Summary 3. Photon is a particle with energy

As explained in the 6th newsletter "The Interesting Story of Light Science.", a huge amount of photons as 1X1018 per second are emitted and these photons have a huge physical impact when it hits object and human body because it accumulates like as water droplets break the rocks.

We have described the behavior of the blue photon in
summary 1 &2. The spectra of artificial light such as fluorescent light and LED that we've developed with emphasis on power efficiency the intensity of light by color is different (ex: various colors which can be observed in the prism), as shown in the figure below.

The blue color in LED and green color in fluorescent light are stronger than natural light that we've adapted to for millions of years. So, the light of fluorescent light and LED is different from the natural light. In physics, the photon have no mass. In fact, the photon is a particle with certain energy, and they have the energy mass that can ring the speaker by using the photon, as we explained in 6th newsletter.

The body cells are regionally different in which they die and are re-born. For example, the stomach wall is regenerated within two days to adjust to stomach acid for the digest. And our skin regenerates over 2~3 weeks and our bones take about ten years for regeneration. But, the eye cells use the cells at birth for life. That means is that the eyes are impossible to regenerate. The fact that the near-sightedness rate in Asia, which uses a lot of artificial lighting, especially fluorescent lights, is very suggestive. Especially, the Chinese government has quickly propose to overcome the problem.

Are short wavelength green and blue lights harmful to the human body? Not absolute. The problem is that is has a different spectrum than the sun. For example, the blue wavelength of 480nm is needed for IPRGC to sense the circadian rhythm. For modern people who live under artificial light sources most of the day, exposure to appropriate blue light in the morning and daytime is essential to good sleep, memory improvement and health.
I will be explained the circadian rhythm in the next topic.

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: Biological rhythm is controlled by light.

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


Seoul Semiconductor /
97-11, Sandan-ro 163beon-gil, Danwon-gu, Ansan-si, Gyeonggi-do, Republic of Korea