Some time back[1], I read a short work that portrayed SETI researchers
in various solar systems all sitting back and waiting to receive a
signal from somebody else.

It appears that the situation is about to change:
<https://phys.org/news/2022-04-blasting-earth-potential-aliens-controversial.html>
tells about it, and gives us a new initialism: "Messaging Extra-Terrestrial
Intelligence".

What could possibly go wrong? Well, you could look at the Inhibitors Universe
of Alastair Reynolds. Or if that's too recent for you, how about Fred
Saberhagen's Berserkers?

What other SF suggests that this might be a bad idea?

(The article mentions Cixin Liu's _The Three-Body Problem_. I've
read that, but never knew what was going on.)

[1] I think that it was a "Probability Zero" piece in the early 1990s.

--
Michael F. Stemper
This sentence no verb.

On Saturday, April 30, 2022 at 10:01:47 AM UTC-4, Michael F. Stemper wrote:
> Some time back[1], I read a short work that portrayed SETI researchers
> in various solar systems all sitting back and waiting to receive a
> signal from somebody else.
>
> It appears that the situation is about to change:
> <https://phys.org/news/2022-04-blasting-earth-potential-aliens-controversial.html>
> tells about it, and gives us a new initialism: "Messaging Extra-Terrestrial
> Intelligence".
>
> What could possibly go wrong? Well, you could look at the Inhibitors Universe
> of Alastair Reynolds. Or if that's too recent for you, how about Fred
> Saberhagen's Berserkers?
>
> What other SF suggests that this might be a bad idea? [snip]

Inviting the Achuultani (from David Weber's Dahak trilogy) over for dinner
may not be the best idea ever. Attracting the attention of the main
antagonists in the Worm Web serial is up there as well.

In article <t4jfg7$2pp$1@dont-email.me>,
Michael F. Stemper <michael.stemper@gmail.com> wrote:
>Some time back[1], I read a short work that portrayed SETI researchers
>in various solar systems all sitting back and waiting to receive a
>signal from somebody else.

Welllll... Gunn's excellent _The Listeners_ has a team listening
at Arecibo, just about to be shut down from lack of results when
they pick up a Drake picture whose zeroes are silence and whose
ones are fragments of radio broadcasts from the 1930s. All sorts
of stuff, not excluding wackiness, ensues. Splendid ending.
>

So our lot, at least, have been signaling for most of a century,

--
Dorothy J. Heydt
Vallejo, California
djheydt at gmail dot com
Www.kithrup.com/~djheydt/

On 4/30/2022 9:35 AM, Dorothy J Heydt wrote:
> In article <t4jfg7$2pp$1@dont-email.me>,
> Michael F. Stemper <michael.stemper@gmail.com> wrote:
>> Some time back[1], I read a short work that portrayed SETI researchers
>> in various solar systems all sitting back and waiting to receive a
>> signal from somebody else.
>
> Welllll... Gunn's excellent _The Listeners_ has a team listening
> at Arecibo, just about to be shut down from lack of results when
> they pick up a Drake picture whose zeroes are silence and whose
> ones are fragments of radio broadcasts from the 1930s. All sorts
> of stuff, not excluding wackiness, ensues. Splendid ending.
>>
>
> So our lot, at least, have been signaling for most of a century,
>
And have, intermittently, been doing so deliberately for several
decades. Plus, ya know, the Voyager probes....

--
I've done good in this world. Now I'm tired and just want to be a cranky
dirty old man.

On Saturday, 30 April 2022 at 15:01:47 UTC+1, Michael F. Stemper wrote:
> Some time back[1], I read a short work that portrayed SETI researchers
> in various solar systems all sitting back and waiting to receive a
> signal from somebody else.
>
> It appears that the situation is about to change:
> <https://phys.org/news/2022-04-blasting-earth-potential-aliens-controversial.html>
> tells about it, and gives us a new initialism: "Messaging Extra-Terrestrial
> Intelligence".
>
> What could possibly go wrong? Well, you could look at the Inhibitors Universe
> of Alastair Reynolds. Or if that's too recent for you, how about Fred
> Saberhagen's Berserkers?
>
> What other SF suggests that this might be a bad idea?
>
> (The article mentions Cixin Liu's _The Three-Body Problem_. I've
> read that, but never knew what was going on.)
>
>
> [1] I think that it was a "Probability Zero" piece in the early 1990s.

