8.04 Lecture 1, Introduction to Superposition

Notes

Going through some experiments on an electron to understand two properties
1. color: white or black
2. hardness: hard or soft
create this “color box” that, based on the position that the electron is shot out, tells us what the color of the electron is
- same idea for “hardness” box
color is persistent if fed into a color box immediately after, same with hardness
however
feeding black electrons to a hardness box, we expect 50:50 hard:soft, and once we put the only hard into a color box again, we get 50:50 white:black, even though we expect 100 black!
- presence of hardness box tampers with color
run 4 experiments, first two behave as “expected”
3rd experiment, feeding a white electron into a hardness box, mirrors bounce and recombine, looking at color
- might expect 50:50, since hardness tampers color
- we see 100 white
try to block paths and see which “path” did electron take, hard or soft
- neither hard, nor soft, nor both, nor neither
- electron in superposition between both paths
something about “combining” this undetermined hard/soft makes it so we preserve color

intuition for superposition
intuition for speed/velocity of an electron
- when we know the hardness, the electron actually doesn’t have a color, it is undetermined, it is not that we cannot “know” the color
everything behaves this way! the “miracle” is that in larger objects, we don’t measure this behavior

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