Quantum theory is bizarre and daft and if somebody told me about this in the pub then I would laugh them outside, and then drown myself in beer. In order to try and understand, we need to forget everything we know about what causes things to happen and what effects are caused. You also need to put to one side reality, certainty, and much more than you would like to. This quantum world is a different world, it has its own rules, rules of probability that make no sense in our world as it struggles to exist today.
In order to grasp the basic principles involved just three key experiments are needed. The three experiments are generally known as the ‘Double Slit Experiment’, Schrödinger’s ‘Cat-in-the-Box Experiment’ and the ‘EPR Paradox’. Sounds good eh?
Quantum theory attempts to describe the behaviour of very small objects, generally speaking the size of atoms or smaller. We find it necessary to have two sets of rules for large and small things because particles do not behave in the same way as larger everyday objects, such as basketballs. We can, for example, say precisely where a basketball is, what it is doing, and what it is about to do.
The same cannot be said for particles. They are, quite literally, a law unto themselves, and why this should be so nobody knows and the people with brains are still trying to come up with an answer. The classic experiment to illustrate this is the famous double slit experiment, originally devised to determine if light travels as waves or particles.
Double slit experiment- It is probably best to see this experiment, so take a look at at the video below and prepare for, errr, Dr Quantum to take you into the realms of quantum physics. Keep your mouth closed otherwise your brain might just pop out.
The double slit experiment is not simply a one of theory that has no use in the real world. This strange behaviour of particles lies at the very heart of our understanding of the physical properties of the world. Quantum theory is used in many applications, including television and computers, and even explains the nuclear processes taking place inside stars.
One possible explanation for quantum weirdness is a theory concerning the nature of the wave that is passing through the experiment. The key concept of the theory, is known as the ‘collapse of the wave function’. The theory seeks to explain how an entity such as a photon or an electron, could ‘travel as a wave but arrive as a particle’. According to the theory, what is passing through the experiment is not a material wave at all, but is a ‘probability wave’.
In other words, the particle does not have a definite location, but has a probability of being here or there, or somewhere else entirely. Some locations will be more probable than others, such as the light areas in the interference pattern for example, and some will be less probable, such as in the dark areas.
Brain Explosion
In this theory, an electron that is not being observed does not exist as a particle at all, (arghh!) but has a wave-like property covering the areas of probability where it could be found. Once the electron is observed, the wave function collapses and the electron becomes a particle. This theory neatly explains the behaviour of the particles in the double slit experiment.
When we are not looking at the particle, the probability wave, of even a single particle, is spread out and will pass through both slits at the same time and arrive at the detector as a wave showing an interference pattern.
When we observe the electron by placing detectors at the slits, it is forced into revealing its location which causes the probability wave to collapse into a particle. If the theory is correct, its implications are enormous.
What it suggests is that nothing is real until it has been observed! I’ll say that again.
What it suggests is that nothing is real until it has been observed!, and once again.
Nothing is real until it has been observed! This does need thinking about. Are we really saying that in the ‘real’ world – outside of the laboratory – that until a thing has been observed it doesn’t exist? This has caused some very well respected cosmologists Stephen Hawking (for one) to worry that this implies that there must actually be something ‘outside’ the universe to look at the universe as a whole and collapse its overall wave function.
John Wheeler puts forward an argument that it is only the presence of conscious observers, in the form of ourselves, that has collapsed the wave function and made the universe exist. If we take this to be true, then the universe only exists because we are looking at it. As this is heading into very deep and murky, smelly water I think we will have to leave it there and move on to the next experiment, phew.
Schrödinger’s “Cat-in-the-Box Experiment”- The way that a quantum wave moves is described by Erwin Schrödinger’s wave equation and describes the probability for finding a photon, or electron, at a particular place. Schrödinger did not however, go along with the ‘collapse of the wave function’ theory, he thought it was pretty daft, and designed ‘thought experiments’ to prove his point. In an attempt to demonstrate the foolishness, or so he thought, of quantum theory, Schrödinger devised the cat-in-a-box thought experiment.
The wave function of the whole system will not collapse until a conscious observer enters the room. At that moment the cat ‘decides’ whether it is dead or alive. Until that moment, the cat is not either dead or alive. Only the act of observation will cause it to become one or the other. Schrödinger described the situation as ’having in it the living and the dead cat mixed or smeared out in equal parts,’ nice!
