---

"Christian Andersen" skrev

Date: 21. december 2004 CET 17:39
Subject: Re: Etableringen af Interstellar kommunikation
news:cq9jj6$2olk$1@news.cybercity.dk

> > Mig bekendt har vi indtil dato kun modtaget ét signal, som muligvis
> > kunne
> > stamme fra en udenjordisk civilisation. I 1973 (vist nok) blev der
> > modtaget
> > et radio-signal (Frekvens ca. 1,42 GHz vist nok), hvis varighed var på
> > henved 23 sekunder. Signalet kom fra samme retning som vor Galakses
> > centrum (Mælkevejen).
> >
> > Desværre har man ikke været særlig meddelsom vedr. oplysninger
> > desangående ....
>
> http://www.daviddarling.info/encyclopedia/W/Wow.html
>
> http://www.planetary.org/html/news/articlearchive/headlines/2001/Wow.htm
>
> http://www.bigear.org/wow.htm
>
> http://en.wikipedia.org/wiki/Wow_signal


Merci buku ...

Øh ... desværre er jeg ikke så god til engelsk, så jeg foretager lige en
data-udskrift:


Jump evt. markør ***


1.
http://www.daviddarling.info/encyclopedia/W/Wow.html

=== citat start ===

Wow! signal

An anomalous, narrow-band burst of radio noise picked up on August 15, 1977,
during SETI observations by the Big Ear of the Ohio State University Radio
Observatory. The signal, which lasted 37 seconds and came from the direction
of Sagittarius, attracted the attention of Ohio State astronomer Jerry
Ehman, who scrawled "Wow!" in the margin of the print-out. It was, said
Ehman

... the strangest signal I had ever seen ... At first, I thought it was an
earth signal reflected from space debris, but after I studied it further, I
found that couldn't be the case.

The signal was near the 21-centimeter line (1,420-MHz) of hydrogen, where
all radio transmissions are prohibited both on and off the Earth by
international agreement; it covered only a narrow spread of frequencies
unlike the broad-band emission typical of most natural radio sources; and it
came from beyond the distance of the Moon. The nearest star in the direction
the telescope was pointing is 220 light-years (68 parsecs) away. A source at
this distance using a transmitting dish as big as the Arecibo radio
telescope (the largest in the world) would require a 2.2 gigawatt
transmitter-extraordinarily powerful but not out of the question. Another
possibility is that a much weaker signal from a more remote source may have
experienced gravitational microlensing by an intervening star. More than 100
subsequent searches of the same region of sky have failed to recover the
signal. However, this is not surprising. A telescope such as the Big Ear
listens to only about one millionth of the sky at a time and a similar dish
on another planet would broadcast to only about one millionth of the sky.
The chance of an alignment between receiver and transmitter, therefore,
would only be about one in a trillion. On the other hand, it is possible
that many such, similarly strong, intermittent and highly directional
signals, are arriving at the Earth every day. Although the Wow! signal
remains unexplained, Paul Shuch of the SETI League has made the interesting
observation that

Either the Wow! signal was the intercepted radiation from another
civilization, or it's a previously undiscovered astrophysical phenomenon.
Either possibility is mind-boggling.

The Wow! signal is used as a benchmark for calibrating the sensitivity of
systems being used in Project Argus. See false alarms, in SETI.

Archived news

=== citat slut ====


2.
http://www.planetary.org/html/news/articlearchive/headlines/2001/Wow.htm

=== citat start ===

The "Wow!" Signal Still Eludes Detection
by Amir Alexander

[ ... Own-break 2004-12-21, billedtekst: ... ]
The "Wow!" Signal
(Courtesy of the Big Ear Observatory)

January 17, 2001: Whatever happened to the "Wow!" signal, the most
promising transmission from space ever detected by SETI? Ever since it was
recorded almost a quarter of a century ago, SETI enthusiasts have speculated
about its origin and wondered whether it could be a beacon from an alien
civilization. The latest attempt to relocate the signal, reported in the
January 10 issue of the Astrophysical Journal, was led by longtime SETI
researcher Robert Gray with funding from The Planetary Society. But although
Gray and his team used the entire Very Large Array in New Mexico, and
although they detected many faint objects in the signal's general vicinity,
they found no trace of an alien transmission. As of now, the "Wow" signal
remains as enigmatic as ever.

