Space & astronomy · the experiment
Listen to the storm of 1 June 2021
Nine radio bursts in 106.5 seconds, and nothing before or after in seven years of listening. Replay the storm CHIME caught, measure its pace and find the moment when the silence stops being chance.
1 · Replay the storm
Beginner
Within the 106.5-second window, how do the nine bursts arrive?
2 · Measure the silence
The nine bursts cut the 106.5-second window into successive waits.
Intermediate
What is the average burst rate within the window?
At this rate, a silence eventually becomes too long to be chance. Stretch the silence after the last burst and find the shortest duration at which the chance of seeing nothing drops below 5%.
3 · Move the source to the centre
The nine bursts all fell in a side lobe of CHIME, about four times less sensitive than the centre. The number of bursts brighter than a threshold scales as that threshold to the power −0.6.
Expert
How many bursts would CHIME have seen if the storm had fallen at the centre?
4 · Count what is missing
After the storm, CHIME kept listening to the source for about 188 more hours. Not one burst.
Expert
At the storm's pace, how many bursts would you have expected over those 188 hours?
Storm heard
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