Thursday, February 22, 2007

Schrödinger's Exam Results

I’ve been thinking…which is a dangerous occupation I know. A friend of mine recently had some exam results coming and wanted to know is she had passed or failed. They were available online but she didn’t want to look Similarly, a colleague of mine was recently sat looking at his pay slip which remained sealed on his desk. I asked him what he was doing and apparently he was owed some back pay but dreaded opening the envelope in case they had got it wrong, again. It seems like procrastination but this got me thinking as I said…

This reminds me of Schrödinger's cat which is a famous illustration of the principle in quantum theory of superposition. Simply put, Schrödinger hypothesised that by
observing something we could see (the cat) we could draw conclusions about things we couldn’t see. The cat serves to demonstrate the apparent conflict between what quantum theory tells us is true about the nature and behaviour of matter on the microscopic level and what we observe to be true about the nature and behaviour of matter on the macroscopic level.

The experiment goes like this: Place a living cat into a box (easier said than done!), along with a vial of hydrocyanic acid and a very small amount of a radioactive substance. If even a single atom of the substance decays, the vial will be broken and the cat will be poisoned. From outside the box, the observer cannot know whether or not an atom of the substance has decayed, and consequently, cannot know whether the vial has been broken, the hydrocyan
ic acid released, and the cat killed. Since we cannot know, the cat is both dead and alive according to quantum law, in a superposition of states. It is only when we open the box and observe a cheesed off kitty or a motionless one that the superposition is lost, and the cat becomes one or the other (dead or alive). This situation is sometimes called the observer's paradox: the observation affects the outcome, so that it can never be known what the outcome would have been if it were not observed.

So, from this I was thinking: Whatever had happened to Schrödinger to make him dislike cats so much and is this why some people like to leave their mail unopened (virtual or paper)? To my friend then, the non-opening of mail is not procrastination, it is rather a test of quantum physics. As long as the envelope remains sealed then the exam results (or pay or anything else) is in a state of superposition, it is only when it is opened that my friend passed her exam and my colleague discovered that his pay was wrong…again. This of course assumes that the exam result has not been decided until the envelope has been opened rather than when it was marked, as the point of observation is only when the envelope has been breached.

Now I’m more of a ‘rip the Elastoplast off quickly’ kind of person. I would rather know than wonder, as knowing means I can move on, celebrate or do something about it if I don’t like what I find. I have no control over the marking of my exams but I do have control over what I write down in the exam, so to me it’s a done deal once I hand that paper in. Sometimes I know I have done okay, other times I’m not so sure but I do know that my result depends on what I have written (and perhaps the mood of the examiner when he marks it!). And as I said to my colleague, the fact that his pay was wrong again was practically a certainty though!


Katherine said...

Dang girl, gotta warn us when you're going to go deep. I would have drank extra coffee so I could follow along better. Now I just feel stupid. sheesh

Katherine said...

He didn't REALLY do that will a cat, right? It was just supposition, right?

OldOldLady Of The Hills said...

I must confess I did not understand that first "experiment" or what it was trying to prove other than killing a cat!
But, I do get what you are saying about the fact that you have no control over what someone else does, only what you do! If I understood that correctly? (LOL)
I of course wish I could control these things outside myself....but, all I know is, it ain't gonna happen!

kenju said...

I'm a rip of the bandage kind of gal too.

Couldn't Shrodinger have used a rat for his experiment?

Shephard said...

Quantum stuff is always intriguing. I'm with you... rip that envelope open! Then move forward with the new reality. :)


Sarch said...

Interesting post.

I find myself trying to remember a time when I've sat willing immobile, treasuring the "not knowing" a little while longer. I'm sure I have done that but nothing comes to mind.

Maybe this makes me a rip it off and jump in kind of person as well.

Dachsies Rule said...

Mom says the day she found your blog was a banner day. You have beautiful pictures AND deep insight. She just helps us write about ourselves.
Mom says the only time she didn't dive into "the envelope" was when she thought *he* was cheating. Once she knew, there was no turning back and no (not so) blissful ignorance.
(The things we can say in anonymity!)

Roxie, Sammy & Andy

srp said...

I was married to a PhD Physicist... Zoology major here... Perhaps some unseen force was at work under the same principle while we were falling apart. Hmmm. He never did like cats. Always said that if you traveled fast enough you'd get there before you started.

This stuff makes ones head throb.

Ps said...

What an interesting post.I loved it.Funnily, when I know that the news is likely to be good (say I have done really well in an exam and I'm expecting good results)then I postpone opening the mail or looking up the result.But when i anticipate something not so good,I always get it over with as quicly as I can!

Dave said...

Pheww! Here from Michele's this morning.

RC said...

So does he like cats now?

Hi, Michele sent me!

Carmi said...

%'m an avoider. Envelopes stay closed and voicemails remain unheard when I know they might carry news I won't like.

I eventually get to 'em, but they're at the bottom of my priority pile. I like to deal with the happies first.

And don't get me started about the cat experiment.


craziequeen said...

Hey babes - Damn Schrödinger...I cna't get past putting a kitty in a box with hydrocyanic acid....

Thank you for last night - I really enjoyed my night out wiff mah was fun!

Here via Michele today

Southern Byways said...

I'm sort of sitting on the fence with this one. There are times when I don't want to know... and then spend a lot of useless time worrying about it. Now is that dumb or what? Next time, I'm going to save myself all that worrying and just "rip it off" and get it over with.

Carolyn said...

Hmmm... maybe that's where the expression "Kick the cat" came from? It's funny how we think staring at an inanimate object can change the content within. Like some people can use telekinesis to move a tangible object through space, why couldn't similar types of concentration power change an outcome within a letter or paycheck? If it were THAT easy, everyone would do it, lol!!

mar said...

"When I hear of Schrödinger's cat, I reach for my gun.“ – Stephen Hawking

Yes, I can wait to open a present but not the envelope you are talking about! I want to know right away!!!

Bob-kat said...

Superposition is not so much about having the power to change something but rather that just simply observing it removes the doubt! Therefore the cat in the box is neither dead or alive until we look and similarly the exam result is not known until the envelope is opened. Up to this point the cat and the result are neither dead or alive, or passed or failed.

BTW - Mr S did not actually conduct this experiemnt and no cats were harmed during the writing of this post.

utenzi said...

That was funny, Bob-kat. A very good way to start a science post. Of course your friend was procrastinating but it was a good way to bring up Schrodinger's Cat--though I'd argue a bit with your use of micro and macroscopic. :-p

I love how you have to leave conventional logic behind when thinking about a lot of physics on the subatomic level.

Michele sent me over, B-K.

PI said...

It just seems so obvious doesn't it? One of my pet theories is the bigger the brain the smaller the nouse.
I delay looking up at my in box willing it to not be spam and when I drop something valuable I stare st it wiiiing it not to break.
Now Pavlov's dogs I understand!
It was bright enough to see you today. Michele sent me.

rashbre said...

A panel with two slits is set up in front of a cat scanner measuring device.

When numerous cats are fired at the panel, the scanner measures the expected interference pattern.

But, when a single cat is fired through a single slit, the cat doesn't know if it's alive or dead.

And of course, WANTED - dead AND alive, Schroedinger's Cat.


PI said...

Apropos of cats; I am spending the week-end with my son's cats. Apart from you bob-kat I am not a great lover of cats. I love to watch them but don't want to cuddle them.
Michele says Hi!

yellojkt said...

It's funny that not knowing is sometimes better than knowing. Weird.

Michele sent me.