Science for the public

    Public for the science

Entropy of Radiation is an educational project for the general public and scientists, created to explain the history, development and uses of the second law of thermodynamics applied to radiation.

Besides this website, the project includes other interactive features such as a Blog, Forum, Newsletter, Quizzes and Free Software.

The Blog

"Reflections on the Motive Power of Heat."

- Sadi Carnot (1824)
"On an Improvement of Wien's Equation for the Spectrum."

- Max Planck (1900)
"On the Theory of the Energy Distribution Law of the Normal Spectrum."

- Max Planck (1900)
"Concerning an Heuristic Point of View Toward the Emission and Transformation of Light."

- Albert Einstein (1905)
"The Theory of Heat Radiation."

- Max Planck (1913)
"On the Quantum Theory of Radiation."

- Albert Einstein (1917)
"Planck's Law and Light Quantum Hypothesis."

- Satyendra Nath Bose (1924)
"Entropy of radiation: the unseen side of light."

- Alfonso Delgado-Bonal (2017)

History of the Entropy of Radiation
and implications

Who discovered the entropy of radiation?
Why is it useful?
What does it mean?

Entropy Radiation Equation

Works on the Entropy of Radiation
form a mathematical perspective

Discover the bibliography of the entropy with all the maths explained.

Earth at night
Educational Resources

Free resources for education
at different levels

Source codes, teaching materials and explanations by top scientists.

About the Entropy of Radiation Project

Find who we are, what do we want and how can you help us
to unravel the mystery of the entropy of radiation.

  • About us

    This project is a non-profit initiative developed by international collaborators.

    Our team

  • Stay in touch

    Join our newsletter to be updated with the latest news on the project, bibliography and more.

    Join us

  • Help Us

    You can help us in many ways. Contact us if you are willing to help.

    Contact us

  • Download

    Are you old fashion? Download one pdf and enjoy all the content.


  • Resources

    Source codes, quizzes, teaching manuals ... it is free !

    Free Resources

  • Newsletter

    Check out the previous newsletter.


Join our email list

You will receive our newsletter and will be updated with the latest news on the entropy of radiation.


The Entropy of Radiation project is the result of an international collaboration of scientists formed by:

Alfonso Delgado-Bonal - University of Salamanca (USAL), Spain.
Celia Blanco - University of California Santa Barbara (UCSB), California
Martin G. Mlynczak - NASA Langley Research Center, Virginia
Axel Kleidon - Max-Planck-Institut fuer Biogeochemie, Germany
Lin Linhua - Harbin Institute of Technology, China