I would like to sound off on a pet peeve of mine. Completely unrelated to cold fusion, but it is technical.
The mass media and many books make some profoundly dumb mistakes about statistics as they relate to demography, longevity, actuarial tables and so on. Some examples -- People misunderstand the concept of average lifespan. You often read that back in colonial times, the average lifespan was 40 so most people were dead by age 50. That is absurd! Here is a typical example: " The life expectancy of a colonial was short. As many as 50% of all women died in childbirth or from childbed disease. . . . Individuals in their forties and fifties during the 17th century were considered 'old.' Statistics peering back to the 18th century indicate the average life expectancy was the age of 45!" http://freepages.genealogy.rootsweb.ancestry.com/~knappdb/colonial_american_marriage.htm No, people in their forties were not considered old. They were considered middle-aged, and lucky. Infant mortality skewed the overall lifespan to around 45 years in colonial American, but a person who survived to age 20 was likely to live to 60. People were not wizened or old looking at 45. Look at portraits and you see that. Of course there were many more diseases, and accidents were more common. Epidemics were somewhat less common in American than Europe. Also this estimate of female mortality from childbirth is too high. "Estimates of maternal mortality, from the 1st recorded unselected series, in the late 18th century range from 5 to 29/1000." http://www.ncbi.nlm.nih.gov/pubmed/3511335 With a rate 29/1000, a women having 10 children stood roughly 1 chance in 3 of dying. Women did have many children back then, but probably not 10. The average family size in 1675 for working people, richer to poorer (yeoman to labourers) was 5.8, 3.9 and 3.2 people. (Laslet, p. 64). The average house had 2 or 3 children. Given infant mortality, in a family of 6 I suppose the wife had ~6 children. Here are age distributions for England and Wales, 1696: Age group, percent 0 - 9 27.6% 10 - 19 20.2% 20 - 29 15.5% 30 - 39 11.7% 40 - 49 8.4% 50 - 59 5.8% 60 and above 10.7% Laslet, p. 103. Those numbers are reliable. They kept good records in the U.K. So, 11% lived to their 60s, and there were more elderly people over 60 than people in their 40s or 50s. The average age was 27.5. One-third to half of burials recorded in a French 17th century record were listed as "children," meaning they were probably under 20 -- too young to be listed by employment. If you reached age 20 and you were still healthy, and you had acquired immunity to measles and smallpox, you had a good chance of seeing age 60. You did not drop dead 7.5 years later. Another example. Some people claim that the modern diet is safe, and obesity is not a problem, because longevity is at record highs. This is a huge mistake. Diet is not the only contributing factor to longevity, but to the extent it does contribute, what you are seeing now is the effect of the U.S. diet in 1920. The people now dying in their 80s and 90s grew up in the 1920s, when the U.S. diet was completely different from what it was today. There was no fast food, obviously. Heck, I never ate a McDonald's hamburger until I was in my 20s, and I have not eaten one since. Fast food did not become widespread until the 1970s, which is also when obesity began to increase rapidly. I assume there is a causal connection. The invention of high fructose corn syrup in 1967, and what the NIH calls "portion distortion" are also probably contributing factors. You cannot draw conclusions about today's diet from today's longevity. To find out if our diet is healthy and promotes a longer life, you will have to wait 30 to 50 years. Chances are, it does not. Today's diets have caused unprecedented high levels of obesity. Obesity usually shortens people lives. See: "Nearly a quarter of teens diabetic or prediabetic, report says" http://www.washingtonpost.com/blogs/on-parenting/post/nearly-a-quarter-of-teens-diabetic-or-prediabetic-report-says/2012/05/21/gIQAh2MVeU_blog.html?hpid=z3 I can't imagine that a generation with such widespread diabetes will survive as long as the cohort now dying of old age. When the people who are now dying were growing up, Type 2 diabetes among people under 30 was practically unheard of. - Jed