The room cannot contain a cat that is both dead and alive at the same time, or a cat that is neither dead nor alive or suspended in limbo but contains either a dead cat or a live cat, until someone looks, and it is then that the actual reality of the situation is determined.
If you think about it then this raises some very odd questions like what is a conscious observer? Would an insect or even a bacteria be classed as a conscious observer?
Shrodinger
Does the universe exist only because we are here to observe it?
Could a cat really be either dead or alive until the moment of observation? This goes entirely against all our common sense experience of life, we would naturally conclude upon finding the cat alive that it had ‘obviously’ been alive all the time. Quantum theory is telling us that we could be very wrong in our thinking regarding what reality really is.
The EPR paradox- this was designed as like Schrodinger’s cat to disprove all the quantum stuff.
The experiment focuses on the phaenomenon of quantum theory known as ‘non-locality’, which concerns communication between particles.
Just as we have seen in the other experiments, the protons will not collapse their probability wave and ‘decide’ which spin to adopt, until they have been observed. If you measure the spin of one proton, according to quantum theory, the other proton instantly ‘knows’ and adopts the opposite spin. So far so good, we have come to expect this sort of behaviour from particles (I hope) so what is the problem with this particular experiment?
Something here is taking place at faster than light speed, although exactly what is not known. Unfortunately no meaningful communication could be made using such a device. Whether or not it will ever have any useful application remains to be seen, but that is not the point. The point is the experiment has proved Einstein wrong, faster than light speed, at least in the quantum world, is a reality. This experiment has now actually been carried out over a distance of 10 kilometres and confirmed as correct.
I always thought there was something odd about the universe and looking at quantum physics just really confirms it. The universe is much more weird than our little brains can fathom. Perhaps one day we will have evolved enough so that we can understand this funny and odd universe.
If you fancy finding out a little bit more and not blowing your brain up then try this book, Quantum Theory Cannot Hurt You: A Guide to the Universe
Here is something on the web that may take you a little bit further
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Just goes to show you how much we don’t understand about our universe. To think that what we see only exists because we think it does brings forth all kinds of wacky possibilities.
If a tree falls in the woods and no one is there to hear it fall, does it make a sound?
It doesn’t exist until there is someone observing and that means I suppose observing(hearing) the sound.
Nice and good articles in here, I’m glad to visiting in your blog, I hope we can make a friends in blogsphere……, come to visit and comment in my blog to friends. Thanks
I’ll have to leave that quantum physic stuff to you LOL … Don’t understand a lick of it.. But if you want to know about quantum bible stuff LOL, then I got what you need… Anyway I will love getting to know you.. Keep up the great job on your site… The comos articles are great and the pictures are awesome:)
Have a great day
Blessings
Rev Deb
Makes sense to me
Thanks for that. The quantum stuff just amazes me and I have yet to find time to delve deeper.
[...] of parallel universes is the many worlds theory. To understand this it might be best to read one of my previous posts on quantum physics. This theory says that measuring a quantum object does not force it into one state or another. [...]
Ahh, but the debate on wheather Stephen Hawking’s or John Weeler’s theory is tru is a fun one. It depends on how you would se things. I could debate for hours on tha topic. I still remain undecided on which front is more probable but I tend to linger more to Stephen Hawkings.
Why do you verge toward Stephen Hawking?
Because it ties all beleifs (well not all but a lot) together. Like when people say they beleive in God, those who tend to laugh on the inside (I normally am one of them) can take a different view on it. I am not religious at all but that debate just keeps me wondering if there really is a God. I dont think there is, but I do think that some how a spectacular power or being keeps the universe alive and genertaing. I don’t mean that the universe is being controlled, I highly disagree with that. I wonder that what if the universe is being observed. But not by God. But John Weeler’s theory also has my respect as well. Back to my begining thought, how it ties it all together, that’s because a lot of religious people don’t like to think of certain events like the big bang or how he universe was created being linked to science. But the theory of Stephen Hawkings sort of, in a wy, proves them wrong. Even though beleifs can never be wrong, it just shows a whole new level of thinking. But once again I am undecided on which theory is more proboble. I want John Weeler’s to be more proboble, but the question really is, which one makes more sense with less complication. Yeah I know, I’m writing a lot…. With science I ramble. But it’s fun.
