Sunstruck pendulums
The reported effect of solar eclipses would also affect all gyro navigation systems in aircraft, ships and submarines. Surely, if it were genuine, it would have shown up in these cases over the years and have been recognised as a problem.
Sunstruck pendulums
Is there any chance that the effect could be caused by the moon gravitationally lensing the gravity field of the sun? Or that the effect is only apparent when the observer is almost exactly aligned with the centres of mass of those two bodies? A lensing phenomenon would rule out the anomaly being observed for lunar eclipses, at least for Earthbound observers.
Valerie Jamieson replies:
鈥� In theory, gravitational waves can be lensed by massive celestial objects. But the moon’s mass is far too small to do this. Gravitational waves are also incredibly weak and no one has detected them so far. They are certainly not strong enough to displace a pendulum.
Gelded giants
I wonder whether the excavators of the Moche giants of Peru (11 December, p 40) have considered whether the exceptional height of the skeletons could have been caused by the “warriors” having been castrated as young boys? When a young calf or a ram is castrated it grows taller and heavier than its normal counterparts. Castration in young animals leads to the epiphyses of the bones remaining unfused for an extended length of time, so the bones carry on growing into adulthood.
That this also occurs in humans is graphically shown by the stone bas-reliefs from the ancient Assyrian palaces from around 600 BC, on show at the British Museum in London. In these friezes, the kings and nobles have large beards and can be easily distinguished from their attendants, who have no beards and are known from the scripts to have been eunuchs. They have the same physical features of tall, heavy bodies and long limbs that are produced by the castration of animals. Maybe the Moche giants were also eunuchs.
Epitaph credit
In your interview with Benoit Mandelbrot you mentioned “Ludwig Boltzmann’s famous formula for entropy” (13 November, p 50). The formula S = k log 惟 carved on Boltzmann’s tombstone in the main cemetery of Vienna is due to Max Planck, one of Boltzmann’s most famous pupils.
Science through poetry
On the exclusive list of great paradigm shifters, Charles Darwin rightly ranks high (4 December, p 23). This achievement would have delighted Charles’s grandfather, Erasmus Darwin, who not only contributed to early evolutionary thinking (12 April 2003, p 48) but also fully understood the phenomenon of paradigm shift.
Simon Singh’s excellent idea of teaching scientific method partly through a study of paradigm shifts finds an early example in Erasmus Darwin’s poetic epic Cosmologia (27 July 2002, p 60). The three parts of this work are structured on a dramatisation of paradigm shift from, in part 1, the ancient Empedoclean model of the four elements, to Linnaean taxonomy versified in part 2, “The loves of the plants”. Part 3 concludes the sequence with an early evolutionary model: “First, forms minute, unseen by spheric glass,/ Move on the mud, or pierce the watery mass./ These, as successive generations bloom,/ New powers acquire, and larger limbs assume;/ Whence countless groups of vegetation spring,/ And breathing realms of fin, and feet, and wing.”
It would no doubt delight Erasmus Darwin even more, in company perhaps with Edward Wilson, to think that an understanding of scientific method might be partly arrived at through a study of poetry.
God of the gaffes
It has been hilarious to read the letters responding to Keith Ward’s aggravating article on religion (27 November 2004, p 19). They ranged from name-calling (“lunatic” and “lame-brained”) through philosophising, to Steve Graham’s rigorous scientific argument.
杏吧原创s are a touchy lot, and nothing gets them going as much as the allusions to a “supreme being”. However, it seems to me that they are merely replacing one god with another. Instead of the traditional “adore-me-or-be-damned” variety they have the “agree-with-me-or-be-condemned” version. The god of science wields Occam’s razor.
People with common sense seem to be caught between the devil and the deep sea. Neither a theologian nor a scientist seem to be able to provide answers to all the mysteries of the universe. Until such time as someone does, how about less bullishness and more humility? What we all need is an honest inquiry, not only into the “how?” but also into the “why?” of the universe, which may well be the only way to the god of truth.
Reading practice
With reference to Feedback’s unusual units of measurement (see Feedback this issue), the Canadian Broadcasting Corporation current affairs radio programme As It Happens sometimes has not-too-serious stories from the UK. At the end of each they locate the place with reference to Reading, Berkshire, in units appropriate to the story. For example, one about a maker of traditional sausages in Grantham might end “Grantham is about 1 陆 million sausage lengths north of Reading.” I have no idea why the custom started.
A pile of what?
I was disturbed to read that “of all the cells that make up the healthy human body more than 99 per cent are microorganisms” (20 November, p 34). I had always assumed my own cells made up more of me than that, but apparently I’m just a 6-foot tall, steaming mass of bacteria. I’m keeping this fact quiet, on first dates anyway.
