Stopping Light in a Cloud of Sodium
Coming to Wonder Science on 21 November 2026.
Cambridge, Massachusetts, autumn 1998 into winter 1999. Danish physicist Lene Hau and her small crew are trying to build the coldest, densest cloud of sodium atoms on Earth and push a pulse of laser light through it slowly enough to outrun on foot. The story follows the machine itself across the Harvard campus: a crate spilled at Johnston Gate, a stainless chamber lowered by chain hoist into a basement, copper gaskets cut on a lathe, a burst cooling line on a rooftop, a tipped nitrogen dewar in a service corridor, a shattered lens on the optics table. The troubles compound until a rooftop leak finds its way down a steam tunnel to the one thing that must never meet water: a jar of metallic sodium. After a flash fire smothered in red bucket sand, the rebuilt apparatus finally works, and in a shielded basement bay a light pulse crawls across a screen at seventeen metres per second, then halts entirely and is released again. At dawn the crew chalks that speed onto the deck of a footbridge over the Charles and races it.
About this story
- Length
- 10 illustrated pages
Who appears
- Lene Hau — physicist leading the experiment
- Zach Dutton — graduate student, the tallest body in every room
- Cyrus Behroozi — postdoctoral researcher, keeper of the sodium
- Marta Kowalczyk — departmental machinist who fabricates the chamber parts
- Ruthie Vance — night cryogenics technician who hauls the liquid gases
What happens on 21 November 2026
This story is finished and scheduled. On 21 November 2026 it opens here in full — every page illustrated — as part of Wonder Science. Nothing on this page is a placeholder: the story exists, it has been reviewed, and this is its address.
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