## Scale models of the Solar System

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iain
Posts: 187
Joined: Mon Jun 14, 2004 8:55 am
Location: Cheshire, England

### Scale models of the Solar System

I knocked up a little script which figures out the dimensions of a model of the solar system (in python, available on my website, though it doesn't do anything special). You pick a body (e.g. sun, earth) and say what diameter it has in your model, and the script gives you the distances.

For example, suppose you represent the Earth as a marble 1cm in diameter. You get the following results (tell me if you think these are wrong - they should be OK)

The diameter of mercury is 0.38 cm
The diameter of sun is 1.1 m
The diameter of neptune is 3.88 cm
The diameter of pluto is 0.18 cm
The diameter of jupiter is 11.21 cm
The diameter of uranus is 4.01 cm
The diameter of mars is 0.53 cm
The diameter of earth is 1.0 cm
The diameter of venus is 0.95 cm
The diameter of saturn is 9.45 cm
Distance from the sun to mercury is 45 m
Distance from the sun to neptune is 35 km
Distance from the sun to pluto is 46 km
Distance from the sun to jupiter is 610 m
Distance from the sun to uranus is 22 km
Distance from the sun to mars is 178 m
Distance from the sun to earth is 117 m
Distance from the sun to venus is 84 m
Distance from the sun to saturn is 11 km
The diameter of Earth's moon is 0.27 cm
Earth's moon is 30.1 cm from Earth

I always tend to forget how much empty space is out there. The Sun is just over 1m in diameter but in my model, I have to place Pluto 46km away. Guess I won't be doing that one in the classroom

wollery
Posts: 96
Joined: Thu Jun 10, 2004 4:49 pm
Location: Liverpool

http://www.exploratorium.edu/ronh/solar_system/
It's not easy being a dolphin!

iain
Posts: 187
Joined: Mon Jun 14, 2004 8:55 am
Location: Cheshire, England

http://www.exploratorium.edu/ronh/solar_system/
Nice site, but less fun than doing it myself (and you have to start with the Sun's diameter - my script allows you to specify the diameter of the Sun or any planet). I'll probably get round to doing a web version in perl, just to do it; but of course the information is freely available on about a hundred sites to anyone with a calculator.

exarch
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Joined: Wed Jun 02, 2004 10:51 pm
Location: Beyond redemption

### Re: Scale models of the Solar System

iain wrote:I always tend to forget how much empty space is out there. The Sun is just over 1m in diameter but in my model, I have to place Pluto 46km away. Guess I won't be doing that one in the classroom
Isn't the English Channel about 40-something km wide? I could be wrong, but I remember it being something like that.
[size=75]Lord high emperor Skinny-god's first heir to the throne[/size]

MRC_Hans
Posts: 519
Joined: Fri Jun 04, 2004 8:11 pm
Location: Denmark
To make the model fit in a class-room, you have to make the Sun 3mm in diameter. But then Jupiter is the only planet that is visible to the naked eye (and only barely so).

For more visualizing, I recommend Celestia: http://www.shatters.net/celestia/

A really cool 3D space simulator.

Hans
[i]Fly pretty, anyone can fly safe...[/i]

Sock
Posts: 794
Joined: Mon Jun 07, 2004 7:35 pm

### Re: Scale models of the Solar System

iain wrote:I knocked up a little script which figures out the dimensions of a model of the solar system (in python, available on my website, though it doesn't do anything special). You pick a body (e.g. sun, earth) and say what diameter it has in your model, and the script gives you the distances.

For example, suppose you represent the Earth as a marble 1cm in diameter. You get the following results (tell me if you think these are wrong - they should be OK)

The diameter of mercury is 0.38 cm
The diameter of sun is 1.1 m
The diameter of neptune is 3.88 cm
The diameter of pluto is 0.18 cm
The diameter of jupiter is 11.21 cm
The diameter of uranus is 4.01 cm
The diameter of mars is 0.53 cm
The diameter of earth is 1.0 cm
The diameter of venus is 0.95 cm
The diameter of saturn is 9.45 cm
Distance from the sun to mercury is 45 m
Distance from the sun to neptune is 35 km
Distance from the sun to pluto is 46 km
Distance from the sun to jupiter is 610 m
Distance from the sun to uranus is 22 km
Distance from the sun to mars is 178 m
Distance from the sun to earth is 117 m
Distance from the sun to venus is 84 m
Distance from the sun to saturn is 11 km
The diameter of Earth's moon is 0.27 cm
Earth's moon is 30.1 cm from Earth

