THE SOLUTION TO Weekly Challenge 7: Spaceship Earth

 Posted by DrJeff on September 15th, 2009

 Copyright 2009  |  About this blog

 

Read Original Challenge HERE.

MW

Photo caption: Computer-generated image of the Milky Way galaxy based on real data.

 

This post is a Dr. Jeff’s Weekly Challenge. It was requested by (teacher extraordinaire) Jami Lupold and her class in the great city of Houston, Texas, USA.

If you’re a teacher and your class has an idea for a blog post, slip me a note!

 

Last week I gave you a scare. It happened when I told you that you’re really on a spaceship hurtling through space. I was in the midst of describing all of Earth’s motions—it spins, it orbits the Sun, the Sun orbits the center of our galaxy carrying Earth and the Solar System along for the ride—and that’s when I saw panic on your face. You started to get a bit dizzy, so I turned on the “fasten seat belt sign” in light of all the conceptual turbulence ahead. To keep your mind off all the spinnin’ and revolvin’ I gave you an assignment to calculate Earth’s speed—your speed—due to these three motions. Does this all ring a bell? No? Why don’t you go and re-read the original challenge from last week, so you can refocus.

 

Good. Now that you’re back. Let’s get to the answers. Did I mention this week’s challenge was in our in-flight magazine in the seat pocket in front of you? By the way, I see you dug your fingernails into your seat, and your fingertips seem a bit blue. (Hope the answers don’t send you into a panic.)

 

And now the answers—


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Weekly Challenge 7: Spaceship Earth

 Posted by DrJeff on September 4th, 2009

 Copyright 2009  |  About this blog

 

MW

Photo caption: Computer-generated image of the Milky Way galaxy based on real data.

 

This post is a Dr. Jeff’s Weekly Challenge. It was requested by (teacher extraordinaire) Jami Lupold and her class in the great city of Houston, Texas, USA.

If you’re a teacher and your class has an idea for a blog post, slip me a note!


 

You wanted to be an astronaut? Poof. Done.

 

You and your friends are on a spaceship called Earth—with all known life aboard. With you sitting there calmly reading this, and no obvious need to hold on to something for dear life, it might seem that the spaceship under your feet is carrying you on a nice steady trajectory through space. Uh … Nope. Right now you’re being carried along on something more akin to a cosmic-sized amusement park ride. Earth is rotating on its axis, it’s orbiting the Sun, and the whole Solar System (the Sun and its planets, dwarf planets, asteroids, comets, and Trans-Neptunian Objects) is orbiting the center of the Milky Way galaxy. The Milky Way itself is moving relative to other nearby galaxies, the local group of galaxies is moving through a greater space, and all this is set against a backdrop of an expanding fabric of space and time across the entire universe. I know!!!! (© Craig Ferguson) Dizzy?

 

[Pleasant Ding] The captain has just turned on the seat belt sign. There may be some conceptual turbulence up ahead. But I’ll make the ride as smooth as possible.

 

OK, I think a Weekly Challenge requesting that you calculate all the spinning, and revolving, and free-flying is a bit much, so let’s concentrate on three things:

 

Here now the Challenge—

 

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