The Components and Origin of the Universe Earth

The Components and Origin of the Universe

Earth in the Universe

Formation of the Solar System l Solar Nebula Theory: l Solar system formed 5 billion years ago from a massive cloud of gas and dust that began to contract http: //www. youtube. com/watch? v=B 1 AXbp. Ynd. Gc&gl=GB&hl=en-GB

Evidence l Theory explains observations that the planets orbit the Sun in the same direction, the planets are all in the same plane, Sun is at the centre, most planets rotate the same way, terrestial are closer than gas

The Organization of the Universe 1. Stars and Solar Systems § most common type of celestial object 2. Star Clusters § groups of stars that formed in the same nebula and are gravitationally bound Open star clusters – groups of 6 to 1000’s of young stars Globular star clusters – groups of 1000’s to millions of older stars

The Organization of the Universe Galaxies § collections of star clusters, planets, gas and dust measuring up to 100 000 light years across. § there are different kinds 3. Elliptical - contain the oldest stars but little gas or dust Spiral (like the Milky Way) many bright, young stars with lots of gas and dust

The Organization of the Universe 3. Galaxies Lenticular – central bulge but no spiral arms Irregular – no definite shape

The Organization of the Universe 4. Galaxy Clusters § galaxies, like stars, are grouped together § the Milky Way and our closest neighbouring galaxy Andromeda are part of the Local Cluster § local clusters are then grouped into Super Clusters and so on How many stars are in the universe? Well… 300 billion stars x 200 billion galaxies = 1. 0 x 1022 stars (20 sextillion stars)

The Organization of the Universe

Our Expanding Universe: ¤ we know the universe is expanding due to the phenomenon of the Doppler Effect ¤ as a fire truck goes past you, its pitch changes (click)

The Doppler Effect and Light ¤ the same thing happens with light energy ¤ energy travelling towards you has a shorter wavelength because it is compressed (bluer light) ¤ energy going away from you has a longer wavelength (redder light) ¤ this is called the RED SHIFT ¤ we see a red shift in the light from distant stars therefore, they are moving away from us

The Doppler Effect and Light

Hubble’s Law ¤ based on this evidence, Edwin Hubble proposed HUBBLE’S LAW ¤ the farthest galaxies are moving away the fastest and the closest are moving away the slowest ¤ think of raison bread dough……. you are sitting on a single raison and so it appears you are sitting still ¤ The red shift and expanding universe are part of the evidence of the Big Bang – a theory explaining how the universe originated.

Dark Matter and Dark Energy scientists were puzzled when some galaxies appeared to be moving away faster than they should be ¤ the deduced there must be upwards of 10 x more mass in a galaxy than we can see ¤ they called this mass dark matter ¤ we now know it is the most abundant matter in the universe but we don’t know much about it ¤ before 1998 scientists thought the pull of gravity would eventually slow the expansion of the universe down ¤ however, in 1998, they discovered that not only is the universe expanding but it gets faster as it goes ¤ this strange energy working against the force of gravity was called dark energy ¤

Origin of the Universe l The Big Bang: l Universe began incredibly hot, dense expansion approximately 13. 7 billion years ago http: //www. youtube. com/watch? v=lh. TSf. OZUNLo

No, not this one

This one…

The Big Bang Theory the Big Bang Theory suggests that all matter and energy expanded from a hot dense mass with an incredibly small volume 2. at first, the universe was hot (10 32 C) and energy went rushing out in all directions energy became cooled enough to become matter 3. matter then cooled enough to form protons, electrons and neutrons (subatomic particles) 4. subatomic particles combined to form mostly hydrogen but some helium nuclei 1.

Evidence of the Big Bang ¤ the universe is filled with gas and as a gas expands it cools the universe is cooling ¤ the red shift shows that galaxy’s are moving away from us universe if growing ¤ we have detected cosmic background radiation that was left over from the intense radiation created during the Big Bang we can hear it ¤ we have found no stars that are older than the age we think the universe is we’re smart

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