I don't think this happens in the film _Independence Day_
but audio <https://en.wikipedia.org/wiki/Independence_Day_UK>
sets up, as was broadcast anyway, as the BBC finishing a week
of coverage of possible alien life, and transmitting signals to
communicate with the aliens. Whereupon one or more giant
saucers launch from the Moon and wreak destruction.
Or something like that. There's some loving imitation of
Orson Welles's _The War of the Worlds_ radio play, and
real or imitated British celebrities in this show.

Michael F. Stemper <michael.stemper@gmail.com> wrote:
> Some time back[1], I read a short work that portrayed SETI researchers
> in various solar systems all sitting back and waiting to receive a
> signal from somebody else.
>
> It appears that the situation is about to change:
> <https://phys.org/news/2022-04-blasting-earth-potential-aliens-controversial.html>
> tells about it, and gives us a new initialism: "Messaging Extra-Terrestrial
> Intelligence".
>

It's when the mission statement morphs into "Hiding from Extra-Terrestrial
Intelligence" that things get starts getting _really_ interesting.

--
Leif Roar Moldskred

On 30/04/2022 11.35, Dorothy J Heydt wrote:
> In article <t4jfg7$2pp$1@dont-email.me>,
> Michael F. Stemper <michael.stemper@gmail.com> wrote:
>> Some time back[1], I read a short work that portrayed SETI researchers
>> in various solar systems all sitting back and waiting to receive a
>> signal from somebody else.
>
> Welllll... Gunn's excellent _The Listeners_ has a team listening
> at Arecibo, just about to be shut down from lack of results when
> they pick up a Drake picture whose zeroes are silence and whose
> ones are fragments of radio broadcasts from the 1930s.

I remember the picture, but did not remember the composition of the
ones. I thought that I had reread this in the last few years, but my
book log says that my definition of "the last few years" still includes
2006.

As far as aliens picking up our domestically-oriented radio broadcasts
is concerned, it ain't gonna happen. Those whole dislike arithmetic
are advised to skip the rest of this post.

Figure 50 kW for the total power output of an AM radio station.
At 8 km (5 miles) it's going to be spread out over a sphere with
radius of 8 km. This means that that power is going to be about
6E-9 watts per square meter (W/m^2).

What happens by the time that the signal gets out to a distance
of one light year (about 9.5E15 m)? The same power is now spread
over a much larger sphere, so that the power density is down to
about 4.4E-29 W/m^2.

Let's look at that original AM radio broadcast. Assume that it was
towards the top of the AM band; say 1310 kHz. Each photon would
have about 9E-28 joules of energy.

Do the division, and we see that that works out to roughly one
photon per second per 20 square meters. Not a lot of signal
strength left. At only one light year.

Nobody in another solar system is ever going to hear Fibber McGee
open his closet, or hear Tonto say, "What you mean 'we', white man?"

--
Michael F. Stemper
A preposition is something you should never end a sentence with.

On 30/04/2022 12.20, Dimensional Traveler wrote:
> On 4/30/2022 9:35 AM, Dorothy J Heydt wrote:

>> Welllll... Gunn's excellent _The Listeners_ has a team listening
>> at Arecibo, just about to be shut down from lack of results when
>> they pick up a Drake picture whose zeroes are silence and whose
>> ones are fragments of radio broadcasts from the 1930s.  All sorts
>> of stuff, not excluding wackiness, ensues.  Splendid ending.
>>>
>>
>> So our lot, at least, have been signaling for most of a century,
>>
> And have, intermittently, been doing so deliberately for several decades.  Plus, ya know, the Voyager probes....

Well, they're not going to be delivering those records any time soon.
Per NASA[1]:

[...] if we define our solar system as the Sun and everything
that primarily orbits the Sun, Voyager 1 will remain within the
confines of the solar system until it emerges from the Oort cloud
in another 14,000 to 28,000 years.

