‘You Can See November from the Washington Monument’
An update to this morning's estimate of the crowd at Glenn Beck's DC rally.
August 29, 2010 - 2:30 pm
As always, we’re getting some new information and finding some errors, so after this morning’s first go-around, let’s take a second pass at estimating the number of people at yesterday’s rally by Glenn Beck at the Lincoln Memorial.
First of all, as commenter “Raymond Shaw” points out, the actual “dense crowd” number used by the National Park Service is five square feet per person, not ten. I missed a step by not explaining that I started using ten square feet in my original estimates last year to account for the difference in density between the really crowded areas near the front and the less dense areas near the back.
|Estimate||10 square feet per person||5 square feet per person||2.5 square feet per person|
|CBS News Estimate||87,000||87,000||87,000|
If we use those Park Service figures, obviously the estimates double or quadruple, as shown in the amended table above.
I continue to think those numbers are too dense. Five square feet per person means a space 24 inches deep by 30 inches wide; 2.5 square feet per person is one 12 inches by 30 inches.
Just to try to make sense of these intuitively, let’s consider standard towel sizes:
|Bath sheet||35 in x 60 in||15 square feet|
|Beach towel||30 x 60||12.5 square feet|
|“Dense” crowd||24 x 30||5 square feet|
|Hand towel||16 x 30||3.3 square feet|
|“Packed” crowd||12 x 30||2.5 square feet|
|Wash towel||13 x 13||1.7 square feet|
So the numbers quoted for the Park Service estimates come down to each person standing on a space a little more than a hand towel for the less dense number, and a bit more than a wash towel for the more dense.
Frankly, if I’m that close to another person for any length of time, I want dinner and a movie.
The pictures we have are apparently from fairly early in the rally, and as I say, I took the conservative approach by only counting what I could see. We can speculate some, though, by guessing that some further number of people arrived and occupied areas outside my perimeter (more about that below) and use that to make some more estimates. So let’s extend that, speculatively:
|Speculative Estimate||10 square feet per person||5 square feet per person||2.5 square feet per person|
|100 percent (was “maximum”)||215,000 people||430,000||860,000|
|CBS News Estimate||87,000||87,000||87,000|
The one thing we can say for certain here is that the CBS News estimate looks more and more foolish.
The second point, which several commenters raised, was that there were a lot of people under the trees. I included the actual Google Earth kml files for the polygon I used in my original piece, but there were technical issues with making them available through the PJM site. So here’s a screen shot of the polygon (click to get full size):
As you can see, I did include a lot of the area under the trees, particularly on the north side of the reflecting pool. It’s certainly possible I didn’t include all the possible area, but again I was trying to make sure any errors were on the low side.
Reader David Thomasson passed along an interesting comparison, as well. David is a professional retoucher who used his Photoshop skills to make this comparison:
Here is a visual aid that might give some idea of the crowd size.
At the WW2 Memorial, the distance between the two pillars is, by chance, 120 yards — the length of a football field including the end zones (you can verify that on Google Earth, which has an extremely accurate ruler):This photo of the Orange Bowl was taken from about the same perspective as the shot of the mall during the Beck rally. I resized it so the field matches the distance between the pillars. The Orange Bowl in this configuration had a capacity of about 76,000. Its maximum capacity reached 80,000 at some point, though I don’t think it was in the configuration shown here:
Now, these pictures could be a little misleading, since there is pretty substantial foreshortening as we head toward the Lincoln Memorial, but taken with the appropriate amount of salt I think it’s a good comparison: CBS News would make this crowd “only” the size of an Orange Bowl crowd, and that doesn’t seem to match at all well.
In any case, I think commenter “FredB” wrote the perfect conclusion:
“You can see November from the Washington Monument.”