This is a presentation first given to the Freethinkers Forum in Tallahassee. It is partly a critque of a book by Amit Goswami.

1. Gary Stilwell The Implications of Quantum Physics Uncertainty and Entanglement

2. Quantum Physics is the physics of the microscopic world - that of the elementary components of reality. Quantum Physics

6. We Have a Light Dilemma Newton (1600s) had said that light was particles Christian Hygens (1600s) had proposed waves *Thomas Young (1800) had proved it to be waves by the famous two-slit experiment Max Plank solved the black body problem by claiming it to be a particle Albert Einstein (1905) explained the photoelectric effect by showing light to be a particle So, what is it? It's a Particle !??

7. *Young's 1800 Two Slit Experiment Light source 1 first slit 2 second slit

8. Two-Slit Experiment - Interference Patterns -- Prove Light is a Wave Only waves can d o this! Try it with rocks in water Light source Two-slits Light and Dark Interference Pattern Diffraction - bending around corners

10. It's a Wave When light passes through both slits the resulting waves interfere with each other This is the same interference pattern we see with water waves If the light passes through only one slit, then there is no interference pattern

12. It's a Particle (like a ball) If we look at the light with a photon detector, then we see a particle - if we don't try to detect it, it acts like a wave This is true even if the light passes through one or two slits We can demonstrate the wave or particle properties of light by changing the type and location of our measuring device We get what we are looking for!

14. It Gets Worse - Matter is Also Both Light (a photon) is energy , so we might buy in to this duality thing But matter ? How does a bowling ball show wave and particle aspects? Electrons fired at a two-slit experiment show exactly the same kind of schizophrenic behavior as light So a matter particle can be viewed as a wave - just like a photon particle can be viewed as a wave This will explain a "weird" implication in the atomic model ---

16. Bohr Atomic Model This model allowed only discrete orbits Electrons radiate or absorb light waves only when jumping from one orbit to another This jumping became known as the quantum leap - going from one orbit to the next without going though the intermediate space between orbits HOW? God of the gaps? photon photon

17. The Electron (A Particle) is Also a Wave! This concept explained why Bohr's atom model worked Only a whole number of waves can fit around the atomic nucleus -- NO partials allowed. This is explained by quantum physics! No need for God of the gaps. deBroglie discovered that matter was a wave Quantum Leap Solved

19. Probability Wave Function Since the position can be spread out - the photon is at all positions - known as superposition .

20. Superposition - could be here, could be there Which slit did the electron or photon go through? Both! Until we actually detect the electron, it is in a superposition state, neither here nor there , but with a probability of being found here and a probability of being found there. The wave amplitude squared gives the probability. Reality consists of two kinds - actual and potential. A quantum entity exists in multiple possibilities of realities known as superpositions. Upon detection (by a measurement) the superposition state ceases to exist and the wave function is said to collapse . Therefore the observer and the observed are inextricably intertwined!

24. Einstein thought that hidden variables, associated with the entangled particles, gave them deterministic rules. He was convinced that there must be physically real things that cannot be described by QM He used entanglement to argue that QM had to be incomplete Einstein said "QM is incomplete"

26. EPR, Bell, Aspect Einstein argued for determinism against Bohr. Devised EPR [variations done on spin ] experiment to refute " spooky-actions-at-a-distance " and Uncertainty. A B C D Measurement Detector Entangled Particle At Time At time D, Bob measures position At time D Alice measures momentum and then knows position is exactly opposite Bob's - therefore knows both with no UNCERTAINTY.

27. Spooky action at a distance is a fact! A diagram of the preceding experiment using electron spin - if D1 is spin UP, we know that D2 must be spin DOWN Looks good. Why not? Emission Detection 1 Detection 2

28. Remember that until measured, they have no particle attributes. If 2 particles are in an entangled state, neither particle has a definite quantum state of its own. 2 entangled particles are regarded as a single system - not 2 systems If we measure particle 1, particle 2 gains a definite state at once even if they are far apart. -- but not due to hidden variables! Bohr said "not so"

31. Implications We've seen several implications already. These follow from the experiments: - Whatever reality is, it must be non-local that transcends local space-time . - The experiments indicate the existence of an invisible non-local reality . - If waves, spread out over vast distances, instantly collapse when measured, the influence of our measurement is not traveling locally . - The world is not determined by initial conditions, once and for all, and every event of measurement is potentially creative and may open new possibilities . - Before these experiments, one could still argue that a local signal between the particles, unbeknownst to us, was mediating the influence, which was thereby strictly obeying material realism.

33. - A consciousness that can collapse the wave function of a particle at a distance instantly must itself be non-local . What does that say about consciousness? - Instead of non-locality being a property mediated by superluminal signals, or hidden variables, one could posit that consciousness operates in some substratum of the world which lies beyond the world of phenomena. Are we sure that material realism is correct? What if the basic stuff of the universe is consciousness? Implications - cont.

34. QT Defies Common Sense and Understanding "If you are not confused by Quantum Physics then you haven't really understood it" Niels Bohr "Common sense is the deposit of prejudice laid down in the mind before the age of 18" Albert Einstein

35. END Discussion? Some slides follow for optional discussion

36. Various Interpretations of QM

39. QT - Probability of Decay 1 - Two Nuclei 2 - One Decays Spontaneously 13 N 13 N

40. Picture of Schrodinger's Cat

41. Quantum Weirdness - The Double Slit Experiment - wave interference

42. Quantum Tunneling Tunneling accounts for radioactivity - a spontaneous emission of a particle from a nucleus Classical Physics Quantum Physics

44. Spooky action at a distance is a fact! A diagram of the preceding experiment using electron spin - if D1 is spin UP, we know that D2 must be spin DOWN Remember that until measured, they have no particle attributes.

45. The Bohr Atom