[Grainiary]

Ref?

SSSF; some time in the past.

Of course, almost all of them are invisible to the naked eye.

[CHEAPPoem]

SSSF; some time in the past.

Of course, almost all of them are invisible to the naked eye.

And I don't much fancy counting the grains of sand.

[Desflahd]

Ref?
::::::::::::::::::::::::


Sure...How many do you want?




Astronomers count the stars
By Andrew Craig
BBC News

Astronomers in Australia say there are 10 times more stars in the visible Universe than all the grains of sand on the world's beaches and deserts.
From the darkest parts of Earth, the naked human eye can see about 5,000 stars; from a brightly lit city street, only about 100.


The scientists looked at just the visible Universe
But modern telescopes tell a different story.

The Australian astronomers used some of the world's most powerful instruments to measure the brightness of all the galaxies in one sector of the cosmos - and then calculated how many stars they must have contained.

From that measurement, they proceeded to work out a figure for the whole of the visible Universe, which they believe is much more accurate than previous estimates.

That figure - presented to the International Astronomical Union conference in Sydney - is the kind that really can be called astronomical: 70 sextillion, or seven followed by 22 zeroes.

That is more than the total number of grains of sand in all the Earth's beaches and deserts. But that is only the stars in the visible Universe within range of our telescopes.

Dr Simon Driver, of the Australian National University, says the actual total could be much, much bigger still. He believes that many of the stars out there have planets, and some of those probably have life.

But they are so far away from Earth, he says, that we may never be able to contact anyone living on them.

[onlyfun_biziness]

In the 1980 bestseller, Cosmos, astronomer Carl Sagan famously wrote that there are more stars in the heavens than all the grains of sands covering the world's beaches. His apparent prescience was based, in part, on the premise that a hand full of sand contained approximately 10,000 separate grains. Sagan presented this estimate when astronomy's principal tools were still fixed very firmly to the Earth- it would be another decade before the Hubble Space telescope gave us a view of the heavens, undisturbed by the blurring effects of our atmosphere, that would enable scientists to make a more accurate calculation.
So, was Carl correct?

First, consider how many grains of sands cover the earth's beaches. Researchers at the University of Hawaii have actually taken a mathematical stab at this number by dividing the volume of an average sand grain by the volume of sand covering the Earth's shorelines. The volume of sand was obtained by multiplying the length of the world's beaches by their average width and depth. The number they calculated was seven quintillion five quadrillion (that's 7.5 followed by seventeen zeros or 7.5 billion billion) sand grains!

Next, consider how many stars fill the Universe. Well, if you were located at or very near the Earth's equator, you would be able to observe about 6,000 individual stars over the period of a year with unaided vision. Of course, there are far more than this visible with binoculars or a small telescope. But, the vast majority that can be seen through small optical instruments would be confined within our own Galaxy because the huge distance to even the nearest galactic neighbor makes spotting their individual stars almost impossible, even through the largest telescopes. So, the best way to count the total number of stars in the Universe is to reckon the population of stars in our own Galaxy and multiply that by the number of galaxies that exist throughout space.

To derive an estimate of the stars in our own galaxy, astronomers have to consider both the number of stars we can see at great distance and the number of fainter stars, such as dwarf stars, which are difficult to observe. Red dwarf stars, as an example, are believed to be the most numerous type of star but they are also very dim. It is also estimated that there are about 200 red dwarf stars for every Sun-like star. Anyway, by taking star counts in relatively small-sized samples of the sky, factoring for dwarf stars and extrapolating the apparent area encompassed by the samples, recent computations have placed the number of stars in the Milky Way at around 400 billion, plus or minus 200 billion- hey, what's a few billion between friends :>)

But, the Milky Way is just one galaxy. The Hubble Space Telescope is capable of detecting about 80 billion galaxies based on analysis of its pictures. For example, where ever the Hubble points, in all directions, thousands of never before seen galaxies are seen extending far into the distance.

So, if we assume that our Galaxy is more or less typical and use the lower estimate, 200 billion, for its total stellar population then multiply that by the number of galaxies within reach of the Hubble Space Telescope, researchers have concluded that there are at least 70 sextillion (that's 7 followed by twenty-two zeros or 70 thousand million million million) stars in the observable universe- this is the latest number as proposed in mid-2003.

To put it another way, there are 10 stars for every grain of sand, eleven times the number of cups of water in all the Earth's oceans, ten thousand times the number of wheat kernels that have ever been produced on Earth and ten billion times the number of cells in a human being!

This is a staggering number- and it's most likely a very, very low estimate because the number of galaxies filling the Universe is thought to be much larger than those the Hubble can see!

All of this is pertinent to the new image that depicts two star forming regions, both about 5,000 light years distant, in the direction of the constellation Sagittarius- looking towards the heart of our Galaxy.

