Materials

We used a FLIR C2 infrared camera throughout the demo. A free program from the FLIR website is required to connect it to a computer.

Other IR Demo Materials

In addition to the camera and laptop, we used a mug of hot water, a cold bottle of soda, two black garbage bags, and a clear glass.

ShopVac and Telescope Stand

We zip-tied the hose to a telescope stand. The vacuum we used was a 2 horsepower, 5 gallon version. We found it to be a bit loud, but doable. Other options are explorable.

Maser Bags

A ziploc bag containing an Easter egg, strips of paper, two starburst, and a roll of tape for the kids to make their masers.

Activites

Looking Through Bags

Put the mug of hot water and cold soda in a black garbage bag. The infrared camera will allow the students to look right through the bag.

Hand in Front of Glass

The glass will block the infrared light, a reversal of the infrared going through the bags, helping the students get the idea that some types of light goes through materials while others don't. The students seemed to really enjoyed this part.

Kids in IR

Pointing the camera at the kids so they can see themselves in infrared.

Mystery Bag

Similar to the looking through the bags at the hot water and cold soda, have a kid hold one in one hand, one in the other and have the class guess which is which.

Maser Creation

This is the heart of the demo. Challenge the students to make all different kinds of "masers" using Easter eggs. We challenged them to have crazy designs, ones that trace the outer regions of the outflow (fly high), ones that trace the base of the jets/outflows (fly low), and designs that fly for long periods of time.

Teaching Points

Astronomical Techniques

Study of outflows and jets. Optical studies are challenging because of dust obscuration. Astronomers use infrared telescopes to see through clouds of gas in space to study the process of star formation. Very easy to connect with seeing through the bags.

(Image: HH24: NASA, ESA, Hubble Heritage (STScI/AURA)/Hubble-Europe Collaboration; D. Padgett (NASA's GSFC), T. Megeath (U. Toledo), B. Reipurth (U. Hawaii) )

Electromagnetic Spectrum and Blackbody Radiation

Talk about what radio and infrared light are and how they relate to visible light. We also talked about blackbody radiation and how hotter objects emit more lower wavelengths of light.

(Image courtesy Wikipedia)

Aerodynamics

Connecting how the egg flies through the air (representing masers in outflows) to other parts of aerodynamics can be a good way to point students in the right direction of creating a different type of "maser clouds", one that flies high, low, or is very stable. We talked about how the paper wings caught the air pushing it up and how having the wings be asymmetrical can cause instability in the egg's flight.

Full Procedure

Set Up:

We connected a computer with the FLIR program (hyperlinked in the IR camera description) installed to a projector. Then we heated up some water in a coffee mug and placed it and a cold beverage on a table with a black plastic bag covering it. I like to point the IR camera at the bag as the students enter so they get curious what's going on and try to figure out why they can see through the bag on the camera but not with their eyes. Then we zip tied the tube of the vacuum to the telescope stand, making sure it is as straight as possible. We prepared the maser bags with two starburst, several strips of papers, a roll of tape, and an Easter egg in advance and had the students work in pairs to encourage collaboration and reduce the amount of resources needed, time and material. We made some eggs in advance to give the kids an idea of what we were looking for, trying to make them as crazy as possible, so it was harder to copy and the kids would make crazy designs themselves.

Infrared Camera Demo:

First we pointed out how with their eyes they can't see inside the bags, but on the camera they clearly can. This is analogous to how the clouds in star forming regions will block stars within them with our eyes but other forms of light, such as infrared, can go right through and let us observe what's inside. Then we introduced the electromagnetic spectrum as a whole and talked briefly about each kind of light (i.e. x-rays like when you go to the doctor with a broken bone, or radio waves is what your car receives to listen to the radio) helping them get an idea how these other kinds of light are used in our everyday life too. We explained how all things emit light, and the hotter something is the smaller the peak wavelength it emits. Light bulbs and the Sun are really hot so they emit light we can see. We are not as hot so we emit infrared light. Then we pointed the camera at the students so they could see themselves in infrared. The idea that the camera can see things we cannot may still be hard to grasp for the students so we did a reversal of the cup and the bag by putting a hand behind a glass. The glass blocks infrared light while visible light passes right through.


Outflow Activity:

First we introduced the picture of the star forming in the cloud of the gas, pointing out we cannot see the star inside in optical and need to use another form of light to see through it. We look at really bright microwave regions in the outflow called masers. Where the masers are depend on the types of masers. We showed our example maser eggs a put them into the outflow, commenting on how high or low they flew and what kinds of masers they would be. We then tell them that they are to make their own "maser clouds" and pass out the bags. We instructed them to raise their hands when they are done and call them up to put it into the outflow. When they come up, we asked them about their maser-egg and what they think will happen to it. After it flies high or low, we told them what kind of maser it is like, and challenge them to make one opposite of the one they have, if it was high make a low one and vice versa. We tried to let them make as many designs as they could in the time allowed, but with a few minutes left we stopped calling them up and discussed various designs we liked and why they did what they did.