# What is the largest number in observable reality we know of with very high accuracy?

Asked by mattbrowne (31585) March 3rd, 2010

He are a few candidates (subject matter experts please comment on accuracy):

Number of atoms in our universe: 10^80 +/- 10^78

Number of stars in our universe: 10^23 +/- 10^22

US national debt as of March 4, 2010 at 11 am: \$12,514,506,202,842.88 +/- \$ 1 billion

Age of the universe: 13.73 billion years +/- 120 million

Population of the Earth as of March 4, 2010 at 11 am: 6,806,200,321 billion +/- 1000

Age of the Earth: 4.54 billion years +/- 450 million

What other large numbers are well known? What about their accuracy?

Observing members: 0 Composing members: 0

Grains of sand in a large bucket?

gailcalled (54512)

99 bottles of beer on the wall.

CMaz (26228)

@gailcalled He wants actual known, observable numbers. So, for your answer, do you actually know how many grains of sand are in the bucket? Even better would be if we knew (or had an estimate of) how many grains of sand existed on our planet.

erichw1504 (26396)

@gailcalled – I’ve heard there’s a relatively good estimate of the number of all sand grains on Earth and the number is smaller than 10^23. But I think the margin for error is larger compared to counting the stars in the universe.

mattbrowne (31585)

@erichw1504: I understood the question. The margin for error in all those huge numbers makes for speculation and not specificy. It is fun to speculate, however.

gailcalled (54512)

@gailcalled I agree, just making sure you understood.

erichw1504 (26396)

Blades of grass. Number of ants on Earth. Mililiters of water on Earth. Volume of the universe.

erichw1504 (26396)

@ChazMaz yeah, that is what i’m talking about!

BoBo1946 (15285)

Lyme ticks in Columbia county (12037).
Mice living on my 20 acres (12165).

gailcalled (54512)

Number of times in a year all men think about sex.

Cruiser (40401)

@Cruiser don’t forget the girls!

BoBo1946 (15285)

Connections between neurons in a single brain!!!! Estimates go up to about 5×10^14.

nikipedia (27475)

Number of times in a year a woman says she’s got a headache.lol!

Number of electrons in one coulomb = 6.241509745×10^18 electrons exactly

stump (3835)

@lucillelucillelucille the fun part is getting rid of that headache!

BoBo1946 (15285)

@erichw1504 – there are approximately 1.36×10^24 milliliters of water on Earth

mattbrowne (31585)

@nikipedia – That’s a great example! I often wondered about those numbers. In most books there are the 100 billion neurons, but in the terms of average synaptic connections per neuron the numbers seem to vary between 1000 and 10000. How come?

mattbrowne (31585)

Milo here; I skew the statistics on the numbers of neurons in a single brain.

gailcalled (54512)

@ChazMaz – Make that 100 bottles of beer on the wall, because in one of the other threats a Flutherite just claimed that Sarah Palin is qualified to become US President and it made me throw a bottle against the wall (does this count?) at least mentally.

mattbrowne (31585)

@stump – Great move towards accuracy. Just give me one second, ah, give me 9192631770 cycles of radiation associated with the transition of the cesium-133 atom.

mattbrowne (31585)

@BoBo1946 -You’re right! :)

@Cruiser – I’m not sure if the 7 seconds are a myth, but this would be 4505142.86 thoughts about sex per year. Low yield might be depressing.

mattbrowne (31585)

@mattbrowne low yield would be depressing. hmmmm now to just figure a way to harness all that thought energy and we could be gazillionaires!! lol!

Cruiser (40401)

I was told that a gazillionaire owns more money than there are universes in the multiverse which supposedly (according to Andrei Linde) exceeds the number 10^10000000000000000. That’s a lot of property out there.

mattbrowne (31585)

@mattbrowne – There is room for error. + or -

CMaz (26228)

Number of neutrons that could fit in visible universe = 10^128, which is greater than a googol, which is only 10^100, but way less than googolplex which is 10^googol

Number of grains that you would have if you placed one grain on a square of a checkerboard, 2 on another square and doubled the amount each time until all the squares are taken (don’t ask how so many grains could be placed) =
About 1.8 * 10^19, 18 quintillion

To put @LostInParadise‘s numbers into perspective. If you wrote down the googolplex on paper, there wouldn’t be room in the entire universe to fit all this paper. And it wouldn’t matter how thin the paper was or how small a font you used. It still wouldn’t fit.

Still, it’s infinitely less than the length of π written out. So if you are looking for a huge number, then the number of digits in π (or similar constants) would be a good bet as it is infinitely large.

utzon (156)

LuckyGuy (35623)

The number of permutations of a deck of cards is 52! (“52 factorial”). This is precisely…
80658175170943878571660636856403766975289505440883277824000000000000
... or approximately 8.0658×10^67.

@hiphiphopflipflapflop: A picture is worth 10^3.065 words. Would you please lay out 80658175170943878571660636856403766975289505440883277824000000000000 decks in an array that shows all the permutations? Thanks.

ratboy (15157)

I can’t follow this thread any more. My brains are leaking out my ears!

Trillian (21106)

What happen to binary?

CMaz (26228)

Length of my penis.

Ivan (13439)

@ratboy Bring me food while I do it… ;)

@LostInParadise – Did you mean 10^128 neutrinos in the universe?

mattbrowne (31585)

Oh, “could fit”. My bad. Somehow I missed the “could” part. The actual number of neutrons is more in the < 10^80 neighborhood, because most atoms are hydrogen (not deuterium or helium or anything larger).

mattbrowne (31585)

@mattbrowne you speak a different language…a good thing!

BoBo1946 (15285)

42 as the meaning of life?

Zen_Again (9901)

@Zen_Again – What do you think is special about the age of 42? There are many people who mentioned this to me. Just curious.

mattbrowne (31585)

Not the age, @mattbrowne – it’s a hitchhiker thing. Youtube Hitchiker’s Guide to the Galaxy and 42 or the meaning of life – better yet – read it or see the movie.

Zen_Again (9901)

What about the number of electrons that can fit into the entire universe if packed as densely as possible?

28lorelei (2509)

@28lorelei – How to overcome the electromagnetic force? And the Pauli exclusion principle?

mattbrowne (31585)

@28lorelei we do not know the full extent of the universe (or whether it is even finite). Not even the volume of the observable universe (going out to the distance light has traveled since the Big Bang, or rather when the universe cooled enough to become transparent) is known to “very high accuracy”.