“Measuring the recess velocity of distant galaxies” Calculating the age of the Universe

Link to the demonstrator: in English


Age: > 16

Duration: 3 hours

Equipment: PC with internet connection 

Contact details

Author: Dr. Matteo Barsuglia (PCCP)
Contact: info[at]frontiers-project[dot]eu



This demonstrator introduces the concept of the expansion of the Universe discovered by Edwin Hubble. Students will reproduce Hubble’s measurements in order to obtain an estimate of the age of the Universe, thanks to real sky images and data taking. They will play the role of an observational astronomer and learn about some fundamental properties of astronomical sources, such as the magnitude and the luminosity distance. They will also learn about light spectra, absorption lines, redshift, and the Doppler effect. Students will reproduce the Hubble diagram and get a measurement of the Hubble constant and the age of the Universe. Students will present their work to the class and discuss how it compare with the most accurate results that astronomers have.


Learning outcomes:

  1. Teach students about the expansion of the Universe and the basics of Hubble observations.
  2. Allow students to understand the daily work of an observational astronomer.
  3. Introduce basic concepts of observational astronomy, cosmology, and image processing.


Prior knowledge:

  • Algebra
  • Wave properties
  • Basics of light spectrum


Concepts introduced:

  • Universe’s expansion and age
  • Spectral lines analysis, Doppler effect, astronomical redshift
  • Standard candles
  • Cosmic Microwave Background



Learning intentions:

By the end of this demonstrator, students should be able to:

  • Explain the expansion of the Universe and its observational discovery
  • Remember the Doppler Effect and the interpretation of redshift.
  • Describe a spectrum and interpret its absorption lines.
  • Explain the idea of standard candles in astronomy.
  • Interpret data evaluating signal/noise ratio.

Key activities:

  1. Videos to engage
  2. Data taking, analysis, and interpretation
  3. Final report and discussion



By the end of this demonstrator, students should be able to answer the following:


  1. Write a couple of sentences describing what you’ve learned about the Big Bang and the expansion of the Universe, explain the Hubble’s law
  2. What the Hubble constant H0 is and how to calculate it.
  3. Describe the basics of an observational astronomer’s work.
  4. Explain how different disciplines are necessary to obtain Hubble’s law and how multidisciplinarity can be crucial to solve complex problems.
  5. Explain how to calculate the age of the Universe using the Hubble diagram.

Start typing and press Enter to search