Sometime in the past week, or three (time blurs when laboring hours on the new website), I promised to tell you about my personal encounter with an LDE or long delayed echo. The reason is that this is very special territory for the inquiring minds who want to know and it is very well-established by real science as being a replicable phenomena.
So what, exactly, is a “long delayed echo?” A clip from Wikipedia in the interest of being concise because I could go on for hours about it:
“Long delayed echoes (LDEs) are radio echoes which return to the sender several seconds after a radio transmission has occurred. Delays of longer than 2.7 seconds are considered LDEs. LDEs have a number of proposed scientific origins.
These echoes were first observed in 1927 by civil engineer Jørgen Hals from his home near Oslo, Norway. Hals had repeatedly observed an unexpected second radio echo with a significant time delay after the primary radio echo ended. Unable to account for this strange phenomenon, he wrote a letter to Norwegian physicist Carl Størmer, explaining the event:
At the end of the summer of 1927 I repeatedly heard signals from the Dutch short-wave transmitting station PCJJ at Eindhoven. At the same time as I heard these I also heard echoes. I heard the usual echo which goes round the Earth with an interval of about 1/7 of a second as well as a weaker echo about three seconds after the principal echo had gone. When the principal signal was especially strong, I suppose the amplitude for the last echo three seconds later, lay between 1/10 and 1/20 of the principal signal in strength. From where this echo comes I cannot say for the present, I can only confirm that I really heard it.
Physicist Balthasar van der Pol helped Hals and Stormer investigate the echoes, but due to the sporadic nature of the echo events and variations in time-delay, did not find a suitable explanation.
Long delayed echoes have been heard sporadically from the first observations in 1927 and up to our time.”
My own LDE experience occurred in 1966, or thereabouts. It was a weekend morning,and I was on the 20-meter band using my old Johnson Pacemaker SSB transmitter at 90-watts and my somewhat improved-upon NC-300 receiver. I was on upper sideband, I was not running the amplifier, the antenna was multi-band inverted-vee at 40-feet (strung off the top of a piece of 4” irrigation pipe that another ham and I had carried on our shoulders 13-miles to get it to my house). The season was fall or spring, since the band was just opening up, and it was sunny as I recall since sun was coming into my basement ham shack which would have placed the time about 10:00 to 11:30 AM because that was when the sun came in….our house was on a hill so the basement window only got about 2-hours of sun at best.
I was calling “CQ 20, CQ 20” which is radio-ese for “Looking for someone to talk to…
As I un-keyed the mic to listen for a returning station, you can imagine my shock when I heard….ME! Except it was me delayed by 3.4 seconds, calculated from saying my then call sign and measuring the portion I’d heard on a digital sound rig much later in life.
Significantly, the signal was dead-to-nuts on frequency and it was S-9 to 20 dB over S-9 so it was stronger than heck against a very low noise level (S-2 to S-3).
I didn’t learn about LDE’s until after I had aced my First Class Commercial ticket around that time frame, so thinking back on the issue date of that (December ‘66) I reckon this took place in the fall when I was a high school senior and a nerd’s nerd in things electronic.
For the period right after the event, I was convinced it was someone simply recording my signal and playing it back with a tape recorder. But when I heard a good chunk of myself asking “…are you playing with me?” come back, I realized that there was almost no chance that someone could record and retransmit my signal that quickly for technical timing reasons that would bore you to tears.
Yes, that was an encounter with a long delayed echo. Mentally the effect would be as if you’d got to a mountain valley, yelled something, not been waiting for an echo, and then hearing just a single echo….no later ones fading off into the distance. One, clean, unambiguous you. And just to compare the delay, in sound it would be like yelling and hearing that one return of your own voice something like 10-minutes later…which I think you’d agree, would be a stumper indeed because damn it, physics isn’t supposed to work that way.
Unfortunately, there are five competing theories about what causes a long-delayed echo – and remember as you think about these that radio waves move around at a pretty good speed: 186,000 miles per second, plus or minus a speeding ticket.
1. The most often use explanation is that “ducted propagation” in involved. This is one that I have never bought into because the phenomena is noted from the lower reaches of the shortwave bands up through 1.250 gigahertz and may exist higher.
Also, because the delay times often run in the 4-5 seconds (encounter with them was about 3.4 seconds). The math on this is pretty impressive: At 4-seconds, a radio wave would have to travel 744,000 miles and return to the original sending station. If we assume a low ducting path, that would mean a radio signal would have to go around the Earth 12-13 times.