By that time, the Record Club will be out of business, and the aliens
won't need to pay shipping to return the record.

--
Michael F. Stemper
Exodus 22:21

On 30/04/2022 15.00, Michael F. Stemper wrote:

> Well, they're not going to be delivering those records any time soon.
> Per NASA[1]:
>
>   [...] if we define our solar system as the Sun and everything
>   that primarily orbits the Sun, Voyager 1 will remain within the
>   confines of the solar system until it emerges from the Oort cloud
>   in another 14,000 to 28,000 years.
>
> By that time, the Record Club will be out of business, and the aliens
> won't need to pay shipping to return the record.

Dang! I forgot the citation:

[1] <https://solarsystem.nasa.gov/missions/voyager-1/in-depth/>

--
Michael F. Stemper
Exodus 22:21

On 4/30/2022 1:00 PM, Michael F. Stemper wrote:
> On 30/04/2022 12.20, Dimensional Traveler wrote:
>> On 4/30/2022 9:35 AM, Dorothy J Heydt wrote:
>
>
>>> Welllll... Gunn's excellent _The Listeners_ has a team listening
>>> at Arecibo, just about to be shut down from lack of results when
>>> they pick up a Drake picture whose zeroes are silence and whose
>>> ones are fragments of radio broadcasts from the 1930s.  All sorts
>>> of stuff, not excluding wackiness, ensues.  Splendid ending.
>>>>
>>>
>>> So our lot, at least, have been signaling for most of a century,
>>>
>> And have, intermittently, been doing so deliberately for several
>> decades.  Plus, ya know, the Voyager probes....
>
> Well, they're not going to be delivering those records any time soon.
> Per NASA[1]:
>
>   [...] if we define our solar system as the Sun and everything
>   that primarily orbits the Sun, Voyager 1 will remain within the
>   confines of the solar system until it emerges from the Oort cloud
>   in another 14,000 to 28,000 years.
>
> By that time, the Record Club will be out of business, and the aliens
> won't need to pay shipping to return the record.
>
One of them has apparently gotten past or into the heliopause (IIRC)
which is another potential definition for "outer edge of the solar system".

--
I've done good in this world. Now I'm tired and just want to be a cranky
dirty old man.

On Saturday, April 30, 2022 at 3:36:15 PM UTC-4, Michael F. Stemper wrote:
> On 30/04/2022 11.35, Dorothy J Heydt wrote:
> > In article <t4jfg7$2pp$1...@dont-email.me>,
> > Michael F. Stemper <michael...@gmail.com> wrote:
> >> Some time back[1], I read a short work that portrayed SETI researchers
> >> in various solar systems all sitting back and waiting to receive a
> >> signal from somebody else.
> >
> > Welllll... Gunn's excellent _The Listeners_ has a team listening
> > at Arecibo, just about to be shut down from lack of results when
> > they pick up a Drake picture whose zeroes are silence and whose
> > ones are fragments of radio broadcasts from the 1930s.
> I remember the picture, but did not remember the composition of the
> ones. I thought that I had reread this in the last few years, but my
> book log says that my definition of "the last few years" still includes
> 2006.
>
> As far as aliens picking up our domestically-oriented radio broadcasts
> is concerned, it ain't gonna happen. Those whole dislike arithmetic
> are advised to skip the rest of this post.
>
> Figure 50 kW for the total power output of an AM radio station.
> At 8 km (5 miles) it's going to be spread out over a sphere with
> radius of 8 km. This means that that power is going to be about
> 6E-9 watts per square meter (W/m^2).
>
> What happens by the time that the signal gets out to a distance
> of one light year (about 9.5E15 m)? The same power is now spread
> over a much larger sphere, so that the power density is down to
> about 4.4E-29 W/m^2.
>
> Let's look at that original AM radio broadcast. Assume that it was
> towards the top of the AM band; say 1310 kHz. Each photon would
> have about 9E-28 joules of energy.
>
> Do the division, and we see that that works out to roughly one
> photon per second per 20 square meters. Not a lot of signal
> strength left. At only one light year.
>
> Nobody in another solar system is ever going to hear Fibber McGee
> open his closet, or hear Tonto say, "What you mean 'we', white man?"