The picture displays the Trifid Nebula, on the right, and on the left, M8, which is also known as the Lagoon. The picture is very wide; in fact you could fit several moons across its width. Between the two nebulae is a portion of the Milky Way's vast star clouds- most of the distant stars are about three times further away than the nebulae. An application used to prepare these images reported that this picture contains slightly over 29,000 individual stars, by the way!

Earth is not located near the center of our Galaxy- we are positioned about half-way to the edge of the Milky Way's flattened, spiral shape and therefore any view of the its central region is occluded by vast clouds of dust that hang along the spiral arms we must look through. Thus, a large proportion of the stars in this picture appear reddened. Many of the bright blue stars are newly formed, most likely, from the two nebulae seen in this image and are thus much closer to us.




http://www.cosmotography.com/images/...=300&width=500

[QvhhbjLy]

The all appropriate paragraph of course is.......

::::::::::::::::::::
To put it another way, there are 10 stars for every grain of sand, eleven times the number of cups of water in all the Earth's oceans, ten thousand times the number of wheat kernels that have ever been produced on Earth and ten billion times the number of cells in a human being!
:::::::::::::::::::::::

As mind boggling staggering as it sounds!

[Anakattawl]

I'd be very interested in how high you can count in binary. Was wondering about that.

Probably not really very high, but it would sure look like a huge number

[DailyRingtone]

I counted rapidly - with out pause - out loud and only got to 132 which a said twice. I think if I slowed down I would be able to go much further.

[psbiuigw]

Once you get past 6, "big mobs" is descriptive enough.

[TubOppomo]

If my answer seemed cynical it was unintended. Seeing how far I could count was something I did in moments of extreme boredom while I was young. I found that regulating my breathing so that it was in time with my counting minimised the likelihood of losing track.

[UMATURLIN]

> If my answer seemed cynical ...

It didn't seem cynical to me.

> From the darkest parts of Earth, the naked human eye can see about 5,000 stars; from a brightly lit city street, only about 100.

That's an overestimate. It's said that in the middle of New York you can't see any. On a clear night well away from cities it's more like 1,000 to 1,500. May be more from mountain tops. I did try counting stars from my back yard once, got round about 150.

[hauptdaunnila]

It's said that in the middle of New York you can't see any.
------------
You might see a few in the Broadway area of New York.

[Natashasuw]

I can count at about 3000ft (or whatever the average international flight level is)

speaking of counting.. did you know that Jerry Nelson, the voice of The Count, died yesterday?

[Poowssnople]

Probably not more than 30: if I have to count something I tend to count to 5 and keep a tally.

I can do a bit better with the fibonacci sequence or multiplication tables because sometimes I use them as a calming exercise

Not very mathematical. Despite the evidence to the contrary, an optimist.

[SashaLionx]

Not sure if it is exactly a mathematically minded thing, but I tend to be sensitive to symmetries. If an explanation is missing something I tend to pick up on it even if I have no idea what is missing. I noticed a long time ago that where many people seemed to be content with basic explanations, I would only be confused by anything but a complete one.

[Pharmaciest]

Psychological experiment. How high can you count without making a mistake or losing count?

1. What is your guess?
2. Now do the count, how high did you get?
3. Do you consider yourself an optimist or pessimist?
4. Do you consider yourself mathematical or non-mathematical?

I did this on myself, but before telling you what I got I'd like to get feedback on what you got.

1. I guess 300
2. I got to 299 whilst simultaneously watching a movie and reading this thread. I didn't make a mistake at 300, just gave up because... well, just "because". If you were offering a dollar for each correct count I believe I could have gone a lot further.
3. Pessimist/delusional optimist
4. Non-mathematical

[TubOppomo]

1. I guess 300
2. I got to 299 whilst simultaneously watching a movie and reading this thread. I didn't make a mistake at 300, just gave up because... well, just "because". If you were offering a dollar for each correct count I believe I could have gone a lot further.

Actually, since you specified that this is a psychological "experiment" (though I'll note, not a very good one... where's your controls, for example? ) I'll say that the above is fairly typical for me. I apparently enjoy proving I can do something I believe I can do right to the point before I actually achieve it. This goal-setting/self-sabotage is a long standing and ubiquitous aspect of my psyche.

[conurgenceDen]

> though I'll note, not a very good one...

I agree. Not balanced to avoid biases for starters.

> If you were offering a dollar for each correct count I believe I could have gone a lot further.

What if I offered $20 for reaching 1000?

[incizarry]

>
What if I offered $20 for reaching 1000?

your experiment becomes an investigation of economic utility, and for me personally... Nah, it wouldn't be worth it.

[Qynvtlur]

I've now tried counting three times. 588 then 597 then 199. Not improving with practice.