Scroll Length?

[Mortal Man]

I think your averaging of multiple control points is a superior method to the single control point I believe Chris and Andrew used.

Firstly, you ought to look at the paper again before claiming we used a "single control point" method.

Secondly, if you read the old threads, you will discover that what William is currently doing, Chris and I did years ago multiple times. We have both performed the "multiple control points" method ad nauseam. I've done it myself at least a dozen times. We are thoroughly familiar with its pitfalls. We are well aware, for example, that the scaling in all of the extant images (and I have seen quite a few) of pJS 1.2 is significantly off. We are well aware of how subjective the method is and how easy it is to bias your results. We are well aware of the scatter in the estimates arising from the control points. We determined that a more accurate and objective method was needed, so we brought a standard tool for pattern recognition to bear on the problem.

I also think it is important to note that the papyrus was damaged, after which there was continued degradation on the damaged edges which could theoretically cause more errors in establishing control point.

Yes, that is another problem with the control points method. The correlation method gives you a best overall fit, which is much less sensitive to secondary damage. It also eliminates the possibility for mischief, where certain points may be picked over others.

Edited November 15, 2011 by Mortal Man

[wenglund]

We are dealing with 4.4 mm differences in the winding lengths.

Let me ask one more time, using your formula, and keeping the outer circumference constant (10.48cm), for each 1mm difference in winding lengths, what is the change in overall scroll length? Just curious.

Thanks, -Wade Englund-

[Vance]

The most difficult part of winding a scroll is getting it started. Sometimes you have to fold it to get it going. Since the inner windings have the smallest radius of curvature, they are the hardest to wind tightly . . .

Ok, so far so good.

This resistance to bending (elastic deformation) would also prevent (or fight against) any space between the innermost windings. The only way to have space in the inner windings is to bend permanently (plastic deformation) the material. To do that you have to wind the scroll much much tighter, or fold it, to cause the plastic deformation and then release the scroll (unwind) so that the plastically deformed material is no longer under the stress of bending.

(and, according to Hoffmann, there is always a bit of space in the core).

Which is contrary to the mechanics of materials as described above.

It gets easier to wind tightly once the radius is bigger.

Not exactly. The previous windings (unless plastically deformed) continue to resist winding. The sum of the forces of each winding comes into play.

So, even though the force for the current winding may be lower than any previous winding, the total force necessary to wind increases with each winding.

Furthermore, the Hor scroll was bound on the outside.

Ok.

It is simply not reasonable to assume that the missing windings were significantly tighter than the outer windings.

Ok, but again, unless there is plastic deformation it is not reasonable to assume that there is space between the inner windings.

The inner windings have a smaller bending radius and therefore will have a higher resistance to this bending. The inner winding (unless plastically deformed) will want to "snuggle" up to the adjacent winding.

Sorry but your description just is NOT reasonable. And nearly everyone can see it.

Take a sheet of paper and roll it up. Restrain it on the outer diameter with a piece of tape or rubber band. Then tell me how much space is between the inner two windings.

[Mortal Man]

Evidently, the Greenfield Papyrus is now separated into 96 sheets (see video HERE), of varied length (between 47 and 80 cm) and widths (around 30 to 54 cm), depending upon the frame they have been put in. A picture of the 1st sheet and dimensions, including the frame, can be viewed HERE.

Evidently, the sheets were originally glued or sewn together, and through the use of a wooden rod ("omphalos in Greek and umbilicus in Latin--see HERE), they were rolled up into a scroll.

Nice finds Wade, thanks for posting this.

I examined the reported dimensions of one of the sheets, and the thickness was given of 1.5 cm. (see HERE)

That is effective thickness. That is virtually always what Egyptologists mean by "thickness"; i.e., they derive "thickness" from the winding lengths as a matter of course. The physical thickness is obviously much much lower.

Speaking of putting thing into perspective, if anyone is interest in seeing a real size image of the scroll before it was unrolled, see HERE. It is quite a bit larger than the burrito-sized image MM posted earlier.

I don't think I've ever seen an "exact size" image that was really exact size.

[Uncertain]

Oh, just the fact that the pictures show, quite clearly, that there is no discernible space between the windings except for the space occupied by the papyrus itself. Other than that, I can't imagine why someone would reach that conclusion.

Perhaps you have access to higher quality photos I have not seen. I am going off of the photos posted in this thread and there is clearly some windings which seem to have a great deal of space between them. I am now starting to wonder if we are talking about the same thing to me it is clearly obvious some windings are separated by a great deal of space. Many of them are not but some of them clearly are. At least when viewed edge on.I drew some arrows to what to me appears to be some obvious gaps between windings certainly gaps lots larger than 500 microns. Also this picture shows the gaps I pointed out at both ends of the scroll so clearly the gaps extend most of the way through the scroll.

Sorry for the quality of the picture. I took this an earlier post and don't have the time or motivation to pretty it up or get another picture. Also it seems a sufficiently good enough quality for my purposes. There really does appear to be some obvious gaps between some of the windings. This can be seen even in a picture as crappy as this one.

