“Everyday Radioactivity”, Hosted by Don Herbert, part of the “Mr. Wizard” film series, 1973, Eastman color, 20 minutes.

Shows operation of vintage geiger counters. Scintillation counter coupled with multi-channel analyzer (Huge Tube

Unit, 1960’s?). Shows in-depth theory of gamma energy measurement. Explanation of background radiation.

Summary:

0:07-0:28: Discussion about how eating lunch provides energy and mentions an invisible energy detected by a probe, coming from a bowl with fruit.

0:51-1:10: The energy is identified as coming from the bowl, and it is noted that everyone is constantly exposed to unseen radiation as part of the natural environment.

1:30-2:05: Introduction to the three types of radiation (alpha, beta, gamma) and their sources, starting with alpha radiation from polonium-210.

2:12-2:33: Explanation of how alpha particles are detected and blocked by paper.

3:01-3:28: Introduction to beta radiation from strontium-90 and its detection, noting that beta particles penetrate paper but are blocked by wood.

4:01-4:27: Introduction to gamma radiation from cobalt-60, which penetrates paper and wood but is mostly absorbed by lead.

5:01-5:08: Summary of the three types of radiation and their properties.

5:45-6:08: Experiment to identify the type of radiation from the bowl, concluding it is mostly beta and gamma radiation.

7:03-7:08: Lead blocks almost all remaining radiation, indicating gamma rays.

7:20-7:46: Identification of potential radioactive materials in the bowl, including polonium-210, strontium-90, and cobalt-60.

8:02-8:10: Introduction to the scintillation counter for detecting gamma radiation.

9:02-9:19: Explanation of how the scintillation counter works, converting gamma radiation to light and then to electric current.

10:05-10:16: The scintillation counter stores and displays gamma energy patterns.

11:00-11:10: Measurement of gamma radiation from cobalt-60.

12:00-12:09: Measurement of gamma radiation from uranium, showing a different pattern from cobalt-60.

12:43-12:45: Measurement of gamma radiation from radium.

13:36-14:05: Comparison of gamma radiation patterns from the bowl to those of cobalt-60, uranium, and radium, identifying the bowl as containing uranium.

14:16-14:26: Explanation that the bowl’s orange glaze contains uranium ore, which is radioactive.

15:03-15:05: Mention of other radioactive objects like radium dial clocks and thorium-coated lantern mantles.

16:07-16:12: Discussion of cosmic radiation and its penetration through the atmosphere and buildings.

17:05-17:10: Mention of cosmic radiation exposure increasing with altitude.

18:01-18:14: Explanation of radiation exposure from food, water, and air.

19:02-19:27: Conclusion that everyone is constantly exposed to natural radiation from various sources.