Astronomy 120: Fall 2008

Homework 1: Due in September 5/8 recitation

Name ___________________________ Section _______

Q1:

Tell us a bit about yourself! We can find your basic stats online (i.e. your year, major, etc.)


 

Q2:

Everybody knows that the Earth is round (right?).

But can you prove it?

In the first part of this question, use what is available to us with modern technology (with the indicated restriction); in the remaining parts, use only those "tools" that were available in the 19th century.

  1. What experiment could you do, or what evidence can you show, to prove that the Earth is indeed round? We can't count pictures of the Earth, since those could be faked (at least according to some conspiracy theory folks).

  2. How would you prove that the Earth is round to someone if you both lived in the 19th century (before rockets, airplanes, long-distance electronic communication, etc)? What evidence could you use? What experiments could you do?

  3. Now, within that 19th century argument, describe three (3) experiments and/or pieces of evidence that the Earth is flat (that is, argue the opposite side of the issue from your previous answer).

Q3:

The Earth takes 365 days to orbit the Sun. Given that the Earth is 1.5x108 km away from the Sun,

  1. how fast is the Earth moving in its orbit, in km/sec?

  2. How fast is it going in miles/hour?

Q4:

The Moon takes 27 days to orbit the Earth. Given that the Moon is 3.8x105 km away from the Earth,

  1. how fast is the Moon moving in its orbit, in km/sec?

  2. How fast is it going in miles/hour?