Highlights From the Forum
October 22 through 28, 2000
(click on the number to go directly to that message)
|1||Shortening the Antenna||Cam Warren|
|2||AE’s Receiver, Modified||Mike Everette|
|3||Challenging Ideas||Mike Everette|
|4||Proving a Negative||Marty Moleski|
|5||Earhart Post-Loss Messages||Ron Bright|
|6||Shoe Wear||Roger Kelley|
|7||Re: Shortening the Antenna||Bob Brandenburg|
|8||The LOP (Again)||Ross Devitt|
|9||In-flight Death in the Electra?||Ron Bright|
|10||Magazine Excerpt||Dennis McGee|
|11||Rescue from Niku||Don Neumann|
|12||Re: Proving a Negative||Marty Moleski|
|13||Re: The LOP (Again)||Alan Caldwell|
|14||Re: Antenna and Propagation||Bob Brandenburg|
|15||Get Thee to a Convent...||Dennis McGee|
|16||Re: Proving a Negative||Marty Moleski|
|17||Back to the Gilberts||Patrick Gaston|
No, Ric, I did NOT say Pan Am techs "were able to correct Gurr’s altering of the antenna length by use of a loading coil". (You have been skimming again, and not paying attention in class!)
Sorry I don’t have the time to explain physics and electronics at the moment (you might try Popular Science, which used to advertise as being "Written So You Can Understand It"!) The only thing Gurr (said he) did (confirmed by Lockheed work orders, was to LENGTHEN the antenna. (I still am suspicious of the parallel "V" he wanted to install on the belly, but you’ve offered photos that seem to indicate it was NOT installed, despite another Lockheed work order). If it was too long for 6210, all that was necessary was to physically shorten it - a very simple job, requiring one insulator and a short piece of "inactive" wire. (Or 2 of same, if you want to keep things symmetrical). Since the topside (requisite 40’) was easily obtained (check your scale drawings), there’s no problem there.
The addition of an appropriate loading coil WOULD improve transmission efficiency for 3105 in theory, but practically (since we’re talking 1/8 wave length for it) probably worth the additional weight and switching requirements.
Of course, anything less than the 250’ trailing wire was woefully inadequate for 500 kc TRANSMISSION, so, trying to be helpful, Gurr added a HUGE loading coil in series with whatever antenna system you choose to believe (I think a belly one) to provide SOME (very little!) 500 kc capability. That turned out to be hopeless (didn’t work en route Miami) so, for various reasons I don’t need to elaborate on, AE ordered it junked.
(And of course I believe, in my stubborn, thickheaded way, that she felt confident her wizard new HF/DF would greatly minimize the need for LF/DF.)
No, little or none of this is documented (more’s the pity!), and you don’t need to take my word for it, any more than (as an adult), you don’t have to listen to ANY proffered advice. It doesn’t bother me!
Finally, as for your denial of inferring inferior performance by radio techs or Colorado pilots, that’s my reading of your comments. No, you didn’t use the word "inept" in either case; let’s just say you "minimized their contributions".)
Cutting to the chase, let me ask our Radio Rangers for an opinion about Cam’s insight into how Pan Am technicians may have physically shortened the antenna by creating a section or sections of "inactive" wire, and is that something we might be able to confirm or disprove with photos of the airplane?
Holy kilocycles, Batman!
When I made the post of yesterday regarding AE’s receiver, I was merely thinking out loud regarding an angle Frank Westlake mentioned -- that AE might have had her transmitter modified for 500, but not the receiver.
Ric, I believe you missed my point entirely.
I was trying to show why it would not make sense to do that... but at the same time, trying to justify it. And my conclusion was (reread my post and you’ll understand):
To modify the transmitter to SEND on 500, without modifying the receiver to HEAR on 500... That makes a much sense as a submarine with screen doors!
It just would not have been done that way. Either that receiver was modified, or she had some other receiver on board that did have a band covering 500.
It makes absolutely no operational sense. Especially in a situation involving potential emergency transmissions. Like I said: in the 30s, many ships and shore stations did not even work HF at all. Much maritime traffic was carried on in the 400-500 kHz range. You’d have a far, far greater chance of getting help, if someone who heard your transmission could call you on the distress frequency. If they could not contact you because they could not transmit on a frequency you could hear, well, too bad.
What happens in many emergency situations is that one station will hear the one in distress, and once the frequency is cleared of traffic for the emergency, other stations can hear... and may be called upon to relay traffic. Much, much confusion would result if the communication were split between LF and HF.
I repeat... either the WE receiver could tune to 500, or she had another one that would.
I can happily accept that as expert opinion. I understand that you’re not asking anyone to accept it as fact.
Janet Whitney wrote that she thinks every statement in the radio pages in the 8th Edition can be challenged...
Well, that’s what this Forum is about: Challenging things, making us think further, making us reevaluate. Maybe we’ll see something in a different light and several more pieces of the puzzle will fit.
