Light is a wave and a particle

[azekeil]

So, if you've ever done A-level Physics (and possibly otherwise) you will have heard the above phrase. I never knew exactly what it implied, but here is a concise description which will bend your mind, but make sense at the same time. Interesting!

Comments

[meltie.livejournal.com]

Dark forces at work.

[azekeil.livejournal.com]

Well, actually, you can't tell if it's light or dark without looking at it.. ;)

[meltie.livejournal.com]

Got a warezed copy of God's debugger? Mind you, taking into account string theory, the backend's got to be pretty hairy...

[thespirit3.livejournal.com]

Quantum stuff us fascinating. An experiment similar to the above as described in the book 'Schroedingers (sp?) cat'. The fact an experiment only behaves in a certain way when we monitor it - the very process of observation being enough to effect the output.

It's a while since I read it though.

[azekeil.livejournal.com]

Ugh. :p

[sepheri.livejournal.com]

This:
http://www.amazon.co.uk/gp/product/0385235690/sr=8-1/qid=1146746421/ref=pd_bbs_1/203-7827427-5995161?%5Fencoding=UTF8
is a very good and understandable book.

[azekeil.livejournal.com]

Shroedinger's cat just explains the Uncertainty Principle; it doesn't explain how light is like a particle and a wave :)

[ev1ldonut.livejournal.com]

No, but it's based on the same principles of quantum theory and is a fascinating read in in its own right, if you can find a decent writeup of it. :)

[azekeil.livejournal.com]

Yup. I did manage to read A Brief History of Time during my A-levels but I haven't read anything since (then I went to uni and I stopped reading as you know ;) )

[azekeil.livejournal.com]

Ah yes, looks interesting :) I actually got quite a lot from the first reviewer's synopsis.

[sepheri.livejournal.com]

I actually never finished reading it but I read half of it during my exhibition last year and got a lot from that.
I am sure I will pick it up again some time.

[thespirit3.livejournal.com]

Yup, and the book does go into detail about light behaving like both a particle and a wave.

I have the follow-up book too (written 10 years later?) but have never got around to reading it. The first was a little heavy going at places - I needed space for my brain to recover, and then ... never picked up the second. D'oh.

[azekeil.livejournal.com]

..an interesting choice of reading matter at ayour fashion exhibition.. ;)

[azekeil.livejournal.com]

Unfortunately I stopped reading when I got to university. Yes I realise the implications of this, but it didn't seem to matter too much.

I need to find the time and imagination to pick up some books dealing with mind-expanding topics such as this and start reading them and taking myself on flights of imagination all over again :)

[sepheri.livejournal.com]

You should have seen the looks I was getting.
They would walk up to my work, realise it was rubber and look down at the teeny girl in the designer dress reading about Quantum Physics.
I love being me!

[azekeil.livejournal.com]

*grin* An intellectual's wet dream, for sure ;)

[sepheri.livejournal.com]

Shame there's no one worth having me ;)

[thespirit3.livejournal.com]

I never stopped reading. I simply never started reading.

Schroedingers Cat was just a hiccup along the way. The closest I get to reading is using reference books. Kinda sad really, but I've just never had the time or interest. Occasionally a subject will grab me, and I'll read every book about it on the planet - but, I've never regularly read for the enjoyment of reading.

Anyway wandering off topic now ...

[azekeil.livejournal.com]

What, as a dream or in reality? :p

[sepheri.livejournal.com]

Either!

[azekeil.livejournal.com]

I used to, but now I find Life™ gets in the way. That's a shame, and a lot of what is wrong with society can be attributed to lack of education, of which I think reading peer-scrutinised works that illustrate current thinking is rather a large part.

[azekeil.livejournal.com]

You're a hard woman to please.

[sepheri.livejournal.com]

Impossible.

[azekeil.livejournal.com]

I wonder if this is a quantum puzzle... *grins*

[gerald_duck]

The whole area of wave-particle duality, of the interface between microscopic quantum theory and macroscopic relativity, worries me.

There have been obvious contradictions and sources of puzzlement for decades. True, we've now managed to bind everything together into string theory, and latterly M-theory. Conflicting theories are reconverging into something consistent and somewhat pretty.

But it all strikes me as enormously complex.

Before we had accepted that the sun not the Earth was the centre of the Solar System, astronomers had already noticed that the various planets didn't follow smooth circular (or elliptical) paths around the Earth. They modelled the glaring discrepancies as epicycles — wheels within wheels. We now know that, in looking at an object's motion around the Earth, they were seeing the superimposition of that body's motion around the sun and the Earth's motion around the sun. Once they put the Sun in the middle, all the epicycles vanished.

I'm pretty sure that M-theory is currently suffering the same kind of problem. Somebody, somewhere, some year soon, is going to begin a sentence with "But wouldn't it be simpler if we…". All of a sudden, a lot of things will make sense.

Einstein wrote all of his important papers about a century ago; we're about due another genius of comparable insight. (-8

In the meantime, this is my favourite book on string theory. It also does a good job of presenting relativity and quantum theory in a comprehensible way, in order to place the discussion in context. Notwithstanding the fact that I don't think our view of the universe is currently terribly elegant, notwithstanding the fact that we ought to have a theory that doesn't need explaining or justifying in terms of the incomplete and erroneous ones that have gone before, this is a good book, and as simple an explanation as you're going to get of the current state of thinking.

[azekeil.livejournal.com]

Yes I agree. Soon we will have quantum computing, and perhaps the 'quantum era' will illuminate the inner workings of things more clearly until suddenly it goes 'ping' for someone and they communicate it to the rest of the world. Interesting thought.

Or perhaps it's more like Douglas Adams' suggestion that the Universe conspires to be unexplainable, instantly replacing itself with a replica that is the same but inherently more complicated when anyone threatens to find out The Truth™ about it...

[gerald_duck]

I quite like Terry Pratchett's theory that "How do you know something's impossible until you've tried it?" isn't quite accurate, and many things aren't impossible until you've tried them. Then the Universe suddenly goes "hang on a moment" and makes it impossible. He notes that with cold fusion this took a little longer than usual. (-8

On the other hand, back outside the realms of fiction, the history of science seems to be a continuous cycle. Someone comes up with a simple theory that explains a lot of stuff and has good predictive power, then some discrepancies get spotted, the theory gets amended and augmented, more discrepancies get spotted, eventually the edifice is looking much less elegant and it's time for someone to rationalise everything with a new theory. It's happened countless times in the past, and I sense it's about time for it to happen again.

[azekeil.livejournal.com]

Well, then, extrapolating that theory, surely then the ultimate theory has to be stupendously simple? Well it works in fiction... ;)

[gerald_duck]

If there is an ultimate theory, my guess is that it will be very simple, just abstracted a long way from where we are now. In the same way that we've made significant advances in the past by understanding progressively more fundamental things, each of which was outside our grasp until we'd spent time investigating the previous, I expect any ultimate theory will deal with things much more fundamental than strings.

Alternatively, it might be turtles all the way down, just progressively simpler turtles.

[azekeil.livejournal.com]

Maybe, then, the ultimate theory is simply that it exists in the manner it does simply because we say so.

[gerald_duck]

Doesn't have much predictive power, though, that. Remember we have to explain not only how things are like this but also why they're not otherwise, and what's going to happen next. :-p

[azekeil.livejournal.com]

My universe-fu is obviously not strong enough yet. I shall meditate on this further ;)

[meltie.livejournal.com]

My exact opinion on the matter. Things have got to be simpler than this. Quantum just isn't beautiful enough.