Even on a really good day, transequatorial ducting doesn’t do that well. (If you don’t know what TE/ducting subset of transequatorial propagation, in general is, a ham radio easy to follow discussion is here and if you’re a retentive EE type, try this link on for size.)
2.”Normal” propagation is sometimes cited, but there are two reasons not to buy this idea. For one, radio waves are subject to inverse-square law declines of signal strength. So that in my case doesn’t fit. And in the second case, the phenomena is noticed well up into the UHF range and this means that the signals can’t be going around the world since above the maximum usable frequency (MUF) the radio waves should head off into space as the reflectivity of the F2 layer goes kaput above the MUF. (The MUF comes down at night which is why you can hear far away AM radio, yada, yada…
3. Signals couple of plasma in the upper atmosphere may sound appealing, but what are the odds that a) conversion would not be noted as such a wide range of frequencies and b) why would such signals decide to arbitrarily come back to their starting point with almost no reduction is strength after as much as 12-15 seconds? This one makes no sense to me.
4. Reflection from distant plasma clouds? Well, nice, but no cigar. Remember the signal I heard? It was not a low-strength signal bounce. This was S-9 to 20-over. No way in hell could a plasma cloud provide that signal strength given the inverse-square law as we know it.
5. Last, but not least is the non-linearity plus mode conversion plasma coupling model. Except that there would be presumably some frequency shift or at least phasing sound and no, in my case it was just good, clear, clean SSB and it sounded identical to what I was hearing on the receiver in my ham shack as I always monitored my transmit signal.
So what else might explain what’s going on? This gets a little complicated but the ARXIV.org website contains this fascinating paper circa 2010 under the heading:
Geometrical joke(r?)s for SETI.
R. T. Faizullin
OmSTU, Omsk, Russia at http://arxiv.org/ftp/arxiv/papers/1007/1007.4054.pdf
Fazullin’s paper is an awesome attack on the fundament mystery of the LDE phenomena and one of the possibilities that he gets top (if you suffer through the the introductory 36-pages of serious math) comes down to the possibility of radio beacon of some kind on the moon!
“Note, that point number 8 corresponds to the Crater Aristillus, the first well-known Greek astronomer, who wrote his work ”About fixed stars” even before Hipparchus. So we finally came back to stars again. If it really is a message, then it’s done elegantly! Also, pay attention to the fact
that this crater is only one degree shifted from the primary meridian (on the aim), so the location of the artefact may be either inside the crater or on the line of intersection of the primary meridian and the crater. This limits the area of search to several hundred square meters.”
All of which is admittedly a very long discussion of the Long Delayed Echo phenomenon, and Fazullin’s heavy math. But it gets us to a very interesting bit of speculation that Arthur C. Clarke may have either been quite prescient or privileged to extraordinary knowledge when he wrote a “science fiction” books called “The Sentinel” which would later be turned into the movie “2001: A space Odyssey.” As Wikipedia sums up the plot line:
The story deals with the discovery of an artifact on Earth’s Moon left behind eons ago by ancient aliens. The object is made of a polished mineral, is tetrahedral in shape, and is surrounded by a spherical forcefield. The narrator speculates at one point that the mysterious aliens who left this structure on the Moon may have used mechanisms belonging “to a technology that lies beyond our horizons, perhaps to the technology of para-physical forces.”
The narrator speculates that for millions of years (evidenced by dust buildup around its forcefield) the artifact has been transmitting signals into deep space, but it ceases to transmit when, sometime later, it is destroyed “with the savage might of atomic power”. The narrator hypothesizes that this “sentinel” was left on the moon as a “warning beacon” for possible intelligent and spacefaring species that might develop on Earth.
In 2001: A Space Odyssey, the operation of the sentinel is reversed. It is the energy of the sun, falling for the first time on the uncovered artifact, that triggers the signal that creatures from the Earth had taken the first step into space.
Which leaves us with a ponder and a task.
The task first: If you’re a ham radio operator, try pointing your beam on the various HF bands at the rising moon for a half hour on each of the HF bands where you have a good antenna and even if the band is otherwise dead. Call “CQ” and listen for LDEs from the moon. If Fazullin is right, you should hear some.
Which leaves us with two ponders: The first is about Clarke: Was he aware of this phenomenon and was it moon-related?
