1. ## Largest Defined Quantity

I was having a discussion with my son about cosmology and the quantum. As we discussed the number of stars in the observable universe, we progressed to atoms then electrons, photons... eventually my son asked "what do you think there is more of?" This got me thinking, and my only conclusion was that a Planck length cube of space is the only definable largest quantity at an estimated 4.65 x 10^185 in the observable universe.

Is there a definable quantity that is known within our observable universe greater than the number of Planck length cubed?

2. Originally Posted by cosmocrazy
I was having a discussion with my son about cosmology and the quantum. As we discussed the number of stars in the observable universe, we progressed to atoms then electrons, photons... eventually my son asked "what do you think there is more of?" This got me thinking, and my only conclusion was that a Planck length cube of space is the only definable largest quantity at an estimated 4.65 x 10^185 in the observable universe.

Is there a definable quantity that is known within our observable universe greater than the number of Planck length cubed?
Well, you might look at all the cubic planck lengths times the number of Planck times since the Big Bang.

3. Originally Posted by antoniseb
Well, you might look at all the cubic planck lengths times the number of Planck times since the Big Bang.
Thanks, that's one I didn't think about.

4. If you're talking physical quantities, that might be a contender.

But there are numbers used in math solutions that make those such that they might as well be zero.

Obviously the Googolplex is a very well known number (ten to the power of a Googol).

But even that is insignificant when compared to t̶h̶e̶ ̶p̶o̶w̶e̶r̶ ̶o̶f̶ ̶T̶h̶e̶ ̶F̶o̶r̶c̶e̶ numbers such as Graham's Number - a number so stupid-big that no amount of "power tower" notation can describe it within the volume of the observable universe.

Grahem's Number needed a whole new notation system just to describe it. And even and that, it still isn't fully described without ''..."s in the Wiki article about it.

At the time of its introduction, it was the largest specific positive integer ever to have been used in a published mathematical proof (as opposed to just making one up for fun).

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Well, you might look at all the cubic planck lengths times the number of Planck times since the Big Bang.
This would probably do it. At least, I can't at the moment come up with any larger physical quantity in the universe that we could measure.

Originally Posted by DaveC426913
At the time of its introduction, it was the largest specific positive integer ever to have been used in a published mathematical proof (as opposed to just making one up for fun).
And to make it even more ridiculous, that number was the upper bound for what the correct right answer could actually be. Do you know what the lower bound was? 6.

6!!!!

So.......in this proof, while Mr. Graham did not find the actual answer, he did narrow down the range to somewhere between 6 and the largest number ever conceived of in a mathematical proof. Don't go to this man for precision! Lol

6. Originally Posted by DaveC426913
If you're talking physical quantities, that might be a contender.

But there are numbers used in math solutions that make those such that they might as well be zero.

Obviously the Googolplex is a very well known number (ten to the power of a Googol).

But even that is insignificant when compared to t̶h̶e̶ ̶p̶o̶w̶e̶r̶ ̶o̶f̶ ̶T̶h̶e̶ ̶F̶o̶r̶c̶e̶ numbers such as Graham's Number - a number so stupid-big that no amount of "power tower" notation can describe it within the volume of the observable universe.

Grahem's Number needed a whole new notation system just to describe it. And even and that, it still isn't fully described without ''..."s in the Wiki article about it.

At the time of its introduction, it was the largest specific positive integer ever to have been used in a published mathematical proof (as opposed to just making one up for fun).
Thanks DaveC!
Personally, I've always been interested in the extremes whether the largest or the smallest etc... I find this stuff really interesting. In the context of the OP my thoughts and the discussion with my son was based on physical quantities within our known universe, ones that we can estimate with some confidence based on mainstream science. Inevitably these discussions tend to evolve into speculative ideas and possibilities, which can also be fun.

My son is at an age now where he is showing real interest in science and to help maintain this I find these types of discussions wow the audience as they try to comprehend the vastness and wonder of the universe we live in. During the discussion we talked about the most massive stars, blackholes... etc and then the smallest particles, the number of stars and galaxies... which is how it lead onto my OP.

7. Originally Posted by Dave241

And to make it even more ridiculous, that number was the upper bound for what the correct right answer could actually be. Do you know what the lower bound was? 6.

6!!!!
Yeah. Kills me.

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Originally Posted by DaveC426913
Yeah. Kills me.
Lol this was Epic.

Regards,
Sloth Smith

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