The most famous signal in SETI history was detected on the night of
August 15, 1977 at the Ohio State University Big Ear Observatory. As on
every other night, while Big Ear was searching the skies for an alien
signal, its observations were being recorded on a printout sheet. A long
list of letters and numbers was continuously being churned out, one long
string for every one of the fifty channels scanned by the telescope. A
series of characters appeared recording an unusual transmission at the
frequency of channel 2: "6EQUJ5" the list read. This startled Big Ear
volunteer Jerry Ehman, a professor at Franklin University in Columbus, who
was monitoring the readings that night. He circled the code for later
reference and added a single comment in the margins" "Wow!" The signal
entered SETI lore as the "Wow!" signal.

The series "6EQUJ5" described the strength of the received signal over
a short time-span. In the system used at the time at Big Ear, each number
from 1 to 9 represented the signal level above the background noise. In
order to extend the scale, the staff added letters, with each one from A to
Z representing increasingly stronger signal levels. 6EQUJ5 represented a
signal that grew in strength to level "U," and then gradually subsides. In
more familiar notation, the signal increased from zero to level 30 "sigmas"
above the background noise, and then decreased again to zero, all in the
span of 37 seconds.

Two aspects of this signal immediately caught the attention of Ehman
and project director John Kraus, who saw the results the following morning.
First of all, 37 seconds was precisely the time it takes the Big Ear
scanning beam to survey a given point in the heavens. Because of this, any
signal coming from space would follow precisely the "Wow!" signal's
pattern - increasing and then decreasing over 37 seconds. This practically
ruled out the possibility that the signal was the result of Earthly radio
interference.



The Big Ear Radio Telescope at Ohio State University
(Courtesy of the Big Ear Observatory)

Secondly, the signal was not continuous, but intermittent. Kraus and
Ehman knew that, because Big Ear has two separate beams that scan the same
area of the sky in succession, several minutes apart. But the signal
appeared on only one of the beams and not on the other, indicating that it
had been "turned off" between the two scans. A strong, focused, and
intermittent signal coming from outer space: could it be that Big Ear had
detected an alien signal?

For a month following the discovery the Big Ear crew tried repeatedly
to relocate the signal, but to no avail. In 1987 and again in 1989 Robert
Gray led "Wow!" searches using the 84 foot radio telescope of the Planetary
Society-funded META array at the Oak Ridge Observatory in Massachusetts, but
found nothing. For his latest "Wow!" hunt Gray managed to secure the
services of the entire Very Large Array in New Mexico, composed of twenty
seven 25-meter dishes. This, according to Gray, was a first: "Contrary to
popular belief since the movie Contact," he emphasizes, "the prestigious $80
million telescope hardly ever listens for broadcasts from the stars."

During two observing sessions in 1995 and 1996 Gray and his colleague,
Kevin B. Marvel, used their telescope time to investigate several scenarios.
One possibility was that the "Wow!" signal in fact represents a weak but
steady transmission that momentarily gained in strength due to interstellar
scintillation. The high sensitivity of the VLA guaranteed that such a source
would be easily detected by Gray's survey. But despite identifying several
radio sources hundreds of times weaker than the "Wow!" signal in the
vicinity, nothing resembling a steady transmission was found.



The Very Large Array in Socorro, New Mexico
(Courtesy of NRAO and Associated Universities, Inc.)

Another scenario assumed that "Wow!" was a brief powerful signal
designed to attract attention to a weaker continuous one. Such a strategy
would be more energy efficient than sending a continuous powerful beacon.
But again, the VLA could detect no signal even 1000 times weaker than the
original signal.

Finally there is the possibility that the signal is there, but is only
broadcast intermittently. Because of their limited telescope time, Gray and
Marvel could only devote less than an hour to any given position. It could
be that the signal is on at other times, when no one is listening. The
problem is in fact unavoidable from any location in the Northern Hemisphere,
since the "Wow!" locale is below the Northern horizon during most of the
day. To account for that possibility, Gray joined forces with Simon
Ellingsen of the University of Tasmania, who will be able to track the area
for 14 hours at a time.

