# Finish this observable universe scale **URL:** \ **Category:** Factual Questions\ **Created:** [October 7, 2017, 7:55pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255 "2017-10-07T19:55:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [October 7, 2017, 7:55pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/1 "2017-10-07T19:55:51Z")
Posted on quora (in part): _“If the Sun were shrunk to the size of a white blood cell (about ten times smaller than the smallest object a human can see), the Earth would be the size of a small RNA virus particle. At that scale, the orbit of Neptune would be just about 2 inches in diameter. Our Milky Way Galaxy would then be… ready… the size of North America and our neighboring galaxy, Andromeda would be 91,000 miles away.”_ Which blows me away (assuming it’s true)! But this was an answer to a question about the scale of the observable universe, which as you can see it didn’t do. So along this same scale, how big would the observable universe be? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [October 7, 2017, 8:06pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/2 "2017-10-07T20:06:35Z")
Okay, assuming that math to be correct (and I’m not digging into it at the moment) the Andromeda galaxy is around 2.5 million light years away. The most distant observed galaxy is around 13.4 billion light years away, or 5.360 times the Andromeda distance. Giving a scale distance of around 487 million miles for that galaxy (and ignoring inflation of the universe that has taken place since the light left that galaxy.) ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [October 7, 2017, 8:25pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/3 "2017-10-07T20:25:04Z")
> [@Darren\_Garrison](#): > > Okay, assuming that math to be correct (and I’m not digging into it at the moment) the Andromeda galaxy is around 2.5 million light years away. The most distant observed galaxy is around 13.4 billion light years away, or 5.360 times the Andromeda distance. Giving a scale distance of around 487 million miles for that galaxy (and ignoring inflation of the universe that has taken place since the light left that galaxy.) Don’t you mean 5\*\*,\*\*360 times the Andromeda distance? I think the calculation is correct, just the statement lacking. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [October 7, 2017, 8:48pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/4 "2017-10-07T20:48:31Z")
Your scale factor is about 7E -15, so the [observable universe](https://en.wikipedia.org/wiki/Observable_universe) would be about 6E 12 m in your model, which is pretty close to the diameter of the orbit of Neptune. I guess this doesn’t really help visualizing the size… ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 7, 2017, 9:05pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/5 "2017-10-07T21:05:29Z")
Maybe **DG** meant the European thousands separator, not the USA one. 😃 ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [October 8, 2017, 1:22pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/6 "2017-10-08T13:22:42Z")
> [@Lucas\_Jackson](#): > > If the Sun were shrunk to the size of a white blood cell … how big would the observable universe be? About the size of a small nebula, or the Earth’s Kuiper belt. You’ve shrunk by 14 orders of magnitude on the following _ **Very rough guide to sizes** _ (many physicists object to defining the “size” of subatomic particles.) -35 – Planck Length -34 – … -33 – nano-yoctometer -32 – … -31 – … -30 – micro-yoctometer -29 – … -28 – … -27 – milli-yoctometer -26 – … -25 – … -24 – neutrino, yoctometer -23 – … -22 – top quark -21 – preon, high-energy radius of neutrino, zeptometer -20 – high energy neutrino, bottom quark -19 – charm quark -18 – quarks (u d), attometer -17 – range of weak force -16 – … -15 – proton, neutron, femtometer -14 – uranium nucleus -13 – … -12 – picometer -11 – helium atom -10 – carbon atom, water molecule -9 – sugar molecule, width of carbon nanotube, nanometer -8 – DNA fragment, cell membrane thickness -7 – HIV virus, UV wavelength -6 – very large virus, small bacterium, IR wavelength, micrometer -5 – blood cell, mist droplet -4 – human egg, width of human hair -3 – largest bacterium, small insect, millimeter -2 – coffee bean, hummingbird egg -1 – hummingbird 0 – man, meter 1 – house, FM wavelength 2 – large ship, AM wavelength 3 – very large factory, kilometer 4 – Mt. Everest 5 – small country 6 – Ceres, Pluto, megameter 7 – Venus 8 – Saturn 9 – the Sun, gigameter 10 – Capella 11 – Rigel 12 – Antares, distance to Saturn, terameter 13 – Kuiper belt, small nebula 14 – furthest comet orbit 15 – Stingray Nebula, Oort cloud, petameter 16 – Eskimo nebula, parsec 17 – Crab nebula, distance to Sirius 18 – Eagle nebula, M54 globular cluster, exameter 19 – large nebula 20 – dwarf galaxy, Lg. Magellanic cloud 21 – Milky Way, zettameter 22 – large galaxy 23 – cluster of galaxies 24 – galactic supercluster, yoctometer 25 – large galactic supercluster 26 – … 27 – Observable universe ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [October 8, 2017, 2:30pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/7 "2017-10-08T14:30:19Z")
