How long you’ll live

02/07/2010

Updating Magic Universe

No, they can’t predict how long you’ll live

Excitement today in the media about the discovery of human genetic peculiarities associated with living to an exceptional old age leaves me sniffy. At the close of the story in Magic Universe called “Immortality: should we be satisfied with 100 years?” I recall:

On the day of his assassination, at what was then the ripe old age of 55, Julius Caesar declared, according to Shakespeare:

Of all the wonders that I yet have heard, / It seems to me most strange that men should fear; / Seeing that death, a necessary end, / Will come when it will come.

The veteran soldier would be bemused by 21st-Century hypochondria. In defiance of common sense and medical economics, the generation with the best life expectancy in history is obsessed with longevity.

Although overpopulation is said to be a great global problem, health educators insist that it is one’s duty to abjure motorbikes and butter and to live as long as possible. Yes, even though longevity may bring physical or mental incompetence so severe that it will cost more to keep you zimmering than to feed an entire African orphanage. As for the fear of death, if Christopher Columbus had been as bridled by cautious officials as astronauts are, his flotilla would not have quit the mouth of Spain’s Rio Tinto.

In the absence of significant disease, ageing sets a natural limit to the human lifespan. According to [Leonard] Hayflick it is about 125 years. Very few people lived past 75 until the 20th Century. But by 2000, 75 per cent of the inhabitants of the most affluent countries were doing so. The greying of the populations took actuaries and the medical profession by surprise.

The increase in human longevity slowed down in the closing decades of the 20th Century. Life expectancy at birth in affluent countries may level out at 80-90 years by the mid-21st Century. As the ageing process makes everyone more vulnerable to disease and gross degeneration, further prolongation of life may require medications yet to be invented.

They are not necessarily a good idea. Foreseeable problems range from tyrants who refuse to die to simply losing the carefree pleasures of retirement if young earners should decline to carry the economic burden of the elderly. Hayflick asked, ‘Would the least imperfect scenario be a future society in which everyone lived to their 100th birthday in good physical and mental health, then to die on the stroke of midnight?’

As Magic Universe relates earlier, Hayflick is the US microbiologist who around 1960 falsified a 30-year-old assertion by a French Nobel prizewinner that ordinary animal cells grown in a lab culture would thrive indefinitely. The natural lifespan of cells in culture, through a few dozen divisions at most, came to be called the Hayflick limit. In 1971, Alexey Olovnikov in Moscow speculated that every time a cell divides the telomeres, the DNA tie-strings at the very ends of the chromosomes, get slightly shorter, and this conjecture was fully verified 20 years later by the Canadian-born biochemist Calvin Harley and his colleagues.

Meanwhile, Thomas Kirkwood at Newcastle pointed out that burdening an animal with the genetic resources that might delay ageing is pointless if it is going to die young, because of the hazards of life. There is a trade-off between youthful vigour and provision for later life. Kirkwood called his idea the disposable soma theory, and evidence in its favour accumulated in the decades that followed.

Any update belongs before the closing section that I’ve quoted, because that still represents Hayflick’s opinion and my own.

Today’s update

Long life runs in families, and the genetics began to emerge in 2010. After comparing DNA from more than a thousand centenarians with a similar sample from the general population, Thomas Perls and his and colleagues at Boston University reported that they had found “genetic signatures” of exceptional longevity. These took the form of clusters of misprints in the DNA called “single-nucleotide polymorphisms” or snips, and 90% of centenarians could be grouped into one or another of 19 different clusters. Besides predicting exceptional longevity with 77% accuracy, using 150 snips, the team found variations between the clusters in the onset of age-associated diseases.

About these results from Boston, Kirkwood at Newcastle commented:

They are not suggesting that they can screen the genes of you and me, for example, and tell us the chance we will live to 100. This would be a tall order indeed, given that only a quarter of what determines the length of human life is genetic. … From what we know already, it is rather unlikely that genetic screens will ever be able to forecast how long an individual will live.”

References for the Update

N. Calder, Magic Universe, pp. 423-428, Oxford UP 2003

Perls ref.: Paola Sebastiani et al., “Genetic Signatures of Exceptional Longevity in Humans”, Science Express, 1 July 2010.

Tom Kirkwood, The Independent (London), 2 July 2010

ADDITION 3 July. I really should take the opportunity to put in a brief but more significant update, about the role of telomerase. It also gives me a diagram for the blog, and it reassures me in my lifelong self-imposed task of reporting Nobel-prizewinning discoveries long before the prizes are handed out.


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Big Cheer for CryoSat-2

30/06/2010

Pick of the pics and Climate Change: News and Comments

Let’s Hear a Big Cheer for CryoSat-2

An early result from ESA’s CryoSat-2 mission detects a “scoop”, or drop, near the edge of Antarctica’s Ross Ice Shelf, probably due to melting at the base of the 400-metre thick slab of floating ice. There are also clear indications of the variable thickness of sea ice in the adjacent ocean. The vertical scale appears to be very different over the shelf and over the sea.

No branch of climate physics has been more befuddled by propaganda than the monitoring of the Earth’s cryosphere. Ordinary melting at glacier snouts that has happened every spring for thousands of years is nowadays captured by TV cameras and presented as evidence of runaway global warming. Dutiful journalists report reductions in Arctic sea ice but ignore increases in Antarctic sea ice. And scientists argue about how thick the sea ice is.