While a 50 kW AM station may have been standard for commercial
US broadcast, its nowhere near the most powerful transmissions sent
from Earth.

The Arecibo S band radar had 1 MW of power, and it was in a beam only
2 arc minutes across. That's about 1/371,000 of a full sphere. So the
signal was about 70 million times as bright as your 50 kW station.

The AN-FPS satellite tracking radar generates 32 MW of power, but
has a 1.4 degree beam width.

Pt

In <8eb17569-12f3-424d-a531-27ecbd195e17n@googlegroups.com> "pete...@gmail.com" <petertrei@gmail.com> writes:

[snip]

>While a 50 kW AM station may have been standard for commercial
>US broadcast, its nowhere near the most powerful transmissions sent
>from Earth.

>The Arecibo S band radar had 1 MW of power, and it was in a beam only
>2 arc minutes across. That's about 1/371,000 of a full sphere. So the
>signal was about 70 million times as bright as your 50 kW station.

>The AN-FPS satellite tracking radar generates 32 MW of power, but
>has a 1.4 degree beam width.

Hi, Peter.

Some of the Voice of America and similar transmitters
were in the megawatt range back then. Very few still around.

Anyway, back 1977ish Dani Eder and I scribbled out just how far
away "we" could be detected.

We used the Empire State Building as the point source, as
it had plenty of radio and tv transmitters on it. For
sensitivity we basically took the Arecibo figures.

So that was quite a but higher than fifty kilowatts...
Plus, not quite a sperical transmission, but kind
of flattened, so at the right time of day it
would be a lot stronger at the receiving site.

The numbers we came up with had the ESB just about reaching
to the Alpha Centuri system.

Note that about six months later there was a similar
article in Science Magazine, where some Real Scientists
wrote up a bit of comparable research. Except they
used the whole Earthwide network of transmitters, so
they pointed out that...

... pointed out a whole bunch of info the extra terrestrials
could work out.

Since at that time the transmision cloud from the US's
East Coast (and the US in general) was much stroneger
than the rest of the world, they figured the ET's would
pick up on the Earth's rotational velocity and, similarly,
the orbital track.

I think they might have mentioned (maybe...) the Doppler
shifts as well.

I do NOT recall what distance numbers they came up with.

And similar to your point: They added that the military DEW and
later incarnation Radars had _much_ higher outputs,
and also narrower beams, so if, anf that, of course,
is a big if, the ETs were in the path and picked
up that sweep, they'd be able to detect us from a
hell of a lot farther.

Hope all's well by you and any of the others
you're in touch with
--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

On Saturday, April 30, 2022 at 9:49:31 PM UTC-4, danny burstein wrote:
> In <8eb17569-12f3-424d...@googlegroups.com> "pete...@gmail.com" <pete...@gmail.com> writes:
>
> [snip]
> >While a 50 kW AM station may have been standard for commercial
> >US broadcast, its nowhere near the most powerful transmissions sent
> >from Earth.
>
> >The Arecibo S band radar had 1 MW of power, and it was in a beam only
> >2 arc minutes across. That's about 1/371,000 of a full sphere. So the
> >signal was about 70 million times as bright as your 50 kW station.
>
> >The AN-FPS satellite tracking radar generates 32 MW of power, but
> >has a 1.4 degree beam width.
> Hi, Peter.
>
> Some of the Voice of America and similar transmitters
> were in the megawatt range back then. Very few still around.
>
> Anyway, back 1977ish Dani Eder and I scribbled out just how far
> away "we" could be detected.

Good to hear from you too. It's been ages. I'm doing fine, but
approaching retirement. Any idea how Dani is doing?

