February 8, 1672 Isaac Newton presented his first results on his work in the field of optics at the Royal Society

On this day (February 8) 1672 Isaac Newton presented his first results on his work in the field of optics at the Royal Society
Newton presented, in that session, the reflecting telescope that he had invented as an alternative to the refracting telescope that Galileo had perfected, which had more problems with chromatic aberration.
The telescope Newtonian reflector uses a primary mirror concave and a secondary mirror flat diagonal.

Advantages of Newtonian design:

  • They are free from chromatic aberrations that are found in refracting telescopes.
  • Newtonian telescopes are typically less expensive for any diameter given objective than telescopes of comparable quality of other types.
  • Since there is only one surface that needs to be ground and polished into a complex shape, the overall fabrication is much simpler than other telescope designs
  • You can more easily a focal ratio short , which which leads to a field of view wider .
  • The eyepiece is located at the top end of the telescope. EThis can allow for a much more compact mounting system, reducing costs and increasing portability.

Disadvantages of the Newtonian design:

  • Newtonians, like other reflecting telescope designs using parabolic mirrors, suffer from coma , an aberration outside of the axis that causes the images to shoot inwards and towards the optical axis.
  • Newtonians have a central obstruction due to the secondary mirror in the light path.
  • For portable Newtonians, collimation can be a problem.
  • The focal plane is at an asymmetrical point and at the top of the optical tube assembly.
As a curiosity, the simple design of the Newtonian telescope has made it very popular among amateur telescope manufacturers.
- Hello, I want to present you an invention
- Newton?
- yes, it's me
- wow, now what has it fallen on your head?
- how?
- the other day you dropped an apple and you presented the law of gravity
- more or less
- what now?
- I have come to present a telescope
- oysters! what did you drop? a planet?
- a star?
- is the sky falling on our heads?
- well, I'm not interested
- how stale
- best question at the Royal Society

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