TIGHAR
Amelia Earhart Search Forum => General discussion => Topic started by: Monty Fowler on January 19, 2016, 01:06:08 PM
-
I have long thought that the Plexiglas fragments found during TIGHAR's 1996 expedition held a lot more promise than any aluminum scraps as far as proving or disproving the Nikumaroro Hypothesis. There isn't near the amount of Plexiglas in an aircraft, and the specs for specific aircraft models might be easier to track down. To my knowledge, nothing has been done to definitively exclude any other aircraft type as a possibility.
The artifact does match the specs for Lockheed Model 10 Part Number 40552 – Window Glass, Fuselage, Cabin: http://tighar.org/Publications/TTracks/12_2/obj11.html (http://tighar.org/Publications/TTracks/12_2/obj11.html). Does TIGHAR still have the paperwork specifically documenting replacement of the cabin windows in NR16020 in February 1937?
The artifact has a definite curvature and consistent thickness. With those things in mind, do those fragments match the Plexiglas from any other candidate aircraft? Would an intense period of focused research and archival work be able to exclude all other possible donor aircraft? I strongly believe so. A few observations:
- Yes, I know Plexiglas can float. Detractors will argue the fragments could have come from thousands of miles away. Our task is to use the information TIGHAR already has to definitively eliminate all other realistically possible donor aircraft.
- The realistic pool of potential donor aircraft is relatively small and has already been established by TIGHAR. Detractors will vigorously argue to the contrary, I am sure. Most of the donor aircraft are represented by a type example at the National Museum of the USAF? Will it be possible to build upon the cooperation that TIGHAR found during the evaluation of 2-2-V-1, the possible patch, at the NMUSAF?
- Although the Plexiglas was chemically analyzed at the time to establish that it was, in fact, Plexiglas, what other tests or new analytic methods could be applied to extract more information about its date of manufacture, country of origin, etc.?
It's never too late to ask new questions of old information. TIGHAR has only to look to the Bevington Object for proof of that. Nailing down the provenance of 2-3-V-2 will greatly strengthen the Niku Hypothesis if it is what we think it is.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
Good points, Chris, but to me, the first step needs to be to establish beyond a doubt that Amelia and Fred's Electra did receive the new 1/8-inch-thick windows. Without that, anything else along those lines is irrelevant because too much doubt can be cast on it.
So, questions for Ric:
1) Does TIGHAR have Lockheed paperwork that specifically ties the new replacement windows to their installation in NR16020? A repair order, invoice, letter, something that states that that-sized window was in fact installed on her Electra? I know what it says on the TIGHAR website, and I have no problem with that. I think it's important to establish just how certain we are so that any criticism can be instantly refuted.
2) Regarding the Winterthur Museum Analytical Laboratory, would it be possible to get a copy of the report, so we can see what was done at the time, to gauge what else could be done with additional testing, to extract as much information as possible from the artifacts?
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
Good points, Chris, but to me, the first step needs to be to establish beyond a doubt that Amelia and Fred's Electra did receive the new 1/8-inch-thick windows. Without that, anything else along those lines is irrelevant because too much doubt can be cast on it.
So, questions for Ric:
1) Does TIGHAR have Lockheed paperwork that specifically ties the new replacement windows to their installation in NR16020? A repair order, invoice, letter, something that states that that-sized window was in fact installed on her Electra? I know what it says on the TIGHAR website, and I have no problem with that. I think it's important to establish just how certain we are so that any criticism can be instantly refuted.
If we had something like that don't you think we would have included it in the research bulletin (http://tighar.org/Publications/TTracks/1996Vol_12/40552.pdf)?
There appears to be no surviving paperwork on most of the changes that were made to the airframe. All we can do is carefully date the photos that show the changes. 1055 was delivered in July 1936 with a bar bisecting the standard cabin windows. I've never seen a photo of any other Model 10 with a bar through the window. The bar was there at the time of the Bendix Race in September 1936. The bar goes away at the same time the window in the door and the large special lavatory window appear. The earliest photo we have that shows those changes is dated to February 8, 1937 - the day Earhart left Burbank with Putnam and McKneeley for Newark, NJ. She would announce the world flight at the Barclay Hotel in Norwich City New York City on February 12.
As shown in the research bulletin, the change in the specs for Part Number 40552 was effective 1-15-37 so it seems likely, but we can't prove, that all of the window changes were made at the same time in the last half of January 1937.
2) Regarding the Winterthur Museum Analytical Laboratory, would it be possible to get a copy of the report, so we can see what was done at the time, to gauge what else could be done with additional testing, to extract as much information as possible from the artifacts?
That work was done in 1996 - 20 years ago. I think it was the first analysis Winthertur did for us. Those were the days before everything was digital. There's no paper report in the file, so we either never had one or, more likely, it got misfiled somewhere along the line. I know we were curious to know whether it was possible to date the plexi based upon its composition. I recall that I made inquiries at Rohm & Haas and they said that the formula for polymethyl methacrylate hadn't changed.
-
There isn't near the amount of Plexiglas in an aircraft, and the specs for specific aircraft models might be easier to track down.
Be my guest.
Yes, I know Plexiglas can float.
Seriously? I can assure you that THIS Plexiglas sinks like a toolbox.
Detractors will argue the fragments could have come from thousands of miles away.
They must be confusing Plexiglas with very small rocks, apples, ducks and witches.
Our task is to use the information TIGHAR already has to definitively eliminate all other realistically possible donor aircraft.
We did the same thing with 2-2-V-1 and now everyone agrees that the artifact could only have come from NR16020 - right?
The realistic pool of potential donor aircraft is relatively small and has already been established by TIGHAR. Detractors will vigorously argue to the contrary, I am sure. Most of the donor aircraft are represented by a type example at the National Museum of the USAF? Will it be possible to build upon the cooperation that TIGHAR found during the evaluation of 2-2-V-1, the possible patch, at the NMUSAF?
For 2-2-V-1 we were examining rivet size, type, pitch, and pattern - all of which could be determined by observation. For the Plexiglas we would need to measure the thickness and precise curvature of every window and every view panel on every gun turret on every candidate aircraft. How do you propose we do that without cutting them apart?
Although the Plexiglas was chemically analyzed at the time to establish that it was, in fact, Plexiglas, what other tests or new analytic methods could be applied to extract more information about its date of manufacture, country of origin, etc.?
Great question.
