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#1
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
#3
Hope this thread takes off
Bookmarked anyway.

http://www.planethunters.org/
^^ Found this in another thread on UG, you can search for exoplanets here
No endeavour rivals science in its incremental progress towards a more complete understanding of the observable universe.
#4
Quote by Sammythedruggie
Just thought i'd leave some of this here
http://www.youtube.com/watch?v=nByekIx7XXw&NR=1&feature=fvwp

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.

#5
I like space, it's big and stuff.
dirtbag ballet by the bins down the alley
as i walk through the chalet of the shadow of death
everything that you've come to expect


#6
I have an astro lecture at 9am tomorrow morning.

Thanks for reminding me -_-'




stratkat
#8
This is my kind of thread. Aspiring Astrophysicist here, feel free to ask me shit.
My signature lacks content. It is, however, blue.
#10
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
#11
Quote by MAC2322
This is my kind of thread. Aspiring Astrophysicist here, feel free to ask me shit.

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?
#12
Quote by 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?


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?
#13
Quote by 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?

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!
Last edited by 18th_Angel at Feb 10, 2011,
#14
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.
#15
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea
#16
Quote by 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?
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.



stratkat
#18
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.
#19
Quote by 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?



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.
My signature lacks content. It is, however, blue.
Last edited by MAC2322 at Feb 10, 2011,
#20
Quote by 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.

Yeah it's clear, thanks.


http://www.youtube.com/watch?v=xE7xRgfPjAI&feature=related
#21
Quote by Masamune
I searched and the last thread on astronomy is a couple of years old.


This made me sad

I can't believe I read your quote after I thought I would make a space thread... ah well, time to get the best picture from there in here!

I love that stupid picture in this thread, by the way. It's awesome!

I will copy my OP from the thread I just made:

Quote by Paramore.
Just thought I would make an awesome thread title for a thread about, well, space!

I don't know why, but every time I see pictures of space or hear people talk about it, it just amazes me. When I used to go to School on the odd occasion we did space in Science and they dimmed the lights to show you pictures of space and stuff, I just sat there like . I don't know why... I just find it really interesting and it's a pretty sight.









Wow... this last picture was amazing


Can I be assistant manager of this thread, or something?
This will start a RIOT! in me
#22
Quote by wizards?
Carl Sagan's Cosmos is one of my absolute favorite books.


I knew there was a reason you're one of my favourite UGers.
...Stapling helium to penguins since 1949.
#23
Quote by 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

But in that same way, everything matters the most. Without each equally significant piece of the puzzle the universe isn't whole. As much as one event might be smaller, it's as much a part of everything as anything else. If that's at all relevant. >_>
#25
Quote by Masamune
Sure why not.
Pretty funny coincidence btw.


LOL I know! all those years (as quoted from you .) without a space thread, and then we make one each in about 25 minutes apart. Maybe aliens are controlling us?

Oh, and here is a post from the thread I made, I thought it was an interesting read and deserves to be here. After all, it would have been a waste of this guys time to write that

Quote by Sinister Waffle
I find it very intriguing, The possibility that anything can technically be out there. The Fact that anything that exists outside of Earth, can infinity change how we view existence.

Also the fact that every light you can see has a possibility to provide life for millions of organisms, synthetics, or what ever that I'll never see.


EDIT: here's the full thread of the other (don't post about space stuff in it, I want mine to be closed .) just for the sake of looking back on it in a few months/years time as we see this thread grow!

https://www.ultimate-guitar.com/forum/showthread.php?p=26438196#post26438196
This will start a RIOT! in me
Last edited by Paramore. at Feb 10, 2011,
#26
huzzah, looks like ive got a thread to hang out in.

Ive been in love with physics and cosmology for as long as i can remember.

If i wasnt going to school for music i would have gone for astrophysics or just physics.

http://www.youtube.com/watch?v=6X47B9x670E

I saw this vid years ago and its similar to the star scale size vid already here but i thought i would throw this one in as the music makes it super badass.

ill be back on tomorrow to chat more aboot the marvels of the cosmos
#27
Quote by Masamune
http://www.youtube.com/watch?v=JkxieS-6WuA. This video blows my mind. Sort of straying from the topic, but I just love this.

Quote by The.Doctor
I actually have this saved to my computer as a .gif file. Amazing.
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea
Last edited by food1010 at Feb 10, 2011,
#28
Quote by food1010
http://www.youtube.com/watch?v=JkxieS-6WuA. This video blows my mind. Sort of straying from the topic, but I just love this.

I actually have this saved to my computer as a .gif file. Amazing.


