Radio Astronomy Notes

There are lots of great websites with information.

• A nice introduction here

• Lots of information here

• Just for fun: here.

Here's just a few hints for making a simple and robust demo. (Most people do more sophisticated setups.)

Use this calculator to design your horn antenna. I used 15db which works fine and is easy to transport and use.   For a demo you can have an audience member easily hold the antenna in their hands and aim it.

I use the total power software, which is much easier to learn and  use than the more common suggestions. This allows one to aim the horn and get a velocity reading in under 30 seconds, which is great for live demos.  The process is straightforward: 

1. click on band explorer icon 

2. click on H-line

3. click on linearize (this can be confusing and may require several clicks before it works). Eventually you should see a fairly flat line with at a significant bump. 

4. Rescale the plot to see the details -- usually, 0-5db. Move your mouse over the bump and read the relative velocity below on the chart -- you don't have to compute anything.

You can also aim the horn at the sun and compare it to the open sky and also compare it to the earth (down) or a person's head!  Use: Noise plot and then rescale so you can see the differences.

Make sure to print out or download a map of the Milky Way Galaxy!  (I like galaxymap.net.) Don't use an LP record as your example: kids have never seen one on a turntable!