To this day we do not know the source of the strongest and clearest
signal ever to come through on a SETI search. Since it was undoubtedly
artificial, and almost certainly of celestial origin, Jerry Kraus speculates
that it may have come from a space probe (human space probe, that is.) that
he and the Big Ear staff were not aware of. That would certainly make it an
intelligent celestial signal, but not an alien one. And still, there is
always the possibility that it was something else - a true signal from an
alien civilization. Unless the signal is detected again, we may never know
for sure.

To learn more about Robert Gray's search for the "Wow!" signal, see
his article in the January/February 2001 issue of The Planetary Report.

For more information on the Original "Wow!" signal, check out the Ohio
State University Big Ear Website.

=== citat slut ====


3A.
http://www.bigear.org/wow.htm

=== citat start ===

The "Wow!" Signal
By Barry Kawa

Jerry Ehman, the "Big Ear" volunteer who in 1977 saw one of the strongest
signals ever detected, poses beside the radio telescope.

From the Cleveland Plain Dealer
Sunday Magazine section, September 18, 1994

As he had done a thousand times, Jerry Ehman glanced over the Big Ear's
computer printouts, not really expecting to find anything unusual.

But what Ehman saw on that Aug. 15, 1977 - and his startled reaction - would
be recorded in radio astronomy textbooks and discussed by researchers to
this day.

Click here for explanation of the code.
[ ... Own-break 2004-12-21, see 3B ... ]

The Columbus man saw a signal so strong that it catapulted the Big Ear's
recording device off the chart. An excited Ehman scribbled "Wow!" on the
printout, a tag that is indelibly linked to the recording.

"I mean, without thinking, I wrote 'Wow!' " Ehman recalls. "It was the most
significant thing we had seen."

Could it be man's first contact with extraterrestrial intelligence? Ohio
State University researchers weren't sure. They trained the massive scope on
that part of the sky for the next month, and have returned periodically
since.

The signal hasn't been recorded again. And although many point to it as a
possible extraterrestrial intelligence sighting, Ehman remains less
convinced.

"Even if it were intelligent beings sending a signal, they'd do it far more
than once," Ehman, now 54, says. "We should have seen it again when we
looked for it 50 times. Something suggests it was an Earth-bound signal that
simply got reflected off a piece of space debris."

Ehman was working as a volunteer then. He had worked at OSU as an assistant
professor in electrical engineering and astronomy, but when the National
Science Foundation cut its funding to the Big Ear in 1972, Ehman was let go,
although he stayed on on a volunteer basis.

He then worked as a professor at Franklin University in Columbus, until his
retirement about a year ago [1993]. Ehman recently rejoined the Big Ear's
volunteer staff.

Now, Ehman is a mini-celebrity. Other volunteers ask him about the famous
"Wow!" signal and it's often mentioned in the meetings. Journalists call him
whenever they write about the Big Ear.

"I just wish when I talked to journalists, there was really something more
to say about it. I'd like to say, 'Gee, that's a signal from
extraterrestrial intelligence," Ehman says with a laugh. "I honestly can't
do that."

Ehman's scientific training won't let him spin a good yarn. But, he says if
the Big Ear staff could have detected the "Wow!" signal again, they might
have been able to identify it.

So, until some listener is knocked off his seat again and the "Wow!" signal
is rediscovered, Ehman's finding remains only a curious historical footnote.

"I can speculate, too, but there's nothing to back it up," Ehman adds.

=== citat slut ====

samt ...

3B.
=== citat start ===

Explanation of the Code "6EQUJ5"
On the Wow! Computer Printout

By Jerry Ehman

The photo of the computer printout of the Wow! source shows not only my
handwritten comment ("Wow!") but also the circling of the 6 characters
"6EQUJ5" lined up vertically in a column. What is the meaning of this code?

