Equadorial anomaly or tourist scam?

[Iamme]

I saw on The Travel Channel the other night, in Samantha Brown's travels to Equador, that here is this tourist trap set up right on the GPS surveyed equator line and this person was demonstrating to the crowd gathered around that when she pulled the plug on her tub of water, situated exactly on the equator, that the water went straight down the drain with no vortex. Then she picked up her sink and moved it like 3 feet and redid the test and this time the water drained out with a vortex, in either the expected CW or CCW diirection. Interestingly enough though, she did not test it again 3 feet on the OTHER side of the equator to see if the water spun out the OTHER direction.

Well?

[Terry]

Scam. There's no way that the coriolis forces have an effect over that small of a scale.

ETA: significant, visible to the human eye effect, I mean.

[Iamme]

When I saw the test, I, being the skeptical type anyway, carefully looked at the amount of water in the sink and how she pulled the plug. The two tests looked identical in every way. (Then again, Chriss Angel's and David Blaine's magic tricks look real in every way also. :) )

But at home, if I was not seeing things, my sink drained out in a vortex one way and the vortex went the other way another time.

Also at that demo site, they had eggs on this board where people were trying to see if they could balance an egg on end.

[Goshawk]

Do bathtubs drain counterclockwise in the Northern Hemisphere? (http://www.straightdope.com/classics/a1_161.html)

Can you stand eggs on end at the vernal equinox and at no other time? (http://www.straightdope.com/classics/a2_089.html)

...Seeing the evidence before their eyes, the rest of the people in the studio promptly began standing eggs on end too.

Later, in the seclusion of his private laboratory, using the strictest scientific procedures, Cecil was able to duplicate Professor Hartness's achievement with his own hands.

Moral: you can stand an egg on end any old time. All it takes is very steady hands.

Also, it seems to work better if you shake up the egg first. This breaks the yolk loose from the bands (chalazae) that keep it suspended in the center of the egg, lowering the egg's center of gravity. But that's cheating.

[fuelair]

Do bathtubs drain counterclockwise in the Northern Hemisphere? (http://www.straightdope.com/classics/a1_161.html)

Can you stand eggs on end at the vernal equinox and at no other time? (http://www.straightdope.com/classics/a2_089.html)easier just to make a small pile of salt, press (gently) the end of the egg into it so it stands, then gently blow away the reast of the salt.:)

[JoeTheJuggler]

I lived in Ecuador for two years, and I can tell you for a fact that the shape of the sink and the direction and force of the water flowing in determines the directions of the swirl. The coriolis force is orders of magnitude too weak to make a difference.

In many cases you can change the direction by swirling the water with your hand (not recommended in toilets).

There is something at the Mitad del Mundo monument (which, incidentally is several hundred meters off of the correct zero latitude) that sounds bizarre but is true (if somewhat exaggerated). Owing to the flatening at the poles (or bulging at the equator), your weight at the equator is slightly less than it would be at the poles (since you are further from the Earth's center of mass). The effect is very slight, and the display at the monument has a chart that tells you how many pounds lighter you should be. IIRC, the numbers were all waaaay too high. (I would even guess that the difference would be well within a person's normal weight variation.)