Category Archives: Issues in Science

Generally, when we hear the term “Quantum Mechanics“, we think of complicated mathematics, incomprehensible physics, and an old guy with a penchant for sticking out his tongue in pictures. This subject is often portrayed by our society as something intimidating, something so intellectually challenging that only a select few can possibly hope to understand. Is it though?  Yes, it may be complicated; Yes, there may be math. Calculus, even! But it is perfectly reasonable to think that any average science undergrad can grasp some of the fundamental principles.

One well known example underlining those principles is the Schrodinger’s Cat experiment. This famous problem came about one day when the Austrian physicist Erwin Schrodinger decided to conduct an experiment. Except, due to ethical, legal, or just plain lack of funding for killing felines for the sake of scientific curiosity, he never did conduct the experiment in real life. Instead, he settled for imagining the whole thing. The premise is this: we have a cat, a radioactive source, and a jar of poison all sitting in a box. Over the course of one hour, the box is left untouched. If the radioactive atom decays, a mechanism attached to a Geiger counter will release a hammer that smashes the jar of poison, leading to a very painful death for our poor, unnamed cat. If it does not, the cat narrowly escapes death by cyanide and is rewarded by living (maybe) another hour.

The point of this experiment is thus: According to quantum mechanics, the radioactive source is a mixture of states – a superposition, if you will, of the atom having decayed and not decayed. Very complicated – but imagine a peanut butter and jelly sandwich, and the thin layer where the peanut butter comes into contact with the jelly and therefore mixes into a synergistic substance that is amazingly both peanut butter and jelly at the same time, then you get the gist. Now here’s the important part: Since our cat’s life is dependent upon the radioactive atom decaying or not, then the cat must also be in a superposition of two possible states – alive, or dead. In other words, unless we open the box and find out for sure, the cat is both alive and dead at the same time. This isn’t to say that it has equal probability of being alive or dead, but (I repeat) that the cat is  literally theoretically  both alive and dead at the same time. Now when we actually open the box, the cat will be forced into a definite state of dead or not dead. But before you open that box, we have a magical, half-alive, half-dead, not-quite-a-zombie, still-unnamed, cat, which we will never see, because the act of observation either kills or saves our cat.

https://www.youtube.com/watch?v=_-2pDxAPPnw

This illustrates the peculiar phenomenon in particle physics: that the act of observing something, an electron, for example, forces it to collapse into a certain state. Whereas when it’s unobserved, it can exist in a combination of many possible states.

Let’s take it out of context, do you think this means our world is only the way it is when we are actively observing it?

• Daphne Wu