Dinosaur tracks?

The link is to the article linked earlier, "21st Century Science Smashes Molecular Clocks". Buried near the end is this passage:

This crash course in 21st century science may be a bit confusing, but the reason for that is not just the complex mathematics involved, but the basic fact that confusion exists over what happened in the past. To add to the confusion, in 2008 fossil collectors discovered a human footprint alongside that of a dinosaur providing evidence for the coexistence of humans and dinosaurs.

Right. And cave men drove cars chiseled out of rock.

So what is this footprint? Well, the link takes users to a YouTube video, describing CT scans made of the so-called "Alvis Delk" footprints. Here's a picture from Little Green Footballs:

(Lest I be accused of throwing in a ringer, there are other photos of the same footprint at the Creation Evidence Museum website.)

The video states that the CT scan of these footprints prove that the mud underneath the prints was compressed, which would not have been the case if the human print had been carved into the rock.

Some initial thoughts:

It would have been nice if, rather than asserting that the changes in density seen in the scans would have been different if the print had been faked, the presenter had shown scans of known fakes for comparison.

A medical CT scanner may not be the best instrument for looking at rock. A medical CT scanner is intended to shoot x-rays through human bodies. The software is written with the amount of attenuation seen in a human body in mind. Unlike a piece of x-ray film, the image in a CT scan is calculated. It takes a bunch of projected images and mathematically "stacks" them to create a two-dimensional slice. But the validity of the reconstructed image depends on the x-ray intensities falling inside the scanner's working range. Objects that are strong absorbers of x-rays will overwhelm the ability of the scanner to correct for them. A well-known phenomenon is a "star artifact", appearing when we try to make a CT image of a patient with a piece of metal embedded in him. Basically, each of the projections shows this very dark spot where all the x-rays are absorbed, and the maximum density allowed in the computer model is not enough to account for the observed attenuation. The software tries to compensate, but it can't, hence the artifact.

For all I know, any sedimentary rock will show similar artifacts on the inside edges of concave surfaces, just as an artifact of the process used to construct the image.
I'd love to see what an industrial scanner – one with harder x-rays, and programmed to expect substances that attenuate x-rays more strongly than human bodies do.

A quick Google search found the blog "Stones and Bones", and this comment:

Baugh told the Mineral Wells Index that, “The compression lines, the density features, do show, and there is no way to fake that,” he said. “It is possible to carve a track in limestone. But there is no way to compress the material in the rock under the track. That is absolutely impossible. That’s why the CAT scans are so important.”

First of all, a medical CAT scan uses a lower energy beam than could be useful on a sandy limestone. That is why real paleontologists use industrial facilities. The University of Houston (added 8/15/08, this was inccorect- I was thinking of The University of Texas, Austin) has a laboratory that has many years of experience with just this type of analysis. This points to the next problem; a medical facility is not staffed by paleontologists or geophysicists. Baugh has no accredited degrees either. He wouldn't know "compression lines" from his own butt crack. However, you don't even need more than the photograph from the Mineral Wells Index, which was much higher resolution than from Baugh's website, to see that this is object is a fake.

I downloaded the photo at full resolution. If you closely examine the photo, you will easily see that there are sandy lenses in the rock; four are visible in the exposed rock between the "toes" of the dinosaur print. Now look at the "human print," particularly the area of the little toe. You will see (with a little magnification) that the top most layer is penetrated by the "toe" and not compressed, and the second layer is partially exposed. The same lens is exposed across the base of the four distal toes. This could not have happend unless the "toes" had been carved out of the rock.

Returning to the "dinosuar" print, there is no compression folding of the sandy layers between the toes which is interesting. First, there must have been if this were a legitimate track. However, there appears to me to be evidence of removal of material from between the central and the medial "toe" as well as along the top edge of the "track."

There also appears to be a patina coating the bottom of the basin. This has two interesting features. First, it is pealing and cracking. This is not appropriate to a real patina. Second, the patina appears in parts of the basin and not others, nor does it appear consistantly in the "human toe prints."
....
Here is how to fake a patina that will look like this fake fossil: Brush the surface with vinegar, and then sprinkle with baking powder followed by baking soda, and let dry. Repeat until you are happy with the results. This is not the only way, or even the best way. But it is simple, and will fool the average fool. Especially easy if they want to be fooled.

