In our universe, there's an estimate of the number of galaxies being between 100 billion and 200 billion, and that's from visual estimates of the visible universe. It could be many more.
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Michael Darnell say: Actually the current estimate is 1,000,000,000,000,000,000,000,000 stars in the *observable* universe (thats a "1" with 24 zeros after it.) There are approximately 400 billion stars in our local "Milky Way" galaxy. So we don't know the total amount, that huge number is just the minimum, so we just know it is at *least* that many, it may in fact be some much much larger quantity. The problem is that we cannot directly count them, we can only estimate because actually counting even just the number of stars in our galaxy at a rate of say 1 star per second would take 12,675 years. For all the stars in the universe given that we can detect about 1 trillion galaxies each containing at least 100 billion stars with modern technology, would take much longer. Counting each of those stars at one per second would take over a thousand trillion years. By that time many that we had counted would have burned out, or gone supernova and many new stars would have formed so the count would still be wrong.
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Nyx say: The "100 billion stars" refers to about how many stars there are in our home galaxy. Or actually, any galaxy.
By using statistical population counts.
https://asd.gsfc.nasa.gov/blueshift/inde...
http://www.esri.com/esri-news/arcuser/wi...
Which ties in nicely with how the Milky Way was discovered.
http://ircamera.as.arizona.edu/NatSci102...
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Sharpie say: NEVER question the scientific method.
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rick29148 say: How do YOU know there AREN'T ???
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Gary B say: 100,000 billion is all we can SEE
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Quadrillian say: There are approximately that many stars in our galaxy. There are about the same number of galaxies in the universe as there are stars in our galaxy.
These are all estimates. Of course noone is stupid enough to sit down and count them one by one. It's like estimating how many grains of sand there are on a beach: you take a thimble full of sand and count the grains. Then you do a rough calculation of the volume of sand on the beach. Then factor accordingly to get an estimate.
Cheers!
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Alpha Beta say: We count them ... you point a telescope into the sky and look, count the points o light. Computers can do this easily and quickly.
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