How big is the Earth?! [Archive]

HotelUser

13-09-2010, 11:49 PM

Apologies if this is posted in the wrong section, I didn't really know where astronomy posts would fit because--well--there isn't many!

http://www.youtube.com/watch?v=HEheh1BH34Q

I thought that was a really cool video!

Neversoft

14-09-2010, 12:13 AM

Haha, that video really puts things into perspective. Imagine VY Canis Majoris were to collapse into a super or hypernova. It would just incinerate everything within like 50 lightyears. Amazing stuff.

Moh

14-09-2010, 12:20 AM

How do they even measure the size of them when they're light years away?

HotelUser

14-09-2010, 01:15 AM

How do they even measure the size of them when they're light years away?

I don't really know. I suppose the billions of dollars our governments spend on physicists must be paying off though :P

Josh

14-09-2010, 01:26 AM

Isn't the world (not just the earth) we live in so amazing?

Alkaz

14-09-2010, 01:50 AM

I guess that puts things into real perspective. I think that red giants was big and I was pretty amazed at them super giants.
It makes me think, the comparison between us and the galaxies out there, what could actually be going on right now at the end of our finger tips.

Moh

14-09-2010, 02:22 AM

Nixt

14-09-2010, 08:10 AM

Couldn't VY Canis Majoris be already dead?

Tbh tho, I thought Jupiter was pretty big >;D

It's pretty amazing space. The thing I don't understand is why we always look for water on other planets because it might indicate life. There may be some other element that we don't know about that could sustain life.

It makes sense to look for elements that we know could sustain life before looking for some fantastical element we have no idea about and may not even exist.

Interesting vid!

Jamesy

14-09-2010, 03:06 PM

it's hard to get your head round, even with a video like this, the sheer scale of objects and the universe itself. Just mad!

Circadia

14-09-2010, 03:23 PM

oml and i thought saturn was big D:

Grippz

14-09-2010, 03:32 PM

I really have never been that interested in astronomy but this video was actually really really good. +rep :)

AgnesIO

14-09-2010, 03:39 PM

That was a brilliant video - thanks for posting David. +Rep

Space is probably the most incredible and interesting thing to think about.

Mathew

14-09-2010, 04:36 PM

Looks like a video that was posted here a few months ago. Absolutely brilliant and we just don't realise how small we are in the "world".. :)

http://www.youtube.com/watch?v=17jymDn0W6U

AlexOC

14-09-2010, 06:56 PM

Wow. that last one was absolutely gigantic compared to Earth :o

Special

14-09-2010, 07:08 PM

but if the last start is so big how come we cannot see it? it can't be that far away or else we wouldn't have found it in the first place

great vid nevertheless

kk.

14-09-2010, 07:20 PM

How do they even measure the size of them when they're light years away?

I = AM

image size = actual size X magnification. basically the same principle, though i bet they use a slightly more complicated version. So they would rearrange to get A = I/M

anyway, it does put things into perspective, and makes it very hard to believe we are the only ones

HotelUser

14-09-2010, 07:48 PM

I = AM

image size = actual size X magnification. basically the same principle, though i bet they use a slightly more complicated version. So they would rearrange to get A = I/M

anyway, it does put things into perspective, and makes it very hard to believe we are the only ones

Yes it does! I think it's next to impossible that we're the only ones.

Phil

14-09-2010, 10:06 PM

Very interesting video. +Rep

but if the last start is so big how come we cannot see it? it can't be that far away or else we wouldn't have found it in the first place

great vid nevertheless

I suppose the same reason we can't see any of the rest of the planets (except the odd event when you can see Mars or another planet). That star is just far to far away for us to see it. Just looked it up, this giant star is 4,900 LIGHT YEARS away from earth!

Rixion

14-09-2010, 10:12 PM

Crikey that's very interesting indeed, the scale is quite good, but how could they forget Uranus! :L

And I thought our Sun was big...

Phil

14-09-2010, 10:17 PM

Crikey that's very interesting indeed, the scale is quite good, but how could they forget Uranus! :L

And I thought our Sun was big...

Ikr, I found this picture of it compared to our sun. http://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Vy-canis-majoris.jpg/240px-Vy-canis-majoris.jpg

Rixion

14-09-2010, 10:40 PM

Ikr, I found this picture of it compared to our sun. http://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Vy-canis-majoris.jpg/240px-Vy-canis-majoris.jpg

It seems uncanny when you think of our big the Earth alone is then there's these gigantic stars that are thousands the size of Earth.

