RELATIVITY and quantum mechanics will be remembered as two great milestones
of twentieth century science. What keeps me awake at night, however, is
wondering what shrimps are doing when I’m not looking at them. This concern may
actually have more in common with relativity and quantum mechanics than one
The shrimps in question swarm around volcanic springs on the ocean floor,
feeding on bacteria nourished by minerals in the hot spring water. This food
supply supports an abundance of life far greater than that usually found in the
deep-sea. I have spent the past three years trying to fathom the lives of these
animals, but their remote habitat has not made this easy.
Although described as eyeless when they were discovered a decade ago, the
shrimps in fact have an unusual “eye” in the form of a heat-sensing organ on
their backs. Unfortunately, the bright lights of our deep-diving submersibles
almost certainly “dazzle” the shrimps during visits to the springs, and this may
modify the behaviour that we see. Hence the problem of what the shrimps are
doing when we’re not looking at them.
The idea that the act of observation unavoidably disturbs the object of
observation is familiar to quantum physicists. Under Heisenberg’s uncertainty
principle, we cannot precisely measure the position and momentum of subatomic
particles, because measurement itself involves bouncing other particles off
them. Quantum mechanics actually goes further to consider that the concepts of
position and momentum may not exist for subatomic particles unless observed. In
the case of the shrimps, I know they must be doing something when I’m not
looking at them, but I just can’t be certain what it is.
Diving to deep-sea hot springs in a submersible is one of the rare highlights
of my research. There are times, however, when I would almost swap that
experience for being able to visit my study site whenever I choose. Although
they share a similar rhythm of tides with rock pools on the seashore, deep-sea
hot springs sometimes seem as remote as our stellar neighbours. The information
that we receive from distant stars and galaxies is always out-of-date, as
nothing can travel faster than the speed of light. Similarly, obtaining
information from deep-sea hot springs is limited by their remoteness.
Astrophysicists avoid the problem by abandoning the concept of absolute time. At
the hot springs, we are not so lucky.
Volcanic eruptions and earthquakes can disrupt the plumbing of the springs,
cutting off the supply of mineral-rich water that supports the life around them.
As I write my thesis, the particular springs I am describing may no longer be
active. In such circumstances, the fate of the shrimps is uncertain. We know
that the shrimps store energy in a kind of “savings account” whilst they are
feeding at the springs. When a spring fails, the shrimp could use this energy to
try to swim to another spring that is still active. The nearest spring may be
over a hundred kilometres away, however, which would make this an epic feat.
Alternatively, the shrimps may stay where they are, living off their reserves in
the hope that the supply of spring water is restored. As smaller and lighter
young shrimp seem well adapted for long-range dispersal by ocean currents
between springs, another possibility is that the shrimps may spend their savings
in one last reproductive effort and go out with a bang, as it were.
Worrying about the fate of shrimps at deep-sea hot springs may been seen by
some as a suggestion that I should get out more. Certainly, questioning what the
shrimps are doing when we’re not looking at them is not a particularly
worthwhile pastime. To justify my existence, I could point out that anything we
find out about animals around deep-sea hot springs may be of value as they offer
a potential source of innovation for biotechnology. However, this would hide the
real reason for my interest in these animals. I want to find out more about the
lives of shrimps at hot springs simply because they are there, and because, like
quarks and quasars, they do not always give up their secrets easily.
Winner of the Wellcome Centre for Medical Science/New Scientist 1997
Millennial Essay Competition