It's never too late to ask new questions of old information. TIGHAR has only to look to the Bevington Object for proof of that. Nailing down the provenance of 2-3-V-2 will greatly strengthen the Niku Hypothesis if it is what we think it is.
I agree. I can't wait to see what you find out.
-
Thank you for the detailed response, Ric, I appreciate it.
One thing most of us long-term TIGHARs have learned is that the bar for claiming to definitively the solve disappearance of Earhart and Noonan is extraordinarily high as far as the general public goes. And, indeed, as far as the professional aviation history community goes. Preponderance of evidence isn't really going to cut it. Removing all possible doubts is the only thing, in my view, that will enable TIGHAR to make the final declaration and have it stick. We can't do that with anything that has been found to date.
So, since you stated, "There appears to be no surviving paperwork on most of the changes that were made to the airframe. All we can do is carefully date the photos that show the changes" and "As shown in the research bulletin, the change in the specs for Part Number 40552 was effective 1-15-37 so it seems likely, but we can't prove, that all of the window changes were made at the same time in the last half of January 1937," that injects a great deal of uncertainty into 2-3-V-2's provenance. TIGHAR cannot definitively prove, through paperwork or some other valid quantifiable method, that the windows in NR16020 were replaced by 1/8th-inch Plexiglas. You can't measure window thickness by using period photographs, as far as I am aware.
That, to me, removes 2-3-V-2 as having any possibility as a diagnostic artifact. I was prepared to spend my own time, money and effort on wringing the Plexigas dry to show it came from our favorite Electra. I can't justify doing all that if the artifact can be so quickly and easily dismissed, but I'm open to having my mind changed.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
In my view, 2-3-V-2 could never be definitively proven to have come from NR16020 no matter how much paperwork might be found. If we had a Lockheed work order that called for the windows on c/n 1055 to be replaced with 1/8 inch plexi it would bolster the probability that the artifact came from one of those windows - that's all - but that probability is already not too shabby.
Until Amelia meets us on the beach and shouts back over her shoulder, "Fred, put your shoes on! They're here." We're always going to be arguing about probability.
-
We're always going to be arguing about probability.
No argument here. But to solve the mystery in the public's mind, it's going to take more than probability. We have to recognize that.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
But to solve the mystery in the public's mind, it's going to take more than probability. We have to recognize that.
Let's think about that.
- What great historical mystery has been solved in the public's mind by the discovery of some single dramatic piece of evidence?
- What is the "public's mind"?
Sure, we'd all like to see an Any Idiot Artifact and we will continue to search for same within the limits of our capability, but the evidence TIGHAR has amassed in the course of 28 years (and counting) of research and field work has convinced thousands that the probability of Earhart having landed and died on Nikumaroro is far higher than any of the other explanations for her disappearance.
If you're looking for something that will silence TIGHAR's detractors I'm afraid you'll have a long wait. The rational public (a term which I hope is not oxymoronic) is convinced by overwhelming probability. Every discovery we make that raises the level of probability moves us closer to a general public consensus that our hypothesis is correct. It is, therefore, especially important that we do a good job making our research known. That's why I'm working on the Electra book.
-
But to solve the mystery in the public's mind, it's going to take more than probability. We have to recognize that.
Let's think about that.
- What great historical mystery has been solved in the public's mind by the discovery of some single dramatic piece of evidence?
- What is the "public's mind"?
Sure, we'd all like to see an Any Idiot Artifact and we will continue to search for same within the limits of our capability, but the evidence TIGHAR has amassed in the course of 28 years (and counting) of research and field work has convinced thousands that the probability of Earhart having landed and died on Nikumaroro is far higher than any of the other explanations for her disappearance.
If you're looking for something that will silence TIGHAR's detractors I'm afraid you'll have a long wait. The rational public (a term which I hope is not oxymoronic) is convinced by overwhelming probability. Every discovery we make that raises the level of probability moves us closer to a general public consensus that our hypothesis is correct. It is, therefore, especially important that we do a good job making our research known. That's why I'm working on the Electra book.
After thorough and patient reading of all materials available ( not only on TIGHAR site, but literally everything - including TIGHAR opponents ) I would say:
95% Nikumaroro theory
4% Crash&sank
1% Other
Best wishes to TIGHAR!
-
If you're looking for something that will silence TIGHAR's detractors I'm afraid you'll have a long wait. The rational public (a term which I hope is not oxymoronic) is convinced by overwhelming probability.
Then I guess we will have to differ on what we think the rational public at large will accept as incontrovertible proof. I believe the rational public, in this day and age, is convinced by the one big thing that cannot be explained away. TIGHAR has ample proof of what can happen when claims are made to the general public that a longstanding mystery has been solved, but the one big thing can still be explained away. I still have that Life magazine article.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
If you're looking for something that will silence TIGHAR's detractors I'm afraid you'll have a long wait. The rational public (a term which I hope is not oxymoronic) is convinced by overwhelming probability.
Then I guess we will have to differ on what we think the rational public at large will accept as incontrovertible proof.
I guess it depends on who we consider to be the rational public at large. I think what we're really talking about is a general consensus that the mystery has been solved. If we differ about something I think it's about what it takes to achieve a general consensus. Is there a difference between "overwhelming probability" and "incontrovertible proof"?
I believe the rational public, in this day and age, is convinced by the one big thing that cannot be explained away.
Can you cite an example?
TIGHAR has ample proof of what can happen when claims are made to the general public that a longstanding mystery has been solved, but the one big thing can still be explained away. I still have that Life magazine article.
So do I. Twenty-four years ago I claimed that 2-2-V-1 was from the Electra and that the Earhart mystery had been solved. Elgen Long said that 2-2-V-1 could not have come from the Electra. There was no public consensus that the mystery had been solved. Seven years later, Elgen Long wrote a book titled "Amelia Earhart - The Mystery Solved." I returned the favor and pointed out that he had stood the scientific method on its head and started with the received wisdom that Earhart had run out of fuel at 08:43 and then backed into the numbers that supported his theory. Once again, there was no public consensus that the mystery had been solved.
Seventeen years later, there is still no evidence to support Long's "Crashed & Sank" theory and there is abundant additional evidence that, although I had some of the details wrong, that 1992 LIFE magazine article was basically correct. There is still no general consensus that the mystery has been solved but we're definitely moving in that direction.
-
Hello, this would mostly be a late response to Monty's initial post.
