Question: Can you *simply* explain the theory/paradox of Schrödinger's cat?

Susan Skelton answered on 16 Nov 2013:

Hi nikki!
What a great question! Schrödinger’s cat paradox has confused many scientists for years!

When scientists look at really really small things, they noticed that they behaved in very strange ways – and were able to do things very different to what we would expect. Some things can even do two things at the same time!

Schrödinger’s cat paradox tries to understand how this might be possible…

In this “thought experiment”, imagine you find a big steel box and put a cat inside. You also put in some gunpowder that has a 50% chance of blowing up in the next 1 minute, and a 50% chance of doing nothing. You seal up the box and go to make a cup of tea…

When you come back, you wonder if the cat is still alive. Until you look inside the box, you have no idea whether the cat is dead … or alive.

But when you do look, it IS either dead, or alive. If you had lots more cats and gunpowder you could repeat this experiment many, many times….. After half of the experiments, the kitty would leap out of the box, and after half of the experiments, kitty goes bye bye.

Schrödinger said that before we look in the box, the cat is both dead AND alive, at the same time. Our act of looking forces nature to act. So our curiosity kills the cat!

But the cat, sitting inside the box, either sees the gunpowder explode and dies, or doesn’t see the gunpowder explode and survives. It is not possible for the cat to see the gunpowder explode and then survive.

So which is the correct case? Can the cat be both dead and alive at the same time???

This thought experiment has confused many scientists for a long time, and they have come up with lots of possible solutions. One explanation is that there could be lots of different universes – so the cat dies in one universe, and in the other it lives happily ever after.

I hope that answers your question. I’m sorry it is a bit complicated – don’t worry if you don’t understand it all – even lots of scientists still don’t! But if you want me to explain anything more, just let me know in the comments.

(No cats were harmed for the writing of this answer 😉 )