Speaking collectively, all of us need to work together on digesting our new group image. Will you be having a follow-up article to help us cope?
Furry stories
Regarding fur-bearing reptiles and tortoises being insects (Feedback, 11 December), in 1900 a ring-tailed lemur (a primate) won the foreign breed class at the Crystal Palace cat show in London. The matter was widely discussed in the general press and in animal fancier publications at the time.
The owner defended his win because the sailors who often brought home lemurs termed them “Madagascar cats”. The judge, a Miss H. Cochran, defended the award by saying “A lemur is a lemur, and a Madagascar cat is a Madagascar cat.”
In the 1920s, it was reported that several of these animals were exported to the US. On their journey these assumed “cats” were fed on cooked meats 鈥� a quite unsuitable diet for a fruit-eating lemur.
Fond of primates
I was delighted to learn that the gift of a baby orang-utan was enough to instil in Tam Dalyell “an affinity with primates” (20 November, p 21). Presumably, until then, he had eschewed all human contact and was racked with self-loathing.
Bare facts
The piece titled “Farmer Buckley’s exploding trousers” (11 December, p 48) was a hoot.
I shudder to think, however, what is going to happen when the US Transportation Security Administration realises that articles of clothing are potentially explosive. All baggage will be prohibited on passenger aircraft; travellers will be required to fly in the nude. Paper gowns might be provided for a small fee.
In addition to food courts and gift shops, airports will be able to add clothing stores to their arrival areas, thereby opening up a whole new line of business.
Gluteus frigidus
Your item on gluteal frostbite (Feedback, November 13) took me back to when I was an RAF navigator in high-flying, light bombers in the 1950s. We sat strapped into our ejector seats over our parachutes, with our survival kit on top of those; the last layer of the kit was a bag of water.
So of course as soon as we got to altitude we were sitting on a block of ice for a number of hours. This did not result, as far as I know, in clinical frostbite, but numb bums were standard and haemorrhoids an occupational hazard.
Sudden death
We were saddened to read of 3500 unexplained deaths in the UK of people aged between 16 and 64 (4 December, p 42). CO-Gas Safety () is an independent charity that tries to prevent people from dying of carbon monoxide (CO) poisoning and helps victims and their families. We also lobby government and industry for changes that will prevent these totally avoidable deaths and injuries.
We maintain that at least some of the deaths described in the article are caused by carbon monoxide gas. Around 50 people in the UK are known to die every year from accidental CO poisoning at home or at work, and some 300 are injured, making it the country’s most common poison.
In France, all dead bodies are tested for CO, but not always in the UK. Have the doctors who declare a death to be unexplained tested every body for CO?
Sunstruck pendulums
There were a few problems with your article on the effects of solar eclipses on pendulums (27 November, p 28). The advance of the plane of a pendulum is not caused by the plane of the pendulum remaining fixed in space. It does not remain fixed, unless it is exactly at the North or South Pole.
That this is wrong is most easily seen by noting that the rotation period of a Foucault pendulum is 24 hours divided by the sine of its latitude. Accordingly, the period of rotation of a pendulum in London is about 30 hours, which is not the rotation period of the Earth.
The daily variability of the rotation rate of such pendulums is well known, and is almost always caused by angular inequalities in the support. The force that causes the rotation of the Foucault pendulum is not gravity, but the Coriolis force. This is a very small force: it is less than the force that causes the original swing of the pendulum by the ratio of the period of the swing to a day. Thus a change in gravity would not cause a change in the plane of rotation of the pendulum.
Certainly no change in gravity would affect torsion pendulums in any way. Gravity plays no role in the oscillation of torsion pendulums. So it is a stretch to assume that something is wrong with gravity because pendulums of various sorts are reputed to behave strangely during an eclipse.
Sunstruck pendulums
Govert Schilling implies that the Earth, the moon and the sun are in perfect alignment at the time and place of a total eclipse. This is not correct. It is the observer, the moon and the sun that are aligned at the time of an eclipse. Whatever the pendulum is detecting, it clearly has nothing to do with gravity pulling on the centre of the Earth.
There has always, since the formation of planet Earth, been a point on its surface where the sun is directly overhead. Likewise for the moon. If the experimenters really want to test their pendulums they need simply travel today to Namibia and wait for the noonday sun to pass vertically above them.
Sunstruck pendulums
Massive bodies bend light, and gravitational lensing is well recorded. So is gravity itself lensed? Would gravitational waves be amplified and focused?
We have named gravitational waves correctly