This document discusses gravity and its role in shaping astronomical structures like galaxies and galaxy clusters. It describes how gravity causes stars at the edges of spiral galaxies to rotate at similar speeds to those at the center, and how galaxy clusters contain 10 times more mass than can be accounted for by visible matter alone. The document also mentions how Einstein's theory of general relativity explains the accelerating expansion of the universe driven by dark energy, which exerts a repulsive force that counteracts gravity on large scales.

1. By: Alejandro Cano, Dani
Martínez, Sergio Núñez &
Carmen Barbero

4. • Gravity has an important
role in this theme
• As you all know, gravity
is the force of attraction
that we feel when we are
near of an astronomical
object
• This was described by Sir.
Isaac Newton in the Laws
of Universal Gravitation

5. • It does not interact with electromagnetic
spectrum.
• It is not visible but the amount of it in the
universe is much bigger than the amount of
matter that is visible
• Matter visible are planets, stars, galaxies..
• The only explanation for its existance is the
gravitational pull.

6. Gravitational Pull
• Appreciated in spiral
galaxies
• Stars at the center
should rotate at a
higher speed than the
ones outside
• The speed is mostly the
same
• As a conclusion the
ones outside are feeling
a gravitational pull.

7. Galaxy Clusters
• If we look to one of this
we can see that there is
10 times more mass than
the one we can account
for
• Coma Galaxy Cluster is
one example
• In this clusters we can
see that it always
remains the same but
galaxies move at high
speed

8. • Mass
• Orbital speed

9. • Coma Cluster

10. • GALAXY-GALAXY CLUSTER-OBSERVER
• Einstein´s ring

11. • Opposite effect:
Negative pressure; repulsion of matter.

12. Expectation: slowing down, GRAVITY
WINS!

13. Expectation: slowing down, GRAVITY
WINS!

14. Space´s expansion is
accelerating

15. Galaxies!

16. • EEuucclliidd ssppaaccee mmiissssiioonn:: measure the expanding universe’s
acceleration.
• FFeerrmmii GGaammmmaa--rraayy SSppaaccee TTeelleessccooppee:: gamma-ray
observations from low Earth orbit.

17. • LLaarrggee HHaaddrroonn CCoolllliiddeerr ((LLHHCC)):: it might produce dark
matter particles. It’s only evidence would be its missing
energy.
• CCDDMMSS ((CCrryyooggeenniicc DDaarrkk MMaatttteerr SSeeaarrcchh)):: detect
particle dark matter in the form of WIMPs (weakly
interactive massive particles).