Summary 2. Photon and Atom

We started the series of “Interesting Story about Light Science” newsletters last April with discussion about how light is produced in the sun i.e. through nuclear fusion of hydrogens. In the following newsletters, we also discussed how all the living organisms on the earth we see today in the natural environment evolved to survive under the sunlight over billions of years.

Earth was formed around 4.5 billion years ago and our solar system is one of more than 100 billion stars in our galaxy, and it is estimated there are over 100 billion galaxies in the universe (some maintain there are about 2 trillion galaxies in the universe). Going to the opposite and most downsizing direction, however, the universe is made of atoms, and the atom is composed of a nucleus and one or more electrons around the nucleus.

It is estimated there are about 100 trillion (1014) cells in our body and human body is composed of about 1028 atoms. What is interesting is that most of the space in the atom is unoccupied. If the size of atom was the size of the earth, the nucleus and an electron would be the size of a football stadium and a football, respectively, and the rest in between would be just empty. If we took out all the empty space between nucleus and electrons in the body in the same way, the size of our body would be just as small as a grain of table salt.

Since light (i.e. photon) have higher energy at shorter wavelength, the photon with red wavelength don’t escape the electrons of atom but the photon with blue wavelength was emitted the electrons from atom. This is the problem of blue light.

Biologist A-Young Lee Ph.D
Biologist Jin-won Kim Ph.D
Biologist Jae-ho Lee Ph.D
Biologist Sang-wook Chung Ph.D
Physicist Sung-soo Kim Ph.D
Electronic and Information Engineering Sooyoung Moon Ph.D
Physics & MBA  Chung H. Lee Adviser

* Next week’s topic:Photon is a particle with energy

You can find "Interesting Story about Light Science” series on the link below.


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