Penguins change the degree of diving angle corresponding to the buoyancy.

 Oita Godo Newspaper (evening edition on June 13, 2009)

Nowadays, human are researching about other living things on the Earth including those living under the sea. Today's scientific column will present about Penguin in Antarctica continent.

The emperor penguins usually go under water more than 500 meters to get the food land. We mistakenly thought "mostly vertically, they dive within very short distance", said Associate Professor Sato of Tokyo University (Oceanic Biological Department).

Associate Professor Sato told that the research team has been analyzed the depth and the speed as one of the penguin's movement called "Data Locker." The result is that the penguin dives slowly with the shallow degree of angle at the depth of 60-70 meters, and then turns to more sloping degree of angle to reach the food land.

The penguin inhales deeply when it dives deeply, on the other hand it inhales just a little when dives shallowly. The inhaled air will be compressed by the water pressure as gradual as the depth the penguin goes thus the buoyancy (floating power) will lessen. However, at the shallow stage which the buoyancy is still powerful, the penguin needs to try hard to dive. At a fixed condition they calculated, the buoyancy at 400-meter depth under the surface of the sea remains only one-fourteenth of the buoyancy at the sea level.

To be easier to understand, Associate Professor Sato gave an example of slope ways. Where the gravity is powerful (such as when we have heavy luggage), we choose to go the long way around with a gentle slope. But where the gravity is lesser, we can go the direct way which is more sloping.

Comment:  Very interesting scientific article. I have not read any scientific column for ages! This one made we want to go back to my high school and restudy the whole science.

PUNTHUCHAT Siripun

Thailand

APS4, Ritsumeikan Asia Pacific University