I
used to know an elderly man who had taught Latin in a prestigious fee-paying
school in the east of England. ‘Many of my pupils,’ he recalled, ‘would wonder,
quite reasonably, why they should compulsorily read a language which no one
speaks.’ He smiled to himself. ‘My reply was always the same: when you leave my
tutelage, I doubt that any of you will retain anything but a tenuous grasp of
Latin. However, your English should be exemplary.’
He
must have had the ‘dead language’ argument bowled at him from every conceivable
angle for forty years; and yet, that same straight bat of his always dealt comfortably
with it. Even so, I am certain that almost all students have come up against a
subject which they were not only thrilled to see the back of, but also
confident that they would never need to revisit in later life. I was one. I
studied ‘Further Physics’ – even the name is scary – just prior to my first
spell at university. One of its constituent topics – Bernoulli’s principle (Figure 99.1) –
practically drove me nuts, not least because it seemed to fly in the face of
common sense. Luckily, my Physics teacher, who was much smarter than he looked,
forced the penny to drop just in time for the exam.
Figure
99.1: Bernoulli’s magnum opus (pardon my use of Latin), published in 1738, was
the first ‘bible’ of fluid mechanics. Readers fluent in Latin will be able to translate its front cover without too much difficulty.
Copyright
expired
That
was thirty years ago. Since then, I have morphed into a multidisciplinary life scientist, and Bernoulli’s principle had, thankfully, never raised its contrary head – until
this year. While sponsor confidentiality forbids me to elaborate on current
research, I think I am at liberty to state that it involves something called
hydraulic conductance, which appertains to the behaviour of pressurized fluids
permeating biological tissues.
Like
nearly all laboratory kit these days, the analytical equipment I am using is
entirely computer-controlled. An ingenious microfluidics system controls fluid
pressure through a digital sensor and records subsequent tiny changes in flow
rate. I have spent most of this year conducting a comprehensive validation
program, proving that this rather expensive toy does what it says on the tin.
If I increase the system pressure, the fluid flows faster in direct proportion.
Last
week, the plot thickened. If I exchanged the sensor for one with different
optimal settings, the flow data came out different. According to the computer,
the fluid movement had slowed. How come? Surely, given that only the sensor had been changed, it should have yielded the same results as before.
Then
came an ominous ‘Eureka’ moment: Bernoulli had returned to haunt me. He had
also solved the puzzle. Daniel Bernoulli (1700-82) (Figure 99.2) was a Swiss mathematician
who studied fluidic movement under controlled pressure. His world-renowned
principle states that if there is a pressure reduction in a system of steady
fluid movement, its flow rate will increase, and vice versa (Figure 99.3). I discovered that
the tubing passing through the second sensor had a larger cross-sectional area
than that of the first. A-ha! This had increased the internal pressure and thus reduced
the speed of flow (Figure 99.4).
Figure
99.2: The godfather of hydrodynamics
Copyright
expired
Figure
99.3: This simple schematic demonstrates the relationship between system
pressure and fluid flow.
Copyright
unknown
Figure
99.4: A theoretical chart showing my recent findings. I had initially expected
the two curves to be more or less superimposed on one another. Bernoulli put
me right.
Copyright
© 2016 Paul Spradbery
As
we still say in Latin: Quod Erat Demonstrandum.
Copyright
© 2016 Paul Spradbery