Specifically the statement in the linked bulletin therein that curvature is probably original due to lack of enough environmental heat to change (I'm paraphrasing)...here's a WW2 document that suggests that deformation will in fact happen in sunlight. I wouldn't have thought Plexiglas would do that but here it is in black and white so I guess its true. I think I read here on the forum somewhere that plexi is the same since introduced so I assume there would be no difference in behavior between 1937 and 1943.
So seeking/finding curvature matches may not be particularly definitive either, even if it was practical to do so.
-
The artifact was found at the remains of a house site in the village. The whole area is shaded by coconut jungle but that's not to say that the plexi may have been at some time exposed to intense sunlight. It could be that the subtle and uniform compound curvature is warping due to heat and the match to the Lockheed engineering drawing is pure coincidence. Just depends on how many coincidences you're comfortable with.
-
Well, it would appear from the document that Dick posted that Plexiglas can deform when exposed to intense sunlight, like that found on a tropical Pacific island. One more thing TIGHAR has to counter with a more well documented argument that the curvature in 2-3-V-2 came from the factory as opposed to Mother Nature. I must ponder this.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
Well, it would appear from the document that Dick posted that Plexiglas can deform when exposed to intense sunlight, like that found on a tropical Pacific island. One more thing TIGHAR has to counter with a more well documented argument that the curvature in 2-3-V-2 came from the factory as opposed to Mother Nature. I must ponder this.
Let's think about how we could test the hypothesis that the curvature in the artifact was caused by exposure to intense sunlight. I don't think I've ever seen an example of Plexiglas warped by the sun but I've seen many examples of Plexiglas "crazing" due to exposure to the sun. It's not at all uncommon in aircraft that sit outside in the sun. The artifact shows no sign of crazing. It should be possible to determine whether Plexi can get hot enough from sunlight exposure to warp without crazing.
-
I have been looking for methods of accurate curvature determinations when dealing with fragments,... 7.4 of this article; https://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/jan2005/index.htm/standards/2005standards6.htm seems interesting ...I believe the determination of 2-3-V-2's curvature was ascertained by placing the fragmented pieces up against an extant Lockheed windowpane, and some may wonder the accuracy of the result, considering the flexibility of plexi, and the test sample used was in fragmented form.
Timeline;.....when did the two fragments found become separated? Do they share the same curvature? If so, that may indicate no additional curvature due to elements after separation, and may narrow the time-frame for warpage to occur. How was the plexi supported after removal from it housing , while on the ground or seas or ??,....If on corral or sand, would the curvature due to heat related bending remain as one would see in standard window design,( a consistent arc shape)... or rather would it take on a non uniform, a twisted bending, cupped shape,if you will, across the artifact, while laying on the scorching sand?
-
I believe the determination of 2-3-V-2's curvature was ascertained by placing the fragmented pieces up against an extant Lockheed windowpane, and some may wonder the accuracy of the result, considering the flexibility of plexi, and the test sample used was in fragmented form.
The curvature was tested by placing the artifact against the cross-section view in the Lockheed engineering drawing and by comparison to an intact Lockheed Model 10 cabin window from c/n 1052 loaned to us by the New England Air Museum.
Timeline;.....when did the two fragments found become separated?
We don't know. They were found together. They fit together, so the saller piece was cut from the larger piece.
Do they share the same curvature?
Yes.
If so, that may indicate no additional curvature due to elements after separation, and may narrow the time-frame for warpage to occur.
If the curvature is due to warpage, the warpage occurred before the small piece was cut from the larger piece.
How was the plexi supported after removal from it housing , while on the ground or seas or ??,....If on corral or sand, would the curvature due to heat related bending remain as one would see in standard window design,( a consistent arc shape)... or rather would it take on a non uniform, a twisted bending, cupped shape,if you will, across the artifact, while laying on the scorching sand?
I take that to be a rhetorical question.
-
I take that to be a rhetorical question.
Yes, a bit of food for thought. I believe due to the lack of that evidence, it is supportive of the plexiglass retaining it's original shape. Storage is one way however; that I can see that may allow a sheet good to take on the characteristics of having been originally arc shaped,... if it were stored on edge without adequate, tight supports on either side, for extended periods of time. However; laying on an uneven surface ,and exposed to heat, I don't see the sheet bending in a uniform arc shape manner, rather the surface plane warping unevenly instead.
-
Per Ric:
The artifact shows no sign of crazing
This October 1937 research paper says Plexiglas up to at least that point in time had a problem with crazing, even while in storage. This perhaps suggests a later date of manufacture for the artifact.
http://nvlpubs.nist.gov/nistpubs/jres/19/jresv19n4p367_A1b.pdf (http://nvlpubs.nist.gov/nistpubs/jres/19/jresv19n4p367_A1b.pdf)
Be forewarned its a 50 something mb file
-
Per Ric:
The artifact shows no sign of crazing
This October 1937 research paper says Plexiglas up to at least that point in time had a problem with crazing, even while in storage. This perhaps suggests a later date of manufacture for the artifact.
Or perhaps not. If you read the full report and look at the photos on page 379, Fig 5, sample 15 (acrylic resin) you'll see that the "crazing" referred to is a slight clouding, not the white, crackly obscuring I think of as "crazing." The artifact is not clear and transparent but exhibits considerably cloudiness to the point that it is more translucent than transparent. In short, the condition of the artifact seems to be entirely in keeping with what would be expected of vintage 1937 Plexiglas that has been exposed to some degree of sunlight for a protracted period.
-
I'm not sure that the photos in the report are of sufficient resolution on their own to say much really. I'm trying to find a 1937 dictionary to see exactly what the definition of the word "crazing" was in 1937...I think we could then, with a good degree of confidence, take that definition to be what the learned authors meant in the report.
Meanwhile,
Per Ric -
The curvature was tested by placing the artifact against the cross-section view in the Lockheed engineering drawing
Note that the Plexiglas remnant measures approximately 4 ¾” in its longest dimension (see first photo below)
The Lockheed drawing defines the cabin window curvature using a straight base line marked with one inch stations and offset measurements to the outside window surface at each station.
http://tighar.org/Publications/TTracks/12_1/PartNumber.html (http://tighar.org/Publications/TTracks/12_1/PartNumber.html)
The copy of the Lockheed drawing shown in the second photo below, was used to demonstrate a curvature match with the artifact, but appears to have been significantly enlarged beyond actual size, evidently by approximately 150%, when compared directly to the known dimension of the artifact (approx. 4.75”).