However, I must respond to some other things.
What this harmonic theory is, is just exactly that: a THEORY. We are testing that theory now. I will admit, I am not convinced of the veracity of it... but the evidence, mostly technical, looks pretty interesting and to a degree compelling. But the jury is still out.
Janet seems to feel that I and others are trying to liken the problem of the antenna, and the transmitter design, to some equivalent problem in the modern era involving ham radio equipment. NONONONO...NO.... NO. I think the technical aspects of this case have been presented pretty well, by Hue Miller, Bob Brandenburg, and myself. I have even tried to explain some things to her off forum, but we still keep coming back to this sticking-point.
It matters not whether an antenna is operating on the ham bands, or on 3105/6210, or 42 MHz or any other frequency... if it is a non-resonant length (as AE’s was) it must be tuned to compensate for its shortcomings if it is going to radiate power. AE’s radio had a limited capability to properly match, or tune, the antenna. The design of the unit was one which definitely encouraged harmonic radiation and a mistuned antenna further aggravated the potential for doing so.
Some of us do indeed have considerable practical experience in this field, including antenna design and operation. There is much, much more involved here than one will ever get out of a book alone... though a good book is the best starting point for sure... but the real world is the true schoolroom.
Harmonic radiation: It could have happened... it probably did happen, almost undoubtedly did. Whether the signals got all the way from Niku to Stateside remains to be proven. And the genuineness of Betty’s record has yet to be proven.
As for what was done to the radio in Miami: Janet says even if Gurr got it wrong, the PAA guys must have fixed it... well, I am afraid the facts are not known. We have no idea what was actually done to that radio in Miami. It all depends on one thing:
WHO DID THE WORK?
Did the guy make a thorough investigation? Or did he assume, as a lot of tech would, that if it was working when it came in, it just needed a cursory check? After all, the receiver received (we think), the transmitter transmitted -- hey, the RF ammeter said there was power going to the antenna.
How familiar was the tech with this radio, this antenna, this aircraft? Did he know the antenna had been modified?
Did he check the freqs? In the 30s there was one way to test for harmonic radiation -- using an absorption wave meter. Spectrum analyzers were years away. Even if he used a frequency standard to check the transmitter, those things were by nature capable of misleading you. Sure, you’d read the freq you wanted to operate on; but there was no real way to differentiate between harmonics and the "real" freq because the standard compared them ALL to the same point. (Been there, done that... I have used one many times when I did not have access to a freq counter. By the way, those did not exist in the 30s either.)
If the work was being done gratis, was it squeezed in among real work, i.e. PAA stuff? How much time did they have?
And remember, anything done to an aircraft required filling out lots of forms for the Bureau of Air Commerce. Now, if NOTHING was actually DONE... if no screws or knobs were turned ... why waste time filling out all the paperwork?
It’d be really interesting to discover something in the Pan Am Archives pertaining to this situation.
LTM (who always
keeps lots of paper in the cabinet because no job is finished till the
paperwork is done) and
Alan Caldwell writes:
> ... Anyone knows
This is a gross simplification.
Some negatives are hard to prove.
Some are impossible to prove.
If the universal form of the statement, as given above, is true, then, by application of itself to itself, it asserts that it is itself unprovable. That makes it strictly a matter of faith.
Here is an example of a negative that may be provable:
Earhart’s plane did not splash down in the Pacific Ocean.
If the any-idiot-artifact (the McGuffin) is found on Niku IIII, then it will prove a negative--in fact, a whole host of negatives: Earhart was not captured by the Japanese, she was not seen by so-and-so, and she never wrote the "Love to Mother" letter. If the McGuffin is not found, then the question will remain open (for those who doubt the compound evidence of the shoes, the bones, the aluminum pieces, and the corroborating stories about wreckage, airplane cables, bodies, etc.).
Here is an example of another two negatives that may be provable:
These two conjoint negatives could be proven by the discovery of the McGuffin on the floor of the Pacific by one of the splashdown groups.
The class of negatives that are notoriously difficult to prove are those that follow the pattern, "There are no abominable snowmen," "There are no alien spaceships visiting the earth," "There are no ghosts," or "There is no God." The inability to prove these negatives derives from the limitation of the human mind, but it is a fallacy to reason from these cases to others that are not strictly analogous.
Back to the case in point: the question of the signal strength generated by AE’s transmitter on various harmonics can only be bracketed by certain abstract considerations. If the McGuffin is found on the floor of the ocean, it will prove that Betty’s transcript derived from some kind of hoax; if the McGuffin is found on or near the reef where Emily claims the airplane parts could be seen, then, as Ric has said, the transcript (and other similar reports) may represent a strange and unusual confluence of variables: battery/generator power, weird antenna configuration, disruptions in the ionosphere, etc.
Since there is no record of all of the conditions affecting the alleged transmission, no controlled experiment can be done either to validate or invalidate Betty’s notebook. In that sense--but not as an application of a universal principle--I do not think anyone will be able to prove that Betty did not hear Earhart. Nor do I think anyone will be able to prove that she did.
