Using Light to Learn About the Universe, Part 3
Spectrometers
A spectrometer is an instrument that measures properties of light and can identify the chemical composition of matter. Because atoms and molecules absorb and emit light at particular wavelengths, unique patterns of absorption and emission lines can be used as signatures or fingerprints to identify the composition of an object.
First, watch this video. As you watch, note what spectrometers can tell us about planet composition and light’s direction of travel.
Next, launch this interactive, which illustrates how spectrometers separate light across the spectrum and how line spectra are created.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Video: Light | Crash Course Astronomy (Excerpt)
Take Notes
- How do scientists use evidence from light received from space to:
- identify the composition of stars?
- confirm that the universe is expanding?
- What evidence from the media could students use to support the claim that dissecting light has allowed scientists to understand what the universe is made of?
