spacecraft around planets and they always go where we
want them to, they don't crash into the planet or go flying off into space
in the wrong direction because somebdy got the equations wrong.

Yes they do. An early probe to mars crashed because someone got the
maths wrong.


we know what the equations are. We can
'slingshot' spaceprobes around planets in order to accelerate them.
And lo and behold the probes end up where we want them.

Yes you can use the equations of Newtonian gravity and calculate these
trajectories with sufficient accuracy in the solar system, but not in a
strong gravitational field where you have to use the more accurate
theory of general relativity, where gravity is modelled not as a force
but as the curvature of spacetime.

I am well aware of the limitations of Newtonian physics.


How could we do that if the theory wasn't 'proven'?
Newtonian gravity was proven to be wrong ~100 years ago.

But only *wrong* where relativistic principles become significant.
Newtonian gravity works for us in most instances, and where it
doesn't we know how to calculate it.

Newtonian gravity is an approximation to GR when you make the mass small
enough. This has been proved.


Einstein didn't replace Newton's theories, he merely built upon them.

Wrong. He did. GR is a completely different theory using different
principles. Newtonian physics wrongly predicts the orbits of the
planets. GR correctly predicts them.