I’ll take the bait. A statement like "Earhart’s plane did not splash down in the Pacific Ocean" can only be proved by establishing the veracity of a positive statement (i.e. that the airplane ended up someplace other than the Pacific Ocean.) However, as you have pointed out, a statement like "there are no ghosts" or "there is no God" is different. I can disprove them by producing a bona fide ghost or god, but the best I can hope for in attempting to prove their truthfulness is my own inability to locate spirits and deities.
Moving right along, let’s consider the less philosophical question of proving or disproving the validity or invalidity of Betty’s notebook as a record, however imperfect, of the words of Amelia Earhart. I agree that there is no way (at least, that is apparent to me) that the notebook by itself could establish that premise. We could possibly disprove the hypothesis by finding some aspect of the event that was beyond the realm of possibility or by finding the notebook of a hoaxer whose broadcast script matches Betty’s notes.
I think the only way to approach this is to develop a positive hypothesis that attempts to explain the post-loss messages in general, accepting that some were hoaxes or misunderstandings, but positing that a goodly number (whatever that means) were genuine. That hypothesis would then be tested by examining all of the post-loss messages that can be found and looking for some pattern that could only be present if the messages were genuine.
For example, let’s say we plot out a timeline showing all the messages and find that we have a random distribution of time and frequency with no better than random occurrences when different people hear something at the same time on the same frequency. That would pretty convincingly disprove the hypothesis. Or --- let’s say we find that there are definite bunches of reports clustered around a specific time and all on the same frequency. That would be a pretty good indicator that most of these folks are all hearing the same thing --- perhaps the same hoax. But what if these bunches all happen to be at times and places and frequencies where signals from Earhart are at least theoretically possible and that such confluences are relatively rare? In other words, what if the only people who hear the presumed hoax also happen to be people who actually could have heard Amelia? In a case like that we’d have to say that either the hoaxer was operating from someplace in the Central Pacific, or these people were really hearing Amelia.
As you know CDR Thompson discredited every post loss transmission except for the one at Wailupe. Only amateurs heard those transmissions, not official navy radio stations and ships, he said.
Stripple cites in his book that for the "final evidence" for the Coast Guard that those amateur receptions were not genuine, he cited the San Francisco District Communication Officer Frank Johnson who plotted all the reciprocals of the great circle bearings the high frequency direction finders had taken on the disputed "Earhart" signals. The line connected Hawaii, SF, (Wyoming), Chicago, and New York. At the time of the west coast reception of the "Earhart" receptions, it was evening or early morning in the Northeast, time of peak radio traffic and long distance propagation.
Stripple doesn’t cite a reference but maybe Coast Guard archives have that Johnson study. Frankly your forum radio experts would have to translate that significance re bearings, peak traffic, etc. to the Earhart intercepts. Maybe this will help radio analyses.
What if...If we assume...Something to think about.
To what extent would walking on coral or coral sands accelerate the wear on ones shoes? If accelerated wear results from walking on coral or coral sands, might this explain the severely worn condition of the shoe recovered by TIGHAR? Did the previous owner wear the shoe while walking about Niku Island?
If we assume that the recovered shoe parts were in fact Amelia’s, and we assume that she survived the landing on Niku, an indication of the rate of wear in that environment would indicate the minimum time during which she survived, or a minimum length of time Amelia was capable of moving about the island.
If the amount of wear on coral or coral sands was severe, and Amelia moved about frequently while wearing the shoes, the amount of time Amelia survived would not be too long. At least four or five days or two weeks at best. If Amelia was in good health and injury free and, if she found the Norwich City cache intact with water supplies, Amelia would be encouraged to remain close to the cache. As a result, the length of her survival would be increased from days or weeks to months and the wear on her shoes reduced due to her lack of activity.
It’s anybody’s guess as to what the wear on the recovered shoes might mean.
Ric, while on Niku Island, did members of past TIGHAR expeditions note excessive wear on their shoes or boots?
LTM (who likes no
shoes during a walkabout along the beach),
Niku is murder on shoes. Not only is the coral rubble on land abrasive but if you go out onto the reef flat (after fish, for example) your feet have to be protected, and the salt water, sharp coral, intense sun and high temperatures just eat up leather shoes or boots. That said, the fact that the shoes whose remains we found were severely worn means only that they were probably worn for a fairly extended period of time ( several weeks to several months, but not several years) on Niku or in other environments similar to Niku’s. In other words, they’re consistent with shoes one would expect to find discarded on such an island so I don’t think that the wear issue is very useful other than being one more clue that is consistent with, but not unique to, Earhart being on the island.
Cam Warren writes:
> Sorry I don’t
have the time to explain physics and electronics
Cam, as it happens, I do have a passing acquaintance with both physics and electronics. So I hope you won’t mind filling in some details for me. I’ll try to keep up with the technical details.
