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Kevin N
Kevin N
06:39
@JohnRennie Hi :)
John Rennie
John Rennie
@KevinN hi :-)
Kevin N
Kevin N
I've been wondering this question for quite a while and it's a bit something like this
The possibility of observing and finding new phenomenons out there is always there, does this mean that there is a chance of that the way an object (or anything really) behaves contradicts or defies the our current understanding of physics?
John Rennie
John Rennie
What you're asking is actually a fundamental principle in physics. When we create a theory it's just a mathematical model to describe what happens when we do an experiment.
For example take Newtonian mechanics. This is a theory created to predict what happens when we apply forces to masses. It tells us F = ma.
And it works pretty well. So that does that mean Newtonian mechanics is some fundamental truth of the universe?
Well ... no!
Kevin N
Kevin N
Agree
John Rennie
John Rennie
Because we discovered that for speeds near the speed of light Newtonian mechanics stops working and we have to use relativistic mechanics instead.
So we observed something new and it broke the previous theory.
Kevin N
Kevin N
06:48
Yes, finally someone that really understands what Physics is meant to do :)
John Rennie
John Rennie
Does that mean relativity is a fundamental truth of the universe?
Erm ... we don't know but probably not.
Any day we might might discover something that breaks relativity.
Kevin N
Kevin N
I've seen a lot of people out there, wouldn't call them "Physicist", but are obnoxiously acting as if they were the one creating the rules and the universe abiding them.
John Rennie
John Rennie
@KevinN all physicists know this really, but most of us ignore it on a day to day basis :-)
Kevin N
Kevin N
Good thing to know then :)
John Rennie
John Rennie
:-)
You can't get on with life if you're always worrying that everything you know could be wrong. So we all just assume our theories are correct and carry on until we discover otherwise.
Kevin N
Kevin N
06:52
So "weird" theories out there might be true after all? But based on our current knowledge of Physics, it isn't just possible or the chances are very slim.
@JohnRennie I was relieved when you said all of this :)
John Rennie
John Rennie
Well I could have a theory of gravity that it's actually invisible gnomes pulling on matter. And I could make this theory sufficiently contrived that it's impossible to disprove by experiment.
Does that mean physicists should take John's theory of general Gnomitivity seriously?
Kevin N
Kevin N
@JohnRennie Gnomes. That's hilarious.
:)
But is it possible, yes :)
John Rennie
John Rennie
If a theory makes a prediction that contradicts experiment then it's wrong and we can safely ignore it
Kevin N
Kevin N
Yes, totally with you on this
John Rennie
John Rennie
If a theory can't be disproved, e.g. because the experiment is impossible at our current level of technology, then it's a judgement call. String theory is like this. It can't currently be disproved and it makes enough sense that physicists take it seriously.
Kevin N
Kevin N
06:57
user image
John Rennie
John Rennie
:-)
But most of the "weird" theories out there make such little sense that physicists are not interested in studying them even if technically they can't be disproved.
I need to go, but I'll be back in an hour or so.
Kevin N
Kevin N
Alright, Thanks :)

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