Alex McColgan

speaker

27,837 appearances 101 recordings 1 series first heard Nov 2024 last heard 5d ago

Alex McColgan’s voice in public audio — every appearance, attributed to the second.

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recordings per month · last 12 months

Recordings per month over the last 12 months — 65 in all, peaking in Aug 2026 with 11.

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Astrum Space · We Thought It Was Impossible, But We’ve Finally Seen It · 31 Aug 2026 podcast

But again, it wasn't a direct detection. voice-verified

We still couldn't say we've actually seen them. voice-verified

Inching ever closer to a discovery, it was just two years later that astronomers moved beyond indirect detection and statistical evidence into the realm of the visible. voice-verified

A team led by Sebastiano Cantalupo from the University of California observed an enormous filament of hydrogen gas. voice-verified

At nearly two million light years across, they spotted it after it was illuminated by a giant cosmic flashlight, a bright quasar shining at it from ten billion light years away. voice-verified

This was the first time part of the cosmic web had been seen directly. voice-verified

Using the same illumination principle, in 2019, astronomers revealed whole networks of hydrogen filaments surrounding a massive protocluster, directly imaging the web on megaparsec scales. voice-verified

But these detections were only possible thanks to our cosmic flashlights. voice-verified

To understand cosmic filaments as they typically exist in darkness, we needed a new imaging technique. voice-verified

And in 2023, scientists made a breakthrough. voice-verified

At the WM Keck Observatory in Hawaii, a team of astronomers had designed a dedicated instrument to search for filaments of hydrogen, more specifically, dim Lyman alpha emission, the spectral fingerprint of hydrogen as it absorbs and re emits radiation. voice-verified

And it works. voice-verified

In fact, they've made entire 3D maps of these filaments. voice-verified

This was just the start of the discoveries. voice-verified

In January 2025, the picture sharpened dramatically. voice-verified

A team of international astronomers captured one of the clearest direct images yet. voice-verified

Using the multi unit spectroscopic explorer, or Muse, mounted on the very large telescope at the European Southern Observatory. voice-verified

They imaged a pair of quasar host galaxies with a cosmic filament about three million light years long. voice-verified

And using supercomputer models built on the Muse data, researchers were able to simulate a filament that matches the one they observed in real life. voice-verified

This was a spectacular achievement. voice-verified

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