Since curves are defined by their radii and changing the scale/enlargement of a drawing of a curve also changes its radius, meaningful curvature matching can’t be done by overlaying an actual curved object on a drawing of that object unless the drawing is actual size so the curvature match between the fragment and drawing may need to be confirmed using a life size copy of the drawing.
-
I'm not sure that the photos in the report are of sufficient resolution on their own to say much really.
There was much more to our assessment of the artifact. The curvature of the Electra cabin windows is compound - that is, the plexiglas is not only curved but also slightly bowed. That's why, as noted that the TIGHAR Tracks article, "To see if it is the same curvature as a Lockheed Electra cabin window we asked our friends at the New England Air Museum in Windsor Locks, Connecticut to send us one from their under-restoration Electra c/n 1052 (Earhart’s was c/n 1055)."
We found that not only did the curve of the artifact match the curve of the window when held edge-to-edge, but when the artifact was laid on the surface of the window the slight "bow" was the same. I know I took photos at the time. I'll see if I can dig them out.
The main thing we needed from the engineering drawing was the specified thickness of the material.
-
Not to be a wet blanket, but we still can't prove 2-3-V-2 came from Amelia and Fred's plane because there is no surviving paperwork stating it was done. The probabilities are certainly tantalizing, though.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
Not to be a wet blanket, but we still can't prove 2-3-V-2 came from Amelia and Fred's plane because there is no surviving paperwork stating it was done.
As I pointed out before, even if we had paperwork stating that 1/8th inch widows were installed on c/n 1055 it wouldn't prove that the plexi found on the island came from one of those windows. The probability seems to be high, but we'll never get closer than that.
-
Dick or Ric,
Can you provide a link to the Tighar Tracks report that contains the photo with the file name 'curvature.jpg' in Dick's last post? That photo does not appear in the Tighar Tracks report Dick provided a link to.
Thanks...
-
I'm not sure that the photos in the report are of sufficient resolution on their own to say much really.
There was much more to our assessment of the artifact. The curvature of the Electra cabin windows is compound - that is, the plexiglas is not only curved but also slightly bowed. That's why, as noted that the TIGHAR Tracks article, "To see if it is the same curvature as a Lockheed Electra cabin window we asked our friends at the New England Air Museum in Windsor Locks, Connecticut to send us one from their under-restoration Electra c/n 1052 (Earhart’s was c/n 1055)."
We found that not only did the curve of the artifact match the curve of the window when held edge-to-edge, but when the artifact was laid on the surface of the window the slight "bow" was the same. I know I took photos at the time. I'll see if I can dig them out.
The main thing we needed from the engineering drawing was the specified thickness of the material.
Ric, if I understand you, there is measurable curvature to 2-3-v-2 on two perpendicular axes, so it’s not simply a fragment from the a bigger piece shaped like the side wall of right cylinder. If Electra windows were designed to be curved along two perpendicular axes, then shouldn’t the Lockheed engineering drawing show both of those curves? Does the Lockheed drawing in fact show both these curves?
What is the radius of curvature of 2-3-v-2, measured along the edge as shown in the curvature.jpg photo? It should be possible to measure this reasonably well without any fancy tools, shouldn't it?
-
Can you provide a link to the Tighar Tracks report that contains the photo with the file name 'curvature.jpg' in Dick's last post? That photo does not appear in the Tighar Tracks report Dick provided a link to.
I don't know where he got that photo but that must be my hand.
-
If Electra windows were designed to be curved along two perpendicular axes, then shouldn’t the Lockheed engineering drawing show both of those curves? Does the Lockheed drawing in fact show both these curves?
You're right. It should, but it doesn't. I must be remembering it wrong (it was 20 years ago). Apparently the curvature is not compound. I do clearly remember holding the artifact up to the edge of the borrowed window and laying the artifact on the surface of the window and getting a perfect match.
What is the radius of curvature of 2-3-v-2, measured along the edge as shown in the curvature.jpg photo? It should be possible to measure this reasonably well without any fancy tools, shouldn't it?
I dunno. How would you do that?
-
What is the radius of curvature of 2-3-v-2, measured along the edge as shown in the curvature.jpg photo? It should be possible to measure this reasonably well without any fancy tools, shouldn't it?
I dunno. How would you do that?
One way to do that is to use the old high school geometry method to draw a circle through any three points not in a straight line. Lay the piece on edge on a large piece of paper and mark three points along the edge - one at each end and one in the middle. Then connect the points with two straight lines. Then, using a drawing compass you can bisect each line and draw a perpendicular line at each of the midpoints. Extend the two perpendiculars until they meet and that is the center of the circle. The distance from there to any of the three marked points is the radius of curvature.
-
Frank asked for the source of the artifact-on-drawing photo...it is included in one of the chapters of this book:
https://books.google.ca/books?id=DDt3AgAAQBAJ&pg=PA12&lpg=PA12&dq=tighar+plexi&source=bl&ots=BxOxnMSDSQ&sig=fpsFjR67BxclDdZ3gmpzskYMUcA&hl=en&sa=X&ved=0ahUKEwjYhIHs443KAhWCWz4KHW6CCpYQ6AEIQzAH#v=onepage&q=tighar%20plexi&f=false (https://books.google.ca/books?id=DDt3AgAAQBAJ&pg=PA12&lpg=PA12&dq=tighar+plexi&source=bl&ots=BxOxnMSDSQ&sig=fpsFjR67BxclDdZ3gmpzskYMUcA&hl=en&sa=X&ved=0ahUKEwjYhIHs443KAhWCWz4KHW6CCpYQ6AEIQzAH#v=onepage&q=tighar%20plexi&f=false)
Ric mentioned the artifact nicely matching the curvature of the sample window when laid upon it and this might be a fairly close verification method I guess. Technically the outer curvature of the window and the inner curvature of the artifact (or vice versa) shouldn't match because their radii differ by 1/8" but I don't know if that difference in radius/curvature would be detectable by eye or feel in practical terms. The artifact-on-drawing method would seem to be more definitive, as long as the drawing is actual size.
-
Guys,
You will need to do two graphics - one inside and one out side - to get the true picture of the plate i.e. it also validates the thickness throughout.
Ted
-
From what I can see of the drawing the chord is 12.8 inches. The offset to the outside of the curve is 1.7 inches by scale, which by the middle ordinate method makes the radius 12.5 inches
Scale 3.25 inches up to 4.75 inches 1.46:1 and the chord becomes 18.7 inches and the offset 2.5 inches which makes the radius 18.1 inches.
