How to weigh a galaxy



The teaching activities consist in measuring the mass of a spiral galaxy, viewed edge-on, using the same procedure employed by astronomers. It is surprising how just a few measurements and the knowledge of a few fundamental laws of physics make it possible to weigh the largest and most distant objects in the Universe, despite the impossibility of carrying out direct measurements and the fact that the only information available to us derive from a few photons which have travelled for tens and tens of millions of years.

What is even more surprising is the fact that the simple measurement proposed here makes it possible to obtain experimental evidence for the existence of the famous dark matter. Dark matter and dark energy are believed to make up to 96% of the total content of the Universe, but they are incredibly difficult to detect and study, other than through the gravitational forces they exert.
Investigating the nature of dark matter and dark energy is one of the biggest challenges today in the fields of particle physics and cosmology. The ATLAS and CMS experiments will look for supersymmetric particles to test a likely hypothesis for the make-up of dark matter.





Download the PDF complete version by clicking on the following link: educational_content_how_to_weigh_a_galaxy.pdf
Educational content developed by Institut d’Astrophysique de Paris



Validated by Discover the Cosmos + How to weigh a galaxy

Last update | 20/06/2013

 
como_pesar_una_galaxia.txt · Last modified: 24/04/2017 13:01 (external edit)
HOU Internacial. Galieleo Teacher Training Program. Universidad complutense de Madrid. DokuWiki IYA 2009