The Cosmic Calendar • If the entire age of the universe (12.5 billion years) was compressed into one year, humans appeared about six minutes before midnight on the last day of the year! How is this calculated? Assumptions: humans “appeared” 150,000 years ago. One year = 525600 minutes. Use a proportion: minutes 525600 minutes x years ,000 12,500,000 years 150,000 Solve for x = 6 minutes
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The Cosmic Calendar If the entire age of the universe (12.5 billion years) was compressed into one year, humans appeared about six minutes before midnight.
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The Cosmic Calendar• If the entire age of the universe (12.5 billion years) was
compressed into one year, humans appeared about six minutes before midnight on the last day of the year!
How is this calculated?
Assumptions:
humans “appeared”
150,000 years ago.
One year = 525600 minutes.
Use a proportion:
minutes 525600
minutesx
years ,00012,500,000
years 150,000
Solve for x = 6 minutes
Are we the new kids on the block?
• The period of massive bombardment (the accretion era) ended 3.8 billion years ago
• Within a few million years single-celled life was reproducing like rabbits in springtime
• Multicellular organisms didn’t show up till about 800 million years ago
From Humboldt State University Museum of Natural History
Deep in TimeRead bottom left then bottom right
Why did it take so long?
• Life might have arisen here several times before the sterilization from bombardment ended—MORE LATER!
• Multi-cellular life on Earth uses Oxidation for energy, this requires oxygen in the air and water, and there wasn’t any until…
• Cyanobateria created oxygen as a waste gas.• Apparently it took nearly three billion years to build
up this level of oxygen…then BANG!--The Cambrian Explosion
For more information on the development of life on Earth:
• You can also remember that 10 kilometers is 6 miles
• Or one kilometer is 6/10 of a mile.
• How many Kilometers in diameter is the Earth?
Answer:
• 12700 km (about 13,000)
• You can also convert this to miles:
• 12700 km x 6 miles/10 km = 7900 miles
• How Far away is the moon?
Answer:
• 384,000 km
• In scientific notion this is:
• 3.84 x 105 km
• In terms of the Earth’s diameter, how far away is the moon (in other words, how many earths can fit between the Earth and moon)?
Answer:
• 30 Earth diameters
• So if the Earth was one foot in diamter (a classroom globe) the moon would be thirty feet away!
• Pretty close, huh!
Distance Quiz continued
Compared with the distance to the moon, the sun is how much farther away?
400 times (150,000,000 km or one AU)
How long does it take light to get from the Sun to the Earth?
8 minutes
Distance quiz p3
• How many Light minutes to Jupiter?• 5 AU x 8 minutes/AU = 40 minutes• How many AU to Neptune?• 30• How many AU in one light year? • 65000• How many light years to the NEAREST star?• 4
Distance quiz –celestrial section
• How many light years away is the farthest star we can see with our naked eyes?
Answer
• About 3000 light years (Deneb is 2200)
• How far to the Center of Galaxy
Answer:
• 30,000 light years (10,000 pc)
• How far to the Andromeda Galaxy?
Answer:
• Two million light years
• Remember—about twenty times the diameter of the Milky Way
Last question!
• How far to the edge of the observable Universe?
• 12 billion light years!
• But what is the observable universe?
• It’s a sphere with a radius equal to the age of the universe in light years.
• If something is farther away than this, then light hasn’t reached yet, so we cant see it!
Time to get Moving—a universe in motion
• Contrary to our perception, we are not “sitting still.”• We are moving with the Earth.
– and not just in one direction – Note that 1500 km/hr = 2200 ft/sec
•Jump up so that you are in the air for half a second…where should you land? •Without gravity and inertia, you would land 1100 feet west of where you started.
We’re moving pretty fast around the sun…
sec 30
secmillion 30
km 1
time
distancespeed
kmspeed
billion
Our Sun moves relative to the other stars in the local Solar neighborhood!
Our Sun and the stars of the local Solar neighborhood orbit around the center of the Milky Way Galaxy every 230 million years!
The sun is about 22 Galactic years old!
The Milky Way moves with the expansion of
the Universe! • Mostly all galaxies
appear to be moving away from us.
• The farther away they are, the faster they are moving.– Just like raisins in a raisin
cake; they all move apart from each other as the dough (space itself) expands.
Time waits for no oneWe live in a changing universe, with a past and future.
As we speed around our star, it is also changing and evolving towards a violent end
Will we be around to watch?
Will humans still be around billions of years from now?
Will any life on earth have the technology to reverse the sun’s evolution, or move on to another star system?