Chemical Poems: Rubidium

Soft, silvery-white metal. Density: 1.53 g/cm³. Its melting point is 37 °C, rendering it a liquid on very hot days. It was discovered in 1861 by the Germans Robert Bunsen and Gustav Kirchhoff and named after the Latin word ruber for “red”, owing to the intense color of one of its spectrum lines. It exists in large quantities in old, massive stars, before they enter into their final phase, where they turn into white dwarfs [1]. Vapor turbines in power plants improve their efficiency (in the conversion of heat into electricity) if rubidium is used as a working fluid in them.

The intake of rubidium salts is used to adjust the circadian rhythm, the internal, almost daily, “clock” of an organism [2]. In general, irregular physiological rhythms, the so-called chronopathological disorders, can be stabilized or adapted to environmental rhythms using rubidium.

Atomic clocks, based on oscillations of rubidium are used in GPS  systems, for example, in the Galileo spacecraft. These systems determine distances by measuring the travel time of radio waves. Their accuracy is to about one meter [3]. Another clock in connection with rubidium, in a much larger time scale, works in combination with strontium: the ratio of isotopes rubidium-87/strontium-87 increases after the solidification of a rock, so that the age of rocks from earth or from outer space can be determined in this way [4].

Rubidium chloride is used as an antiepileptic and antidepressant [5]. It also helps to resist infections by increasing the pH-value in the cells.


[1] D. A. García-Hernández, Science 2006, 314, 1751–1754.

[2] H. Klemfuss, D. F. Kripke, Pharmacology, Biochemistry and Behaviour 1994, 47, 409–412.
[3] J. Camparo, Physics Today 2007, 60, 33–39.
[4] C. J. Allegre et al., Science 1975, 187, 436–438.
[5] J. Kroghmoe, J. Am. Chem. Soc. 1960, 82, 6196–6197.

The best you can do
if you loose your inner rhythm
is to eat
a clock.
One with Rubidium,
which also helps
against depression,
epilepsy
and microbes.

Engineers
have good reason
to put it in turbines.
And so do stars,
which fill up
with it
before they die.

Use it as a timer
for comets and moons.
And never forget:
If you loose the beat,
then swallow
a clock.