Thank goodness that the European Space Agency’s CryoSat-2 satellite is at last commissioning in orbit. Duncan Wingham of University College London, leader of the project, released the Ross Ice Shelf image yesterday at ESA’s Living Planet Symposium in Bergen.

The mission had a difficult history, with the original CryoSat being lost on launch in 2004, and CryoSat-2 going into an incorrect orbit in April of this year. But now we can expect much more accurate radar measurements of ice altitude over land and ice shelves, and of “freeboard” in the case of sea ice, which is a measure of its thickness. Perhaps we’ll soon begin to get the hard facts about “polar melting”. They’re long overdue.

For another take on “polar melting”, see my history of the Greenland ice sheet at https://calderup.wordpress.com/2010/05/06/warming-of-greenland/


Ceramic superconductors disappoint

28/06/2010

Predictions revisited

Why ceramic superconductors are disappointing

Helping to explain one of the biggest let-downs of 20th Century technology is a report from a US-European team centred at the University of Florida. It was released yesterday online by Nature Physics. Any scientifically minded person over 35 may remember the huge excitement about ceramic superconductors in 1987. For example, Time magazine called them “a discovery that could change the world” and continued:

That discovery, most scientists believe, could lead to incredible savings in energy; trains that speed across the countryside at hundreds of miles per hour on a cushion of magnetism; practical electric cars; powerful, yet smaller computers and particle accelerators; safer reactors operating on nuclear fusion rather than fission and a host of other rewards still undreamed of. There might even be benefits for the Strategic Defense Initiative, which could draw on efficient, superconductor power sources for its space-based weapons.

Most scientists believe.” Now where have we heard that before?

Writing in Scientific Europe (1990), Ian Corbett of the UK’s Rutherford Appleton Lab summarized the ceramics story, but much more cautiously.

Sensational events are rare in materials science, but superconducting ceramics attracted media attention of a kind normally reserved for football cup finals. In a heady year that followed their discovery in 1986, even respected newspapers implied that our lives were going to be revolutionized overnight, and that an instant fortune awaited anyone who was quick off the mark in exploiting the new superconductors commercially. Such exaggerated expectations were soon damped down by the reality of the technical problems still be overcome.

The scientific breakthrough was real enough. The phenomenon of superconductivity, in which a material loses all resistance to the flow of an electric current, was previously known only in certain metals and alloys, and at temperatures below -250 oC, close to absolute zero. A wholly new class of superconductors opens the way to higher operating temperatures and presumably to wider applications in the electrical and electronic ind ustries.

Georg Bednorz (left) and Alex Muller. Image AIP

In the autumn of 1987 one of the fastest Nobel Prizes ever was awarded to Georg Bednorz and Alex Muller of IBM’s Research Laboratories at Ruschlikon near Zurich – just a year after the first publication, in Zeitschrift für Physik, of their observation of apparent superconductivity in a ceramic material, lanthanum-barium-copper oxide, and at a somewhat higher temperature than any previously authenticated in other materials.

The promise of new applications remains, but unless another unexpected discovery changes the prospects, the road ahead appears at the time of writing to be long and stony.

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Wisdom of Kilgore Trout

25/06/2010

Predictions Revisited, Updating Magic Universe, and Climate Change: News & Comments

The Wisdom of Kilgore Trout

While checking a reference for yesterday’s posting I came across an epigram concerning human behaviour that I declared, back in 1983, should rank with Einstein’s E=mc2 in physics. I quoted it in 1984 and After, but it really ought to be written on every blackboard in the world.

Who said so? None other than Kilgore Trout, the imaginary science fiction writer invented by the real-life science fiction writer, Kurt Vonnegut. In Breakfast of Champions, Vonnegut re-caps a Trout story called Plague on Wheels.

A space traveller called Kago told the Earthlings about the self-reproducing automobiles on a dying planet named Lingo-Three.

Kago did not know that human beings could be as easily felled by a single idea as by cholera or the bubonic plague. There was no immunity to cuckoo ideas on Earth.” Within a century of Kago’s arrival the Earth was dying too, littered with the shells of automobiles.

Getting an interview with Vonnegut was never easy, but when I managed it my key question was whether Kilgore Trout’s epigram expressed his own opinion. He said, Yes it did.

Before this accidental prompt, I wasn’t going to bother to comment on a paper published this week in the Proceedings of the National Academy of Sciences, no less. Anderegg et al. claim that scientists convinced about man-made global warming are cleverer and better respected, as well as much more numerous, than scientists who are unconvinced.

Now I’ll say that it’s scary but not surprising that the National Academy of Sciences should permit a division of experts into an ingroup and an outgroup, and an evaluation of them by arbitrary tests that have nothing whatever to do with the inherent substance or merit of their research. Unsurprising because it accords with Kilgore Trout’s insight into human behaviour, which has been well verified in psychological experiments.

Alec Nisbett of BBC-TV filmed one experiment called Klee-Kandinsky, executed for real with unsuspecting schoolboys, for our documentary “The Human Conspiracy” (1975).  I also summarize the experiment in Magic Universe, in the story “Altruism and aggression: looking for the origins of those human alternatives”.

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