In the terrible 2004 film Godsend, Robert De Niro plays a sinister obstetrician who helps a couple clone their dead son but secretly manipulates "intangibles" in the fetus so that the new child will show traits of his own dead son, who happened to be evil.

While uncovering this well-thought-out and plausible scheme, the boy's father (Greg Kinnear) interviews a nanny the obstetrician once hired. "He was a doctor?" the father asks, and she replies, "A baby doctor, yeah." Then she leans closer and whispers her suspicion: "Only ... he seemed more like a scientist to me."

We [scientists] are distrusted, feared, but most of all, misunderstood. --Adam Ruben

For me, as a scientist, when I watched the movie, those words weren't exactly the ominous bombshell the screenwriter probably intended. It was as though the nanny had said, "Only ... he sometimes ate Corn Flakes."

Her comment made me consider how the public views scientists -- and how universal that perception must be for a screenwriter to presume that "scientist" is a zinger of an insult. (Maybe I should try that sometime. "Hey, jerk! Your mother is a synthetic chemist!")

We are distrusted, feared, but most of all, misunderstood. We work, after all, in one of the only two professions that idiomatically follow the word "mad" -- the other such profession being "hatter."

Is it any wonder, though, that people don't understand what scientists actually do? Think of all the demonstrations you watched as a kid, your first introduction to the field. Among the brightly colored liquids bubbling with dry ice, did a physicist show you a diagram of a particle accelerator? Did a microbiologist talk about colony-forming units? Did a geologist explain how to date a core sample?

Or was your liaison to the scientific universe some doofus in a lab coat who showed you how to make your own silly putty? (Two parts glue, one part liquid starch.)

I recently watched the online trailer for a stage scientist named Doktor Kaboom!. (I presume it's a pseudonym. Either that, or his grandparents had it changed from Kaboomowitz at Ellis Island.) From the trailer, I gleaned that Doktor Kaboom!'s primary mission, as one might imagine, is making various household objects go kaboom. Watching him catapult a banana across the stage, I realized exactly how Doktor Kaboom! and his ilk perpetuate myths about scientists.

"He's completely misrepresenting us," I complained to my wife as the video clip played. "He's making us look awesome."

And yet most of us grew up with similar entertainers as stand-ins for scientists. Sure, we learned science in the elementary school classroom (with disproportionate emphasis on the life cycles of frogs and butterflies), but all encounters with practitioners of the field led us not to labs but to auditoriums, watching manic comedians in flight goggles demonstrate "experiments" that real scientists never do.

Here are some of my favorites:

Let's All Gawk at Liquid Nitrogen:

Liquid nitrogen is used in cryogenics, industrial cooling, and tissue preservation, but who cares? What's important, we tell kids, is that if you dip a rubber ball in liquid nitrogen, you can smash it with a hammer. And if you dip a flower in liquid nitrogen, you can smash it with a hammer. Yes, I know one of the pieces of the rubber ball landed over there. No, you can't go get it. Stay in your seat. Or I'll smash you with a hammer.

Goop:

It's not quite a liquid; it's not quite a solid. It's goop! It's wacky! It's science-ish! And it's almost as much fun for kids to play with as it is for parents to scrub off the ceiling!

Fizzy Explosions:

Volcanoes are complex geothermal phenomena, and as every kid knows, a volcanic eruption is caused when someone puts a tablespoon of baking soda into a crater of vinegar. Oh, and that ash cloud over Iceland? A careless tourist dropped a pack of Mentos into Mount Saint Diet Coke. Experiments like these teach kids important chemical reaction mechanisms, such as A + B → Explosion!

Imagine their disappointment when they become chemists and learn at their first OSHA training session that they're supposed to avoid making their labs explode.

Potato Gun:

With some PVC piping, a wooden dowel, and the magic of air pressure, this demonstration shows kids how an otherwise useless potato might, thank goodness, be turned into a weapon. Sometimes supplemented by the recently popularized mini-marshmallow gun, "science" projects like these fall into the category of "Things You Help Kids Make But Then Threaten to Take Away."

Dry Ice Inflates Rubber Glove:

There is no end to the practicality and benefit of science. Filling a rubber glove with dry ice, tying off the wrist, and watching it inflate turns an otherwise worthless rubber glove into a completely valuable inflated rubber glove, which you can then show to people as you say, "Look! I have an inflated rubber glove!"

Air Displacement:

Perhaps the most baffling science experiment, because it never worked, was the one based on the principle that liquid cannot flow out of a container without being displaced by air -- thus, one can poke a hole in the bottom of a sealed bottle, and its contents won't go anywhere. Wrong. I can't tell you how many times I had to clean carpets in my house after declaring, "It's okay, Mom! Science says the soda won't come out!"

Meet a Zoo Animal:

1. This is (cute name).

2. We found him in a (sad place to find a hurt animal).

3. When fully grown, he will weigh (impressive number) pounds.

4. And he will eat (impressive number) pounds of food every day.

5. This one's a baby, but if he were an adult, he would kill (you, me, all of us).

6. Look at the size of those (teeth, wings, claws)!

7. We have to be really quiet.

So if you're Doktor Kaboom!, Professor Ker-Splat, or Nobel Laureate "I Didn't Think It Would Blow Up But Then It Totally Went Pfweeeeeeeeeeeee!," maybe it's time to vary the act a bit. Forget about the eyedropper in the 2-liter soda bottle and put together a show based on what scientists actually do.

Good morning, children, and welcome. Today's science demonstration will require a laptop, a printer, and 20 liters of coffee. This experiment is called "Applying for Funding."

Can I have a volunteer from the audience? Yes, you with the cell phone. (Why do you have a cell phone? Good Lord, you're only 8. You don't need a cell phone. Who would you call? I feel old.)

And what's your name? Billy. Everyone, let's have a round of applause for Billy. All right, Billy, here's the challenge. This grant application is due to the National Science Foundation tomorrow. I spent the past 72 hours refining my specific aims so that they describe work I've already done. But in the process, I accidentally changed the numbering of my references.

Billy, I want you to go through this document and reorder the citations alphabetically. Then we'll take a break to falsify a proposed budget, and in just 4 months we'll likely discover that we have to close the lab!

What's that? When do we do the actual science? Ah, naïve Billy.

Real scientists never enter a lab. We work our whole lives to become, if we're lucky, managers of sorts. We oversee, we organize, and we teach. We attend meetings and send e-mails. We think, we write, we debate, we format, and we complain. The day-to-day job of a scientist -- a real one -- isn't too different from that of, say, an insurance claims adjuster.

And the actual science? Well, Billy, that's why we have graduate students.