Middle Ordinate method
Measure the chord of any curve in this case in inches it only matters the units are kept constant.
Measure the maximum offset to the top of the curve
0.5* the chord = b
offset = a
R=a+b^2/2*a
Bottom Line use a compass, string or piece of lath to inscribe a 12.5 inch circle and the curve should match the 1:1 drawing.
Use the same equipment to measure a 18.1 inch circle which should match a 1.46:1 blow up of the drawing.
My best guess is a .16 inch offset on a 4.75 inch chord which is difficult to match to an 18.1 inch radius circle.
Neff
-
If Electra windows were designed to be curved along two perpendicular axes, then shouldn’t the Lockheed engineering drawing show both of those curves? Does the Lockheed drawing in fact show both these curves?
You're right. It should, but it doesn't. I must be remembering it wrong (it was 20 years ago). Apparently the curvature is not compound. I do clearly remember holding the artifact up to the edge of the borrowed window and laying the artifact on the surface of the window and getting a perfect match.
What is the radius of curvature of 2-3-v-2, measured along the edge as shown in the curvature.jpg photo? It should be possible to measure this reasonably well without any fancy tools, shouldn't it?
I dunno. How would you do that?
Ric, I think what you need is a radius gauge (I tried inserting a url to a catalog listing for one, but the url contains a character the forum software doesn't like). Maybe you know somebody who can lend you one that will do the job?
-
The copy of the Lockheed drawing shown in the second photo below, was used to demonstrate a curvature match with the artifact, but appears to have been significantly enlarged beyond actual size, evidently by approximately 150%, when compared directly to the known dimension of the artifact (approx. 4.75”).
I don't understand how you decided that the drawing was significantly enlarged. As far as I know, it was a 1:1 copy of a portion of the original drawing.
-
This is getting a bit ridiculous. We did a good empirical study using the engineering drawing and an actual Lockheed 10 window and found them to be a match with the artifact. I see no reason to think that work was flawed.
We did not then claim, and we do not now claim, that it proves anything other than that the artifact and the Lockheed part appear to be made of the same material and have some of the same physical features. Maybe the plexi is from NR16020. Maybe it's not. But it doesn't make sense to spend further time and resources nitpicking it.
-
Ric,
I most respectively request you will reconsider. 2-3-V-2 is a unique Tighar artifact in that it has a single in or out criteria. Unlike the post lost signals were someone long ago decided which were credible or incredible. 2-2-V-1 which you have described among other things as an IQ test or Jeff Glickman's photo analysis which we have agreed sometimes requires considerable skill in the art to understand. The in or out criteria for 2-3-V-2 is radius. Dick Janson has favored us by expressing his concerns that the artifact is appearently being compared at 1.5:1 here. Surely it is worth a little time to rule in or out the one and only artifact we have, that I know of, that has a simple in or out cartiera.
Neff
-
But it doesn't make sense to spend further time and resources nitpicking it.
By the same extension, then, it doesn't make sense to continue discussing anything else TIGHAR has found on Niku, does it?
I originally expressed enthusiasm for going full court press on 2-3-V-2 because I believe that if it did come from Amelia's Electra, it could be a diagnostic artifact. The fact that there is apparently no surviving paperwork proving that 1/8-inch Plexiglas was installed in the Electra means, to me, that it's veracity can always be questioned. You can imply all you want, and TIGHAR has liberally and repeatedly done that with this artifact, but at the end of the day it appears there is no realistic way to use it the way that I had hoped to.
Which is unfortunate.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
Middle Ordinate method
Measure the chord of any curve in this case in inches it only matters the units are kept constant.
Measure the maximum offset to the top of the curve
0.5* the chord = b
offset = a
R=a+b^2/2*a
Not that it really matters at this point, but I did come up with a different formula for the above:
R = (a^2 + b^2)/2a
Derivation:
from the drawing, R = x+a and R^2 = x^2 + b^2
from the first equation, x = R-a and substituting this into the second equation,
R^2 = (R-a)^2 + b^2
R^2 = R^2 -2aR +a^2 + b^2
2aR = a^2 + b^2
R = (a^2 + b^2)/2a
-
Dick Janson has favored us by expressing his concerns that the artifact is appearently being compared at 1.5:1 here. Surely it is worth a little time to rule in or out the one and only artifact we have, that I know of, that has a simple in or out cartiera.
I did as you requested and spent more than a little time trying to figure out how to double-check the initial analysis of the artifact. We no longer have access to a Lockheed 10 window so I can't duplicate that comparison. I agree with the need to make sure that the comparison of the curvature of the artifact with the curvature on the Lockheed engineering drawing needs to be at a 1:1 scale. The problem is, the paper drawings, if they still exist, are not accessible. The best we can do is a photocopy made from microfilm of the drawings at the NASM Archive, but how do we make sure we're looking at a 1:1 print out? I reasoned that if I scaled the curvature cross-section on the drawing to a 1/8th inch thickness for the plexiglas, the drawing would, by definition, be at 1:1 scale. I did that and then compared the curvature of the artifact to the curvature on the drawing by overlaying the artifact on the scaled 1:1 drawing. The results are shown below.
-
There appears to be a dimension of 22-11/16" at the top. I cant read the others but am using just a I-phone. If a print of the film measures the same it is 1=1. Larger dimensions are better when checking scale. If it is not to scale, the image can be rescaled in Autocad and printed to any scale including 1:1. I can do this if there are readable numbers. There is always some distortion when checking other numbers after doing this, but not much. If the copy you start with has been thru a roller type printer , it will be distorted more between two 90 degree axis, but not much.
-
Using AutoCAD I scaled the image using the largest dimension I could read at (22 11/16"). After this, the dimensions on the right all dimensioned to 1" except the bottom one. Two different scaled drawings are attached.
-
it looks like a match to me Greg, 1:1
-
The 4.75 inch piece appears to span 3.25 inches on the drawing.
If I scale using the marked 1 inch increments as a reference:
The line width is .070
Depending on where on the line I choose to do my scaling
Centre to centre an eight inch = .161
inside to inside .060
outside to outside .22.
.125 somewhere between 1.76:1 and .48:1
May I suggest placing the 4.75 inch piece along the curve so that it spans 4.75 of the one inch lines?
Neff.
-
May I suggest placing the 4.75 inch piece along the curve so that it spans 4.75 of the one inch lines?
Neff, look at the artifact. The shape of the piece won't let me do that. I used the longest stretch available (that top edge).
