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Flashcards in Placeholder 4 Deck (5)
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1

How long does it take our solar system to complete an orbit of the Milky Way?

It takes 250 million years on average to complete the obrit.

The human race has existed only 1/10 of 1% of that orbit.

REF:  Universe Brian Cox

2

What is the second law of thermodynamics?

Matter goes from low enthropy [sandcastle] to high enthrophy [a pile of sand].

Examples:

Abandonded house falls apart.

A star will die out

Humans will erode and die

Eventually the existence of life on this planet will become impossible.

Some day the sun will fill the entire horizon.[Red Giant]

3

Where is our closest Red Dwarf star?

It is Proxima Centauri, our closest star.  A mere 4.2 light years away.

Our Sun's lifespan is about 10 billion years.  Proxima's lifespan is trillions of years.  Why?  Because it is a Red Dwarf star and burns its fuel very slowly.  Red dwarfs will be the last living star in our universe.

4

If we sent Voyager 1 to our nearest star, Proxima Centauri, how long would it take to reach it?

Voyager launched in 1977 has an initial speed of about 24,000 mph.   Scientists sent it on a loop around a planet to slingshot it out into space at double the speed.  So now it is traveling at about 50,000 MPH out into space. 

If they sent it to Proxima Centauri from earth with this slingshot boost of speed, it would take Voyager 88,000 years to reach our closest star.

5