Each of the first 50 columns of the computer printout shows the successive
values of intensity (or power) received from the Big Ear radio telescope in
each channel (10 kHz wide) in successive 12-second intervals (10 seconds was
used for actual sampling and another approximately 2 seconds was needed for
computer processing). In order to conserve space on the printout, Bob Dixon
and I decided to use a coding method that would result in only one
alphanumeric (i.e., either alphabetic or numeric) character for each
intensity. The computer was programmed to keep a continuously-updated
account for each channel of a baseline value and an rms value (rms stands
for "root mean square", which is equivalent to the statistical term
"standard deviation"). The actual intensity (after the baseline value was
subtracted out) was then divided by the rms value to obtain a scaled value
(i.e., the number of standard deviations above the baseline). Since there
was space for only one character to be displayed, we decided to take only
the integer value of this scaled intensity for values in the range 0 to
9.999... . The truncated value of zero was printed as a blank (space). The
truncated value of 1, 2, 3, 4, 5, 6, 7, 8, and 9 were printed directly. For
scaled intensities of 10 to 35, inclusive, the capital letters of the
alphabet were used. Thus a truncated value of 10 was printed as an "A", 11
as a "B", etc. If the scaled intensity ever got to 36.0 or above, the
program would simply start over again at zero (e.g., a truncated value of 38
would be printed the same as that of 38-35=3, namely a "3").

Thus, the "6EQUJ5" code in channel 2 means successive intensities as
follows:
6 --> the range 6.0 - 6.999...
E --> the range 14.0 - 14.999...
Q --> the range 26.0 - 26.999...
U --> the range 30.0 - 30.999...
J --> the range 19.0 - 19.999...
5 --> the range 5.0 - 5.999...

The value "U", meaning the range 30.0 - 30.999..., was the largest value
ever seen. We do not believe that the intensity ever got above 31.0 and
hence no rollover (subtraction of 35) ever occurred. It would have been easy
to spot in a sequence of 6 or 7 numbers that should follow the antenna
pattern of the telescope.

The six successive values in channel 2 fit the antenna pattern of Big Ear
very well. I have also done a correlation analysis of the six data points
with the mathematical functions: (1) gaussian = normal curve; and
(2)(sin(x)/x)^2. The data fit each of those two functions very well with
correlation coefficients of over 0.99 (i.e., almost a perfect fit). I also
fit the data to each of the two actual antenna patterns (of the two horns)
using the moderately strong radio source OY372. The correlation coefficients
were again over 0.99. There was not enough difference between the two
correlation coefficients to determine which horn the Wow! source was
received in.

=== citat slut ====


4.
http://en.wikipedia.org/wiki/Wow_signal

=== citat start ===

Wow! signal

From Wikipedia, the free encyclopedia.

(Redirected from Wow signal)

The Wow! signal was a strong narrowband radio signal detect by the
astrophysicist Jerry R. Ehman on August 15, 1977 by a SETI project at the
Big Ear radio telescope of Ohio State University, that is apparently of
non-terrestrial and non-solar system origin. It lasted for 72 seconds and
has not been detected thereafter. All searches sofar for the signal were
unsuccessful, both by J. R. Ehman and others. The real nature of the signal
is therefore unknown, only a few possibilities can be ruled out.

The bandwidth of the signal is less than 10 kHz. Two different values for
its frequency has been given, 1420.356 MHz (J. D. Kraus) and 1420.456 MHz
(J. R. Ehman), but both very close to the the frequency of 1420.405 MHz
produced by the hyperfine transition neutral hydrogen in the universe. Also
two possible equatorial coordinates are given: R.A. = 19h22m22s ± 5s or
19h25m12s ± 5s, and both dec. = -27°03´ ± 20´ (epoch B1950.0).

Amazed by the signal, how the narrowband it was, and the exact match to the
intensity variation a localized signal would produce in the antenna used, J.
R. Ehman circled on the computer printout the "6EQUJ5" letter code (the
intensities detected are coded by space = intensity 0, "1"-"9" = intensities
1-9, "A" = intensity 10, "B" = intensity 11, and so on) of the intensity
variation and wrote the comment "Wow!" on its side. This comment became the
name of the signal.

