How many stars are in the Universe?

[NoahTheBoa]

To quote a great man, "Billions and Billions."
[flash width=400 height=300]http://www.youtube.com/watch/v/5Ex__M-OwSA[/flash]

[l3eeron]

Seriously...


this number can only be estimated. To be more accurate, guessed at. We have a few "perceivable maximum parameters" when we do the calculations, but we're only human, and I feel our perceptions are quite limited.

So, it's kind of a loaded question. How many stars?

100 billion X 100 billion, at least (as a minimum) that we can see. = 10 with 22 Zeros after it!

100,000,000,000,000,000,000,000 (and this is the Lowest estimation number of stars!)



I will not go into my personal beliefs as to how/why everything is here. But, anyone who wants to talk, This is my favorite subject, Hit me up on steam friends and we can respectfully argue/agree to see each other's ways... I love to know people's idea of God and/or Nature.




It's one big beautiful entropic mess to me

[MrBlah]

So... here we go:

I started with the Hubble Ultra Deep Field. It contains about 10,000 galaxies, or 10^4. Estimate 100 billion stars per galaxy, or 10^11. Take the ratio of the size of the HUDF to the rest of the sky, or basically speaking, the sky is 12.7 billion times larger than the that of the exposure of the HUDF, so 1.27x10^7.

Multiply these together and you get 1.27 x 10^22 stars in the observable universe.

Using a video representation of the observable universe developed by the American Museum of Natural History and tanking a few angles in order to determine a ratio of what we haven't seen compared to what we have(this is not a distance thing here, its a percentage), basically, we have only seen 58% of the volume of space that surrounds us. From that, I get a constant of 1.71 to multiply the amount of stars in the Observable Universe by.

This gives us 2.17 x 10^22 stars in the Observable Universe.

Here is that video representation:
[spoil][flash width=480 height=385]http://www.youtube.com/v/17jymDn0W6U&hl=en_US&fs=1&[/flash][/spoil]


Doing a little bit more research on the fact, I found that there are an estimated 7 x 10^22 stars in the Observable Universe. Pretty close there eh? only 3.2x smaller.

Since the diameter of the Entire Universe can be(and is thought to be), in theory, at least 10^26 times larger than that of the observable universe, you can use that value along with the amount of stars in the Observable universe to get an estimate for the amount of stars in the Entire Universe. Treat the amount of stars in the observable universe as a volume and do some algebra. Reverse the expression used to determine volume to get a radius, multiply that by 10^26 and then use the expression to determine volume to come to a conclusion.

7x10^100 stars in the Universe.

However, since you can not see galaxies behind the other galaxies, the number goes even higher. If you watch the movie, you will see that there is a much higher density of observed galaxies closer to us. The farther away we start to consider, the more galaxies there actually are.

[l3eeron]

*sniffle*

I love potatoes

[CastleDoctrine]

[quote="l3eeron";p="239192"]*sniffle*

I love potatoes[/quote]

[l3eeron]

If you take the entropy of boiling oil and multiply it by the kinetic energy stored within the potatoes... you reach a state of total bliss... more commonly known as French Fries.

[MrBlah]

[quote="l3eeron";p="239192"]
*sniffle*

I love potatoes
[/quote]

does that mean you would donate your points to me?

[Buzzy Beetle]

Even though people are busting out logics and math... I'm gonna guess... All of them.

[Boss Llama]

One thing I love about this sort of discussion, is the inherent reminder of how many other civilizations are out there. The arrogance/egotism of so many humans to believe that we are somehow special, the only ones, etc, just falls flat on its face.

Using even some basic middle-of-the-road numbers to plug in to The Drake Equation, you still get a number of around 1000 intelligent, communicating civilizations per galaxy. That gives us, using Blah's numbers, 7x10^92 intelligent, communicating civilizations.

I don't believe aliens have visited us or anything, the universe is so vast that you'd pretty much have to violate the laws of physics as we understand them to even begin travel on that scale, but I do like the idea that there an incomprehensibly large number of civilizations out there, probably all of which are debating the same "are we alone?" question amongst themselves, just as we are :-)

[arfy4]

The universe is ever expanding and the amount of timne it takes for light to travel from the edge of the universe to earth means no one will ever know how many stars are in the universe.

[MrBlah]

[quote="arfy4";p="239243"]
The universe is ever expanding and the amount of timne it takes for light to travel from the edge of the universe to earth means no one will ever know how many stars are in the universe.
[/quote]

Is the universe really expanding though? We aren't the center of it and I don't believe anyone has actually located a center.

Typically, when someone refers to the Universe, they refer to the Observable Universe. As you are doing right now. Thus, we are the center of the Observable Universe because all that we can observe is the light that falls upon our planet. As technology progresses, we can see farther into the cosmos and make more accurate maps of what we can see. In relation to ourselves, the Universe will, for all intents and purposes, always be expanding because as time progresses, we will be able to see more of the light that falls upon our planet.

[Flobee]

This thread put the theme to The Big Bang Theory in my head.

[flash width=640 height=385]http://www.youtube.com/v/YmVwVcSw5Eg&hl=en_GB&fs=1&[/flash]

[Boss Llama]

[quote="MrBlah";p="239245"]
Is the universe really expanding though? We aren't the center of it and I don't believe anyone has actually located a center.
[/quote]

The red shift in the light from all available objects, in all directions, from all points of measurement, has shown that everything is flying away from everything else at an incredible speed. From this red shift, it's possible to draw the conclusion that expansion is occuring. I believe that additional evidence is found in the temperature of the universe at large, though my modest readings in astrophysics aren't recent enough for me to recall exactly how this proof works - I believe it's basically the fact that given all the giant nuclear reactors out there, the universe would be much hotter and brighter if it weren't expanding.

As far as a center, it's true, I don't believe anybody has located a "center" so to speak, but that's not necessary to demonstrate expansion. Heck, in a curved spacetime model, there isn't a center to find. The center is simultaneously everywhere, and nowhere. Really, though, studies beyond our past light cone, aka, the observable universe, will have to remain theoretical.

[Fraulein Arztin]

[quote="loka";p="239152"]over 9000[/quote]
agreed lol

[Corgasm]

Threads like these make my head hurt!