1 / 4

Ch 15.4 Expanding Universe

Ch 15.4 Expanding Universe. We know: light is a form of energy that travels as a wave. each colour has a wavelength. the visible spectrum has different colours . longest wavelength: red shortest wavelength: violet.

moses-nixon
Download Presentation

Ch 15.4 Expanding Universe

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ch15.4 ExpandingUniverse

  2. We know: • light is a form of energy that travels as a wave. • each colour has a wavelength. • the visible spectrum has different colours. • longest wavelength: red • shortest wavelength: violet. • different stars have characteristic colours (their own specific colours).

  3. Each galaxy emits its own spectrum, or range of colours in a pattern that astronomers recognize. • Since 1912, astronomers have been able to observe the light spectra (pattern of colours) given off by nearby galaxies. They found the spectrum of a moving object is different than that of a still object.

  4. Astronomers use a spectroscope to look for the pattern of the spectrum (to tell them exactly what galaxy it is) but also the colours of the lines. • If the lines are moving toward the red end of the spectrum, they have a longer wavelength. This means the galaxy is moving away from us. • This movement is called the Red Shift. • BUT: • all galaxies show a red shift, some are bigger than others. • This means that all galaxies are moving away from us and each other.

More Related