Alysha Dan Melissa Kyle Mr. Walter

 Subatomic particles from outer space, the exact location is still unknown.  These particles interact with our atmosphere and form cosmic ray showers.  Cosmic ray detectors can detect these showers on Earth. What are cosmic rays?

The cosmic ray detector A particle from the cosmic ray shower (muons) strikes the scintillator and forms a photon of light. This photon of light is detected by the photomultiplier, which then converts it to an electric signal. The amount of electric signals per minute was recorded.

Problem Do different gases change the cosmic ray count? Hypothesis We believe that different gases will affect the cosmic ray count.

Materials  Dry ice (CO 2 )  Cosmic ray detector  Helium  Garbage bag  Tupperware  Liquid nitrogen  Nylon tie  Laptop with Probeware  8 oz. Styrofoam cup  Zach (liquid nitrogen waiter)

Procedure 1.Gather materials. 2.Set up cosmic ray detector (CRD) in lab on a table.

Procedure (cont) 3. Plug the CRD into the laptop. 4. Set Probeware to record data every 30 seconds for 5 minutes. 5. Run the first control experiment with nothing on the CRD.

Procedure (cont) 6. Run another control experiment with the Tupperware container covering the opening on top of the CRD. 7. Run an experiment with 3 scoops of dry ice (size of baked Cheetos) in Tupperware container.

Procedure (cont) 8. Run an experiment by filling a garbage bag with helium. Stuff the garbage bag into the Tupperware container and tie off with a nylon tie. Here is Zach, taking out the trash

Procedure (cont) 9. Then, run a 3 rd control experiment by placing an empty garbage bag in the Tupperware. 10. Run an experiment by pouring liquid nitrogen into an 8 oz. Styrofoam cup and placing the cup in the Tupperware. 11. Observe and compare data.

Improvements  Run each experiment three times and average to account for sample size.  Use a larger container for gases.  Use a completely air tight container.

Results : Control

Results : Air

Results : CO 2

Results : N 2

Results : Air bag

Results : He bag

Results : bar graph

Results : line graph

P-Value  Control vs. Air in Box.4528  Air vs. CO  Air vs. N  Air vs. Empty Bag.7512  Empty Bag vs. He Bag.7156

Conclusion Our hypothesis was that the presence of a gas over the cosmic ray detector would in fact change the count of cosmic rays. We were unable to reject the null hypothesis of no difference with any confidence. Our sample size was quite small, but at any rate, there was very little convincing data to support our hypothesis. The counts of the cosmic rays were very erratic as well. The variance was therefore also quite high, meaning higher deviation and high error.