Monday, October 7, 2013

The Universe, Galaxies and Planet Earth

The known Universe contains ~200 billion galaxies and is ~13.72 billion years old.

The Milky Way Galaxy contains ~200 billion stars and is ~13.2 billion years old.

So, there could be a galaxy in the universe for every star in the Milky Way Galaxy.

Planet Earth is 4.54 billion years old (the moon is 4.527 billion years old).

One million Earths could fit inside the Sun.

The Milky Way Galaxy is 100 billion times larger than the Sun.

The average distance between stars is 20 million million miles.

~4.3 billion years ago: First rocks formed
~4 billion years ago: Atmosphere and ocean formed.
~3.9 billion years ago: End of Late Heavy Bombardment (asteroids and comets)
~3.85 billion years ago: Origin of life: First prokaryotes (simple cells, no nucleus)
~3.5 billion years ago: Photosynthesis began in cyanobacteria
~2.4 billion years ago: Great Oxygenation Event (GOE)
~2 billion years ago: First eukaryotes (complex cells)
~1 billion years ago: First multicellular organisms such as red algae
~900 million years ago: A day on Earth was 18 hours and a years was 481 days.
~600 million years ago: First fungi, jellyfish, sponges, worms (first primitive brain & eyes)
~570 million years ago: First arthropods (ancestors of insects, arachnids and crustaceans)
~543 million years ago: Cambrian explosion  (Complex animal life starts).
~500 million years ago: First fish (chordates)
~470 million years ago: First land plants 
~420 million years ago: First jawed fish
~400 million years ago: First insects
~385 million years ago: First seeds
~380 million years ago: First tetrapods (four feet)
~375 million years ago: First forests
~360 million years ago: First amphibians
~320 million years ago: First reptiles
~300-180 million years ago: Pangea (super continent) existed.
~251 million years ago: Permian Extinction
~240-65 million years ago: Dinosaurs existed
~220 million years ago: First mammals
~140 million years ago: First birds (feathers before flight)
~135 million years ago: First flowers
~130 million years ago: First marsupial mammals
~100 million years ago: First eutherian (placental) mammals
~65 million years ago: First primate-like mammals, or proto-primates
~60 million years ago: First grasses
~35 million years ago: First monkeys
~14 million years ago: First apes
~6 million years ago: Hominids branch off from other primates
~4.5 million years ago: Australopithecines (early bipedal hominids)
~2.3 million years ago: First humans (Homo habilis)
~250,000-30,000 years ago: Neanderthals existed.
~150,000 years ago: Anatomically modern people (Homo sapiens)
~35,000 years ago: Symbolic art for first time
~11,300-5,500 years ago: Stone Age (Neolithic)
~10,000 years ago: End of last Ice Age and start of First Agricultural Revolution
~6,000 years ago: First cities (Damascus is one of the oldest continuously inhabited).
~5,500-3,400 years ago: Bronze Age
~5,000 years ago: First written languages: Mesopotamian cuneiform and Egyptian hieroglyphs
~3,400-1,600 years ago: Iron Age
~3,450 years ago: First written Greek
~3,200 years ago: First written Chinese
2,400-1,537 years ago: Roman Empire existed (not counting Eastern Empire)
~1,550-650: Dark Ages (Middle Ages) Ends when the Renaissance starts.
714-90 years ago: Ottoman Empire existed.
~180 years ago: Industrial Revolution started.

great chart

Formation of atmosphere and ocean

The oxygen released due to photosynthesis is
because of water, not carbon dioxide.

great timeline

  Origin of Life with David Attenborough
          First Life, BBC  National Geographic: The Story of Earth HD  History of the World - History Channel Documentary

Types of Galaxies
Hubble discovered that the universe is "expanding" and that
there exists billions of galaxies, all moving very quickly.

Most abundant elements in the Sun

Elements in Earth's air

Elements in Earth's crust

Elements in the human body

There are more atoms in a human body
than there are stars in the universe.

 It takes 225 million years for our Sun to travel round the galaxy.
It takes 8 minutes for sunlight to reach the Earth.

It take one year (365 days) for Earth to revolve around the sun.
Earth moves at ~66,000 miles per hour.
The path of the revolution is an ellipse, not a circle.
It rotates every 24 hours (spins on axis 1,000+ miles per hour)
It is because of the 23.5% tilt of the Earth's axis that there are seasons
In the Northern Hemisphere, Earth is closer to the sun in the winter, 
furthest in summer. The average distance from the Earth to
the Sun is 93 million miles.

Hubble telescope

Telescopes are like time machines.
With the Hubble Telescope it is possible to see the universe
when it was only 800 million years old.

Since stars are so far away (many light years),
we see the stars how they used to look.

tiny planet Earth from Voyager I in 1990 from edge of Solar System

World population in 2013: 7.2 billion
People that have lived on Earth: ~106 billion

There exist about 8 million species in 2013.
It is estimated that there have been 4 billion 
species that have existed on Earth. 

In regard to language, there are about 6,700 languages in 2013.
It is estimated that there have been as many as 100,000 languages.


Of the 8 million (could be many more) species alive today, only
5,400 are mammal species, and only 435 of those are primates.

There are 75,000 living species of chordates.
64,000 species are vertebrates.
(Only 3% of animals are vertebrates)

The average life-span of a species is 4 million years.