Wow, thanks everyone. The universe is a big place! ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 8, 2017, 2:59pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/8 "2017-10-08T14:59:11Z")
> [@septimus](#): > > Very rough guide to sizes My Dad claimed that humans were at the midpoint of the smallest and largest scales, therefore humans are special, therefore Jeebus. Based on that summary, it looks like bacteria are closer to the (geometric) midpoint between the Planck Length and the observable universe. I, for one, welcome our new prokaryotic overlords. ---
**Author:** ![Baron\_Greenback](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/baron_greenback/32/48_2.png) [@Baron\_Greenback](https://boards.straightdope.com/u/Baron_Greenback)\ **Post date:** [October 8, 2017, 5:20pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/9 "2017-10-08T17:20:32Z")
> [@Lucas\_Jackson](#): > > Wow, thanks everyone. The universe is a big place! Space is big. You just won’t believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space. 😉 ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 8, 2017, 8:40pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/10 "2017-10-08T20:40:28Z")
> [@Riemann](#): > > My Dad claimed that humans were at the midpoint of the smallest and largest scales, therefore humans are special, therefore Jeebus. Based on that summary, it looks like bacteria are closer to the (geometric) midpoint between the Planck Length and the observable universe. I, for one, welcome our new prokaryotic overlords. The fact he was off by 4 orders of magnitude out of 60 is by far \*not \*the largest fault in that whole worldview. ---
**Author:** ![digs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/digs/32/14889_2.png) [@digs](https://boards.straightdope.com/u/digs)\ **Post date:** [October 9, 2017, 2:00pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/11 "2017-10-09T14:00:52Z")
> [@Baron\_Greenback](#): > > Space is big. You just won’t believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space. 😉 Our town (Madison, WI) has [the solar system laid out](http://www.spaceplace.wisc.edu/planettrek.htm). Starting near the middle of town is a two-foot diameter “sun” plaque, a block or so away is a sign explaining Mercury and showing its relative size (a small ball). Then, following the commuter bike path, comes Venus, Earth, Mars, then a long ride (but they threw in Ceres\*) to Jupiter, followed by Saturn (basketball size)… by the time you get to Uranus, you’re out of town, and by Neptune you’re past the next town… And marble-sized Pluto is 23 miles away (in Mount Horeb, where you can put your kickstand down outside The Grumpy Troll Brewpub…). Really gives you the feeling of all that empty space between planets. \*based on an Isaac Asimov line, I always say “Wow, I made it to the World Ceres!” even if I’m all alone. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [October 9, 2017, 6:54pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/12 "2017-10-09T18:54:06Z")
> [@Riemann](#): > > My Dad claimed that humans were at the midpoint of the smallest and largest scales, therefore humans are special, therefore Jeebus. Based on that summary, it looks like bacteria are closer to the (geometric) midpoint between the Planck Length and the observable universe. I, for one, welcome our new prokaryotic overlords. If you disregard “Planck length” as not corresponding to any object (though “Strings” are about this size if they exist at all) then man is about smack-on at the geometric mean between smallest (neutrino) and largest (galactic supercluster) ! I don’t know about Jeebus though. Did Godot ever show up? ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [October 9, 2017, 7:16pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/13 "2017-10-09T19:16:54Z")
