Favorite experiments?

February 27, 2008 5:56 PM

What are your favorite experiments?

I love reading about really clever, well designed or revealing experiments, particularly psychology experiments, like the ones on this page and in this book by Lauren Slater about some classic experiments. What are some of your favorite experiments in psychology (or any field really). Also of interest are recommendations for books like Slater's.

posted by AceRock to science & nature (23 comments total)

Imagine that you've volunteered for an experiment, but when you show up at the lab you discover the researcher wants you to murder an innocent person. You protest, but the researcher firmly states, "The experiment requires that you do it." Would you acquiesce and kill the person?

I like the classic see-how-far-volunteers-will-go when they think they are shocking other volunteers (who are paid actors). It's number two on The Top 20 Most Bizarre Experiments of all time.

Another good list:
Guardian: Elephant on Acid, Dog head grafts, and a seesaw to revive the dead.
posted by pedmands at 6:31 PM on February 27

You might be very interested in Vilayanur Ramachandran's work. He works with people who have very specific brain damage as a way to understand the working human mind.

If you go down to the references on Wikipedia,you'll find his TED talk and the real gem, which is his series of Reith lectures for the BBC, incredibly interesting.
posted by Static Vagabond at 6:34 PM on February 27 [2 favorites]

Horizontal motion is independent of vertical motion (like for a projectile): teacher shoots a dart out of a blowgun, which is at the same height as a block held up across the room. The block is attached to an electro magnet, which is turned off by the breaking of a laser beam (the beam is just outside the end of the barrel). The dart travels across the room, falling at the same rate as the block, and sticks in the block just before it hits the floor.
posted by spikeleemajortomdickandharryconnickjrmints at 6:42 PM on February 27 [3 favorites]

Ah! Static Vagabond's post reminded me of Paul Bach-y-Rita (who I just discovered has died!), who experimented with various cognitive deficiencies. He would teach people with inner-ear malfunctions to balance by stimulating the tongue with electrodes, blind people to see by 'painting' the feed from a video camera on the back of a patient with vibration, and all sorts of other wacky stuff.

He was a big proponent of Neuroplasticity.
posted by pedmands at 6:43 PM on February 27

In genetics, the Meselson-Stahl_experiment is legendary for it's power and simplicity.

You might be interested in reading Cognitive Daily if you're looking for interesting psychology experiments. They cover lots of good science, and do it really well.
posted by chrisamiller at 6:44 PM on February 27

my favorite experiment is a bit lower-level than Psych. Also, I don't have a citation, but I'm pretty sure it was published in Cell in the early to mid 80's. It involved some cultured neurons, an electron microscope, some neuro-bio equipment and an apparatus known as "the cold hammer." it resulted in some awesome pictures which confirmed the membrane fusion theory of secretion.

Most importantly though "the cold hammer."
posted by Good Brain at 6:46 PM on February 27

Sorry, that was more of a demonstration rather than an experiment. The only one I know from psychology (again, more of a demonstration) was demonstrating observation bias: professor divided class into two groups: male and female. The "experiment" was to determine if there was a difference in reaction time based on gender. For the male population, the professor said "Ready?" and then flipped the switch. For the females, he just flipped the switch, catching them by surprise. Also, time was measured out to the hundredths. He rounded up for males, left it for females. It took a while for people to catch on, and it was a lot more subtle than I'm making it sound.
posted by spikeleemajortomdickandharryconnickjrmints at 6:47 PM on February 27

spikelee. . .mints: that's absolutely a experiement, and a good one, because it has a testable hypothesis. If gravity is independent of horizontal motion, then the dart and the block should fall at the same rate and collide. You shoot the dart, and Voila! Hypothesis confirmed!
posted by chrisamiller at 7:07 PM on February 27

I think my favorites are the studies by Daniel Simons on inattentional blindness and change blindness, the best being the gorillas in our midst version and the real life change blindness studies You tube video here. They are always a big hit in my psychology classes as well. Interesting studies also include the Stanford prison experiments, especially if you find any video. Ugh, I have more I'm just too sleepy to come up with them right now.

You might also be interested in Oliver Sacks' books, they are usually about interesting psychology cases and are well written
posted by JonahBlack at 7:11 PM on February 27

The Pitch Drop Experiment proving some "solids" are really very-high-viscosity fluids.
posted by Mitheral at 7:39 PM on February 27

We used to do evil things in my engineering classes, based on a few psych classes I had taken in Behaviorism. Over the course of a few weeks, we trained a teacher to stand in the far left corner of the classroom, just by paying attention when he stood in one area, and ignoring him when he stood in another. Over time, the "attention" region got smaller and smaller.

