• Question: How did you know that the sun uses nuclear fusion, and when you did, how did you know how to recreate it?

    Asked by AT-FK on 29 Nov 2021.
    • Photo: Craig Hickman

      Craig Hickman answered on 29 Nov 2021:

      Hi AT-FK

      Good question. Like many scientific discoveries, there were lots of people involved. I will try my best to answer this, but I do not know the full story.

      You may have heard of the famous equation

      E = M C squared

      Albert Einstein formulated this equation in 1905. It describes how mass can be converted to energy, via fusion or fission.

      In 1920, British astrophysicist Arthur Eddington was the first to suggest that stars draw their apparent endless energy from the fusion of hydrogen into helium. It took another theoretician, Hans Bethe, to precisely identify the processes that Eddington had postulated. This won him the Nobel Prize in Physics in 1967.

      At this point, we had an understanding of the very extreme conditions required to create a fusion reaction (VERY high pressure and temperature), but we did not know how to create these conditions on earth. Stars have the advantage of being very large, so their huge mass allows gravity to create the pressure and temperature required to start up the fusion reaction.

      Soviet physicists Igor Tamm and Andrei Sakharov were the first to conceptualise a Tokamak – a device that could create and contain the conditions required for fusion. This was inspired by a letter by Oleg Lavrentiev. The first working tokamak was attributed to the work of Natan Yavlinsky on the T-1 in 1958.

      Lots of other scientists and engineers have contributed to the knowledge of how to create a fusion reaction on earth, and there are still many scientists and engineers working on this now.

      Sources:

      https://www.scientificamerican.com/article/was-einstein-the-first-to-invent-e-mc2/
      https://www.iter.org/mag/3/29
      https://en.wikipedia.org/wiki/Tokamak

Comments

  • Photo: Craig

    Craig commented on :

    To answer “How” these scientists knew this, and how they know how to recreate it – Lots of research, experimentation, and coming up with new ideas that other scientists then discuss and review. Over time, the ideas that best explain reality are the ones that stick around.