Masamune

It seems like a lot of you are interested in this subject because of all the love for Carl Sagan I've seen in the pit. I searched and the last thread on astronomy is a couple of years old.
I'll start off with a few things that are probably familiar to a lot of you.

Scale of the planets and stars
Carl Sagan-Pale Blue Dot

and some pics

Each of those are galaxies as they were billions of years ago.


The Helix Nebula


Crab Nebula, it's a supernova remnant.


Milky Way


Cat's Eye Nebula

So yeah...discuss

__________________
http://groups.ultimate-guitar.com/florida/
^Floridians of UG group ಠ_ಠ
"One good thing about music, when it hits you, you feel no pain."

Sammythedruggie

Just thought i'd leave some of this here

http://www.aolnews.com/2011/02/02/scientists-discover-solar-system-with-6-planets/?icid=maing|aim|dl2|sec3_lnk2|40960

http://www.youtube.com/watch?v=nBye...=1&feature=fvwp

http://apod.nasa.gov/apod/archivepix.html

Sammy2K7

Hope this thread takes off
Bookmarked anyway.

http://www.planethunters.org/
^^ Found this in another thread on UG, you can search for exoplanets here

__________________

Masamune

The whole concept of a fabric of space-time has always been kind of a mind-fuck for me.

Anyway here's something I just found, thought it was kinda funny.

__________________
http://groups.ultimate-guitar.com/florida/
^Floridians of UG group ಠ_ಠ
"One good thing about music, when it hits you, you feel no pain."

Trowzaa

I like space, it's big and stuff.

__________________

EuBoat

I have an astro lecture at 9am tomorrow morning.

Thanks for reminding me -_-'

__________________

wizards?

Carl Sagan's Cosmos is one of my absolute favorite books.

__________________

MAC2322

This is my kind of thread. Aspiring Astrophysicist here, feel free to ask me shit.

__________________

Sammythedruggie

Pluto isn't a planet anymore btw =P

food1010

Astronomy is sweet, I'm in an astromony course at my high school. It's mostly learning the night sky, but we do dive into the parts of the universe that can't be seen by the naked eye at times, and it blows my mind.

__________________
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea

Masamune

I have a question, it's about the whole red shift blue shift thing. Wouldn't you have to know what the wavelength of light was originally to determine how much it shifted? How do astrophysicists do that?

__________________
http://groups.ultimate-guitar.com/florida/
^Floridians of UG group ಠ_ಠ
"One good thing about music, when it hits you, you feel no pain."

Sammythedruggie

I could be completly wrong, but I think they use the absorbtion spectra of something we know (say its hydrogen) and then compare it to the spectra of the object, allowing the distance to be calculated.


Like I said I could be completlely wrong. Really good question though. Got any insight MAC?

18th_Angel

You can compare the light of closer galaxies and seem them less red shifted, can't you? Otherwise there's things like spectroscopy and generally studying the objects to see what kind of stars are there, weather they be heavy in metals or otherwise.

__________________
Inhuman evil take down!

jemjabella42

We watched the Pale Blue Dot in one of my anthropology classes.. i love that film. Totally puts life into perspective - basically nothing matters overall, it's just a bunch of tiny situations that make up an entire puzzle, and that puzzle makes up an even bigger puzzle. it's crazy

__________________


Ne me quitte pas mon chere.

food1010

__________________
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea

EuBoat

There are absorption lines in the spectra of stars which we can look at.

For example, we know that the Hα line has a wavelength of 656.28 nm. By measuring the wavelength of this line in the spectrum of a particular star and how it's shifted from this known value, we can determine it's velocity relative to us.



I explained that poorly, but I hope the meaning is clear.

__________________

WhiskeyFace

Eagle Nebula

__________________
Red Bird~

'There is hope - but not for us'

SaintsofNowhere

I love space. It's one of the most interesting topics to think about because, hey... it's the whole universe. Everything else concentrates on something on Earth... studying space is studying the entire universe and existence.

MAC2322

Yes, actually.

Because we know what kind of stuff stars and planets are made of. Different elements (in this case mostly hydrogen, helium and sodium) emit and absorb different light frequencies (and radiation). By comparing the light being emitted to the light that would be emitted if it weren't moving we can determine how fast it's moving.

EDIT: EuBoat said it exactly right a few posts up, but a bit more technically.

__________________