I almost feel guilty.
posted by browse at 7:41 PM on February 27 [5 favorites]

The Amazing Color-Changing Card Trick with explanation (YouTube video).
posted by exphysicist345 at 7:44 PM on February 27 [1 favorite]

I'm fascinated by the 1971 Standord Prison Experiment in which students became guards and prisoners.
posted by olecranon at 8:06 PM on February 27

The Harrad Experiment, hands down.
posted by I EAT TAPAS at 8:16 PM on February 27

chrisamiller - spikelee...mints is right - it's not a true experiment. True experiments require the manipulation of an independent variable. Since gender can't be manipulated (assign people randomly to "male" and "female" groups), it's not a true experiment, but rather a demonstration.

Same with Milgram or shooting an elephant in the ass with a syringe full of LSD - not experiments, but demonstrations. I don't know how tightly you need to stick to the definition of an experiment, though - some of these fall into "quasi-experiment" territory.

In the same way, the cigarette industry always said that no true experiment showed that cigarettes led to cancer, since people couldn't be assigned to "Heavy smoker for 20 years" and "nonsmoker" groups - people self-selected and could only be assigned after the fact.
posted by mamessner at 8:16 PM on February 27

mamessner,

chrisamiller and spikelee...mints were referring to the gravity experiment, not the gender reaction time demonstration/experiment.
posted by entropic at 8:57 PM on February 27

You have a point, entropic. In mind, the variable was the speed at which you blow the dart (horizontal speed), and that you would vary this to show that vertical speed is independent. I suppose that wasn't explicit in the description, though.
posted by chrisamiller at 10:22 PM on February 27

To answer your question about book recommendations, AceRock, try Robert P. Crease's The Prism and the Pendulum. And, from Physics World, where the readers were asked to suggest experiments for Crease's book, here's the final list and the top alternates:

1 Young's double-slit experiment applied to the interference of single electrons
2 Galileo's experiment on falling bodies (1600s)
3 Millikan's oil-drop experiment (1910s)
4 Newton's decomposition of sunlight with a prism (1665-1666)
5 Young's light-interference experiment (1801)
6 Cavendish's torsion-bar experiment (1798)
7 Eratosthenes' measurement of the Earth's circumference (3rd century BC)
8 Galileo's experiments with rolling balls down inclined planes (1600s)
9 Rutherford's discovery of the nucleus (1911)
10 Foucault's pendulum (1851)

Others experiments that were cited included:

Archimedes' experiment on hydrostatics
Roemer's observations of the speed of light
Joule's paddle-wheel heat experiments
Reynolds's pipe flow experiment
Mach & Salcher's acoustic shock wave
Michelson-Morley measurement of the null effect of the ether
Röntgen's detection of Maxwell's displacement current
Oersted's discovery of electromagnetism
The Braggs' X-ray diffraction of salt crystals
Eddington's measurement of the bending of starlight
Stern-Gerlach demonstration of space quantization
Schrödinger's cat thought experiment
Trinity test of nuclear chain reaction
Wu et al.'s measurement of parity violation
Goldhaber's study of neutrino helicity
Feynman dipping an O-ring in water

Of course these are all experiments in physics, more than in psychology, but if you want compelling science writing, Crease is up to the job.
posted by cgc373 at 4:33 AM on February 28

chrisamiller beat me to the mention of the Meselson-Stahl experiment, which has been called the most beautiful experiment in biology.
posted by DevilsAdvocate at 5:11 AM on February 28

I'm surprised it was left off the list of physics experiments above, but I have always been partial to Michaelson and Morley's experiment. It changed the way physicists viewed the universe and laid the groundwork for Einstein's ideas. Another nice list is here.
posted by TedW at 5:41 AM on February 28

Oh! For the audio/fire nerds out there- something to try at home! The Ruben's Tube!
posted by pedmands at 6:33 AM on February 28

The Foucault pendulum.
posted by weapons-grade pandemonium at 8:59 AM on February 28

I've always been interested in mixed-mode traffic experiments like this Amsterdam experiment: it's interesting to me how solving gridlock is only one piece of the puzzle of city traffic planning, and how many of these studies amount to experiments in group psychology.
posted by breezeway at 10:07 AM on February 28