There is, however, a particular hypothesis regarding the physical evidence that cries out
for critical skepticism: the idea that no 767s hit the World Trade Center.
This argument has a singularly obvious hurdle to cross:
We have many pieces of hard evidence-video recordings and photographs-that clearly show
a 767 crashing into the south tower of the WTC on September 11th.
We also have a video recording of the first impact on the North tower,
but plane in the image is not identifiable as a 767 because of it's small size in the frame.
In contrast, there is no hard evidence, such as a video, photo or small plane debris,
that establishes the presence of a small plane or any other object besides a 767 hitting the WTC.
The proponents of the no-767 get around this by claiming that the planes in the videos
we have were superimposed in real-time by the television networks
using advanced graphics technology, and they proceed to identify
a number of anomalies in the videos and in the physics of the impacts
which they claim indicate that the 767 was not actually there.
Their case is supplemented by analysis of witness testimony
and some other circumstantial evidence.
Holmgren and Webfairy base their analysis on the fact that a 767 is not visible
in the 1st strike mpeg, and therefore was not there in real life.
Of course it's not visible-the reduction in resolution removed
half the visual data, and compression artifacts distort the shape of the plane.
Holmgren and Webfairy show a profound lack of knowledge of digital imagery
by failing to consider that this movie was a highly compromised version
of the original footage.
And in so doing, they also show a lack of respect for their colleagues
in the 9/11 Truth Movement by engaging in tenuous, risky speculation
in areas where they lack the necessary expertise and discipline.