The Limits of Thought
This post is for Rupert Read who promised us the occasional philosophical reflection on his blog.
I like questions too.
Science tells us that the absolute minimum temperature is −459.67° Fahrenheit. This is a theoretical figure assumed to be when atomic motion stops. We measure temperature by atomic motion, that is the agitative state of atomic matter – atoms, molecules etc. So when it stops we can’t measure it any more.
However, there appears to be no theoretical maximum temperature that I am aware of. But consider this. The laws of physics as we currently understand them tell us that there is a maximum speed – the speed of light, 186,000 miles per second. So, if the agitative state of atomic matter reaches the speed of light it can go no further, so there must be a maximum theoretical temperature.
The limitation here, of course is the way we measure it.
Now consider Relativity theory. Nothing can travel faster than the speed of light. But is that also a limitation based on the way we measure and experience it?
Let’s have a thought experiment. Let’s suppose that it is possible to travel faster than the speed of light and that a spaceship is travelling towards us at say twice speed of light. What would we see? The light emitted from the spaceship would be lagging it so it would arrive before we saw it. And what would we see while it is on its way here? We wouldn’t be able to see it or anything behind it. Would it therefore look like a Black Hole?
And how many Black Holes are out there?
6 comments:
I think it's that nothing with mass can travel faster than the speed of light - although light doesn't move at a constant speed apparently.
If the ship travels towards us faster than light we wouldn't see it until after it arrives, you wouldn't see anything unusual at all - just as when a bullet travels faster than the speed of sound you are shot before you hear the bang.
If the ship simply passed by us without harm we'd actually see it coming towards us after it was long gone, but it would essentially be an illusion - just as some of the stars we see in the sky no longer exist.
"Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns -- the ones we don't know we don't know."
Zen and the Art of Rumsfeld.
He has here omitted the things that we don't know that we know (famous as the detective fiction brainwave)?
http://www.newton.dep.anl.gov/askasci/phy00/phy00027.htm
As Rupert Read (the most self-referential man in the universe according to scientists) might say, "Whereof one cannot speak, thereof one should be silent"
But that's never stopped anyone. No is the short answer though. It's 100+ years since Einstein's idea and nothing has yet contradicted special releativity. If it were possible to go faster than light then things would go horribly wrong, such as things hapening backwards. Which reminds me, Times' Arrow is a good book.
If things started happening backwards, then we would also be measuring them backwards, so how would we know?
further to my post yesterday:
in relation to Times' Arrow and touching on Weggis' questions, the smooth and stable expansion of the universe is thought to mitigate against time-symmetric explanations - this means that if the universe crunches then things will not run backwards as it does so.
The quantum theory which allows for multiple simultaneous states of an object could be seen to favour the possibility of time travel but this is through the creation of a parallel universe so the past or future you go to is not YOUR past or future but an alternative one. I would imagine the need for phenomenal amounts of energy would be a sticking point too. And there are problems with singularities and time travel too but I don't understand at all and I'm bored now.
btw, Einstein said that time is simply what a clock reads - if you're on the verge of delving into deeply philosophical areas regarding grammar etc and making it more confusing that it is.
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