Telescopes and Optics

Study Notes

Optical devices designed to make distant objects appear closer.
Composed of an objective lens in refractors and a primary mirror in reflectors.
Light-gathering ability is determined by the diameter of the lens or mirror, known as the aperture.
A larger aperture collects more light, resulting in a brighter image.
Magnification is influenced by the lens combination, but aperture is more critical for image quality.

Binocular telescopes consist of two identical mirrors, allowing for binocular vision.
Design involves multiple considerations:
- Two telescopes are needed for magnification.
- Matching magnification between lenses.
- Erect image display.
- Must be handheld and focusable, preferably jointly.
- Parallel optical axes and adjustable interpupillary separation.

Comprises three main parts:
- Objective Lens Assembly: Gathers light and forms an image.
- Eyepiece Lens Assembly: Examines the image formed by the objective lenses, includes a focusing mechanism.

Porro-prism Binoculars: Characterized by offset objective lens tubes and angled prisms.
Roof Prism Binoculars: Feature straight tubes, resulting in a more compact design.

Defined as the flow of electrical power or charge, closely related to magnetism.

A physics branch investigating electromagnetic forces between charged particles.

Ancient World: Knowledge of magnetism among Greeks, Romans, and Chinese; development of geomantic compasses in China; lodestones named after Manisa, Turkey.
13th Century: Petrus Peregrinus documented a magnet's magnetic field and identified North and South poles.
17th Century: William Gilbert published De Magnete, proposing the Earth as a giant magnet.
18th Century: John Michell and Charles-Augustin de Coulomb studied magnetic forces; Coulomb researched electricity but did not link it with magnetism.
19th Century: Key figures like Hans Christian Oersted demonstrated the link between electricity and magnetism, while Faraday discovered that changing magnetic fields can induce electric currents.