You will see different things regarding a black hole, depending on if you are the one falling in, or observing something falling in (the two events will look very different).

A white hole appears on paper when you do the math with the equations that describe a black hole and you remove all the mass. A white hole is the simplest kind of black hole (no charge, no rotation), and this does not happen in the real world. When you add matter to the space-time equations, the white hole option disappears. Although it sounds cool, it’s purely science fiction at this point.

Space can have particles in it or not. When it does, you can detect them: if they are oxygen molecules, you’ll be able to breathe. If there aren’t many particles at all (in outer space, there’s only 4-5 particles per cubic meter, which is pretty much zero!), it’s called a vacuum and you won’t be able to hear anything because there’s no particles to transmit the sound waves (sound waves travel by whacking into each other – see Unit 6 for more info on this). However, photons are able to travel through a vacuum (which is how you feel warmth from the sun and see starlight at night). See Unit 9 for more info on this.

Laura here. Did you know that Charon, in Greek mythology, is the ferryman over the River Styx that transports dead souls into the underworld? Did you know that Orion was a Greek hunter who was friends with Artemis, the goddess of the moon?
And last of all, did you know that Perseus was a Greek hero who killed Medusa, the snake haired monster, and rescued Andromeda, a princess, from being eaten by a sea monster?

I think it’s really interesting how Greek mythology and Astronomy tie in together (I’m a bit of a Greek mythology buff!)

Laura

I have a few questions:

1. Do black holes have two openings, like a front and back door?

2. Do we see black holes from one entrance only?

3. White holes, I understand, are like the opposite to black holes and shoot matter out rather than suck it in. Therefore, could a white hole be the back door of a black hole? i.e. matter is pulled in the front door, or black hole, and then shot out again out the back door, or white hole.

4. Is space, something or nothing? Following on from that, is the space between the electrons and nucleus of an atom a vacuum?

Sonya

1. A planet is any object in orbit around the Sun with a diameter greater than 2000 km.
2. A planet is any object in orbit around the Sun whose shape is stable due to its own gravity.
3. A planet is any object in orbit around the Sun that is dominant in its immediate neighborhood (has cleared out its orbit around the sun), so the asteroid belt is not a planet.

Neptune is really, really far away and according to the calculations of the scientists from their data measurements, some of the carbon has solidified into diamonds. Wouldn’t that be cool to have – a Neptunian diamond?

Side Note: when the sun is all done with its fuel, scientists estimate that it will fizzle out into a hard black diamond the size of the earth.

1. If jupiter’s a gas ball,how’s it a planet?

2. Does neptune really rain diamonds?

**********************************************

Q: My little brother Collin is wondering “Is Uranus 11 times bigger than earth?”
Holly Thomson (Collin Thomson age

A:Uranus is about 4 times the size of the earth, and called an ice giant.

*********************************************

Q: Are there any astronauts in space right now? How many earth years are in a light year? Just wondering.
Holly Thomson age 11 -HAT
PS. Thank you for answering everybody’s questions!

A: Sure there are – just visit the ISS website to find out the latest mission news:
http://www.nasa.gov/mission_pages/station/main/index.html

And a light-year is a measure of DISTANCE, not time. It’s how far light goes in one year. A light year is 5,865,696,000,000 miles (5.8 trillion miles).

***************************************************************

Q: On the planet Iapetus, is the ridge that goes all the way around it the same “makeup” as Iapetus?

A: That’s one of the questions scientists have – we currently don’t know – but that would certainly settle the question, wouldn’t it? There aren’t any current missions planned to Saturn once Cassini is done, though, so it may be awhile until we figure this one out!

***************************************************************

Q: Does Neptune really smell like farts? also On nebulas, are those explosions “frozen” like that?
Clay, age 11

A: Neptune is blue because of the thick methane (fart) atmosphere. And the explosions are so massive that they ‘look’ frozen, but are actually expanding and fading away.

****************************************************************

THANK YOU for this teleconference! Our family is having so much fun and learning SO much! This was so nice of you to do this for all of us. THANKS, AURORA! -Steffit

****************************************************************

Aurora,

Thank you for the class! This was the first time we have participated in anything like this and it was very interesting. I was concerned about being able to hear you during the conference, and concerned also about being able to make the call, but both worries were unmerited. Your muting the call made it very easy to hear you and logging in was a breeze! Thank you for your time and effort in making science fun for all of us.

From Alaska,
Samantha Sampson