How can there be more stars in the universe than there are grains of sand on the earth?

Question

I read about this fact recently. Is it true? Somebody help me fathom this.

Answer 1

The thing about them both is numerically there are countless amounts of both. Even if one could count all the grains of sand on the earth or all the starts in the universere we don't even have a number that exist to our imaginations that could fathom that amount. We don't know how many stars there are because we can't even see our entire universe, and it is so vast, expansive and ever changing that the number would be essentially infinite. The same with all the grains of sand. Think about all the coastline in the world and how much sand must be there. But that's not the end of the sand. The coast lines extends miles into the oceans and seas. And not to mention Little Billy's Ant farm in Little Town, USA--who's going to count those grains.

SO--the basic idea is that there are lots of both, and I think it's presumptious for anyone to say there are more of one than the other.

Answer 2

I really do feel sorry for people who give up on questions needing big numbers like this and just say oh, it's so big that nobody could have any idea how big it is.

The Andromeda Galaxy is about 2 million light years away, but it's closer than average, so if we guessed that galaxies average 3 million light years apart, and the edge of the universe is 14,000 million light years away in each direction, that would be room for nearly 10^12 galaxies.

The number of stars in our galaxy is estimated to be between 2 x 10^11 and 5 x 10^11. So the total number of stars in the universe is 10^23, give or take a factor of about 4. It's a big number, but it can be estimated sensibly enough.

Now sand grains come in a huge range of sizes, but geologists call it "medium sand" if its grains are from a quarter to a half millimetre in diameter. Suppose we take a third of a millimetre, then a thousand grains in a line would stretch for a foot, so a thousand million (that's 10^9) would fill a cubic foot.

With as many grains of sand as there are stars, we would have 10^14 cubic feet of sand. That's enough sand to cover a square a thousand miles long, a thousand miles wide and four feet deep, which is a lot of sand, but it isn't a ridiculous amount. I think it's more than the world's beaches, but less than the beaches plus the deserts, especially when you think how many feet deep some of them are.

Answer 3

The universe is not infinite, (remember it was born from a single point) but it's much bigger than we all think. I don't believe there's been a single person in history who has been able to imagine the real scale of the universe, we humans just can't do it. We can come up with a number to represent the size of the universe, and that number may be correct, but can you picture it in your head?. When you think that, it's easy to realize that no effort will ever make us really understand how big is this thing, and that's why that famous postulate from Carl Sagan seems so difficult to believe. We can estimate both quantities wth relative accuracy and come to the conclusion that there are more stars in the universe than grains of sand on Earth, but our minds just can't get it.

Answer 4

It was the late Carl Sagan that proposed this, but I think he said "on all the beaches" in the world. I think if we include the deserts, it would be a little over the top.

But even so, go down to a big beach and run the sand through your fingers. Then think of the size of that beach, and then all the beaches in the world. It is staggering, and gives a much better idea of the extent of the universe than just quoting numbers.

But to quote numbers. There are hundreds of billions of stars in each galaxy and hundreds billions of galaxies

Multiply 100,000,000,000 by 100,000,000,000 and you get a rather large number.

Answer 5

Even though it would be impossible, we can theoretically count all the grains of sand on earth - the number is not infinite.
But the universe (as far as we know) is infinite, and the number of stars is also infinite.
Infinite beats not-infinite every time.

Answer 6

Easy when you think that Earth is a billion times smaller than a grain of sand compared to the universe!!

Answer 7

There are a finite number of grains of sand and a finite number of stars. Us humans have a difficult time understanding...but we're getting better

Answer 8

Interesting question sir...

In order to help you fathom this proposal, i am pretty good on stars, but not so good on grains of sand...

So, how many grains of sand are there on Earth?

Let's start there...

Answer 9

extra stars than grains of sand .... by using fact the type of sand grains in theory is constrained .... while the type of stars is extremely endless (mild has a constrained velocity .... so daily we are reached by potential of "new" mild coming from the horizon of galaxies; so daily arise new galaxies from at the back of horizon).

Answer 10

This fact is true. our universe is constantly growing and expanding. many telescopes do not even have the capability of seeing relatively far. for many stars extremely far away, it may take hundreds of years still for the light to reach earth.