> The only thing
Gurr (said he) did (confirmed by Lockheed work
Wasn’t the antenna feedpoint moved also?
What effect did the new feed point location have on the antenna and feed line impedance as seen by the transmitter?
> If it was too
long for 6210, all that was necessary was to physically
Was the antenna too long for 6210? What fraction of a wavelength was the antenna at 6210? How would shortening the antenna affect its performance on 3105?
> Since the topside
(requisite 40’) was easily obtained (check your scale
I assume you are referring here to the design intent of the transmitter. But what antenna configuration did the transmitter design anticipate? Was it a vee configuration with an off-center feed? Or was it a straight end-fed wire?
Are the two equivalent in terms of feedpoint impedance?
If not, what are the differences?
> Of course, anything
less than the 250’ trailing wire was
Are you stating as a fact that AE had Gurr’s loading coil junked at Miami?
Does your belief that Gurr’s coil was used with a belly antenna imply that Gurr was mistaken in his May 1982 letter to Fred Goerner, in which he said "I improvised a loading coil and resonated the top antenna system"?
>Cutting to the
chase, let me ask our Radio Rangers for an opinion about Cam’s
The Pan Am techs could have shortened the antenna, as Cam suggests, by inserting "inactive" wire. It would be done by cutting the antenna to the desired length and then filling the space between the ends of the antenna and the vertical stabilizer attachment points with "inactive" wire separated from the "active" wire by insulators. The added insulators would have to be about the same size as those used to attach the original antenna ends to the vertical stabilizer points, and would be at least as visible in photos. So if it happened at Miami, then post-Miami photos should show the new insulators.
Yes, the antenna feed point was changed. Prior to the Luke Field wreck the dorsal vee fed into the fuselage at a point on the top of the fuselage just above and forward of the starboard side cabin window. The wire then ran down the interior cabin wall to the transmitter. When the airplane came out of the repair shop in Burbank in May the feed point had been altered so that the wire came down from the antenna and fed into the fuselage way down on the starboard side of the airplane just opposite where the transmitter was installed on the cabin floor.
There are lots and lots of good photos of the airplane after it left Miami and the insulators on the dorsal vee are easy to see. There are two insulators right up close to the forward mast and others right up close to the attach points on the vertical fins. There are no insulators elsewhere on the wire. Cam’s hypothesis is disproved.
> What TIGHAR describes
is running on the
As I understand celestial navigation, the one thing Noonan should have been pretty sure of is his Latitude. He should have had a very good idea how far north or south they were from sun shots. The thing he should not have been able to place was his longitude because of the head/tailwinds etc.
Nope. I don’t pretend to sing in the Celestial Choir, I just book the hall, but here’s the way it has been explained to me (many, many times).
The sun comes up in the same spot relative over a wide range of latitudes, so a sunrise LOP gives you no useful latitude information (you already know that you’re not, for example, up near Midway). It does, however, give you rather precise longitude information because the Earth rotates west to east and the sun becomes visible along a specific longitudinal line at a specific time. The line, of course, is at 90 degrees to the sunrise and is not exactly in line with the lines of longitude (337/157 as opposed to 360/180), but it is predictable and precise. Once Fred gets his initial LOP at sunrise and advances it through his intended destination, he can continue to take observations as he goes along to confirm that he’s making the progress he predicted. This is known in the trade as "shooting speed lines." The result is that by the time he reaches the advanced LOP that falls through Howland he’s had several opportunities to confirm that it’s accurate. Ten miles was his demonstrated standard but whether he was north or south (i.e. latitude information) was not something he could know.
I just received the entire transcript (4 pages) from Univ. of Wyoming that mentions the Earhart saga. You have already posted the excerpts but I have found a couple of additional interesting excerpts that will continue to add to the mystery and probably fuel more speculation about Noonan. And Vidal.
First, the interviewer asks "Gene, you knew Amelia Earhart quite well, didn’t you." Gene answers with an incomprehensible statement. "Yes. We were good friends for 12 years ... (and) I first knew her in 1930 ..." Well AE disappeared in 1937, we think, so does that give a clue that the interview was in 1942? Can the forum figure out this addition. Shouldn’t he have answered "seven years"?
He goes on to describe Amelia: "... a tomboy ... yet was like a little girl in some respects ... wrote poetry ... under another name ..." and other insights to AE’s personality.
The interviewer then asks Gene if he "knows anything about the last flight." "Yes, I know quite a bit about it. It’s a shame there were so many wild reports as to what might have happened to her. It really was not so complicated."
He describes how he helped her with the preflight preparations and that her only "worry" was not to miss Howland, and that her plan was to head for the Gilberts when she had four hours of fuel left, and land on a beach.
Now here is the kicker. "She was dependent upon her navigator to locate the plane’s position with reference to Howland ..."Because she changed her messages to the boat (the Itasca] from " ’ we’ to ’I’ " and seemed quite helpless in locating Howland, we can almost assume something had happened to the navigator or his equipment. The navigator sat ... in the rear... and she could barely see ... and ... would have to crawl over the gas tanks ... to get to where the navigator sat. However she couldn’t leave the controls."
