Things Every Person Should Know About Astronomy #1


Uploaded by tdarnell on 16.05.2012

Transcript:
Hello Space Fans. I'd like to take this opportunity to thank all of you who have voted in YouTube's
"on the rise" contest. At every turn, you guys have been there when things got close
and now we're nearing the end.
There's still time to vote , so please take a second if you haven't yet. The link is in
the description box below.
As gratitude for your support, I made this video of Things Every Person Should Know About
Astronomy.
Now, because you watch this channel regularly, hard core Space Fans already know most of
this. But this is for the newcomers who may find our channel as a result of our efforts
this week.
Here are some things every person should know about astronomy.
There are an estimated 1.6 planets for every star in the Milky Way Galaxy, this means there
are more planets in our galaxy than there are stars. If there are about 100 billion
stars in the Milky Way, that equates to 160 billion planets. And that's just in our galaxy.
There are around 100 billion galaxies in the universe
I don't care what you've heard, but the reason the Apollo astronauts did not fall off the
Moon because the Moon has its OWN gravity.
There are EIGHT planets in the solar system. Get over it! (Hold up 9 fingers and slowly
put down pinky, "Dooo ittt"). There.
There were large, massive galaxies the size of the Milky Way as early as a 100 million
years after the big bang. Most of the stuff in the early universe just fell straight into
them, like water in a siphon.
The seasons on the Earth are caused by the tilt of its spin axis with respect to its
orbit, not the distance from the sun.
When two galaxies collide, it is very unlikely that any stars will collide because the average
separation between stars is about a hundredth of a light year. That's like having one ping
pong ball every 3.2 kilometers. Very few stars would touch.
Black holes evaporate.
If Eternal Inflation is true, which presents the idea that an infinite number of possibilies
occurred in a finite amount of time, then that implies that there are an infinite number
of possibilites for every particle in the universe. This means that every possible incarnation
of you has existed at some point in the history of the universe.
Every possible you.
There are two classes of black holes: stellar sized ones (the size of stars), and supermassive
ones, millions of times larger in the centers of galaxies.
Supermassive black holes got supermassive from dozens or even hundreds of collisions
with other galaxies that also had black holes.
The universe is expanding and the rate of expansion is speeding up.
Energy is not conserved in an expanding universe.
It would take 30 billion years for eight self replicating probes to explore 4% of the galaxy.
Two billion years if we increase that number to 200 probes.
Human beings could not exist without stars. The elements that make us up come only from
the deaths of stars. Nowhere else.
The universe is 13.7 billion years old and we can prove it.
Black holes convert about 10% of the mass that falls into them into energy making them
actually quite luminous.
Black holes can only consume matter so fast, called the Eddington limit. The is the point
where the gravitational force inward matches the outward force of the luminosity of the
accretion disk. Any more material in the accretion disk will over come gravity and start to blow
away
Black holes are the most efficient mechanism for extracting energy from matter.
String Theory is supremely irritating, but may be right.
Solar storms eject on average 10^22 grams of material (primarily electrons) out into
the solar system.
The Big Bang didn't need a cause.
The Cosmic Microwave Background is the cooling remnants of the Big Bang and is an imprint
of the universe when it was only 300,000 years old.
It will take 296,000 years for the Voyager 2 probe to will pass within 4.3 light years
of Sirius, the sixth closest star to us.
in our galaxy, there is a star about every light year apart on average.
The next solar cycle is expected to peak sometime in 2013 - 2014.
It is NOT Turtles all the way down.
And finally, The Hubble Deep Field is the most important image ever taken.