July 8, 2010
Sometimes it’s good to take a moment and reflect on topics that may give us pause and provide some perspective to the routine of our daily existence. Here a few orthogonal observations I have found interesting.
Stellar nucleosynthesis, heavy elements and the human body
Of the hundreds of known atoms on earth only the lightest (hydrogen, deuterium, helium, lithium and trace amounts of beryllium) could have been made directly during the big bang. Heavier elements, up to iron, could be manufactured by fusion during the normal life cycle of stars. Elements heavier than iron are created only during the violent, explosive death some stars experience, the supernovas. The resulting heavy elements produced by a supernova explosion are scattered through space to become the building blocks of other stars and planets, including Earth.
I find it fascinating and somewhat humbling to realize that the heavier elements that exist on Earth and that make up a small part of the human body originated in one or more massive supernova explosions some untold eons ago. Literally, we are all stars.
There are more stars in the universe than grains of sand on the earth.
Maybe… Of course the real answer is unknown but a few back of the envelope calculations are sometimes enlightening.
Grains of sand:
Stars in the universe:
Our galaxy has 2*10e11 stars (http://www.faqs.org/faqs/astronomy/faq/part8/section-3.html)
There are 8*10e10 galaxies (http://www.faqs.org/faqs/astronomy/faq/part8/section-4.html)
Number of stars = (2*10e11 stars in our galaxy) * (8*10e10 galaxies) = 1.6e21 stars in the universe
Since these are purely estimates we can take rounding liberties and round up the grains of sand to 10e19 and round down the number of stars to 10e21. The two order of magnitude difference means that for every grain of sand on earth there are 100 stars in the universe.
Note: The above summary was based on this posting: http://answers.google.com/answers/threadview/id/539329.html
Blue pigment does not exist in the avian world. Birds that appear blue to us do so because their feathers have small air pockets that refract light so that the feather appears blue. A blue bird’s feather that is back lighted will appear gray, not blue. Sometimes, things are not as they appear.
Oysters and sex
This entry will probably be ranked higher in the search engines than any other posting but it’s not about the purported aphrodisiac effect of this bivalve. It’s about the sex of oysters, or should I say sexes?
Oysters are born as males and some change into females as they age. Environmental conditions can also induce the transformation from male to female independent of age. An individual oyster can change gender several times during its life making gender a relative state.