So do we have a incapacitated or dead navigator? Did she change her pronouns? Could explain why AE couldn’t figure out where she was or how to get to where she wanted to go.
The Itasca radio log doesn’t indicate a shift in pronouns from "we" or "us" to "I", and the last (officially reported) message says "We are on ...." So does that mean that there were additional messages from Earhart after the 08:44 message, in which she changed pronouns and we Earhart researchers have never seen. Or was Vidal nuts. His remark comes well after the official Itasca log was released.
Vidal ended with the "keeping in mind her thoroughness, she must have turned back to the Gilbert Islands ... as she planned to do. ..." No mention of an other alternate and the Gilbert Is threads through this transcript.
The Univ. of Wyoming could not shed any further light on the interviewer, the time, circumstances, and where the rest of this transcript is. The copy of the transcript that I have is typed with a standard typewriter and used quotes on the interviewer’s questions and on Vidal’s responses. This suggests that it was taped, but doesn’t eliminate that this was a transcription of shorthand. There doesn’t appear any other reference to estimate the time of interview except the top line says, "I left Chng-tu [sic] on the next plane." Thus the interview took place after Chng-tu.
So the archivist was correct. This transcript leaves us with more questions than answers.
I don’t follow how Vidal’s statement "We were good friends for 12 years ... (and) I first knew her in 1930 ..." indicates that the interview was done in 1942. It either suggests that Earhart survived until 1942 or that Vidal had his years or addition messed up.
As you note, the Itasca log documents no pronoun change so either Vidal was privy to radio messages we don’t know about or he didn’t know what he was talking about. It does seem to be the case, as we discussed in the context of the "last communication" Rollin Reineck wrote about, that there was a rumor going around official circles about messages being heard that were not included in the Itasca log.
The more we learn about this Vidal interview the less credible his information becomes.
The following is excerpt from a Letter to the Editor of Flight Journal magazine and appears in the December 2000 edition. The letter was about the Lockheed 12A. I thought it may be appropriate in view of the recent discussions on the forum.
LTM, who reads too
many "av mags"
It’s worth mentioning, I think, that [Lockheed 12A] NC18955 was repatriated from Canada, initially as N60775 (not 60755), and was subsequently reregistered by movie stunt pilot Paul Mantz as NC16020 -- no doubt, in an effort to evoke the Earhart image for profit. It later crashed and burned, thus promoting the yarn in Amelia Earhart Lives that the Electra had somehow survived. Author Klaas [not further identified] apparently didn’t know the difference between an L10 and an L12A.
Thanks Dennis. Interesting stuff. It was Joe Gervais, not Joe Klaas, who misidentified the wreck of N16020, and it was TIGHAR member Frank Lombardo who researched and exposed the Air Comics photo of the Electra Junior supposedly wrecked by Earhart.
Alan Caldwell writes:
>The one thing --
the ONLY thing -- he can do that will virtually
Yeah! Why is this so hard to understand? Everyone wants to put the Electra in some mythically large expanse from which no one could pick a decent starting point. To be true, Noonan would have had to be a hopelessly bad navigator. The accuracy and expertise of his skills are known and AE’s "We must be on you" or words to that effect show that at least THEY thought they knew closely where they were.
The simple logic of flying SE on the LOP until connecting with one or more of the Phoenix chain islands is inescapable, however there still remains the question: ...how do we get AE/FN located & rescued?
There is presently no evidence to support the proposition that AE/FN ever received any further radio messages from the Itasca (following the last message Itasca received from AE/FN) or subsequently received any radio signals from the approaching USS Colorado or the Lexington Task Force. Additionally, the USN & USCG insist no bona fide radio signals were received from AE/FN following the last message received by Itasca. (Rollin Reineck’s website insists that there was at least one message that was intercepted on Howland by US Army personnel indicating AE/FN had turned North on the LOP.)
We have no evidence to support any basis for determining just what actual knowledge AE/FN had concerning the Phoenix Island Chain, but the general consensus of opinion seems to be that they would have known that it was very sparsely populated (Lt. Lambrecht expressed great surprise that Hull Island was inhabited) & well off any known shipping lanes, making rescue by the Itasca (the only known (to AE/FN) vessel close enough to effect any rescue) highly questionable, if they received no confirmation that Itasca was still receiving their radio signals. (Presuming they did continue to signal Itasca on the flight SE to the Phoenix Chain.)
Perhaps this scenario provides additional importance for continuing efforts to ’decode’ the ’Betty’ notes (if shown to be a bona fide transcript of a legitimate broadcast from AE/FN) for some possible, obscure clue to just what the actual post-landing situation was, on whatever landfall the flight terminated.
