Skip to main content
SpringerLink
Log in

Radiation Energy and Beam Limitation

  • Chapter
  • First Online:
Pohl's Introduction to Physics

  • 1698 Accesses

Abstract

In our whole discussion of image formation and optical instruments, the details of lens fabrication and ray diagrams have not been emphasized; instead, we have used the limiting boundaries of light beams as an explanatory principle. This decisive point will also lead us to an understanding of energy transport by radiation, whether or not it is accompanied by image formation.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Log in via an institution

Institutional subscriptions

Notes

  1. 1.

    The unit of a solid angle is, like the unit of every angle, simply the number 1. It is often expedient to give the number 1 in this connection the name ‘steradian’ (sr). See also the footnote at the end of Chap. 17. More details are given in Vol. 1, Sect. 1.5.

  2. 2.

    The radiation which is emitted by the sun comes from a layer about 200 km thick, which is increasingly cooler towards the outside. Near the edges of the solar disk, the paths of the radiation through the cooler regions of the layer become longer. At the very edge, one therefore measures (of course depending on the wavelength) around 60 % lower values of the radiance than at the center of the solar disk.

  3. 3.

    Here, as always, we assume the same material in front of and behind the lens, for example air.

  4. 4.

    E. W. Tschirnhaus, 1651–1708, mathematician, owner of a farm at Kieslingswalde, near Görlitz, and member of the Paris Academy from 1682 on, constructed a ‘burning mirror’ in 1686 with an opening diameter of 2 m and a focal length of 1.3 m, made of polished copper, and used it to melt materials.

Author information

Authors and Affiliations

  1. Fachbereich Physik, Freie Universität Berlin, Berlin, Germany

    Professor Dr. Klaus Lüders

  2. Department of Physics, Cornell University, Ithaca, NY, USA

    Professor Dr. Robert Otto Pohl

Authors
  1. Professor Dr. Klaus Lüders
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Professor Dr. Robert Otto Pohl
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Klaus Lüders .

Editor information

Editors and Affiliations

  1. Fachbereich Physik, Organisation: Freie Universität Berlin, Berlin, Germany

    Klaus Lüders

  2. Department of Physics, Cornell University, Ithaca, New York, USA

    Robert O. Pohl

Rights and permissions

Reprints and permissions

Copyright information

© 2018 Springer International Publishing AG

About this chapter

Check for updates. Verify currency and authenticity via CrossMark

Cite this chapter

Lüders, K., Pohl, R.O. (2018). Radiation Energy and Beam Limitation. In: Lüders, K., Pohl, R. (eds) Pohl's Introduction to Physics. Springer, Cham. https://doi.org/10.1007/978-3-319-50269-4_19

Download citation

Publish with us

Policies and ethics

Search

Navigation