It has been speculated whether interstellar scintillation of a weaker
continuous signal - similar to the effect of atmospheric twinkling - could
be a possible explanation (although this still would not exclude the
possibility for the signal being artificial in its nature). However, even by
using the significantly more sensitive Very Large Array, such a signal could
not be detected, while the likelihood of a signal below the Very Large Array
level could be detected by the Big Ear radio telescope due to interstellar
scintillation is extremely low, less than 10-40.

[edit]
Reference
a.. About The Wow! Signal
(http://web.archive.org/web/20030210203047/www.bigear.org/wowmenu.htm) (Big
Ear Observatory's web site from the Internet Archive)

b.. A. Alexander, "The 'Wow!' Signal Still Eludes Detection"
(http://www.planetary.org/html/news/articlearchive/headlines/2001/Wow.htm)

c.. S. Shostak, "Interstellar Signal From the 70s Continues to Puzzle
Researchers"
(http://www.space.com/searchforlife/seti_shostak_wow_021205.html)

d.. R. H. Gray & K. B. Marvel, "A VLA Search for the Ohio State 'Wow'",
Astrophys. J. 546, 1171-1177 (2001).
(http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v546n2/40506/40506.
html)

e.. R. H. Gray & S. Ellingsen, "A Search for Periodic Emissions at the Wow
Locale", Astrophys. J. 578, 967-971 (2002).
(http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v578n2/54084/brief/
54084.abstract.html)

Retrieved from "http://en.wikipedia.org/wiki/Wow!_signal"

=== citat slut ====


***


Skønt jeg ikke er god til engelsk, gav det alligevel en hel del oplysninger:


1.
Datoen:
August 15, 1977 (kilde 1, 2, 3 samt 4)


2.
Varigheden:
37 seconds (kilde 1 samt 2)

Kilde 3B:
>
> Each of the first 50 columns of the computer printout shows the successive
> values of intensity (or power) received from the Big Ear radio telescope
> in each channel (10 kHz wide) in successive 12-second intervals (10
> seconds was used for actual sampling and another approximately 2 seconds
> was needed for computer processing).

Kilde 4:
>
> It lasted for 72 seconds and
> has not been detected thereafter.

samt henvisningen ...
>
> c.. S. Shostak, "Interstellar Signal From the 70s Continues to Puzzle
> Researchers"
> (http://www.space.com/searchforlife/seti_shostak_wow_021205.html)


3.
Frekvensen:

Kilde 4:
>
> The bandwidth of the signal is less than 10 kHz. Two different values for
> its frequency has been given, 1420.356 MHz (J. D. Kraus) and 1420.456 MHz
> (J. R. Ehman), but both very close to the the frequency of 1420.405 MHz
> produced by the hyperfine transition neutral hydrogen in the universe.


4.
Amplityden
6EQUJ5
(1-9,A(10)-Z(35) = antal enheder over beggrundsstøjen)

Dette skulle give:

Kilde 3B:
>
> 6 --> the range 6.0 - 6.999...
> E --> the range 14.0 - 14.999...
> Q --> the range 26.0 - 26.999...
> U --> the range 30.0 - 30.999...
> J --> the range 19.0 - 19.999...
> 5 --> the range 5.0 - 5.999...

Et grafisk billed kommer da til at se nogenlunde således ud:

30_______________________________________0______________________________
29____________________________________0___0_____________________________
28_________________________________0_______0____________________________
27_______________________________0__________0___________________________
26_____________________________0_____________0__________________________
25____________________________0_______________0_________________________
24____________________________0________________0________________________
23___________________________0_________________0________________________
22__________________________0___________________0_______________________
21__________________________0____________________0______________________
20_________________________0______________________0_____________________
19________________________0________________________0____________________
18_______________________0__________________________0___________________
17______________________0____________________________0__________________
16_____________________0_____________________________0__________________
15____________________0_______________________________0_________________
14___________________0_________________________________0________________
13__________________0__________________________________0________________
12_________________0____________________________________0_______________
11_______________0_______________________________________0______________
10______________0________________________________________0______________
09_____________0__________________________________________0_____________
08____________0____________________________________________0____________
07__________0______________________________________________0____________
06_________0________________________________________________0___________
05________0__________________________________________________0__________
04_______0_____________________________________________________0________
03_____0_________________________________________________________0______
02___0_____________________________________________________________0____
01_0_________________________________________________________________0__
00_________0_________0_________0_________0_________0_________0_________0

Og det ser da i grunden meget fornuftigt ud ...

