Sunday, December 20, 2009

A ton of CO2

Sophomores have firm convictions:

Neil Armstrong never walked on the moon.
We will all die in 2012.
Aliens walk among us.

In class I try to avoid opinions. In the short run, many of my lambs will remain confused.

It is not my job to convince Amanda that Neil Armstrong walked on the moon--as soon as I use my position of authority to make a point, I've lost my chance to teach a child how to think.

It is my job, however, to make them skeptics, to have a sense of what we do not know, to suspend judgment while using their God-given senses and rationality to come to their own conclusions, conclusions that might change should new evidence become available.

As a result, I fear that some day a mother will tell my principal that I did not vigorously dispel the notion of aliens, of rigged moonwalks, of the impending doom 3 short years away.

Or maybe the parents believe these things, too.

One of the hardest things in high school science is convincing kids that gas is made of stuff. Bring in a chunk of dry ice, place it on the teacher's desk, and let it sublimate its way to nothingness.

"What happened to the dry ice?"
(My students look puzzled at the idiot asking the question)
Um, it, uh, disappeared?

"Yes, but what happened to the carbon dioxide?"
(Eyes roll. The teacher is either really deaf, really slow, or reaaaaaalllly annoying.)
We already told you.

And they did.

An American artist (from L.A., in a dish of delicious irony) has sculpted a giant box of flashing images, to represent a metric ton of carbon dioxide. It was unveiled for the UN Climate Change Conference in Copenhagen, and will travel a bit for the next few years, proving that all sides are capable of lunacy.

I would be impressed if the box swelled up with rising temperatures, or shrunk when a high pressure weather system passes through. But it doesn't.

A reporter or two has mentioned that the cube represents the volume of CO2 at standard pressure--but fail to mention temperature. Maybe the ideal gas law is too complicated to discuss.

(It's not. But it's more fun to be mesmerized by flashing boxes of lights than to think.)

If you want to show children how much a ton of carbon dioxide weighs, show them the solid product of a very common reaction.

Show them a block of oak, a cup of sugar, or a bowl of salad. Ask them where most of the plant "stuff" comes from.

Take them outside and show them your town's largest oak tree. Comes from the same stuff.

CO2 + water --> plant stuff and (bonus!) oxygen

The oxygen comes from the water, it turns out. All the carbon dioxide ends up in the wood.
It works the other way, too. Burn sugar completely, and you get this:

plant stuff and oxygen --> CO2 + water

You can show this in class. I keep a propane torch handy. Light it, briefly aim the flame at something cool and non-flammable (the faucet on my desk makes a good target), and see the water vapor fog up on the object.

It amazes me every time. Water from fire.
(When you hold your hand over a lit grill you can get the same effect--that's not sweat on your palms.)

The global warming "debate" has broken down into camps of rival religious groups. You can still read the science behind the news. Good science requires skepticism, a point lost in the noise from the mob.

Science gives us knowledge, but not wisdom.
Technology gives us power, but not principle.

Power without principle, knowledge without wisdom, will spell the end of our species, though perhaps not through global warming.

There may be a reason intelligence per se is not an adaptation found in most species. Life has been around for here for over 3 billion years, and I've no reason to believe it won't be around for billions more.

I know I won't be around to see it. It would be nice, though, if one of my descendants does.

The cube photo is all over tarnation,this one from LA Curbed, which credits Obscura Digital.
The footprint is from NASA, and is in public domain.

And this is my 400th post here--go me!


John Spencer said...

My kids believe the same things. Though, there really are aliens. Most of my students are not only aliens, but "illegal" (If we go by our law. If we follow the law of the Treaty of Guadalupe Hidalgo, I'm an illegal alien and they are citizens.)

Jenny said...

I've just been reading Classic Feynman (rereading parts of it for the umpteenth time). Your comment about power, but not principal rang strong in my ears as it seemed to echo his thoughts.

Kate said...

I keep sending you quotes. Perhaps that means that I don't have an original thought in my head. Perhaps it means that I teach English and I'm making text to text connections. Perhaps I think you will enjoy the irony or humor or universal human truth. Perhaps it's all of the above - and today I send you a bit from So Long and Thanks for All the Fish by Douglass Adams and the character John Watson (aka Wonko the Sane):

I'm a scientist and I know what constitutes proof. But the reason I call myself by my childhood name is to remind myself that a scientist must also be absolutely like a child. If he sees a thing, he must say that he sees it, whether it was what he thought he was going to see or not.
See first, think later, then test. But always see first. Otherwise you will only see what you were expecting. Most scientists forget that.

Happy almost Solstice. My eldest turns 16 today, the first of my three solar babies (the other two born on Imbolc, as you may remember.)

Paul Cornies said...

'Science gives us knowledge, but not wisdom.
Technology gives us power, but not principle.'

After Copenhagen another observation:

Politics gives us plenty of posturing but few solutions.

Another bleak generalization about the future of our planet?

Blogger In Middle-earth said...

Kia ora e Michael!

Your point about avoiding opinions - I've thought long and hard about this, for decades. The fact is that Science is all about opinion. Fact.

It's how opinion is assimilated that brings about an understanding of what Science is. It's in learning how to form an opinion that makes a would-be scientist skeptical.

I always revert to the conundrum of the model for light - that it behaves as if . . .

. . . and we can bring forward models, based on opinion, to explain in metaphorical ways how light can be regarded.

But without skepticism that you mentioned, and an ability to form an opinion, the learner can neither understand what great minds have seen, nor can they contribute to Science by putting forward better models.

All the best of the season to you.

Catchya later

doyle said...

Dear John,

Your ability to bring your students' stories to life beyond their neighborhoods makes the words "illegal aliens" sound harsh (which, of course, they are). You raise a good point about the "illegal" part.

Dear Jenny,

I love Classic Feynman! It's been a few months since I've read it, but Feynman has influenced me, maybe more than I realize.

Dear Kate,

I'm not sure original thoughts exist in anyone's head--but your wide range of quotes continue to entertain me (and others), and sharing universal human truths (with its concomitant irony and humor) is always appreciated.

Imbolc is just 6 weeks away now. Do your kids know you call them "solar babies"?

Dear Paul,

I have faith that life will survive whatever stress we manage to create. It is my hope that humans survive, as well, but that may require a larger act of faith than I can muster.

Live for today, and act for tomorrow, I guess. What else can we do?

Dear Ken,

Science is based on opinion insofar as it is based on stories. What separates science from opinion, however, is the shared rules for this particular kind of storytelling--all models hinge at some level on observable phenomena.

Of course, scientists do have different opinions on how to interpret data at times.

Best of the season to you, and everyone else as well. It's a joy to have people come by and comment here.