-
May I suggest placing the 4.75 inch piece along the curve so that it spans 4.75 of the one inch lines?
Neff, look at the artifact. The shape of the piece won't let me do that. I used the longest stretch available (that top edge).
A possible experiment
Print the 1:1 drawing to “actual size”. Make sure the printer is not set to “fit” or something else by checking the dimensions after.
Spray mount the 1:1 drawing to cardboard or foam core.
With an exacto knife cut a slot along the curves that is longer than the full length of the artifact. The problem may be the drawn curve is not that smooth in places from what I could tell, so the slot could be cut a hair or up to 1/16" wider than 1/8” to not damage it and allow for the un smoothness of the drawn curve.
See if artifact passes thru the slot. Any gaps because the slot was wider can be observed to see any differences in curvature.
.
-
OK, the edge you are comparing is 6cm call it 2.375.
This means the difference in offset between 12 in radius and 18 in radius is now less than the line thickness.
So, Lay a nice straight edge say an engineer's scale across the ends of the 2.375 inner chord and then use a caliper probe to the centre, the point of maximum deflection called offset. If the offset is around .060 it's 12 inch radius and matches the radius of the Drawing.
If offset is more than .066 or less than .054 that's outside 10% and would appear to me to preclude it matching the drawing.
Luck
Neff
-
If the offset is around .060 it's 12 inch radius and matches the radius of the Drawing.
If offset is more than .066 or less than .054 that's outside 10% and would appear to me to preclude it matching the drawing.
Doing as you describe there's an element of "eyeballing" involved (my micrometer is too thick to fit inside a space that small) but the offset is between .056 and .058.
-
Dick Janson has favored us by expressing his concerns that the artifact is appearently being compared at 1.5:1 here. Surely it is worth a little time to rule in or out the one and only artifact we have, that I know of, that has a simple in or out cartiera.
I did as you requested and spent more than a little time trying to figure out how to double-check the initial analysis of the artifact. We no longer have access to a Lockheed 10 window so I can't duplicate that comparison. I agree with the need to make sure that the comparison of the curvature of the artifact with the curvature on the Lockheed engineering drawing needs to be at a 1:1 scale. The problem is, the paper drawings, if they still exist, are not accessible. The best we can do is a photocopy made from microfilm of the drawings at the NASM Archive, but how do we make sure we're looking at a 1:1 print out? I reasoned that if I scaled the curvature cross-section on the drawing to a 1/8th inch thickness for the plexiglas, the drawing would, by definition, be at 1:1 scale. I did that and then compared the curvature of the artifact to the curvature on the drawing by overlaying the artifact on the scaled 1:1 drawing. The results are shown below.
Ric,
Look again at your photo scaled+curve.jpg. Closer examination of it shows quite obviously, I think, that the scale of the copy of the Lockheed drawing you are using is not 1:1. The full-scale distance between each of the "station" lines showing distance between a chord line and the outer edge of the window glass (e.g., 1-7/16 in., 1-31/64 in., 1-17/32 in.) is 1 in. Measure any one of these 1-in. distances with your ruler and you get about 3/4 in. Or, take the the 1-7/16 in. measurement on the drawing (or any of the other chord line-to-outer window edge measuremennts) and measure it with your ruler. For the 1-7/16 in. measurement labeled on the drawing, it measures about 1-1/8 in. using your ruler.
The ratio between drawing's labelled measurement and measurement by your ruler is about the same in both examples I've given:
3/4 in. divided by 1 in. = 0.75
1-1/8 in. divided by 1-7/16 in. = 0.78
Clearly, the copy of the Lockheed drawing you are using to compare the artifact to is not 1:1 scale.
This doesn't necessarily mean the curvature of your plexiglas artifact does not match the curvature shown in the Lockheed drawing. Looking at the chord line-to-outer window edge measurements for the entire window as shown in your TIGHAR Tracks report on the plexiglas artifact, the measurements are slightly different for the bottom half and top half of the window glass. The top and bottom halves of the window glass may not have had the same curvature. The curvature of your piece of plexiglas might match the other half of the window glass.
Jeff P.
-
The full-scale distance between each of the "station" lines showing distance between a chord line and the outer edge of the window glass (e.g., 1-7/16 in., 1-31/64 in., 1-17/32 in.) is 1 in. Measure any one of these 1-in. distances with your ruler and you get about 3/4 in.
You're right, but if I scale the drawing to match the 1 inch station lines, the thickness of the plexi will be larger than the 1/8 inch specified. Are we to assume that the thickness of the plexi shown in the drawing is not drawn to scale?
-
Ric,
Thank you for your time and trouble. I am satisfied that the piece of plexiglass is approximately 12 inch radius which is the same radius and thickness of the Electra side windows in the drawing. I think probably worth filing the photo against the 1.5:1 drawing and the rebuttal that radius was confirmed by the middle ordinate method.
As far as the drawing, in that era the drawing was likely a pen and ink drawing on tracing paper or vellum so blueprints of the drawing for production work could be easily made. In the case of an engineering change the thickness of the window being hard to draw with .070 ink lines may have been left slightly oversize since what the document was depicting was inner radius.
I would always advise use of written dimension over drawn dimension especially in older documents.
Neff
-
Clearly, the copy of the Lockheed drawing you are using to compare the artifact to is not 1:1 scale
Okay. Once more with feeling. I scaled up the drawing to match the 1" station lines and the curvature of the artifact is still bang-on.
Can we all agree that wherever the hell this piece of plexi came from it has the same thickness and curvature as Lockheed Part Number 40552 effective 1-15-37?
-
I am satisfied that the piece of plexiglass is approximately 12 inch radius which is the same radius and thickness of the Electra side windows in the drawing.
Thank you.
-
By the same extension, then, it doesn't make sense to continue discussing anything else TIGHAR has found on Niku, does it?
Sure it does. We do it all the time.
I originally expressed enthusiasm for going full court press on 2-3-V-2 because I believe that if it did come from Amelia's Electra, it could be a diagnostic artifact.
The problem in this case was that your premise was invalid. 2-3-V-2 never had the potential for being a diagnostic artifact.
Nonetheless, I think the re-examination you prompted had value.
-
Something seems to be missing?
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
Something seems to be missing?
Yes, an inappropriate posting was removed. A Forum subscriber read a critique on another forum critical of our recent discussion here about Artifact 2-3-V-2. He said that the critique raised several points that have not been discussed here. Rather than raise those points himself he posted a link to the critique.
