This Power Point program visualizes the world of Quantum Mechanics for the novice physics student. Rather than consisting of static slides, the screens are designed to move dynamically in order to make the subject matter more easy to comprehend.

1. The Strange World of Quantum Mechanics DESIGNED BY CHARLES HENDERSON 2004

2. Target Filter Screen Photon “gun” Photons are shot through a slot toward a target, a photographic plate.

3. Going through one slot, several shots hitting the target at slightly different places might appear like this. They have the appearance of bullet holes.

4. But remember, even though this model shows TWO particles Going through both slots, only ONE particle is shot. The one bullet goes through both slots. Photon “gun” Photons are shot at a photographic target; but this time, there are two slots, offset from the center.

5. When photons are fired through two slots in a separator screen, the pattern appears like this:

6. The reason the pattern looks like parallel strips, rather than dots like bullet holes, is because the incoming “bullets” act like waves that collide and cancel out parts of each other. Waves cancel each other where they intersect. On a photographic plate, white strips represent the points of intersection, where they cancel each other.

7. Thus, the plate consists of parallel stripes where some waves have intersected. And not

8. A plate that looks like one peppered with bullet holes.

9. When only ONE photon is shot through two slots, it somehow goes through both slots and becomes a series of waves

10. Could it be that the particle is not a ball from the outset but a WAVE from the start? If so, why does it ACT as though it is a ball when there is only ONE slot?

11. The next slide demonstrates how it might look if “particles” are really only waves.

12. Like water waves, a big wave hits both small openings; then goes through as two waves that expand and collide with each other

13. What has happened? Does the original particle “KNOW” that there are two slots and separates into two particles in order to go through both slots? If so how does the particle “ KNOW ” there are two slots?

14. When we consider what a particle can KNOW in the quantum world things get even stranger. Suppose we wanted to know WHICH particle went through a given slot? For example, suppose one particle is green, the other red, and we decide to observe a slot to see which color shows up. In a quantum experiment, we would have to check, for example, for a green particle at one slot. If it turns out that the particle is NOT GREEN, we could infer that it has to be RED.

15. You can check for eithergreen or red at each gate

16. Strangely, whatever color you check for at either gate is always what you get!

17. Somehow, it seems that the particles (or whatever is behind them) always “know” what color is being checked for at any time and always show the observer what they are looking for! Scientists have never been able to “fool” the particles by setting up any type of examination. The particles always know BEFORE the experiments are set up what the scientists will be checking for!

18. But it gets crazier! Suppose you set up a detector to see WHICH SLOT the particle goes through?

19. Detector One Gate When you do, the particle always appears as a bullet. Or the Other Gate Detector

20. When there are no detectors, the particles are always waves.

21. The sub-atomic world is much more different than the macro world we see about us. How can particles exist in both a packet and a wave form? It could be that the smallest units of the universe exist in some form that we cannot, at present, understand or have never seen. What we do know about the atomic structure is that matter doesn’t really look like the model we use, that of the solar system with a central core (the sun) and planets circling it.

22. The standard model helps us understand the atomic structure; however, Heisenberg’s principle of “uncertainty” makes it clear that “particles” are “smeared” out around the central core, as opposed to being in one certain position at any given time. Standard Atom Model Quantum Atom Model

23. We can then conclude that the individual units that make up the material of the universe exist simultaneously as both particles, like tiny balls, and waves.

24. The basic idea behind quantum mechanics is that nothing is absolute in the universe, every event is a “probability.” Nothing is really known until someone observes an event. Everything is a PROBABILITY WAVE in which anything is possible before it happens or is observed. When an event is observed, it is no longer a probability. In physics terms, the probability wave “collapses into reality. At that point it is a certainty. Only when an event is observed by a person does the “probability” collapse into reality. The entire universe, then, is an unfolding, a revelation of what “could” be possible into what actually is. To the quantum mechanics physicist, we live in an “all possible universes” existence.

25. The macro-universe, which is comprised of the elements of the micro-world, is a strange place indeed. What quantum mechanics brings to our understanding of the physical laws of the universe is that they operate differently when dealing with sub-atomic particles; also, those laws often seem to be contradicted. The strangest concept to understand is that sub-atomic elements, whether particle or wave, seem to: Know what we want to do with them before we perform any operations on them They can convey information to each “other” at speeds faster than light, a condition Einstein says is impossible.

26. The “probability” concept can be better understood by looking at a scenario devised by scientist Erwin Schrodinger: He envisioned a cat inside a box. Inside the box, along with the cat, is a container of cyanide.

27. A random hit by a gamma ray from space may hit the container and activate a release mechanism. If that happens, the cat will be killed. Looking at the box from the outside, one cannot tell whether a gamma ray has hit the container. Therefore, the cat is eitherdead or alive.

28. The “probability” exists that one or the other of the cases is true. Only by opening the box, can you determine what hashappened. When the box is opened, there is no longer a “probability” that the cat is either dead or alive. Mere “probability” collapses into a reality of what has or has not happened.

29. Dr. Schrodinger said that the cat is technically, “neither dead nor alive” until an observer “collapses” the probability wave by actually observing the outcome! THIS IS QUANTUM MECHANICS

30. This has been a summary of the weird, weird ways of Quantum Mechanics Photo by Charles Henderson By Charles Henderson 2005 Missouri