Friday, January 16, 2009

[space] how to get the head around its vastness

When did you last sit back and contemplate space?

Thought so.

An interesting post by Bag concerned how one little error b---ered up a whole space journey - how would you feel? You've managed to get that far and then comes the one error. Blip. Gone.

Have you considered just how far that spaceship might have travelled by that stage and how vast space actually is? This was just a set of numbers in the head until a cool comparative scale model came to hand:

First, collect the objects you need. They are:

Sun-any ball, diameter 8.00 inches
Mercury-a pinhead, diameter 0.03 inch
Venus-a peppercorn, diameter 0.08 inch
Earth-a second peppercorn
Mars-a second pinhead
Jupiter-a chestnut or a pecan, diameter 0.90 inch
Saturn-a hazelnut or an acorn, diameter 0.70 inch
Uranus-a peanut or coffeebean, diameter 0.30 inch
Neptune-a second peanut or coffeebean
Pluto- a third pinhead (or smaller, since Pluto is the smallest planet)

Put the Sun ball down, and march 10 paces.
Put down Mercury and march 9 paces further.
Put down Venus and march 7 paces.
Put down Earth and march 14 paces.
Put down Mars and march 95 paces.
Put down Jupiter and march 112 paces.
Put down Saturn and march 249 paces.
Put down Uranus and march 281 paces.
Put down Neptune and march 242 paces.
Put down Pluto and take a rest because the next part is going to tire you out.

You have marched more than half a mile! Now, leaving aside the fact that the orbits aren’t two dimensional, it’s time for the next little jaunt 4000 miles [on our model] to find Proxima Centauri.

Light travels 186,283 miles (or 299,793 kilometers) per second. It could travel, for instance, 7 1/2 times around the Earth in one second.

Moon to Earth 1.28 light-seconds [2.4 inches]
Sun to Earth 8.3 light-minutes [26 yards]
Sun to Jupiter 43.27 light-minutes [132 yards]
Sun to Pluto 5 1/2 light-hours [1019 yards]
Sun to Proxima Centauri 4.22 light-years [4000 miles]

So there we are. Your homework - on this model, how far across is the universe?

H/T Bag


CherryPie said...

I would love to see that model demonstrated, but can I skip the homework? It is Friday after all ;-)


Great,mind boggling post.
I bet you were a fabulous teacher,James.

Anonymous said...

The Universe is 93 billion light years across so on that scale we are looking at a lot of walking to put your markers in place. 93 trillion miles. 20 times the distance from the Earth to Proxima Centauri. You should get a bike. A really fast bike.

Anonymous said...

Duh. 5 times the distance not 20.