I've read the critique in question. The author's argument is that the "shatterproof glass" specified in the Lockheed engineering drawing is glass, not Plexiglas, but he offers nothing to support that contention but his own opinions and assumptions. Plexiglas was certainly in use in aircraft applications as early as March 1936 when NACA began testing it in response to concerns about crazing (see http://nvlpubs.nist.gov/nistpubs/jres/19/jresv19n4p367_A1b.pdf) and Rohm & Haas was advertising its use in Lockheed aircraft in 1937.
-
The full-scale distance between each of the "station" lines showing distance between a chord line and the outer edge of the window glass (e.g., 1-7/16 in., 1-31/64 in., 1-17/32 in.) is 1 in. Measure any one of these 1-in. distances with your ruler and you get about 3/4 in.
You're right, but if I scale the drawing to match the 1 inch station lines, the thickness of the plexi will be larger than the 1/8 inch specified. Are we to assume that the thickness of the plexi shown in the drawing is not drawn to scale?
Ric,
Trying to tie up a loose end from the earlier discussion in this thread about the scale of the copy of the Lockheed drawing you have ....
I think I have figured out why your approach of measuring the thickness of the window on your copy of the drawing didn't work. Looking again at your photo "scaled curve.jpg" back in Reply #40 in this thread, the thickness of the window you measured on your copy of the drawing appears to be slightly less than 1/8 inch, by perhaps 1/64-th of an inch. Possibly the difference from 1/8 in. is smaller less than that.
The text of the 1996 TIGHAR report on the pieces of plexiglas (http://tighar.org/Publications/TTracks/1996Vol_12/40552.pdf (http://tighar.org/Publications/TTracks/1996Vol_12/40552.pdf) and http://tighar.org/Publications/TTracks/12_1/PartNumber.html (http://tighar.org/Publications/TTracks/12_1/PartNumber.html)) says that Lockheed Drawing No. 40552 shows a change, dated 15 January 1937, of the thickness of the window glass from the previous 5/32 in. to 1/8 in.
Assume the drawing was drawn showing the window thickness as 5/32 in. I argued up-thread that your copy of the drawing is 3/4 the size of full-scale. This would make the thickness of the window as measured on the copy of the drawing
5/32 X 3/4 = 15/128 in.
This is slightly less than 1/8 = 4/32 = 8/64 = 16/128 in. and seems to approximately match what you measured for the window thickness on the copy of the drawing, as shown in your photo "scaled curve.jpg".
The thickness of the window should obviously be shown somewhere on Drawing No. 40552. Note in "scaled curve.jpg" that there are two arrows on the drawing immediately to the right of the word "glass" in the "shatter proof glass" label which are set up to show the thickness of the glass. If the writing to the immediate left of the upper arrow in this pair is the actual measurement, it is unreadable. However, note that there is a circled letter "A" immediately to the right of the word "shatter" and also a circled letter "D" below and to the right of the circled "A". These refer to notes A and D in the "changes" section of the title block of the drawing. These notes were apparently used to track the changes in the thickness of the window (and also changes in the window material) rather than changing the actual drawing each time to show the new window thickness. (At the very top center of "scaled curve.jpg", there is also visible what looks to be one half of a circle, probably another circled letter indicating another change note. My guess would be this is circled "C", which would correspond to change note "C", indicating the change from plate glass to shatterproof glass.)
In doing this little study of the drawing, I noticed a couple errors in your transcription of the dimensions on the drawing and some other possible errors:
(1) In the transcribed version of the changes section of the drawing, Note D reads "thickness 1/8 was 1/32". Based on the information in the text, Note D almost certainly should read "thickness 1/8 was 5/32".
(2) In the transcribed version, near the center of the drawing showing the curvature of the window, the overall height of the window is shown as "12-15/64 +0, -1/16". However, all distances between "stations" for the window are shown as 1 inch except the bottom-most one, which is shown in the transcribed version as "31/64". So either the fractional portion of the overall window height should be 31/64, or the bottom-most station measurement should be 51/64 -- can't tell which one is correct.
(3) (Possible errors in transcription) At the top of the window, the transcribed measurements for the chord line-to-outer window surface are shown as 1-9/64, 1-13/64, 1-23/64, and 1-29/64 inches for the first four window "stations". The corresponding differences between these measurements are 4/64, 10/64, and 6/64 inches. This doesn't seem to make sense for a smoothly curved window surface -- the 10/64 difference looks to be out of place, making the chord line-to-outer window surface transcribed measurements suspect..
Jeff P.
-
Thanks Jeff. I think that all makes sense.
-
I'm glad you chose to moderate the language in your reply to my query, since I'm the one who started that discussion over in the other forum.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
I'm glad you chose to moderate the language in your reply to my query, since I'm the one who started that discussion over in the other forum.
I'm glad you're glad. I have never been accused of being a moderate person and I am occasionally excessively immoderate. I'm trying to improve.
-
Today we're launching our first Forum Membership Drive. Like nonprofit public radio and television, this Forum is freely accessible to everyone and free from advertising, pop-ups, and other commercial distractions. And like our counterparts in the broadcast world, our ability to provide this service depends upon funding generating by tax-deductible membership in the parent nonprofit organization. Borrowing a page from the NPR playbook, we'll periodically take a time-out from our usual "programming" to ask for your support.
There are currently 1,296 people registered to this Forum. Only a small percentage are members of TIGHAR. If you use and enjoy this Forum we're asking, not requiring, you to join TIGHAR. Our goal for this our first Forum Membership Drive is 50 new TIGHAR members. Until we reach that goal I'll be responding only to questions and comments posted by currently paid-up members of TIGHAR, so please include your member number (as most of you do anyway) at the end of your post.
The sooner we reach our goal, the sooner we can get back to regular Forum action.
You can join TIGHAR or renew your membership HERE or send a check to:
TIGHAR
2366 Hickory Hill Road
Oxford, PA 19363
Or, if you prefer, you can phone me with your credit card information at 610-467-1937. I'll be honored to take your call.
-
Something seems to be missing?
Yes, an inappropriate posting was removed. A Forum subscriber read a critique on another forum critical of our recent discussion here about Artifact 2-3-V-2. He said that the critique raised several points that have not been discussed here. Rather than raise those points himself he posted a link to the critique.
I see. Since I'm not in a position to judge what is or isn't inappropriate in here, could it have simply been moved to the Alternate Lines of Inquiry section, which is for "Lines of inquiry not officially endorsed by TIGHAR," as opposed to being outright deleted?
