1. Summary of the first and
second tasks
Resumen del primer y
segundo tema
2. The universe
• We call the universe to the set of matter, energy, time
and space existing.
At first, it was thought that the Universe was just formed by
the Milky Way. Several models were created in this
period:
The geocentric model stablished that every object in the
space revolved around the Earth, which was thought to
be motionless
The heliocentric model proposed that the Sun was
motionless and the planets and the moon revolved
around it.
The discovery of the Andromeda Galaxy supposed that
scientist realised that our galaxy is not alone, the
universe is much more extense.
3. The Big Bang Theory
• It stablishes that the universe was formed after a big
explotion: The Big Bang. It also supposes that the
universe is in expansion since the Big Bang.
• After that the Universe was very hot and formed by a
plasma of protons and electrons. The formers formed
atomic nuclei. Then the Universe cooled down and
nucleosynthesis ended.
4. Materia oscura y universo en
expansion
• Es la materia que no vemos pero detectamos su masa
dinamica
• La masa de la materia oscura sumada a la materia
brillante es insuficiente para detener la expansion del
universo con lo cual dicha expansion sera eterna
• Estudiando la velocidad de la expansion del universo
podemos observar que la actual es mayor que antes por
lo que podemos deducir que hay una fuerza que no
conocemos que hace que la expansion sea acelerada
5. La exploracion del espacio
• La atmosfera supone una barrera para la
radiacion electromagnica ya que retiene parte
de esta
• Por ello las diferentes potencias del mundo se
encuentran en una continua carrera por
conquistar el espacio, gracias a esto, el hombre
a podido alcanzar la luna
• La exploracion espacial tiene aplicaciones en
muchas campo: investigación científica,
observación
6. Cumulus and galaxies
• Galaxies are huge groups of stars, gas and dust. They
have different shapes and sizes.
Spiral galaxies contain a central area and several arms.
The Milky Way is a good example.
Elliptical galaxies are the largest ones and they haven’t
got any arms.
Irregular galaxies are the most abundant and do not
have definite form.
• Nebulae are clouds of gas and dust. Stars are formed
here, and also the result of their explosions when they
die.
• Quasars are stellar objects that emit radio waves.
• Black holes where light is “trapped” because the
gravitational attraction is very high.
7. Stars
• They are huge spheres of hydrogen and helium gas and they are
born in nebulae. It has several phases:
1. Protostar: the nebula contracts due to the gravitational attraction,
forming stellar-mass fragments, mainly formed by hydrogen.
2. When the helium starts to be formed from H in the nucleus, they
become young stars, and it starts to release energy to the
surface, which becomes hot.
3. It becomes a red giant star when the layer of production of energy
is not in the nucleous any more, but in an outter part of the star.
The star expands because of the increase in temperature, and
therefore, in thermal and reactive pressure, apart from the
increase of density in the star. The surface becomes red because
it cools down. When the H is consumed the star contracts and
forms a white dwarf star. When it cools down, it forms a black
dwarf star.
4. Sometimes the nucleous starts producting energy in the
nucleous, forming oxygen and Carbon, and more and more
energy is producted and becomes a red supergiant star. The end
of this star can be similar to the one in red giant stars, but it can
also explote.
8. Formacion de los planetas
• Parte de la materia resultante de la explosion de una
estrella permanece alrededor de la nueva estrella
formando un disco protoplanetario, en el cual
aparecerán más tarde los planetas por una serie de
procesos.
• Nuestro Sistema Solar tiene 4 planetas interiores
rocosos (Mercurio, Venus, la Tierra y Marte), cuyo
núcleo es metálico y cuya corteza es de aspecto
rocoso, y 4 exteriores gaseosos (Júpiter, Saturno, Urano
y Neptuno) cuyo núcleo también es metálico y que
tienen una corteza compuesta por gases, sobre todo H y
He.
• En el sistema solar existen otros objetos en el Sistema
Solar (siguiente):
9. • Satélites: cuerpos celestes que giran alrededor de los planetas.
• Asteroides: Objetos de menor tamaño que los planetas y los
satélites. Un ejemplo es el cinturón de asteroides entre Marte y
Júpiter.
• Cometas: objetos de núcleo sólido formado por H2O y NH3 que
desprenden sustancias al acercarse al Sol, las cuales forman parte
de su cola.
• Fragmentos de planetas, cometas y asteroides: Van a la deriva por
el espacio y pueden caer sobre la superficie de los planetas. Su
masa varía de unos pocos gramos a toneladas.