So, having spent a little bit more time on the photo of this fake, I feel that I understand a bit more about how it was produced. A legitimate dinosaur track was found and removed. Incompetent, unprofessional "Cleaning" damaged it. An parital overprint, or simple erosion depression was "improved" by adding "toes." The faked surfaces were smothed over with a simple kitchen concoction to make a "patina." Artifact fabricators next bury the fake for a year or two, or they smear it with fertilizer and leave it exposed. This helps weather the object and obscure tool marks.

Added later:

The bubble pops.

If you used the cheap kitchen patina method I mentioned above, there is the chance that the acid will create a gas bubble in a depression. This lifts the fake patina and is visable as little bumps, or they form pits.

I just enlarged the photo again, focused on the center toe of the "dinosaur." There are two obvious pits of broken bubbles created by a recently applied acid wash seen on the distal portion of the "track." Looking further, there is one more near the distal end of the medial toe.

It occurs to me to wonder about something. What happens to the x-ray density of limestone if you subject it to that patina process? Vinegar is a weak acid, and could easily dissolve small amounts of the limestone. The baking powder and baking soda could seep in to the matrix. This might wind up creating a layer of compressed limestone – the very layer of compressed stone that's taken as "proof" of authenticity.

In a comment, he adds:

In addition to the excellent critique of this canard, there is an even simpler mistake made by the counterfeiter. The center "toe" of the dinosaur footprint was an indentation in a raised soil matrix which surrounds the distal end of the digit and which extends into the central area of the "human" indentation (which by the way is a remaracably flat foot). In order to step onto an existing indentation in soft sediment and raise a mound of soil in front of the digits to the same height as the native soil on the far side (outside) of the original indentation, the foot of the dinosaur would have needed to slide forward, pushing, or bulldozing soil ahead of it. There is no evidence of movement within the dinosaur footprint, but subsequent erosion could have removed shallow grooves. However, based on the heel of the dinosaur footprint it is evident that this animal was not moving forward at a rapid rate and that the foot did not skid in the sediment. The foot was placed pretty much directly downward and lifted in much the same manner. The flat base of the dino footprint is further evidence that the animal was not moving rapidly (there are typically deeper heel and toe indentations when an animal is "running" which is also the condition in which the heel indentation has an initial strike surface which is not vertical beutwhich records the angle of contact with the ground as the animal moved forward. Under that scenario, the toe imprints are also deeper as the animal spings off its toes to maintain forward momentum.

Hmmm. A comment by "Anonymous" (Turns out to be Gary S. Hurd):

I did a bit more reading on X-ray CT of geological specimens at the University of Texas, Austin site. The so-called compression density changes are an error caused by incorrectly calibrating the difference between air, and rock. This caused the image software to outline the open "track." This is particularly a problem with beam energies that are too low for the sample material. Medical CTs use a beam of less than 140 kev, geological material should be examined well above this, even as high as ~400 kev.

The phoney "compression density" is really the density difference between air and rock.

Thought so. And, from deadman932:

I'm sure the radiologists did their professional best in looking at the rock itself, but it's a lot more difficult than it appears, if my reading my reading on the topic is any indicator.

There's very little data on using CAT scans to determine density variations in homogenous consolidated rock. Normally, what people look at is porosity variations, cracks or "inclusions" -- maybe fossils that vary in density from the "host" rock.

At 120-Kv levels, there's real problems in attenuation / beam hardening as well as other artifact-inducing factors. People have to know what they're doing with various materials, and calibrations have to be right. I personally don't think most radiologists would know the data on this, since they don't handle fossils all that much and don't neccessarily know the geological factors that can affect x-ray analysis, and the data is RARE.

One of my comments on the article:

Unrated I'm curious. Stipulating that this one particular footprint can be shown to be a human footprint (as distinct from a dinosaur footprint that got pushed out of shape, or "enhanced" by subsequent carving), and stipulating that humans and dinosaurs did coexist, it seems to me there's a lot of other evidence completely lacking. This evidence would include dinosaur fossils that show signs of having been butchered, including collections of dinosaur bones with tool marks in garbage heaps near human settlements. One would also expect to find dinosaurs with human bones (and frankly, any number of modern mammalian bones) in their stomas, and human and modern mammalian bones in dinosaur coprolites.

Paleontologists have traced the migrations of humans into the Americas by noting when various large prehistoric mammals went extinct. If humans and dinosaurs co-existed, they seem to have had almost no impact on each other. Facts -- such as the putative fact of human/dinosaur coexistence -- produce clouds of evidence, whose individual bits would support each other in telling a common story. So far, the putative fact of coexistence has, at most, one isolated fact. At most.