Natural radiation

Natural background radiation is an ever-present, low-level radiation in our environment. This experiment uses a nuclear radiation detector located near the web server to detect it. When radiation passes through the gas-filled tube inside, it disturbs the gas atoms and produces a brief electrical pulse, counted as one detection. The detector cannot identify where the radiation came from or what caused it. But one thing is certain: all detected radiation originates in quantum events.

What you are seeing

The boxes summarize recent counts. The charts show live detections, detection history, and how complete one-minute counts compare with the distribution expected from random detections.

Live detections

Detection history

Counts this minute
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Counts this hour
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Counts today
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Average counts/day
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Average counts/week
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Average counts/month
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Counts per minute distribution

Each bar shows the percentage of complete one-minute intervals containing that number of detections. The line shows the Poisson distribution expected from the observed mean.

Collecting complete one-minute measurements…

What is quantum here?

Natural background radiation stems mainly from quantum mechanics operating inside unstable atoms. These radioisotopes are naturally present in soil, stone, building materials and the air. Their centers (the nuclei) are unstable because of the number and arrangement of protons and neutrons in their center. To balance this, they release particles or excess energy. This radioactive decay, which happens at random moments, makes the atom more stable. There are three main types:

  • Alpha decay: an alpha particle (helium nucleus: two protons + two neutrons) released by a heavy nucleus, like uranium in soil.
  • Beta decay: a beta particle (electron or positron) emitted when a neutron inside an atom transforms into a proton or vice versa.
  • Gamma decay: a high-energy photon called a gamma ray emitted by a nucleus, often after alpha or beta decay.

When the average decay rate is approximately steady, the unpredictable individual detections produce a characteristic Poisson distribution of counts across equal one-minute intervals.

A small fraction of natural background radiation stems from cosmic rays: high-energy particles, primarily protons and atomic nuclei, that travel through space at nearly the speed of light. They originate from violent cosmic events like exploding stars in our galaxy, as well as from our Sun. When they strike Earth’s atmosphere, they collide with atoms and produce showers of secondary particles that reach the surface. These high-energy collisions are quantum events.

Almost as an added bonus, the interaction of radiation with the gas in the detector also involves quantum events. When radiation strikes a gas atom, it ejects one of its electrons. This ionization is a quantum event. The freed electron is accelerated by the electric field and triggers an avalanche of further ionizations, producing the electrical pulse counted as a detection.

About the detector

Location
Not available
Source status
Disabled
Detector model
Not available
Firmware
Not available
Detector type
Not available
Safe range
Not available