EL-Baz and his colleagues adapted a methodology originally developed to count dunes in a desert and trees in a forest in order to determine the number of participants at the October 16, 1995 Million Man March.
On October 18, ABC News in Washington scanned (at 300 dots per inch) a series of color prints (from 35 mm negatives) taken of the march by the National Park Service. The scanned images were uploaded through the internet to the Center for Remote Sensing.
The photos were taken from a helicopter with a hand-held camera and showed views of the crowd along the Mall. They were taken from several different heights and at various oblique angles. Scientists at the Center downloaded the images to their computers and began literally to count heads in places where the crowd was dispersed.
The process began with two graduate students breaking the photos down into small sections and enlarging those sections on their computer screens. By concentrating on open areas where individuals were clearly visible, they painstakingly "clicked" on the shadows corresponding to each marcher.
In areas where the crowd was tightly packed, Dr. El-Baz and his colleagues estimated the maximum density per unit area - that is, how many individuals could stand in a single square meter. He simply measured a square meter on the lab floor and saw how ma ny of his students would fit comfortably. He found that six was a high-density count and concluded that six people per square meter corresponded to the most densely packed areas of the march, such as the base of the Capitol and the area around the half-d ozen closed-circuit television screens on the Mall.
Now, "The Mall" is nearly 3 times larger than "The Ellipse," it is reasonable to see how impossible it is to consider a number of 500,000 of people who attended the Sheehan/anti-war rally at The Ellipse and then to the streets.
Dr El-Baz figured, as a maximum, 6 people per square meter. Since only half of the ellipse was taken up by the crowd which leaves 26 acres or 105 square meters. Multiply that by 6 and you get 631,308. That is if people are packed like sardines at a concert trying to get a closer look at their idols which was not the case here. Comfortably two persons could be able to occupy a square meter of space (roughly 3.3 feet by 3.3 feet square) whether carrying a sign or not as in the case in one anti-war protest that took place at The Mall in 2002. Since they walk to their destination and they tend to sit on the grassy lawn with anywhere from 1 to 2 persons per square meter, if it's a reasonably sized event. Since this is the case, the total number of people who attended the anti-war rally gets notched down to about 200,000. But the occupation of space is never uniform for every square meter since you have large banners being carried by 2 or more people, large signs being carried by one person, and mommies or daddies pushing their babies in strollers taking up more needed space and so on. People milling about occupies the full square meter of space. So, in effect the total number of people is realistically over 100,000 but under 150,000.The march route itself consist of approximately 3.5 miles of street pounding after arriving at the Ellipse for the anti-war rally. With an overly conservative estimate of what a typical width of a Washington D.C. street (including sidewalks) is approximately 100 feet wide. With 3.5 miles of linear space comes to about 4 acres or 16,700 square meters. And if it's in a "packed sardine" scenario with 6 persons per square meter, it comes to a street holding capacity of about 100,000. Bad news if there's a stampede. But being packed like sardines how would they move? 100,000 is an unrealistic number just for the march route alone which would be wall to wall people. The number would be more like anywhere from 10,000 to 20,000 thousand people that walked the street while others go and do their own rants and antices since they come in disorganized and untimed waves according to one liberal Mahablog:
I have no idea how many people were there, and I think it would be difficult to estimate because the demonstrators, being liberals, did not follow directions. The plan was to rally at the Ellipse next to the White House and then march from there. Only a small part of the crowd actually went to the Ellipse, however. Most seem to have just showed up and either stayed in groups scattered all over Capitol Hill, or else they just did impromptu unofficial marches as a warmup to the Big March.
Total crowd capacity including the Ellipse and the march route of 3.5 miles of street and sidewalks, you'd have it at about 800,000 to 900,000 in a complete packed sardine scenario. So, considering 500,000 it is a laughable figure.
Washington Post has it pegged at 200,000 for attendance. But the police has it at 150,000. But the rule of thumb goes here when it comes to crowds. At a protest rally = 2 persons per square meter. At a concert (or even on the Capitol steps with limited number of signs being carried) = 6 persons per square meter. In a phone booth? About 25. All in all, realistically I believe the number is more likely over 100,000 but under, perhaps, 150,000. But 200,000 may be just a tad bit too much.
So much for the Kos Kids for stretching the truth on numbers here.
UPDATE: Of course, gotta figure in the heavier/overweight people protesting out there when one person would take up more of its fair share of 1 meter square of space. In today's society there are more people who are overweight than not. Thanks for the reminder, Sherry.