Dark energy, the mysterious force driving the accelerating expansion of the universe, is one of the biggest open questions in physics. A Canadian radio telescope has just shown a new way to study it. The CHIME experiment can now detect the faint radio glow of hydrogen from the universe’s past entirely on its own, Space.com reported on 13 October.
What is CHIME?
CHIME, the Canadian Hydrogen Intensity Mapping Experiment, is a radio telescope built to map how hydrogen is spread through the cosmos. That map, in turn, carries information about how the universe has expanded over time.
What changed
Until now, CHIME could only map hydrogen by cross-checking its data against galaxy surveys from other telescopes. Those surveys cost millions of dollars and only cover regions dense enough to form stars. Now CHIME has shown it can detect the hydrogen signal by itself.
The first result
Using just 94 nights of observations from 2019, the team detected a hydrogen signal from when the universe was about 5 billion years old.
“Our data indicate that roughly 2% of the hydrogen in the universe was in neutral atomic form at this time, broadly consistent with other measurements,” said Shabbir Shaikh of Arizona State University.
What comes next
CHIME has now collected seven years of data. The team hopes to use it to trace hydrogen back to about 3 billion years after the Big Bang, building a faster and much cheaper picture of how dark energy has shaped the universe.
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Source: Space.com, 13 October 2026.
Featured image: Canadian Hydrogen Intensity Mapping Experiment – overall by Z22, CC BY-SA 4.0, via Wikimedia Commons.
