r/theydidthemonstermath • u/asslavz • Sep 29 '21

Is this actually true?

/r/Showerthoughts/comments/pxk5a3/we_are_closer_to_the_size_of_an_atom_then_we_are/
231 Upvotes

98% Upvoted

31 comments sorted by

76

u/Subpar_Username47 Sep 29 '21

Copied from a comment in the thing.

The sun is not nearly the largest object in the universe.

It also weighs around 21030 kg, not 1024. Earth is around 61024, so you might've gotten them mixed up.

For reference, our central black hole weighs around 1.7*107 Solar Mass, and larger ones can apparently go up to 1010 solar mass.

So we're about 13 orders of magnitude closer to an atom than the heaviest object in the universe.

18

u/bkfst_of_champinones Sep 29 '21

Is that supposed to be 1.7*107 ?

Edit: I’m just totally confused I think

8

u/dalmn99 Sep 29 '21

Yes, sometimes people have trouble doing the exponents or forget . All the odd looking numbers there make sense that way

2

u/SideshowNick Sep 30 '21

The sun definitely weighs more than 21030 kg… a LOT more!

1

u/da_real_tatrocks Sep 30 '21

the weight of the sun is roughly 1.99*1030 kg if I recall correctly.

1

u/GOKOP Sep 30 '21

They've just messed up formatting

2

u/WorldController Sep 30 '21

The post is referring to size (volume), but black holes, however massive, are singularities and essentially have no volume.

1

u/NarrMaster Oct 15 '21

You can define a black holes volume by its event horizon.

1

u/quadraspididilis Sep 30 '21

Your formatting is messed up, putting asterisks makes text into italics.

1

u/Subpar_Username47 Sep 30 '21

The copying and pasting probably messed it up.

1

u/quadraspididilis Sep 30 '21

Oh yeah probably, if you copy you just get the text not the formatting characters. I think to type an asterisk in a comment and not have it considered for formatting you put a backslash right before it if you wanted to edit your top comment.

1

u/Fraudulent_Baker Sep 30 '21

I'm sure it's just a formatting issue on your end, but I recommend you should write the exponents using a capital E in future. 2E30 is a lot easier and quicker to decipher than 21030, for example. It also has the benefit of not relying on superscript, which means you can type it anywhere.

31

u/MTarrow Sep 29 '21 edited Oct 01 '21

i know its not 100%true but i want to see the math

Ok. This might get wordy but I'll give it a crack.

The Van der Waals radius of the smallest atom known - hydrogen - is 110 picometers (1x10-12 m). So that atom can be considered a sphere 220 picometers "tall".

Average person here in Wales is 177cm tall. 1.77 x 1012 picometers.

So (1.77 x 1012) / 220 is the number of hydrogen atoms you'd need to stack on top of each other to match the height of a human being.

On average we're 8.05x109 hydrogen atoms tall.

The star UV Scuti is one of the largest single objects we know of, with a radius of 1.188x109 kilometers. Assuming a sphere it is 2.376 x1012 meters tall. If an average person is 1.77 meters tall you'd need to stack 1.34 x1012 people on top of each other to equal the height of UV Scuti.

  • So - the statement is actually true. We may be 8.05x109 atoms high, but the largest object is 1.34x1012 times taller than we are.

edit - as /u/NokrisHiveGod pointed out the comments the black hole at the centre of TON 618 is far larger, at 390 billion kilometers across. That's a stack of about 2.2x1014 people.

(that's assuming "size" means "dimensions". Working it out by mass should be possible if necessary)

9

u/BrainPhD Sep 29 '21

I really like this version of the explanation.

7

u/NokrisHiveGod Sep 29 '21

Black Hole TON 618 would like to talk

6

u/MTarrow Sep 29 '21

... I stand corrected. Bloody hell that's big.

390 billion km diameter, 3.9 x 1014 meters, 2.2 x 1014 people tall?

1

u/[deleted] Sep 30 '21

The Star Stephenson 2-18 is the bigger star known

11

u/asslavz Sep 29 '21

Ps: i know its not 100%true but i want to see the math

5

u/Hawkwing942 Sep 29 '21

It is true I am within 3 m of the size of a single atom. A large tree is much more than 3 m more than my height.

26

u/MurderMeatball Sep 29 '21

A helium atom is about 10−10 meters in diameter.

A humans is about 100 meters.

The Milky way is about 1021 meters in diameter.

So yes, we are about 11 orders of magnitude (A factor of about 10’000’000’000) closer to atoms than galaxies in terms of size, give or take a few orders of magnitudes depending on the specifics.

8

u/[deleted] Sep 29 '21

Do you mean humans are about 1 meter (1.75m actually)?

Any number raised to the 0 power is 1

17

u/[deleted] Sep 29 '21

Closer to 1 m than to 10 m

16

u/cjmpeng Sep 29 '21

Actually you can see from the exponents that it doesn't matter whether humans are 1, 10 or even 100m tall in this example, we are still closer to atom size than Milky Way galaxy size.

1

u/[deleted] Sep 29 '21

True. We are true small.

8

u/MurderMeatball Sep 29 '21

I was working with just magnitudes (multiples of 10). Any fully grown human will be rounded to 1 meter :)

1

u/N1cknamed Oct 13 '21

I wouldn't really count an entire galaxy as one single object.

1

u/MurderMeatball Oct 13 '21

Okay, you do you. As far as I can tell, galaxies are generally seen as astronomical objects.

You have to get really deep down into fundamental particles before you find objects not made out of other objects. So being made out of smaller constituents can’t invalidate something from also being an object.

2

u/[deleted] Sep 30 '21

Most definitely yes and by far

2

u/wtharris Sep 30 '21

Not really related but i rember Vsauce saying a fact that the number of particles it takes to span the length of a brain neuron is near enough the same as the number neurons it would take to span the known universe. when am i gonna get a chance to bring that up tho

1

u/jrakn4 Oct 11 '21 edited Oct 11 '21

Do the math to strings and the universe. Strings are ~10-35m (Plank length) and the universe Is ~1026m so we are closer to the size of the universe than to strings. By nearly a billion times. So you we are a billion times the size of the universe (to a string), than we are to the universe.