Quantum Theory, Causality and Determinism

Look into Quantum Entanglement. Basically it shows that when two separate particles are shot off in opposite direction, and a 'spin' is applied to one particle, the other reacts accordingly. What this does is open new ways of thinking about causal relations that aren't strictly spatial.

Hi Darunia - What do you mean by non-linear time?

Well like in the theory of special relativity there is no concept of past present or future. It's like the map idea of every event having it's own bit of space time. So it's only the human concept of past, present and future that makes us suppose time is linear when instead it's a constant. And it's possible to move between these events like we can move about in space, if we could travel at such speeds or sustain wormholes.

Ohh, so I was getting different theories confused. But I thought their was a Qunatum Theory where all events were happening at stimitanously but we were perceiving them as the past, present or future etc?
Or theres a quantum theory that suggests we can travel backwards in a loop of space-time?
If not does Quantum Theory effect our idea of time at all?

Hey, I'm planning on doing an essay which has a title somewhere along the lines of "What effects does Quantum Theory have on causality and determinism?"
I know some areas of how effects determinism, such as the uncertianity pinciple etc., as there are quite alot of books on that topic. However I'm not uite show how/if it affects causality. Can anyone suggest some good research books or ideas on this title?

Yes, it is important to know what we do not know, but I guess, Alan, it's not very important to let other people know what we do not know, which gives us free reign to copy and paste advanced mathematical physics we know we don't understand. :whistling:

Cant you see I was just kidding adding a little humor?

We must sometimes lighten up a bit

Do I understand all that maths, absolutely not?

I do understand how extremely complex it really is and that is what tickled my tummy

Alan

And besides wheres the fun in education if you dont challenge yourself?

Haha, yeah well one day I will understand that maths stuff, after uni, I understand some of the concepts behind it already anyway. And I've changed the topic slightly to a (slightly) easier more philosophical topic which is now something like "How Quantum Mechanics/Physics effects our view of reality."
And besides wheres the fun in education if you dont challenge yourself?

Hi Darunia

I'm sure you've already looked into Schrodinger's cat (or the measurement problem as it is known) and the electron double-slit experiment. Other ponderables are the EPR paradox and the Stern-Gerlach experiment. In general, there is the problem of interpretation in QM. QM predictions are derived mathematically, with scant attention to philosophical understanding. Some see this as a virtue, some as a sign that QM lacks a fundamental basis.

There are five main postulates in QM and you should probably be familiar with them.

1. All systems are described by wavefunctions (waves that vary in time and/or space) - note this is almost never a simple sinusoidal wave.

2. A measurement of a system can only yield specific measured states (eigenfunctions), each having a corresponding measurement result (eigenvalue).

3. The initial wavefunction of the system may comprise more than one allowed state(the expansion postulate)...

4. ...but because we can only measure one, after measurement the system must be in the measured state (collapse of the wavefunction).

5. How much of the measured state was present in the original wavefunction determines the probability of measuring that state.

For instance, I may have a measuring device that can measure -1, 0, or 1. To begin with, the system wavefunction describes a mixture of these states: 0.35x(-1) + 0.6x(0) + 0.53x(1). The probability of measuring, say (0) is 0.6 squared, or 36%. After measurement, I get the result (1). Thus the system is now in state (1) with probability 100%.

That is as close to a philosophical basis as QM gets. Shocking, eh? But there's plenty of scope for philosophy in there. Are objects really waves, or are waves just the best way of doing the maths? What does it mean to be more than one thing at once when we can only see objects as being one thing? How does simply observing something change it's state? Does this suggest consciousness has special powers in nature? Are processes really probabilistic or is there some underlying determinism that we're unaware of?

Now you revert to physics , so please allow me to do the same? :perplexed:

I am fairy informed in physics and made reference to Schroedinger and his silly harl alive half dead kittens, and unprovable hypothesis atthat