> ... Some negatives
can be established;
> That’s just a
semantic game. Every positive hypothesis can be stated as a
This is not just semantics. If we’re going to talk about proof, then we are invoking the laws of reason, and it makes sense (to me) to proceed consistently and thoughtfully in their use. Semantics is essential to the establishment of axioms, formal procedures, and algorithms. No semantics, no logic.
It is a mistake to say, "No one can prove a negative." This is a slogan, not an axiom of logic nor the conclusion of a proof. People may wish to invoke it to give rhetorical support to their position--it has a nice ring to it--but it is not a law of logic nor of historical research.
Here is a typical dialogue in which the magic wand of the Unprovable Negative is waved over a set of difficulties:
For lack of a better term, let’s call these "worldwide existential negatives." They are only a small class of all possible negatives. They cannot be established by direct observation because no single human observer can cover the whole earth at one time in order to declare by personal authority that the McGuffin doesn’t exist.
I can establish some local existential negatives. I can say with some certitude that Santa Claus, leprechauns, ghosts, and alien invaders are not here in the room with me, because this is a space that I can inspect directly and accurately. There are also no automobiles parked in my bedroom. I am not in a position to say that there are no hair mites in my eyelashes because I lack the equipment to inspect my eyelashes--the problem of definitively declaring either the existence or non-existence of mites on my own body is incapable of resolution through my own personal observations.
In the case of Betty’s notebook, I can state with perfect assurance that I have never heard low-power voice transmissions skip to my short-wave receiver from a small island in the Pacific. I’ve never owned a short-wave receiver. I may have played with someone else’s once or twice, but with no comprehension of what I was doing. I am not allowed to generalize from my experience that no other human being has ever heard such weak transmissions from the Pacific to North America. I am not capable of observing all possible transmissions and receptions on all frequencies under all possible ionospheric conditions. Since I know the limits of my observational powers, I know I cannot prove this particular negative. And, on the assumption that your mind is as limited as mine, I presume that you cannot prove it, either.
If TIGHAR finds the McGuffin, then it leaves open the possibility that Betty heard AE and FN; it raises the probability that others may have heard them, too. If TIGHAR fails to find the McGuffin, the possibility still exists that they came down somewhere else and were able to transmit for a short time. If the McGuffin is located in the depths of the ocean, that establishes a local existential negative with a vengeance: whatever Betty heard, it wasn’t AE and FN. But pure logic is of no use in deciding between these three cases.
So, to answer your question in your own terms, "the characteristic that distinguishes the genuine negative, unprovable hypothesis" from counterfeit negative, unprovable hypotheses is observability. If I have the power to search the relevant space, I can decide for or against the hypothesis. If I do not have the power to search the relevant space, I cannot "prove the negative."
The observability test only works if we assume that our own perception of our observational powers is accurate. Example: You’re quite satisfied that there are no automobiles in your bedroom because you’re confident that you could find one if it was there. It is also easy for me to accept your conclusion because I trust your ability to look around the room and confirm the absence of motor vehicles. Conversely, your hesitancy to make a judgment about the presence of hair mites in your eyelashes seems to be a reasonable recognition of your limited observational powers.
But let’s pick a grayer example. You’ve lost your car keys and have searched your bedroom and have concluded that you have proved the negative hypothesis that "My keys are not in the bedroom." Two weeks later the cleaning lady finds the keys behind your dresser. You thought you had proved the negative hypothesis by observation but what you really proved was that you couldn’t find your keys. The same applies to the cars in your bedroom. We can talk about gradations of credibility but we can’t talk about absolutes. The only way to prove that your car keys are not in the bedroom is to find them (establish the truth of a positive hypothesis) somewhere else.
The automobile-in-the-bedroom is, in fact, an example of a true unprovable negative hypothesis because it is nonspecific as to what car we’re talking about. We can prove, for example, that my 1991 Toyota VIN number so-and-so is not in your bedroom by noting that it is sitting here in my driveway, but there is an impossibly large number other cars that could be there.
I suggest, therefore, that the test of a genuine unprovable negative hypothesis is specificity rather than observability.
Ross Devitt wrote:
>As I understand
celestial navigation, the one thing Noonan should have been
Actually the sunshots will give FN his Longitude not his latitude. Successive sunshots or speed lines will also give him his ground speed and thus his headwind component. Add drift or latitude to that and he has his actual wind.
We continue to focus solely on the sun whereas there were other celestial bodies available (discounting cloud interference) with which FN could not only plot a latitude but a pretty accurate position. He could have plotted his position within 3 miles but there are many factors which could have induced errors making a slightly larger area more likely.
If he had no cloud cover to obstruct his celestial there is no reason to believe he was more than a few miles off. NONE. If true, they most likely missed Howland simply because scattered CU made it difficult to spot the island. If there WAS cloud cover then where the plane was is more difficult to determine. The answer would depend on what navigational information FN had and when he had it. For example if his last accurate fix was an hour or two short of Howland the error could be significant due to wind effect. If, on the other hand, FN was able to plot wind and drift from the sea he should have been able to greatly reduce the error.