Phil

14-09-2010, 10:45 PM

It seems uncanny when you think of our big the Earth alone is then there's these gigantic stars that are thousands the size of Earth.

And that's just inside the Milky Way! Imagine the size of some of the planets or start in another one of the billions of universe! Yes, that is the biggest star that we know of and yes it was discovered about two hundred years ago but that doesn't mean there are far bigger out there. Space is kinda big.

Rixion

14-09-2010, 10:55 PM

And that's just inside the Milky Way! Imagine the size of some of the planets or start in another one of the billions of universe! Yes, that is the biggest star that we know of and yes it was discovered about two hundred years ago but that doesn't mean there are far bigger out there. Space is kinda big.

Yeah, the milky way apparently isn't that a large galaxy, god knows what the size of a large galaxy is.

Phil

14-09-2010, 11:02 PM

Is that a picture of all the galaxy's at the very end? It's quite hard to know as we don't know how many there are but there are some pretty big ones there.

N!ck

15-09-2010, 12:14 AM

Is that a picture of all the galaxy's at the very end? It's quite hard to know as we don't know how many there are but there are some pretty big ones there.

That picture at the very end is quite a famous one in astronomy (I'm meaning the one where it says there are billions of galaxies and zooms out from it). Basically, they took the Hubble space telescope and pointed it at a tiny portion in a dark part of the sky (I'm talking dark even in terms of what that very sensitive telescope picks up). They left the lens open for a long period of time so that it collected a lot of light and that image was the result. Everything in that image is a galaxy, containing billions of stars each :).

http://www.spacetelescope.org/static/archives/images/screen/opo0428b.jpg

You can read more about it here http://en.wikipedia.org/wiki/Hubble_Ultra_Deep_Field

HotelUser

15-09-2010, 12:58 AM

http://www.youtube.com/watch?v=D3AfNXdg2Tk

That's another video that really put things into perspective for me.

kk.

15-09-2010, 06:43 PM

Our sun is 1 of 100 Billion (100,000,000,000) stars in just the milky way. Can you see how many galaxies are in that picture above, and now multiply 100,000,000,000 by that. Then the many other galaxies there are. then the amount of planets around each star. Phenomenal.

Moh

15-09-2010, 06:57 PM

Isn't the name "Milky Way" the name of the Galaxy earth is?

Do you think space ever ends?

Jordan

15-09-2010, 07:00 PM

Isn't the name "Milky Way" the name of the Galaxy earth is?

Do you think space ever ends?

Yeah it is,

and that's a good question, maybe it just gets slowly empty maybe just black nothing there like a desert

kk.

15-09-2010, 07:04 PM

Isn't the name "Milky Way" the name of the Galaxy earth is?

Do you think space ever ends?

I think there's two theories. one that the universe is constantly expanding from the centre. and two that we are actually going into the centre. Something like that anyway because its sort of impossible to think that there is an edge to the universe, but there is. there has to be. Or at least you just keep going around in a circle, in which case it originated in a big bang and its expanding

Mathew

15-09-2010, 07:40 PM

Do you think space ever ends?

This is a question we did a lot on during GCSE Physics last year. We spoke about three different theories.

One being that space is constantly expanding, it will just keep going forever and ever.
Another is that it will get to a certain point and just stop.

The final one which fascinates me the most (and what I believe is the most likely) is that space will keep expanding until a certain point and then start retracting again. When space retracts, everything will crash into each other and there will be another Big Bang. From there, life will be destroyed and whole story will start again. Organisms will grow, bacteria will be produced, animals will evolve and eventually, humans will come along again. Who knows? We may not be the first humans, we could be part of a massive cycle lasting trillions of years and eventually, there will be a whole new set coming along, ready to discover everything that we have.

Absolutely brilliant topic.

Arron

15-09-2010, 09:09 PM

hmm i dont know much about the galaxy but i know for sure its amazing. for those who think space ends somewhere, well whats on the other side? or is space just in a MASSIVE bubble which contains stars and stuff ;D

as for the video, wow... 1101 years was it to fly round the star once on a commercial plane? it's actually really frightening..

N!ck

15-09-2010, 09:15 PM

There is nothing "outside" space. The universe isn't expanding in to anything. It's space itself that's expanding.

Phil

15-09-2010, 10:27 PM

kk.

15-09-2010, 10:34 PM

It says 1100 years but at the plane traveling 900km/h I think but I'm pretty sure they travel at around 450km/h so it would actually take 2200?

planes go around 550mph, so multiply that by 1.6 and you get 880km/h. But it would take even less time in a concord!