(This part is repeated from the previous post): NASA and the Smithsonian Institute maintain a database called the Astrophysics Data System. Harvard University is kind enough to host it here. Available to you and I is an abstracting service which will return brief descriptions of articles found by keyword searches. You see where I'm going here?
For a description of coverage and limitations of the database, click here. Then, let's have some fun.
A search for the word Mars in titles and abstracts performed on April 21 2007 returned 20,978 results.
(This is where the new stuff starts): Here we report on 5-year periods going back to 1900. We show annual percentage growth on the previous 5-year total. It isn't pretty--much more like real life than any smooth logarithmic curve. In 22 five-year periods, we show an annual percentage growth above 14% (shown in bold) in only 3 five-year periods(you need a 14.87% annual growth to double every five years). In 7 of the five-year periods, there is a decline in publications (inefficient post, wars, depressions, Mars being further away... lots of logical reasons why this might have occurred).
The serious question is, if our studies of Mars, which have benefited from major government funding from several large governments, and have also benefited from being topical, exciting, and having large sources of data available recently, do not show exponential growth, where would we expect to actually find a doubling of human knowledge every five years? If not here, where?
What I think it shows me is that when there is a lot of funding, real news, a research goal, and the availability of new and important data, we focus on the subject, do the research and improve knowledge. But for extended periods, things just sort of tick along, improving respectably in many years, but showing declines in others. What do you make of the following?
Click if you want to see the numbers.
Period Ending 5 yr Total Annual Pct Growth (on preceding 5-year total)
2006 5569 10.6
2001 3365 9.66
1996 2122 <2.89>
1991 2457 9.34
1986 1572 <4.15>
1981 1943 8.77
1976 1276 21.25
1971 487 9.31
1966 312 17.72
1961 138 2.83
1956 120 11.07
1951 71 2.42
1946 63 2.38
1941 56 8.06
1935 38 <12.48>
1930 74 <6.76>
1925 105 14.65
1920 53 <11.39>
1915 97 <8.59>
1910 152 9.63
1905 96 0
1900 96 <7.66>
One thing I think we can all agree on--it would have been really cool to be researching Mars between 1961 and 1981.
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