Pt

In <72b91470-7797-4e12-bcd4-0d516a8ad701n@googlegroups.com> "pete...@gmail.com" <petertrei@gmail.com> writes:

>> Some of the Voice of America and similar transmitters
>> were in the megawatt range back then. Very few still around.
>>
>> Anyway, back 1977ish Dani Eder and I scribbled out just how far
>> away "we" could be detected.

>Good to hear from you too. It's been ages. I'm doing fine, but
>approaching retirement. Any idea how Dani is doing?

Father Time, my wife, and I are on a first name basis,
but otherwise ok.

Haven't heard from Dani in decades. I wrote to a couple
of e-mail addresses a while ago but didn't hear back.

hmmm.... just found the following about him:

https://www.reddit.com/r/space/comments/g1bgdi/im_dani_eder_a_space_systems_engineer_aka_as_a/

Best wishes over there.
--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

On Sunday, May 1, 2022 at 12:01:47 AM UTC+10, Michael F. Stemper wrote:
> Some time back[1], I read a short work that portrayed SETI researchers
> in various solar systems all sitting back and waiting to receive a
> signal from somebody else.
>
> It appears that the situation is about to change:
> <https://phys.org/news/2022-04-blasting-earth-potential-aliens-controversial.html>
> tells about it, and gives us a new initialism: "Messaging Extra-Terrestrial
> Intelligence".
>
> What could possibly go wrong? Well, you could look at the Inhibitors Universe
> of Alastair Reynolds. Or if that's too recent for you, how about Fred
> Saberhagen's Berserkers?
>
> What other SF suggests that this might be a bad idea?

Lovecraft. "Hello, Great Old Ones! Here we are. Please descend and drive us all mad."

-Moriarty

Dimensional Traveler <dtravel@sonic.net> schrieb:
> On 4/30/2022 1:00 PM, Michael F. Stemper wrote:

>> Well, they're not going to be delivering those records any time soon.
>> Per NASA[1]:
>>
>>   [...] if we define our solar system as the Sun and everything
>>   that primarily orbits the Sun, Voyager 1 will remain within the
>>   confines of the solar system until it emerges from the Oort cloud
>>   in another 14,000 to 28,000 years.
>>
>> By that time, the Record Club will be out of business, and the aliens
>> won't need to pay shipping to return the record.
>>
> One of them has apparently gotten past or into the heliopause (IIRC)
> which is another potential definition for "outer edge of the solar system".

https://xkcd.com/1189/ has a detailed record of how many times Voyager 1
has left the solar system.

On 30/04/2022 20.35, pete...@gmail.com wrote:
> On Saturday, April 30, 2022 at 3:36:15 PM UTC-4, Michael F. Stemper wrote:
>> On 30/04/2022 11.35, Dorothy J Heydt wrote:
>>> In article <t4jfg7$2pp$1...@dont-email.me>,
>>> Michael F. Stemper <michael...@gmail.com> wrote:
>>>> Some time back[1], I read a short work that portrayed SETI researchers
>>>> in various solar systems all sitting back and waiting to receive a
>>>> signal from somebody else.
>>>
>>> Welllll... Gunn's excellent _The Listeners_ has a team listening
>>> at Arecibo, just about to be shut down from lack of results when
>>> they pick up a Drake picture whose zeroes are silence and whose
>>> ones are fragments of radio broadcasts from the 1930s.
>> I remember the picture, but did not remember the composition of the
>> ones. I thought that I had reread this in the last few years, but my
>> book log says that my definition of "the last few years" still includes
>> 2006.
>>
>> As far as aliens picking up our domestically-oriented radio broadcasts
>> is concerned, it ain't gonna happen. Those whole dislike arithmetic
>> are advised to skip the rest of this post.

>> Nobody in another solar system is ever going to hear Fibber McGee
>> open his closet, or hear Tonto say, "What you mean 'we', white man?"
>
> While a 50 kW AM station may have been standard for commercial
> US broadcast, its nowhere near the most powerful transmissions sent
> from Earth.

Certainly not. But I was talking about domestically-oriented
transmissions, since that's the category that Gunn's "fragments of
radio broadcasts from the 1930s" falls into.

--
Michael F. Stemper
Life's too important to take seriously.