Keep in mind FN was an expert at this not a novice. Also keep in mind he had a lot of possible sources for plotting his position NOT just the sun. There was the moon and planets plus an ability to plot drift.
We keep viewing this flight as if FN ONLY had the sun, if that, and that he DRd from half way on the leg and was hopelessly lost.
If the weather did not interfere FN had to know where he was and how to get any place else. That means to the Phoenix or Gilbert group or even to the Marshalls had he chosen.
The question then is which would they have chosen. The easy choice is the Phoenix because they were closest and there was less chance of missing them altogether.
This should have been the choice even if they were in weather and didn’t have a good position for the SAME reasoning. They would want the most fuel left upon arrival as possible.
I can not see any reason to believe they were greatly off course either to the north or to the south. If they were that would mean FN had to have been the worst navigator imaginable or he had no navigational information at all from half way out to Howland. That of course could be true but once he arrived in the vicinity celestial was clearly available again if weather reports were accurate. If his first fix showed he was far to the north or south why would they say they thought they were "right on you?" Why would they then run up and down an LOP? The answer is they knew or believed they were close and not far to the north or south. If this analysis is correct the Marshalls make NO sense at all and we’re left with a fairly simple choice of heading toward the closest land and land that is less risky to miss.
The remaining possibility is they did something stupid or for a reason we have not yet fathomed.
For Hue Miller:
Since I am doing the antenna and propagation simulation studies, I assume your invitation to "grind these facts" is directed to me.
Unfortunately, I don’t see any facts to "grind", but then, I’m having difficulty following your line of reasoning and may be missing the obvious. So please bear with me while I ask some questions.
> In reply to a
question of mine, elsewhere, re harmonic output
What is the relevance of the harmonic radiation properties of military transmitters to the harmonic radiation properties of AE’s transmitter?
Assuming that the figures given to you are factual, do they include any implicit caveats, such as transmitters carefully tuned and feeding appropriately matched and loaded antennas?
Should we make the same assumptions for AE’s transmitter? Why?
Given that Terman (Radio Engineering, 1947) cites relative power levels for the output of a well designed Class-C harmonic generator ranging from -1.8 dB at the second harmonic to -6 dB at the 5th harmonic, would you say that the figures given to you assume a high antenna?
Should we assume a high antenna for AE’s transmitter? Why?
> But let’s say
the WE is really bad about harmonic radiation, for
What is the analytical basis for assuming the 2x harmonic is "only 10 dB down". Why not 6 dB, or 5 dB or 3 dB, or . . . . ?
Is the radiated harmonic power level solely a function of power input to the antenna? If not, what other factors govern harmonic radiation levels?
> So when you do
the computer simulations for path, Betty’s antenna, etc. etc.
Why 5 watts?
Isn’t the radiated power along a given space vector a function of the input power to the antenna, the antenna’s radiation efficiency, and the antenna’s dimensional gain pattern?
Did you take those factors into account in arriving at your 5 watt figure? If not, how did you arrive at 5 watts?
What factors determined the radiation efficiency of AE’s antenna at 3105 and 6210? What were the respective efficiencies at those frequencies?
> Then when you
consider the 3x harmonic possibility, imagine what wattage
Why 1 watt? Why less? Why not more?
Are you assuming that the antenna gain pattern is invariant with respect to frequency?
Are you assuming constant radiation efficiency? If not, what variation versus frequency are you assuming?
If radiation efficiency varies with frequency, how much difference should be expected at the harmonic frequencies? How did you calculate the answer?
What was the radiation efficiency of AE’s antenna at 3105 and 6210?
How did the antenna gain patterns at those frequencies compare to the gain patterns at the various harmonics?
Could the antenna gain at the harmonic frequencies be enough to compensate for relative input power loss at the harmonics? Why?
Could a combination of higher antenna gain and higher radiation efficiency result in higher net radiated power at the harmonics than at the fundamental frequencies? Why?
> That reception of Betty’s would appear to be a real "DX catch".
Why? What calculations have you done that lead you to that conclusion?
You have only mentioned output power as a determinant of whether Betty could have heard the signal.
Are there other factors that should be taken into account? What about ionospheric propagation loss, atmospheric noise, and the characteristics of Betty’s antenna? How do they vary with frequency?
Is there a net gain in signal-to-noise ratio at the harmonic frequencies, relative to the fundamental frequencies? Why?
> (or more) of other
SWLs somehow missing the reception,
How do you know there were hundreds or more SWLs who missed the reception?
How many were listening on the same frequency as Betty at the same time on the day she heard the signal?
How do the possible numbers or locations of other SWLs bear upon the feasibility of Betty hearing the signal?
> Even a transmission
on 16 MHz would maybe have been tuned across by listeners
What about transmissions on other frequencies? Would such transmission also have been tuned across?
How do you quantify "maybe"?