And further, did someone leave a transponder up there and is that why the nations of Earth haven’t been particularly interested in going back to the moon? Seems the PowersThatBe have a pretty good gig going…so much so, that much might be explained by a slow disclosure path controlled by those in powerful places.
You might want to watch 2001 again…Fazullin may be right!
Was Star Trek Telling Us Something
Just for entertainment value, you may be interested in the article over at the 2012TheBigPicture site which explores how both the TV show and follow-on movies in the Star Trek series had a lot of ‘high tech’ in them that seems almost to be of predictive nature.
I’m not quite sold. As I point out (endlessly) Chester Gould had Dick Tracy using the wrist-radio long before cell phones, not to mention Diet Smith’s anti-gravity approach which involved putting a series of “gravity amplifiers” on his space car….which led Dick to Moon girl and….well, let’s not go there. My point is simply that Gene Roddenberry was a most excellent fellow and all, but the case for him having “insider secrets” is weak.
A lot of writers throughout history have been able to envision logical developments of future from simply extrapolating where things are today. Being able to leap tall buildings is still not quite practical unless you have a backpack rocket system (although these exist) and we certainly have flying faster than a speeding bullet down.
Bending steel with our bare hands and stopping locomotives always seemed like dumb benchmarks of humanity. I’ll stick to my Victor welding rig and box and pan break for the bending jobs and when it comes to locomotives, no need to stop them.
Amtrak does that just fine, and mostly intentionally.
Captain Midnight’s Lightning Adventure
Captain Midnight is very busy these days, sends his regrets, but in the Captain’s world, times like this are spent very busily looking after the interests of the country we so much enjoy.
Oh, and cleaning up from his lightning strike.
If I follow the gist of what happened, seems Thursday evening it was pouring down cats and dogs where the Capt’n lives. And his home, which will celebrate its 200th birthday shortly has this very old and porous chimney.
Said chimney was very wet on the outside and when lightning appeared in the area, his chimney acted like an attractor for a side-strike off a nearby strike and Mrs. Capt’n reported seeing “electricity dance” on the inside of the chimney.
The Capt’n himself was quite taken back by events. Normally the only thing coming down a chimney should be old St. Nick and we’re about six months out of phase for something like that to be happening. He was also taken aback by the damage which was mostly limited to wiring, blowing out and light fixtures and so forth.
Still, he promises to share more as field work (brush-hogging), real work (keeping us safe), and now – getting things back into pre-lightning condition – permit.
He did offer a short observation in his part of ‘Merica, though, quite the talk of local farmerly types in his area: On a recent morning (within the past few) is was 58 F. outside on his porch as he trundled off. “Never been like that before,” he reports.
Normally this time of year temps in the morning run in the very high 60’s to mid-70’s. The Capt’n isn’t so sure he believes all this global warming stuff, either. Being another data-driven sort, he too is collecting data. But with the pole flip on the Sun (as noted in the previous section) we have to note that the Capt’n is a serious farmer himself as time allows.
And I had a call from a fellow down in Houston yesterday…another worker in the public’s behalf. He’s looking at a “back-up” place up in our neck of the woods. Which gets me to pondering the implications of more people (bright and extremely well-informed) eyeing the exits, or at least looking for a recreation/back-up place outside of a large city.
Can’t say as I blame them, especially when for less than $100,000 there are still foreclosure bargains to be had in the hinterlands. And our friends who make large returns in the tax lien investment arena are still finding deals offering double-digit returns in what’s otherwise a pretty dismal investment environment.
This Forbes article from last winter, by the way, is a good overview of tax lien investing if you’re wondering how to deploy your mattress money at something better than bank depreciation.
The charts are bigger this morning. Check.
Mention I will be posting as section are complete, not necessarily 7:55 AM presactly? Check.
I have the links opening on new tabs now which should help site performance. Check.
I posted a set of instructions for how to eliminate one click so it’s not such a shock to the senses to read more on this site. Check.
Migrating to full-on cloud with a VPS will be done this weekend (mention some tweaking with be going on attendant to that on Saturday and Sunday). Check.
And remind people that I am, at heart, a geek among geeks and to steal a corporate positioning statement to (ostensibly) non-commercial use: progress is our most important product.
Coming up tomorrow for Peoplenomics. subscribers:
Mr. Ure’s visual course in radiation survey meter periodic maintenance. With fears for terrs about, we will, as always, plan for the worst and hope for the best!