"Think you've got some contaminants in your hydrogen line, do you, superior sir?"

They sent messages by modulating a hydrogen line in the spectrum of the nearest star.

It is only when the two temperatures differ, or decoupled, that the hydrogen line can be observed.

Blessed be blue for its hydrogen line.

What if they had bombs all set to take out the hydrogen lines?

But I swear they looked like they were going to blow up the hydrogen lines.

Another possibility, he said, was loose fittings where the hydrogen line connects with the orbiter.

A spectrometer may also be employed at 1420 MHz for study of the 21-cm hydrogen line.

In the early years, it took days to chill, and remove the impurities from, the hydrogen lines.

Many species have used the cold hydrogen line to search for other minds circling other stars.