Man kan dog *undre* sig over, at kurven hælder.

Dette burde vi da ikke have forventet, dersom vi antager, at det har været
et radio-fyrtårn (i bevægelse), som har udsendt signalet, eller hva' ?

I Kilde 3B (af Jerry Ehman) står der, at ...
>
> The six successive values in channel 2 fit the antenna pattern of Big Ear
> very well. I have also done a correlation analysis of the six data points
> with the mathematical functions: (1) gaussian = normal curve; and
> (2)(sin(x)/x)^2. The data fit each of those two functions very well with
> correlation coefficients of over 0.99 (i.e., almost a perfect fit). I also
> fit the data to each of the two actual antenna patterns (of the two horns)
> using the moderately strong radio source OY372. The correlation
> coefficients
> were again over 0.99. There was not enough difference between the two
> correlation coefficients to determine which horn the Wow! source was
> received in.

Kilde 2 kommenterer da også (dog mht. tiden, de 37 sek.), at ...

> ... This practically
> ruled out the possibility that the signal was the result of Earthly radio
> interference.

.... altså et falsk signal (fra en "støjsender" på jorden).


5.
Overvågning:

Kilde 2 angiver, at ...

> ... University of Tasmania, who will be able to track the area
> for 14 hours at a time.


6.
Retningen:

Kilde 4:
>
> ... Also
> two possible equatorial coordinates are given: R.A. = 19h22m22s ± 5s or
> 19h25m12s ± 5s, and both dec. = -27°03´ ± 20´ (epoch B1950.0).

Hmm ... hvorfor er der hele *2* RA-målinger, og hvorfor er de forskellige ?

Kilde 1:
>
> The nearest star in the direction the telescope was pointing is 220
> light-years (68 parsecs) away. A source at this distance using a
> transmitting dish as big as the Arecibo radio telescope (the largest in
> the
> world) would require a 2.2 gigawatt transmitter-extraordinarily powerful
> but not out of the question.

Kernen i vor galakse er på position RA 17t 42m, Dec. -29°

Vores position skønnes at være ret tæt på galaksens skive, idet bæltet
omtrent gennemskærer punktet Lon 180° Lat. 0°.

Med andre ord:
Dersom Liv-2 udsender fra en radio-fyrtårn, som udsender til *hele*
galakse-skiven ved at dreje hele omkredsen rundt, da er vi en potentiel
modtager ...

Søgning 1:
Searching NED within 50.0 arcmin of 19h22m22.00000s, -27d00m00.0000s
224 objects found in NED.

Søgning 2:
Searching NED within 50.0 arcmin of 19h25m12.00000s, -27d00m00.0000s
199 objects found in NED.


Det interessante (set fra vores position) er, at punktet 19h22m, -27d
befinder sig i en ret linie ca. halvvejs mellem to stjerner (Ypsilon og
Rho-1, NB! Måske har jeg aflæst de græske bogstaver forkert).

Punktet 19h25m, -27d befinder sig ligeledes halvvejs mellem disse stjerner,
dog noget forskudt, således at de 3 punktet tilsammen danner nærmest en
retvinklet trekant.

Der er *ingen* andre synlige objekter i nærheden, når vi bruger en lille
kikkert!

Er dette en tilfældighed ?

Eller er der her tale om en art 3-D måde at identificere sig selv på ?

Er der noget til stede som kan give os informationer om de to stjerner, dels
deres afstand herfra, dels deres spektralklasse ?

Informationerne skal evt. bruges i tilknytning til ...
3494 news:O5Vxd.76662$Vf.3625030@news000.worldonline.dk

-

Som sagt ... mange tak Christian ...


Med venlig hilsen,
Mogens Kall, The servant of Michael
--
SETI: Win (vind) 3500 Danish Kr. (around 600 US $), jump ...
3493 news:UIMxd.76610$Vf.3624746@news000.worldonline.dk
(use perhaps http://www.google.dk/grphp )
File-number: 3500