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
...could it have simply been moved to the Alternate Lines of Inquiry section, which is for "Lines of inquiry not officially endorsed by TIGHAR," as opposed to being outright deleted?
No, it could not. I have explained why it was removed.
-
The moderators of this Forum work hard to insure that its postings reflect TIGHAR's standards in scientific rigor, primary source research, and civil discourse. Their efforts have made this by far the world's largest, most active, and most intelligent venue for the discussion of aviation historical investigations. The TIGHAR Forum delivers value. We ask only that those who dine at the table help in a small way to pay the tab.
You can join TIGHAR or renew your membership HERE (http://tighar.org/store/index.php?route=product/category&path=40) or send a check to:
TIGHAR
2366 Hickory Hill Road
Oxford, PA 19363
Or, if you prefer, you can phone me with your credit card information at 610-467-1937. I'll be honored to take your call.
-
I originally expressed enthusiasm for going full court press on 2-3-V-2 because I believe that if it did come from Amelia's Electra, it could be a diagnostic artifact.
The problem in this case was that your premise was invalid. 2-3-V-2 never had the potential for being a diagnostic artifact.
Nonetheless, I think the re-examination you prompted had value.
I strongly disagree that 2-3-V-2 has no potential to be a diagnostic artifact, i.e., it has to be from our Lockheed Electra. It has an apparently unique curvature, in a known thickness, and that could have been tied directly to Amelia and Fred's Electra - IF there was paperwork stating that the windows in her aircraft were replaced with 1/8-inch thick Plexiglas, as opposed to something else, that would match 2-3-V-2 as it currently exists.
But there isn't, and all the photos in the world aren't going move 2-3-V-2 any further down that road, despite my fondest and most enthusiastic hopes, because the utility of using one-dimensional photographs is limited when trying to analyze three-dimensional objects.
Which is disappointing, and to me 2-2-V-1 is looking more and more like it will fall into that category as well, again despite my fondest and most enthusiastic hopes. All the photos in the world (some of which I helped find) aren't going to move it any further down the proof road either, unless multiple, independent, public and replicable analyses are completed and they keep coming out the same way. But it sure would be nice if we could find some paperwork to go along with it, bureaucrat that I am.
LTM,
Monty Fowler, TIGHAR No. 2189 EC
-
I'm obviously having trouble getting through to you on this. Let's ask the question in another way. Is there any difference between a "diagnostic artifact," a "smoking gun," and an "Any Idiot Artifact?"
-
As I was taught:
A diagnostic artifact in terms of industrial Archaeology is usually negative. A 1936 silver quarter could have been dropped last year. A 2000 copper nickle quarter sure did not get dropped in 1936. A 1936 silver quarter mixed with other artifacts consistent with the 1930s could be diagnostic.
A smoking gun would be enough of the piece of plexiglass determine it is the size as well as radius and thickness to be a window of a Lockheed 10.
An any idiot artifact would be a Western Electric 13C transmitter, with CW and AM capability with 3 crystals still in it 500 khz,
3105 khz and 6210 khz.
At this point we have a small piece of plexiglass the radius and thickness of which match a Lockheed drawing of plexiglass that was to be installed on Lockheed L10s. We do not have written evidence this change was make to Earhart's L10. We have evidence the Pacific has numerous WWII aircraft wrecks. Given the fact the plexiglass has been worked/sawed and artifacts such as a comb made from .030 aluminum sheet has been found on Niku. It seems a reasonable conjecture that the natives scrounged and quite possibly traded in plexiglass and aluminum sheet. So we have an artifact of unknown origin that is consistent with a drawing of windows on some Lockheed L10s.
Neff
-
To expand on Neff's point re possible native salvage of Plexiglas, it is interesting to read that WW2 servicemen were also known to avail themselves of aircraft wreck bits.
http://dailycaller.com/2015/02/13/world-war-ii-sweetheart-grips/
-
I strongly disagree that 2-3-V-2 has no potential to be a diagnostic artifact, i.e., it has to be from our Lockheed Electra.
As you can see from the sniping, the Plexiglas can never be more than an intriguing possibility. For a "smoking gun" or "any-idiot-artifact" coincidence, no matter how profound, doesn't cut it. An artifact has to be demonstrably unique to NR16020. 2-3-V-2 is simply not complex enough to meet that standard. If, instead of a cut fragment, we had a full window skeptics could (and would) say there is no way to prove that the window came from that particular Lockheed 10. Ditto for a Western Electric 13C transmitter (somehow imported from Mili?). Anything found in the village was brought there from somewhere else - either somewhere else on the island or some other place near or far away. No way to know.
For some of us, the many "coincidences" we've uncovered over the years amount to a compelling preponderance of evidence. Smoking guns are in the eye of the beholder. For some it the PanAm bearings that cross near Gardner. For others it's the "clear signs of recent habitation" seen by Lambrecht, or Betty's Notebook, or the freckle cream jar, or the numbers on the sextant box, etc., etc., etc. But I become increasingly convinced that the only thing that will meet the any-idiot standard is conclusively identifiable Lockheed 10 wreckage discovered in situ. If it still exists its somewhere on the reef slope and the only way to find it is with manned submersibles.
-
If it still exists it's somewhere on the reef slope and the only way to find it is with manned submersibles.
I would modify this a bit: "If it still exists, the first place to look is on the reef slope, and the only way to find it there is with manned submersibles."
I'm not sure that we can prove the negative: "The airplane cannot have floated far enough away from the reef not to have landed on the reef slope."
Reef slope first. If that is where the wreckage is, great. If not, there is still the possibility of the ocean floor.
One step at a time.
-
Bingo.
-
I would modify this a bit: "If it still exists, the first place to look is on the reef slope, and the only way to find it there is with manned submersibles."
I'm not sure that we can prove the negative: "The airplane cannot have floated far enough away from the reef not to have landed on the reef slope."
That's true, but from a practical standpoint if the plane floated more than two nautical miles out from the island the wreckage is deeper than the subs' 2,000 meter depth limit.
-
Ric / Marty - "If it exists"? Really?
Under what scenario would the Electra or parts thereof cease to exist? Beamed up by the Enterprise? Aliens?
Gotta be out there somewhere.
Andrew
-
Gotta be out there somewhere.
You're right. "Findable" is probably better than "exists," and of course "findable" depends on the availability of the resources necessary to find it.