Please do show us where the photo of the Greenfield Papyrus shows a winding with a large space between them. I sure don't see it. Nor do I see such a thing in the other photos I posted. Quite to the contrary, the photos show that the scrolls are rolled rather tightly and uniformly from the center! That's why I suggested you guys are in an alternate universe. Cook/Smith are making an argument for a scroll winding that bears no resemblance to any of these photos of rolled scrolls. Nor does it conform to the Toronto scroll that John Gee observed.

See Andrew's fruit roll-up scroll for an example of what they predict: something that has no analogue in reality.

At any rate, I have to do real work today, so I'll have to bow out of the conversation for the remainder of the day. I'll try to catch up tomorrow, since it's my wife's birthday, and we'll be going out tonight.

As I mentioned Andrews fruit roll up picture does not match his prediction. He predicts an average white space of 500 microns between windings this is less space than this dot ".". His picture has far more white space than that.

Best,

Uncertain

Edited November 15, 2011 by Uncertain

[Mortal Man]

Someone in the British Museum must be using a variant of the Cook formula in order to calculate papyrus thickness.

Bingo.

Or more precisely, Cook/Smith must be using a variant of the formula in the British Museum.

[Uncertain]

That is effective thickness. That is virtually always what Egyptologists mean by "thickness"; i.e., they derive "thickness" from the winding lengths as a matter of course. The physical thickness is obviously much much lower.

So what say you Wade? If MM is indeed correct the effective thickness is many multiple times thicker than the actual papyrus certainly much more than two or three times so should we be suspicious of the British museum?

Perhaps send them emails criticizing their methodology? I kid I kid .

Best,

Uncertain

Edited November 15, 2011 by Uncertain

[Mortal Man]

Bill, it appears that, in response to this question, Andrew has taken pretty much the only course of action available to him: fall silent. In fact, even all his cheerleaders have fallen silent. (Fifth Columnist, where are you? You're welcome to answer Bill's question, too.)

I just now read this post.

If alleged shrinkage of the papyri supposedly affects the overall average thickness of the papyri (presumably casting some kind of doubt on our measurements), why does that same shrinkage effect not similarly affect your measurements of the winding lengths?

Look at the mummies the scrolls come with. Their skin is a lot thinner (sometimes worn down to the bone) but they're not significantly shorter; i.e., they still fill the coffin. It's all about surface area.

You see, folks: Andrew is attempting to make some kind of analogy concerning grapes and raisins, but the fact is that we're all measuring raisins here, and no one is trying to predict how big the grape was in 200 B.C. We're all making measurements of the papyrus's dimensions NOW in order to estimate what it's total length would be NOW. No one is making measurements of the dimensions of the papyrus in 2011 in order estimate what it's length was in 200 B.C.

We're trying to estimate what its length was in 1835.

In short, this entire discussion of papyrus shrinkage and damage, etc., is a diversionary sideshow. It has no meaning whatsoever.

I completely agree.

[Mortal Man]

Again, this entire line of argumentation advanced by Cook et al. is a diversionary sideshow that has no meaning at all.

I'm not the one who keeps bringing up the thickness measurements.

I completely agree that they're a diversionary sideshow.

[Mortal Man]

Once again illustrating the fact that you are not even remotely familiar with the subject matter. There is no such thing as a "standard and widely accepted Egyptological method.". No one has ever attempted to predict the missing length of a scroll on the basis of its surviving fragments until John Gee and now I have attempted it. There is no record of anyone attempting it. Friedrich Hoffmann proposed a method for doing it, but no one (until John Gee a few years ago) ever attempted it based on Hoffmann's proposed methodology. Again, there is no such thing as a "standard and widely accepted Egyptological method." We're breaking new ground here.

Another gem for my collection.

Having some delusions of grandeur Will?

And you are exposing yourself once again as an ignorant cheer leader.

FC has demonstrated a better understanding of our paper than anyone else to date.

[Mortal Man]

I doubt he needed me to devise anything for him. It just so happens that I devised it before I found him. Once I proposed the strategy to him, he agreed that it would work perfectly.

It was actually quite amazing how the whole thing worked out. One might even say there was a bit of inspiration at work, were one inclined to believe in such things.

Inspiration: the act of breathing or inhaling.

You weren't snorting the papyrus, were you?

[Mortal Man]

we're all dealing with a raisin. The grape is irrelevant. No one is trying to measure a raisin in order to determine the original size of a grape.

At least Chris and I aren't.

[Nemesis]

So let me get this straight, you don't buy into the fruit roll up either?

Your not helping the discussions. As for the rest of you less digs at each other would be nice. They are not necessary and detract from what otherwise could be an interesting thread.