> [@digs](#): > > Our town (Madison, WI) has [the solar system laid out](http://www.spaceplace.wisc.edu/planettrek.htm). Starting near the middle of town is a two-foot diameter “sun” plaque, a block or so away is a sign explaining Mercury and showing its relative size (a small ball). > > Then, following the commuter bike path, comes Venus, Earth, Mars, then a long ride (but they threw in Ceres\*) to Jupiter, followed by Saturn (basketball size)… by the time you get to Uranus, you’re out of town, and by Neptune you’re past the next town… > > And marble-sized Pluto is 23 miles away (in Mount Horeb, where you can put your kickstand down outside The Grumpy Troll Brewpub…). > > Really gives you the feeling of all that empty space between planets. > \*based on an Isaac Asimov line, I always say “Wow, I made it to the World Ceres!” even if I’m all alone. What’s amazing to me is how gravity works that far away. I mean aren’t the comets even much farther that Pluto? ---
**Author:** ![digs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/digs/32/14889_2.png) [@digs](https://boards.straightdope.com/u/digs)\ **Post date:** [October 10, 2017, 12:55pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/14 "2017-10-10T12:55:33Z")
> [@Lucas\_Jackson](#): > > What’s amazing to me is how gravity works that far away. I mean aren’t the comets even much farther that Pluto? That just goes to show us how huge, and how empty, space is. Think of rocks and icicles as far away as Pluto and the comets, and the biggest thing pulling on them that tiny yellow star that looks like a pinpoint of light… ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [October 10, 2017, 1:25pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/15 "2017-10-10T13:25:00Z")
> [@digs](#): > > Our town (Madison, WI) has [the solar system laid out](http://www.spaceplace.wisc.edu/planettrek.htm). Starting near the middle of town is a two-foot diameter “sun” plaque, a block or so away is a sign explaining Mercury and showing its relative size (a small ball). > > Then, following the commuter bike path, comes Venus, Earth, Mars, then a long ride (but they threw in Ceres\*) to Jupiter, followed by Saturn (basketball size)… by the time you get to Uranus, you’re out of town, and by Neptune you’re past the next town… > > And marble-sized Pluto is 23 miles away (in Mount Horeb, where you can put your kickstand down outside The Grumpy Troll Brewpub…). > > Really gives you the feeling of all that empty space between planets. > \*based on an Isaac Asimov line, I always say “Wow, I made it to the World Ceres!” even if I’m all alone. [Ours](http://www.swedensolarsystem.se/en/) is bigger than yours. 😃 (I live just thirty minutes bicycle ride outside Pluto/Charon.) ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [October 10, 2017, 1:36pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/16 "2017-10-10T13:36:41Z")
That is very cool! ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [October 10, 2017, 1:45pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/17 "2017-10-10T13:45:21Z")
> [@digs](#): > > Our town (Madison, WI) has [the solar system laid out](http://www.spaceplace.wisc.edu/planettrek.htm). Starting near the middle of town is a two-foot diameter “sun” plaque, a block or so away is a sign explaining Mercury and showing its relative size (a small ball). Next time, they’ll do it on a logarithmic scale. 🙂 ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [October 10, 2017, 4:08pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/18 "2017-10-10T16:08:03Z")
> [@Quartz](#): > > Next time, they’ll do it on a logarithmic scale. 🙂 Base 10 won’t cut it, though. Nothing on Earth, even Sweden and Wisconsin, would fit a comprehensible model for us 0 order of magnitude guys. However, as a matter of calculation, you could choose which subset in **septimus** ’s ordering and figure out the positions. In fact, more subsets could be accommodated if the Earth were apportioned conceptually as a spherical slide rule–a notional nomogram–a nice word pair, IMHO, with geographic signposts. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 10, 2017, 11:48pm UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/19 "2017-10-10T23:48:10Z")
I have an even bigger scale model of the Solar System. It’s 1:1 scale. I keep it here and there, mostly there. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [October 11, 2017, 1:47am UTC](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255/20 "2017-10-11T01:47:46Z")
> [@Chronos](#): > > I have an even bigger scale model of the Solar System. It’s 1:1 scale. I keep it here and there, mostly there. Very Borges. [Next page](https://boards.straightdope.com/t/finish-this-observable-universe-scale/798255.md?page=2)