scale of the universe Download

Transcript
Goal to understand the scale
of the universe
Objectives:
1) To explore our local part of space called
the Solar System.
2) To understand the distances between
stars.
3) To understand the sizes of galaxies
4) To learn about the local group
5) To learn about the distances to galaxy
clusters
6) To scale down the observable universe
First, the overall size
• 100000000000000000000000000000 m
• 1026 m, 13 billion light years
The Earth
• 8000 miles in diameter.
• 25000 miles in circumference.
• Our moon is 250,000 miles away.
Solar system
• Our sun is on average 93 million miles
• (1 Astronomical Unit, or AU)
• Sun itself 800,000 miles in diameter.
• If our sun were a small marble, 1 cm in diameter,
the earth would be the width of a human hair
located a distance of 1.16 m from the sun.
• Neptune, the furthest planet at 30 AU, would be
35 m away from the marble that is our sun.
Nearest star to sun
• Alpha Centauri Proxima (red dwarf) – 4.2
light years
• If sun was a marble (1cm) Alpha Centauri
would be 312 km away (about Chicago).
400
light
years
1500
Light
Years
http://www.ldps.ws/Mirror/Universe/galaxy.html
The math
• If the distance from our sun to Alpha
Centauri Proxima were 1 cm the diameter
of our galaxy would be about 240 m and
would have a thickness of about 5 m.
• Our galaxy has about 400 billion stars and
a mass of about 1 trillion solar masses (1
solar mass = mass of our sun)
Local group http://www.anzwers.org/fr
ee/universe/
Local Group
• If the diameter of our milky way were
reduced to the size of a small marble:
• Andromeda Galaxy (nearest spiral) would
be 20 cm away.
• Entire local group would have a radius of
about 30 cm (1 foot)
Nearby
region of
the
universe
1 billion
light
years
Universe
What does that mean?
• If our galaxy were a marble (1 cm in
diameter) then the observable universe
would be 1.3 km in diameter
• Suppose we wanted to travel there?
• It would take tens of billions of years Earth
time each way.
• 100 billion galaxies in universe.
http://htwins.net/scale2/
Conclusion
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The universe is a really huge place.
Distances between stars is huge.
Galaxies are huge.
Distance between galaxies are huge.