Is there a common set of specifications that characterize "the general coverage type receivers of the day"? What are the values of those specifications?
Instead of assuming a generic receiver, why not assume the actual make and model of receiver that Betty used?
> To get from one
area of interest to another you have to cross the
Are you suggesting that every frequency on the dial will be tuned across by every listener simultaneously at any given moment?
> Also, the Maine
reception was right
And the conclusion we are to draw from that assertion is . . . ?
I look forward to your answers and the facts they will bring.
LTM, who loves to
Judging from clarity, logic, and persistence of Ric’s and Marty Moleski’s comments on proving a negative, it appears they were both raised by a family of Jesuits.
LTM, who avoids
LOL! Oh Dennis, if you only knew! For my part, I’m the product of about 300 years of rabid Presbyterianism. The only Jesuits my family ever knew were the ones they probably burned. I’ll let Marty tell you who he is, if he should care to do so.
> The observability
test only works if we assume that our own perception of
That is correct. We who send funds to TIGHAR are relying on your observational powers to tell us whether or not the McGuffin is on Niku. If you don’t believe in these powers, you’d better give back the money.
The same observational powers are at work in determining the structure of atoms, the qualities of the periodic table, the laws of biochemistry, and the other finds of natural science. Why should I accredit other people’s observational powers but doubt my own?
> Example: You’re
Correct. If you don’t know how to run this test, then perhaps we could get Pat to take over TIGHAR.
> But let’s pick
a grayer example. You’ve lost your car keys and have
The way that she proves me wrong is by the correct use of her observational powers. This does not prove that we can’t rely on such powers. It proves that I must be careful when I make claims about things that are more difficult to locate than a car.
> ... We can talk
about gradations of credibility but we
You just made an absolute statement. If you really believed what you said, you wouldn’t have said it.
> The automobile-in-the-bedroom
is, in fact, an example of a true unprovable
You’ve changed the case that I imagined. I only said "a car." If you want to make up a different case, that’s fine, but it doesn’t affect the point that I made using my case.
Let me generalize: the standards for deciding on whether a negative is true or false vary with the object sought. Cars, unlike Santa Claus, leprechauns, aliens, or God, occupy space/time and are composed of matter/energy. We know what cars are and we can confidently declare whether or not they are in a bedroom or not. The McGuffin is like the car. I think you are right to go searching for it because it won’t hop out of sight the way leprechauns do.
> I suggest, therefore,
that the test of a genuine unprovable negative
I don’t think it is either/or, but both specificity and observability. In order to decide that something does or does not exist, we do have to be able to specify what it is that we are trying to observe. (That is how Aristotle justifies the principle of identity and non-contradiction. You can’t deny the principle without using it to specify what you deny.)
Goedel’s Incompleteness Theorem is an excellent example of proving a universal negative:
This kind of negative is not the kind of universal existential negative we’ve been discussing, but it does show that people who know how to prove things can prove a negative. Turing showed that you cannot predict in general whether algorithms will return an answer or not. In posing and proving this negative, Turing invented an imaginary computer which is still used as a model for thinking about what computer can and cannot do.
The solution of Fermat’s Last Theorem turned on the proof that a certain class of multidimensional forms did not exist, but I do not have room in this margin to show you the proof.
I’m sure the rest of the forum will thank us if we return to speculating about the meaning of "uncle"
As usual, Don Neumann hits the nail squarely on the head. Granted that the Phoenix Group was closer than the Gilberts. Granted that, by sheer happenstance on the morning of July 2, 1937, FN’s sun line (if advanced correctly through Howland) ran into or near Gardner. Granted that following the 157/337 LOP would have been a perfectly logical thing to do, if distance-to-landfall was the sole or even chief motivating factor.
By definition, then, any decision to head for the Gilberts would have been motivated by factors other than sheer distance. Assuming that Earhart felt both island groups were within range (even if just barely so in the case of the Gilberts), then Don has capably identified some of those potential factors.
In essence, TIGHAR’s theory assumes the following thought process: "I don’t care where we land, Fred. Just find the closest island and get us there before we run out of gas!" The Gilberts theory assumes that AE looked beyond the exigencies of the moment: "Yeah, Fred, I agree the Phoenix Group is closer but there’s nothing there and who’s going to find us? I think we have enough fuel left to get back to civilization."
Either decision is defensible, depending upon the situation as it appeared to Earhart at the time. I do not pretend to know which one she made. Nor is the Gilberts theory likely to produce a McGuffin, as hardly anybody thinks they actually succeeded. Anecdotal accounts of a low-flying, fork-tailed airplane or mysterious wreckage washing up prior to the war are probably the best that can be hoped for.
A word on Vidal: Thanks to Ron Bright, we now know that the interview transcript does contain internal inconsistencies which tend to depict a flawed or failing memory. However, the fact that the Gilberts are mentioned repeatedly indicates to me that this particular recollection was fixed pretty firmly in the old boy’s mind. Let’s not write off Gene just yet.
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