Tasks

1. Locate the absorption or emission lines of the well-known Balmer series (H_α, H_β, …, H_ε) of hydrogen (H) in the spectrum by carefully increasing the z-value. The absorption lines of calcium (Ca) and the emission lines of oxygen (O III) are also prominent.
2. Transfer the table to a spreadsheet program and add the corresponding redshift z.
3. Create a z(d) diagram in the spreadsheet program and examine the trend. Describe your observation and translate it into a mathematical language (model).
4. To check your model (trend; mathematical function), you can examine the galaxy NGC 3368.
   It is 35 × 10⁶ light-years away from us. Predict the redshift value z using your model!
5. Check your result using the spectrum of NGC 3368:
6. The quasar 3C 273 is a very distant object of enormous luminosity. Investigate its spectrum for redshift.
7. Using your model and the redshift z, calculate the distance to the quasar 3C 273.
   
   --- All done so far? Then continue with step 8:
8. Enter the distance to 3C 273 in the table and compare your result with the literature value.
9. The classic application of the double effect known from acoustics to wave optics yields:
   z = v/c .
   Here, v is the recessional velocity of the wave-emitting object and c is the speed of light.
   Calculate the recessional velocity of some of the galaxies above!
10. Determine your Hubble constant H₀ using your measurement results.
11. Compare your Hubble constant with the current literature value.
12. Discuss whose movement is becoming apparent here!
13. Consequence: The distance in light-years (ly) is simultaneously a measure of time in years.
    Discuss the implications of your mathematical model for the year zero of the universe.