Language Tree

Pangea (Pangaea) with modern-day countries labeled

North America was completely separated from Pangea
about 130 million years ago. The South American plate
was separated by 80 million years ago. By 3 million years
ago, North and South America had once again connected.

  Earth during the past 650 million years and future Earth during the past 600 million years

The Earth and the continents (plates) after 250 million years
are predicted to one super continent once again. Names I have
seen for this are Pangea Amasia, Pangea Proxima and Pangea Ultima.

SURFACE PRESSURE100,000 mb1,000 mb6 mb



The variations in concentration from the Earth to Mars and Venus result from the different processes that influenced the development of each atmosphere. While Venus is too warm and Mars is too cold for liquid water the Earth is at just such a distance from the Sun that water was able to form in all three phases, gaseous, liquid and solid. Through condensation the water vapor in our atmosphere was removed over time to form the oceans. Additionally, because carbon dioxide is slightly soluble in water it too was removed slowly from the atmosphere leaving the relatively scarce but unreactive nitrogen to build up to the 78% is holds today.

There are species that only exist on Madagascar and India.

From Soup to Cells—the Origin of Life

A microbe-like cellular filament found in 3.465 billion year old rock
A microbe-like cellular filament found in 3.465 billion year old rock
Evolution encompasses a wide range of phenomena: from the emergence of major lineages, to mass extinctions, to the evolution of antibiotic resistant bacteria in hospitals today. However, within the field of evolutionary biology, the origin of life is of special interest because it addresses the fundamental question of where we (and all living things) came from. Many lines of evidence help illuminate the origin of life: ancient fossils, radiometric dating, the phylogenetics and chemistry of modern organisms, and even experiments. However, since new evidence is constantly being discovered, hypotheses about how life originated may change or be modified. It's important to keep in mind that changes to these hypotheses are a normal part of the process of science and that they do not represent a change in the basis of evolutionary theory.

When did life originate?
Evidence suggests that life first evolved around 3.5 billion years ago. This evidence takes the form of microfossils (fossils too small to be seen without the aid of a microscope) and ancient rock structures in South Africa and Australia called stromatolites. Stromatolites are produced by microbes (mainly photosynthesizing cyanobacteria) that form thin microbial films which trap mud; over time, layers of these mud/microbe mats can build up into a layered rock structure — the stromatolite. Stromatolites are still produced by microbes today. These modern stromatolites are remarkably similar to the ancient stromatolites which provide evidence of some of the earliest life on Earth. Modern and ancient stromatolites have similar shapes and, when seen in cross section, both show the same fine layering produced by thin bacterial sheets. Microfossils of ancient cyanobacteria can sometimes be identified within these layers.
stromatolites at Shark Bayclose up of a stromatolite at Shark Bay
Modern stromatolites in Shark Bay, Australia

cross section of fossil stromatolitescross section of fossil stromatolites
Cross sections of 1.8 billion year old fossil stromatolites at Great Slave Lake, Canada

Where did life originate?

Hydrothermal vent photo
A hydrothermal vent at the bottom of the ocean
Scientists are exploring several possible locations for the origin of life, including tide pools and hot springs. However, recently some scientists have narrowed in on the hypothesis that life originated near a deep sea hydrothermal vent. The chemicals found in these vents and the energy they provide could have fueled many of the chemical reactions necessary for the evolution of life. Furthermore, using the DNA sequences of modern organisms, biologists have tentatively traced the most recent common ancestor of all life to an aquatic microorganism that lived in extremely high temperatures — a likely candidate for a hydrothermal vent inhabitant! Although several lines of evidence are consistent with the hypothesis that life began near deep sea vents, it is far from certain: the investigation continues and may eventually point towards a different site for the origin of life.

What happens to the helium formed in the sun?

All the helium in the universe has been created by the fusion of hydrogen atoms, either in the early universe or in stars.
What happens to the Helium? Most stars, after converting a significant portion of their hydrogen to helium undergo an internal change. The internal core collapses, and heats up, until it is hot enough to fuse helium into larger atoms, for instance, by combining three helium atoms into carbon. At this same time, some helium will fuse with that carbon to produce oxygen. Outside the core, in what's called the envelope, there is still enough hydrogen to fuse into more helium. But the core begins fusing into larger atoms. This, by the way, is the transition from a 'normal' star like our sun to a Red Giant.
It's basically a free-for-all for creating larger and larger atoms. As soon as the helium in the core runs out, the star collapses again, heats up, and starts fusing carbon and oxygen into larger atoms. If the star is massive enough, this keeps happening until iron is fused. At which point a hotter core still won't lead to fusion. The star collapses, becomes unstable, and POW. Explodes, forming a supernovae and neutron star.

"The main lesson of Biogeography is that only evolution can explain the
diversity of life on continents and islands. But there is another lesson as well:
the distribution of life on earth reflects a blend of chance and lawfulness.
Chance, because the dispersal of animals and plants depends on unpredictable
vagaries such as winds, currents, and the opportunity to colonize....
But there is also lawfulness. Evolutionary theory predicts that many animals
and plants arriving in new and unoccupied habitats will evolve to thrive there,
and will form new species, filling up ecological niches. And they will usually
find their relatives on the nearest island or mainland. This is what we see, over
and over again. One cannot understand evolution without grasping its unique
interaction between chance and lawfulness-an interaction critically
important is understanding the idea of natural selection."
Jerry Coyne

No comments:

Post a Comment