Activity 6

Does radiation increase with altitude?

Make your predictions before the images are revealed. Lock them in, then compare three real detector images to see whether the evidence matches what you expected.

Name Partner(s) Date

Predict, before the images are revealed

Two questions about altitude and radiation

Question 1. The same detector runs for the same time at three locations: on the Earth surface, on an airplane, and on a satellite. Rank them from fewest to most visible tracks.

Satellite, then airplane, then Earth surface (most tracks at ground level) Earth surface, then airplane, then satellite (most tracks in space) About the same at all three locations

Question 2. If the track count does change with altitude, what is the most likely reason?

The atmosphere absorbs or deflects some particles before they reach the ground, so fewer tracks appear at lower altitudes Gravity pulls radiation downward, so most particles collect near the ground The detector works differently in space because of temperature changes

Write your reasoning in your own words.

Predictions locked. Now reveal and examine the three images.

Observe

Read the detector images

Reveal the images once your predictions are locked. For each one, look at how many tracks you can see, how dense they are, and what shapes appear most often.

Track-shape reminder: dot = photon (X-ray or gamma), curly worm = electron (beta), round blob = alpha, long straight line = muon or other high-energy particle.

TIMEPIX detector image recorded at the Earth surface — Image A Earth surface

TIMEPIX detector image recorded on an airplane — Image B Airplane

TIMEPIX detector image recorded on a satellite — Image C Satellite

Lock in your predictions first.

Location	Track density (sparse, medium, dense)	Most common track shape(s)	One specific thing you notice
A. Earth surface
B. Airplane
C. Satellite

Drag to order the three locations from fewest to most visible tracks, based on what you actually see. Tap the arrow on mobile to move an item up.

↕ 1 A. Earth surface
↕ 2 B. Airplane
↕ 3 C. Satellite

1 = fewest tracks, 3 = most tracks.

How do the track shapes or lengths change between the three images?

Explain

What does it mean?

Did the images match your prediction? Explain why the number of tracks changes with altitude, and what role the atmosphere plays. Then say whether your original prediction was supported, and if not, what you would change about your reasoning.

Why does a fair comparison between the three images require the same detector area, the same measurement time, and the same display settings?

Your predictions

Compare these with what you actually saw in the images.