Bitter lemons

Wanda Díaz-Merced was born in Gurabo, a small town of low-rise homes beside the Loíza River in Puerto Rico. As a girl, she watched the stars and dreamed of becoming a doctor, but diabetes took her sight before she’d finished college.

How can you stargaze — appreciate and interpret the kaleidoscopes we get from the Hubble and James Webb telescopes, like the Lemon Slice, a citrine nebula 4,500 light years away — if you can’t see anything? But there’s a dirty secret; those telescope pictures are colorized, touched up, shifted along the light spectrum, to make invisible waves visible. So, Wanda Díaz-Merced made invisible waves audible.

In ‘Peter and the Wolf’, Sergei Prokofiev’s “symphonic tale for children”, the composer assigned each character an instrument and a signature — a theme tune — so we could tell who’s who: the grandfather is a bassoon, the wolf French horns, and the hunters a shocking barrage of bass and kettle drums. The action is vivid.

Heavenly bodies have frequency signatures which, when shunted along into the sound spectrum, give them timbres or “tone colors” — theme tunes — based on their age and density and interactions, which Díaz-Merced as musical director has assigned. Young stars rumble (lots of vibration), and a simple star sounds like the long blast of a big rig horn. Here’s the skittering Delta Scudi Star.

Díaz-Merced’s “sonification” does more than make astronomy inclusive; she has discovered a new signature — an interaction between a red giant and a white dwarf — that sighted scientists missed. She is pushing her profession on.

Yes, we sometimes get the bitterest lemons. Perhaps you missed out this week on a promotion that you were supremely qualified for, but it doesn’t have to reduce you, however sour and lingering the taste. Wanda Díaz-Merced, the aspiring doctor and stargazer, grew up to be a fêted astronomer, advocate, and star listener.

You can watch Professor Díaz-Merced's TED talk here.

Join her and learn how to listen to the cosmos by volunteering here.