I tend to keep an open mind about the God thing as well but there does seem to be something observing our universe so that it exists.
when I try and understand string theory that gives me that feeling as well. underlying reality there must be something that is causing all this oddness in the quantum world and I’m not sure it’s a man with a book!
Haha. Yeah. There does seem to be a possibility of something observing the universe, but i’m not completely convinced its the God that some beleive in. It could be A god, but no necessarily THE God. It could be something we don’t beleive in yet or never will. We should write a book. We’ve got the stuff!
I suppose you have heard the theory that the universe is a giant quantum computer. Now who’s operating that? Probably some spotty kid who’s thinking about loading world of warcraft.
A guide to the universe by Dave and Chris, I love it.
hahaha. Yeah. And the spotty kid on the computer would have to be thinking about the wonderful games of Runescape and Tetris Online and deffeating the evil bosses. Now that would be something…
Who knows on a distant planet in a different galaxy far, far away…
It’s lucky we can imagine and are not limited to our knowledge alone.
If we couldn’t imagine then we never would have solved the Big Bang theory. We probobly wouldn’t have even enerated a thought for the firt television or computer.
Have you read Stephe Hawking’s book on the hteory of everything? It’ pretty interesting. You seem like you would like it.
Yes I have dabbled with that and a lot of science fiction. The parallel universe book I mention in the post parallel universes is also a mind widening exercise.
I am a fan of science ficion also. A very good science fiction series that also involves philosophy, is Ender’s Game. The following books are Speaker for the Dead, Xnocide, and Children of the Mind. Also, what amazes me in this book, is that the author creates his own interpretation of the Internet when this was written before it was invented. And I must say it’s very accurate.
Ender’s Game sounds a bit like starship troopers with humans fighting insects but I may give it a whirl.
Looking at the cover of the book, it seems nothing like it except for the similarity of fighting alien bugs. After reading the summary of the book, I admit it has similarities, but Ender’s Games has all these details (such as a made up game, and a completly new political system) and ideas up his sleeve that I dont think Starship Troopers has.
Anyways, do you reccomend any Science fiction novels? Or just good science books that deal with what we’ve been talking about?
Peter f Hamiltons void triology has kept me going, The dreaming void is the first one and the last will be published soon. I like new books as they have mostly new ideas.
You have given me an idea to have a book page, look out for it above.
If you ever fancy writing a post then let me know you seem to have some excellent ideas
I feel stupid. This whole time I’ve been talking to the author of the blog and I had NO idea. Wow. Anyways, I’m about to look up at you book page. I assure you if I have any ideas I’ll let you know.
I dont know. I may try posting my own blog, but still not sure. Deffinatly worth considering though!
OOP! I have an idea for your book page. Along with books you reccomend, you should do a reveiw on one or two. Also, email a few people that read and comment on your blog and ask for books they reccomend.
Good ideas, I’m having a little problem with the book page it will be up soon.
Cool. I guess our conversation s drawing to an end… I ust say, it’s been fun exchanging emails with you.
Yes, me too. If you want to contact me try the contact form then you’ll get my email. Can’t give it here because of spam.
See you around!
Ha ha. Yeah. I’ll make sure to contact you soon.
I’m kinda confussed about this hole article, can someone explain it a bit easier
I know it doesn’t help at it is one of those subjects that you need to read again and again.
It is a very odd side of physics but has been proven and if you think that it’s hard then try looking up “strings”. Only three people in the world are said to understand this
[...] I have covered these both before in a quantum physics post. [...]
Awesome post.
Once you read enough and live enough it is very clear and logical how our Universe works. In fact it is increasingly important that people begin to understand quantum physics and it’s application in our world. Perhaps it just needs to be explained to the masses in a way that’s accesible to them.
In the beginning there was change.
A war between two opposing, yet previously peaceful tribes.
As time passed it became obvious that the only path to peace was compromise.
Compromise led to peace.
Different, yet stable peace.
As time passed the war was only remembered in history books.
But everyone new that one day change would come again.
Expansion begat change,
Change begat Compromise,
Compromise begat further Expansion,
Thus is the way for all beings, large or small.
What we witness in the twin slit theory is compromise.