Observing Stars
Our view of the sky at night is possible because of the emission and reflection of light. 'Light' is the better-known term for the electromagnetic spectrum, which includes waves in the visible, ultra-violet, infra-red, microwave, radio, X-ray and gamma-ray regions. The scale of the spectrum is so large that no region is distinct, several overlap each other.Each of these regions in the electromagnetic spectrum represent transverse waves, travelling as electrical and magnetic fields which interact perpendicularly to each other, with different ranges of wavelength. The magnetic field oscillates vertically and the electric field horizontally, and each field induces the other. By the end of the nineteenth century, Maxwell gave a realistic value for c, the speed of light: The relationship between the speed of all electromagnetic radiation, wavelength (l) and frequency (f) is shown to be c = l f. Because the Universe is so vast, interstellar distances are so great that light emitted can take upwards of millions of years to reach us. Such large distances are often measured in ‘light-years’; one light-year (ly) is the distance travelled by a wave of li
. . .
Some common words found in the essay are:
Bang Low, Sun Earth, ESA Hipparcus, Observing Stars, Universe Bang, Mpc-1 Doppler, Earth Earth, Earth Unsurprisingly, Tan Distance, T4 Stefans, electromagnetic spectrum, surface temperature, black body, electromagnetic radiation, light emitted, regions electromagnetic spectrum, balmer series, regions electromagnetic, surface temperatures, absolute magnitude, radio waves, inverse square law, falls visible region, region electromagnetic spectrum, visible region electromagnetic,
Approximate Word count = 2940
Approximate Pages = 12 (250 words per page double spaced)
|
 |