I actually seen a better one than that. It was basically a bar that just scrolls across a page and it goes on for a while if you take it slow. It's awesome.

I posted this earlier in the thread, but does anybody else find this REALLY beautiful? :O



Imagine seeing THAT in the sky at night. Who would love a glass roof so you could stare in to the sky at night, except it looked like THAT? :O
This will start a RIOT! in me
#29
Quote by Paramore.
I actually seen a better one than that. It was basically a bar that just scrolls across a page and it goes on for a while if you take it slow. It's awesome.

I posted this earlier in the thread, but does anybody else find this REALLY beautiful? :O



Imagine seeing THAT in the sky at night. Who would love a glass roof so you could stare in to the sky at night, except it looked like THAT? :O


If you lived in the country, it would be well worth it. I'm looking to invest in a telescope soon to do some real stargazing.
My signature lacks content. It is, however, blue.
#30
Quote by Paramore.
I actually seen a better one than that. It was basically a bar that just scrolls across a page and it goes on for a while if you take it slow. It's awesome.

I posted this earlier in the thread, but does anybody else find this REALLY beautiful? :O

(Invalid img)

Imagine seeing THAT in the sky at night. Who would love a glass roof so you could stare in to the sky at night, except it looked like THAT? :O
I just love stargazing in general. There are a lot of really neat asterisms out there. Star clusters like the Pleiades and the Hyades are some of my favorites.



I love seeing those red giants in the sky too.
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea
Last edited by food1010 at Feb 10, 2011,
#31
Quote by 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.


Is related to how we know the distance of stars relative to earth?
#32
Quote by MAC2322
If you lived in the country, it would be well worth it. I'm looking to invest in a telescope soon to do some real stargazing.

I remember back in the day my best friend's dad (who lived across the street from me) would set up his telescope in his front yard and I would always go over and do some stargazing with them. I miss those days.
Also growing up kind of close to Cape Canaveral probably made me more interested in space. I remember going outside a lot during space shuttle launches and staring at the space shuttles going up in the sky.
Last edited by Masamune at Feb 10, 2011,
#33
Quote by SaintsofNowhere
Is related to how we know the distance of stars relative to earth?
I'm not sure what you're asking.

We use a completely different method (trigonometric parallax) to determine distances to stars and the like.

EDIT: As MAC2322 said there are other ways of measuring distances, but I can't for the life of me remember what they are and my notes are a whole 2 metres away.



stratkat
Last edited by EuBoat at Feb 10, 2011,
#34
I spent an inordinate amount of nights last summer sleeping in mine or a friend's (female, stargazing with a guy would be a bit...odd :p garden watching the stars. It was incredible.
...Stapling helium to penguins since 1949.
#35
Quote by SaintsofNowhere
Is related to how we know the distance of stars relative to earth?


Relatively although not entirely. The distance of stars can be calculated in various ways, with closer stars being measured through a parallax* and stars that are further away have to have their redshift, luminosity and size taken into account to calculate their distance.

*Parallax:

Look at something in your room that's a relative distance away. Close one eye. Now open it and close the other. See how it seems to move related to other objects? Your eyes use this difference to calculate how far away an object is, even if you don't notice it. The same thing is done with the Earth, with two pictures being taken six months apart (so that the Earth has changed place within it's orbit as much as possible) and then distance can be calculated with the two images.


EDIT:

V Sombrero Galaxy is one of my personal favorites.
My signature lacks content. It is, however, blue.
Last edited by MAC2322 at Feb 10, 2011,
#36


Yes, I know this picture is enormous. I don't care, the bigger the better when it comes to these things.
#37
Quote by EuBoat
I'm not sure what you're asking.

We use a completely different method (trigonometric parallax) to determine distances to stars and the like.


I was wondering if the wavelength thing had something to do with knowing the distance of stars.


Can you explain it? ...roughly summarize anyway?
#38
Quote by SaintsofNowhere
I was wondering if the wavelength thing had something to do with knowing the distance of stars.


Can you explain it? ...roughly summarize anyway?


The wavelength can be used to calculate red shift. As the stars all move away from each other, light from them is 'stretched' into the red and infrared areas of the spectrum. You can calculate the distance of a star using the amount of redshift. I don't know the details really, someone else is probably better qualified to answer.
...Stapling helium to penguins since 1949.
#40
This is something that I think is really fascinating.
http://www.youtube.com/watch?v=VFMmzKDonRY&feature=related
We're all made of star-dust.

If anyone has the time, watch "A Universe from Nothing" in the related vids. It's about an hour long. It's pretty interesting IMO.