This lesson uses a simple discrepant event to demonstrate the underlying cause for early miscalculation of the size of the Milky Way galaxy. By standardizing the Cepheid period-luminosity relationship without recognizing there were two types of... (View More) Cepheid variable stars with intrinsic differences in absolute magnitude, a distance calculation error occurred. Requires two lamps and two soft-white light bulbs: 25 watt and 60 watt (estimated materials cost is for light bulbs). This lesson is part of the Cosmic Times teachers guide and is intended to be used in conjunction with the 1955 Cosmic Times Poster. (View Less)

This is an activity about spectroscopy. Learners make their own spectroscope and measure the wavelengths of spectral lines. Then, they will record the colors, patterns, and wavelengths of the lines from various light sources. This activity requires... (View More) use of gas discharge tubes and power supplies. This is Activity J-6 of Universe at Your Fingertips 2.0: A Collection of Activities and Resources for Teaching Astronomy DVD-ROM, which is available for purchase. (View Less)

This is an activity about spectroscopy. Learners make their own spectroscope and measure the wavelengths of spectral lines. Then, they will record the colors, patterns, and wavelengths of the lines from various light sources. This activity requires... (View More) use of gas discharge tubes and power supplies. This is Actividad 10.1 as part of El Universo a Sus Pies, a Spanish-language curriculum, available for purchase. (View Less)

This is an activity about the Doppler effect. Learners will use long springs or ropes to examine the frequency and wavelength of various waves. Then, they will observe a demonstration of the Doppler effect for sound waves, using this understanding... (View More) to investigate the shifted spectra of sample galaxies. Finally, learners will user their data to create a graph of distance versus recession speed, illustrating Hubble’s Law regarding the expansion of the Universe. This is Actividad 8.3 as part of El Universo a Sus Pies, a Spanish-language curriculum, available for purchase. (View Less)

This is an activity about the Doppler effect. Learners will use long springs or ropes to examine the frequency and wavelength of various waves. Then, they will observe a demonstration of the Doppler effect for sound waves, using this understanding... (View More) to investigate the shifted spectra of sample galaxies. Finally, learners will user their data to create a graph of distance versus recession speed, illustrating Hubble’s Law regarding the expansion of the Universe. This is Activity H-8 of Universe at Your Fingertips 2.0: A Collection of Activities and Resources for Teaching Astronomy DVD-ROM, which is available for purchase. (View Less)