Welcome to the SSHOw: Science Sunday HangOut – woot!
Be there, this Sunday at 2 pm ET.
Do you have a question for us?
Originally shared by ScienceSunday
Stick around on Sunday for the SSHOw
This Sunday ScienceSunday will introduce you to SSHOw: Science Sunday HangOut – woot! The curators, Rajini Rao Allison Sekuler Robby Bowles and Chad Haney will introduce themselves briefly and then each answer a question from you. Start submitting your questions in the comments below. We’ll start at 2 PM ET this coming Sunday, September 23. The HO will be on-air.
Please give us feedback about the time of the HO for future HOs. We want to select a time that will reach the largest #ScienceSunday audience. Once we finalize the time, expect us to do approximately 30 min. of HO each Sunday to discuss our favorite post or chat with a guest scientist.
The image below is of a gecko “claw”. It’s what allows it to hang around. However, you don’t need that to hang around #ScienceSunday
We took a single gecko foot hair (seta) and made the first direct measurement of its adhesive function. These tiny setae are only as long as 2 diameters of a human hair. That’s 100 millionths of a meter long. Each seta ends in up to 1000 even tinier tips. The tips are only 200 billionths of a meter wide –below the wavelength of visible light. We used a microscopic force sensor designed by Tom Kenny at Stanford to measure the tiny forces of adhesion of the gecko seta.
We discovered that the seta is 10 times more adhesive than predicted from prior measurement on whole animals. The adhesive is so strong that a single seta can lift the weight of an ant 200 µN = 20 mg. A million setae could lift the weight of a child (20kg, 45lbs). A million setae could easily fit onto the area of a Dime. The combined attraction of a billion spatulae is a thousand times more than a gecko needs to hang from the ceiling. Maximum potential force of 2,000,000 setae on 4 feet of a gecko = 2,000,000 x 200 micronewton = 400 newton = 40788 grams force, or about 90 lbs! This is 600 times greater sticking power than friction alone can account for. Weight of a Tokay gecko is approx. 50 to 150 grams.
These exciting results were published in the journal Nature v. 405: 681-685.
#ScienceEveryday when it isn’t #ScienceSunday