I always tend to forget how much empty space is out there. The Sun is just over 1m in diameter but in my model, I have to place Pluto 46km away. Guess I won't be doing that one in the classroom
You could make it an extra credit homework assignment. Place the 1.1 meter Sun on your desk, explain to the students how to figure out the distances to the planets, then tell them the first one to bring you the object you have placed directly east (north, south, or west) at Pluto's distance gets an A for the week, or whatever. Pick a landmark or something unusual at the 46 Km location and put something astronomically related there. If there is a motel or something 46 Km away, ask the desk clerk to hold the object until someone comes and asks for it.

You get the idea.
"Sock is funny!" - [url=http://www.pennandteller.com/03/coolstuff/penniphile/sockpage.htm]New York Times[/url]

iain
Posts: 187
Joined: Mon Jun 14, 2004 8:55 am
Location: Cheshire, England

### Re: Scale models of the Solar System

Sock wrote:You could make it an extra credit homework assignment. Place the 1.1 meter Sun on your desk, explain to the students how to figure out the distances to the planets, then tell them the first one to bring you the object you have placed directly east (north, south, or west) at Pluto's distance gets an A for the week, or whatever. Pick a landmark or something unusual at the 46 Km location and put something astronomically related there. If there is a motel or something 46 Km away, ask the desk clerk to hold the object until someone comes and asks for it.
Apart from the risk of lots of kids turning up with things they've stolen in the mistaken belief that their object is the one I placed, I think that's a great idea.

Sock
Posts: 794
Joined: Mon Jun 07, 2004 7:35 pm

### Re: Scale models of the Solar System

iain wrote:
Sock wrote:You could make it an extra credit homework assignment. Place the 1.1 meter Sun on your desk, explain to the students how to figure out the distances to the planets, then tell them the first one to bring you the object you have placed directly east (north, south, or west) at Pluto's distance gets an A for the week, or whatever. Pick a landmark or something unusual at the 46 Km location and put something astronomically related there. If there is a motel or something 46 Km away, ask the desk clerk to hold the object until someone comes and asks for it.
Apart from the risk of lots of kids turning up with things they've stolen in the mistaken belief that their object is the one I placed, I think that's a great idea.
Or maybe you could work the problem backwards. How far away is the nearest observatory or science museum? Maybe you could talk to the director of such a place and work something out. Then scale your Sun accordingly. Place the other planets along the path to the museum/observatory.
"Sock is funny!" - [url=http://www.pennandteller.com/03/coolstuff/penniphile/sockpage.htm]New York Times[/url]

exarch
Posts: 897
Joined: Wed Jun 02, 2004 10:51 pm
Location: Beyond redemption

### Re: Scale models of the Solar System

Sock wrote:
iain wrote:
Sock wrote:You could make it an extra credit homework assignment. Place the 1.1 meter Sun on your desk, explain to the students how to figure out the distances to the planets, then tell them the first one to bring you the object you have placed directly east (north, south, or west) at Pluto's distance gets an A for the week, or whatever. Pick a landmark or something unusual at the 46 Km location and put something astronomically related there. If there is a motel or something 46 Km away, ask the desk clerk to hold the object until someone comes and asks for it.
Apart from the risk of lots of kids turning up with things they've stolen in the mistaken belief that their object is the one I placed, I think that's a great idea.
Or maybe you could work the problem backwards. How far away is the nearest observatory or science museum? Maybe you could talk to the director of such a place and work something out. Then scale your Sun accordingly. Place the other planets along the path to the museum/observatory.
We had something similar to that in my home town. It was a long street with trees on either side, and on the side of the road they had placed stone markers, polished on top, at the locations of the planets. The first one was the sun, with a circular marking drilled out of about 15 cm in diameter, and then all the markers were at the right distance all the way from one end of the road to the other, which was about 1 km long. The only stone marker with anything larger than a drilled hole was jupiter, but it wasn't very big either, just a slightly larger hole
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RCNelson
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Joined: Thu Jun 10, 2004 12:38 am
Location: Fremont, CA, USA
In a similar vein:

'Powers of Ten' scales

iain
Posts: 187
Joined: Mon Jun 14, 2004 8:55 am
Location: Cheshire, England
I can't remember which book, but there was an interesting point made that, humans (and pretty much every other living creature on the planet, before we get too excited) are at about the half way point size-wise. Our size compared to the predicted size of strings (a la M theory) is of the same order of magnitude as the size of the universe compared to us.

iain
Posts: 187
Joined: Mon Jun 14, 2004 8:55 am
Location: Cheshire, England

### I got it wrong

I've spotted a mistake in my script while I was converting it to perl - a missing 0 in the original meant that distances in km were out by a factor of 10. Oops.

The correct figures are

The diameter of saturn is 9.45 cm
The diameter of jupiter is 11.21 cm
The diameter of uranus is 4.01 cm
The diameter of pluto is 0.18 cm
The diameter of mercury is 0.38 cm
The diameter of earth is 1.00 cm
The diameter of sun is 1.10 m
The diameter of mars is 0.53 cm
The diameter of venus is 0.95 cm
The diameter of neptune is 3.88 cm
Distance from the sun to saturn is 1.12 km
Distance from the sun to jupiter is 610.18 m
Distance from the sun to uranus is 2.25 km
Distance from the sun to pluto is 4.64 km
Distance from the sun to mercury is 45.40 m
Distance from the sun to earth is 117.28 m
Distance from the sun to mars is 178.70 m
Distance from the sun to venus is 84.83 m
Distance from the sun to neptune is 3.53 km
The diameter of Earth's moon is 0.27 cm
Earth's moon is 30.14 cm from Earth

exarch
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Location: Beyond redemption
And all us unskeptical folks, we just accepted your original faulty experiment without asking any questions
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iain
Posts: 187
Joined: Mon Jun 14, 2004 8:55 am
Location: Cheshire, England
exarch wrote:And all us unskeptical folks, we just accepted your original faulty experiment without asking any questions
Probably goes to show something or other; answers on a postcard...

Sock
Posts: 794
Joined: Mon Jun 07, 2004 7:35 pm

### Re: I got it wrong

iain wrote:I've spotted a mistake in my script while I was converting it to perl - a missing 0 in the original meant that distances in km were out by a factor of 10. Oops.
Oh, great. You left your students wandering around the Oort Cloud looking for Pluto.
The correct figures are

The diameter of saturn is 9.45 cm
The diameter of jupiter is 11.21 cm
The diameter of uranus is 4.01 cm
The diameter of pluto is 0.18 cm
The diameter of mercury is 0.38 cm
The diameter of earth is 1.00 cm
The diameter of sun is 1.10 m
The diameter of mars is 0.53 cm
The diameter of venus is 0.95 cm
The diameter of neptune is 3.88 cm
Distance from the sun to saturn is 1.12 km
Distance from the sun to jupiter is 610.18 m
Distance from the sun to uranus is 2.25 km
Distance from the sun to pluto is 4.64 km
Distance from the sun to mercury is 45.40 m
Distance from the sun to earth is 117.28 m
Distance from the sun to mars is 178.70 m
Distance from the sun to venus is 84.83 m
Distance from the sun to neptune is 3.53 km
The diameter of Earth's moon is 0.27 cm
Earth's moon is 30.14 cm from Earth
You could almost walk a round trip from the Sun to Pluto and back in a class period. Lecturing all the while.

How big would a comet or asteroid be on this scale? If you held it up at Pluto and asked the chances of hitting a moving Earth from there, it might make a comforting impression.
"Sock is funny!" - [url=http://www.pennandteller.com/03/coolstuff/penniphile/sockpage.htm]New York Times[/url]

exarch
Posts: 897
Joined: Wed Jun 02, 2004 10:51 pm
Location: Beyond redemption

### Re: I got it wrong

Sock wrote:How big would a comet or asteroid be on this scale? If you held it up at Pluto and asked the chances of hitting a moving Earth from there, it might make a comforting impression.
With Earth at 1cm diameter, really, really, really tiny. Heck, at that scale you couldn't even hit Earth with a rifle standing next to Pluto if you wanted to.
[size=75]Lord high emperor Skinny-god's first heir to the throne[/size]