Nemesis

[wenglund]

Yes indeed it would if the sheets where laid flat one on top of another. I certainly would not expect 400 microns of space. If on the other hand the sheets were rolled up and I had seen examples of sheets with an obvious average distance between windings of greater than 400 microns. Than no it would not raise red flags to say the average space between windings is 400 microns

To test your claim, try this experiment: take 5 sheets of printer paper and as a stack roll them lengthwise into a spiral with a diameter of 3.3cm. Then, take a stack of 7 other sheets and see if you can easily fit the corner of the second stack between each of the windings of the first stack. If you can't, then perhaps you can begin to understand the problem that we are having with Cook/Smith calculations.

Thanks, -Wade Englund-

[Mortal Man]

I agree.

However, I made some rough measurements using the full size image of the rolled up scroll and plugged them into the standardized formula used to determine spiral lengths. And, as much as I hate to admit it, the calculations are somewhat favorable to Andrew/Cook:

Diameter of scroll: 20cm

Diameter of innermost winding: 2cm

Number of windings: 100

Distance between windings: 898 m

Length of scroll: 3749cm (123 ft.)

However, we are talking here about a much thicker scroll from a different era, with more than six times the diameter of the JS papyrus, and more than 3 times the diameter of the innermost winding, with about the same number of windings according to what I calculate, though more than 5 times the windings according to Andre/Cook figures, which obviously allows considerably greater room for loose winding. So, it may be like comparing a burrito grande tortilla to a half dollar sized crepe.

Nice work Wade (although I'm not sure the "Distance between windings" is really 898 m ).

It's nice to see others taking the initiative to do these investigations themselves.

[wenglund]

That is effective thickness.

I don't think so. As previously indicated, the scroll has long since been unrolled and separated into individual sheets (I believe there are 96 sheets). The thickness dimension that I quoted was only for that one sheet. I couldn't find a thickness measurement for any of the other sheets I looked at. I suspect that the thickness given was for that one sheet, likely including the frame.

And, I now agree with you and Will about the uncertainty of the image actually being the exact size. It is too bad, though, that we can't now get the desired dimensions.

In regards to what I mentioned earlier about papyrus possibly consisting of individual sheets that were glued or sewn together to form a long scroll, I meant to ask you and Will or anyone else who may know, whether the JS papyri were constructed in that way?

I ask because if they were, and if the sheets were "glued" together, then I am wondering if perhaps some of the cracks and folds you and Chris and others have worked from, may be areas where the individual sheets were attached rather than winding markers. (the individual sheets may be a different length than the windings)

Thanks, -Wade Englund-

Edited November 15, 2011 by wenglund

[Mortal Man]

The scroll John Gee saw unwound in Toronto was only a little over 6 meters long, and yet it had over 100 windings.

So now it's over 100 windings? How many exactly?

[wenglund]

Perhaps you have access to higher quality photos I have not seen. I am going off of the photos posted in this thread and there is clearly some windings which seem to have a great deal of space between them.

That is part of the problem of working with or from photos. Some of the areas you suppose are gaps appear to me to be shadows caused by slightly folded-over or recessed raged edges of some of the windings. Who knows?

However, have you given my experiment a try?

Thanks, -Wade Englund-

[wenglund]

So what say you Wade? If MM is indeed correct the effective thickness is many multiple times thicker than the actual papyrus certainly much more than two or three times so should we be suspicious of the British museum? Perhaps send them emails criticizing their methodology? I kid I kid . Best, Uncertain

See my response to MM above. If any critical emails need to be sent, it would be to MM for understandably jumping to a false conclusion. Rib, rib.

Thanks, -Wade Englund-

[Mortal Man]

Wouldn't you agree that at least at some point the disparity between effective and physical thickness may become problematic?

Absolutely not. There is nothing from either a mathematical or physical standpoint that says the physical thickness of the decayed scroll must be related to the rate of decrease in winding lengths. The Greenfield Papyrus has an effective thickness of 15 mm but a physical thickness probably less than 1 mm.

[wenglund]

Absolutely not. There is nothing from either a mathematical or physical standpoint that says the physical thickness of the decayed scroll must be related to the rate of decrease in winding lengths. The Greenfield Papyrus has an effective thickness of 15 mm but a physical thickness probably less than 1 mm.

After reading your excellent explanation earlier about decay occurring more at surface areas, I may now agree with you, though I am not sure how exactly it factors into the respective equations or relates to my response to Uncertain.

Thanks, -Wade Englund-

Edited November 15, 2011 by wenglund

[Mortal Man]

Absolute assertion, and disproven by the photos of the rolled-up scrolls I have posted several times:

Where the center void has been crushed. And I've stated several times that it's not a big effect.

[Mortal Man]

Papyrus. Very fine, thin papyrus.

Then ~10.4 centimeters is almost certainly the half winding length.

Do you have any pictures of it?

[wenglund]

So now it's over 100 windings? How many exactly?

I am estimating 106.

Thanks, -Wade Englund-

[Mortal Man]

Let me ask one more time, using your formula, and keeping the outer circumference constant (10.48cm), for each 1mm difference in winding lengths, what is the change in overall scroll length? Just curious.

Changing Will's third winding from 10.13 cm to 10.03 cm would change his length from 314 cm to 244 cm.