MythBusters Mini-Myths: "Egg-uinox", "Break-Step Bridge", "Mini Shark Myths"

You can only balance an egg on its ends during the spring and fall equinox.

busted

There is nothing special about the spring and fall equinoxes that allow you to balance an egg on end. You can do it on any day of the year as long as you’re dexterous enough. Hard boiled eggs balance better than raw eggs however.

A bridge can be collapsed by the vibration caused by pedestrian traffic.

plausible

A simple beam bridge was built for testing. It was able to hold Adam’s weight until he started bouncing on it.

Sharks tend to be attracted to brighter colors like yellow.

plausible

When all the results were calculated, the sharks tested preferred to go for the "yum-yum yellow" seal dummy before the other ones (red, blue, black, white, silver).

Sharks can detect a single drop of blood dropped into a pool of water.

busted

The sharks detected fish blood, however they either did not detect human blood or did not care about it. Also, like any scent, the sharks weren’t able to detect the blood until their noses came into contact with the blood particles, and the smell grew weaker as the blood got diluted by the water, meaning that a single drop of blood in a particular area of the pool would not be detectable by any shark that was not in that area, and was not swimming right into the blood.

A shark’s skin is rough enough to be used as sandpaper.

confirmed

When compared to various grains of sandpaper, the sharkskin that Adam and Jamie acquired was comparable to a very high-grain (400 to 600) of sandpaper, and can be used as such, even on a rotary sander.

There is a rule of thumb a casual observer can use to adequately estimate the size of a shark.

busted

Out of all the measurements taken of lemon sharks, only one (from nosetip to dorsal fin tip) could consistently be used to estimate the shark’s size, and it, in itself, requires an up-close and personal measurement, something that would be too difficult and dangerous to be done by a casual observer.