Looking in all the wrong places

Sorry Jonathan. You lost me.
I can't make any sense out of your ideas to use a pulsar as a beacon.

Massive objects needed to create 1 bit of info, no way to create
an omnidirectional signal, and no way to control the beam direction.

"RD" == Rob Dekker writes:

Sorry to repeat myself, but surely you don't need a beacon by a
pulsar, because the pulsar is the best beacon you could have. All
you have to do is modulate it.

RD Sorry for not catching that. So, how do you modulate the signal
RD of a pulsar at-will ?

If I had the capability, I'd try to make the pulsar do something
unusual. One thing to try would be to try to shoot an asteroid (or
something) at an isolated pulsar so that the pulsar would "spin up" a
bit. Pulsars typically slowly spin down, and isolated pulsars should
not, in general, spin up. Of course, the result might look a lot like
a pulsar "glitch," in which the pulsar pulse period changes by a small
amount. In that case, I'd try to shoot asteroids in at a regular rate
so that the pulsar would "glitch" on a regular basis. After the 4th
or 5th glitch on some regular basis, I'd expect anyone monitoring the
pulsar would notice.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

In message , Joseph Lazio
writes
"RD" == Rob Dekker writes:

Sorry to repeat myself, but surely you don't need a beacon by a
pulsar, because the pulsar is the best beacon you could have. All
you have to do is modulate it.

RD Sorry for not catching that. So, how do you modulate the signal
RD of a pulsar at-will ?

If I had the capability, I'd try to make the pulsar do something
unusual. One thing to try would be to try to shoot an asteroid (or
something) at an isolated pulsar so that the pulsar would "spin up" a
bit. Pulsars typically slowly spin down, and isolated pulsars should
not, in general, spin up. Of course, the result might look a lot like
a pulsar "glitch," in which the pulsar pulse period changes by a small
amount. In that case, I'd try to shoot asteroids in at a regular rate
so that the pulsar would "glitch" on a regular basis. After the 4th
or 5th glitch on some regular basis, I'd expect anyone monitoring the
pulsar would notice.


I like it! Much better than my own idea of actually changing the beam in
some way. Presumably no-one's actually seen this yet?

"JS" == Jonathan Silverlight writes:

JS In message , Joseph Lazio
JS writes

RD Sorry for not catching that. So, how do you modulate the signal
RD of a pulsar at-will ?

If I had the capability, I'd try to make the pulsar do something
unusual. One thing to try would be to try to shoot an asteroid
(...) at an isolated pulsar so that the pulsar would "spin up"
a bit. Pulsars typically slowly spin down, and isolated pulsars
should not, in general, spin up. Of course, the result might look
a lot like a pulsar "glitch," in which the pulsar pulse period
changes by a small amount. In that case, I'd try to shoot
asteroids in at a regular rate so that the pulsar would "glitch" on
a regular basis. After the 4th or 5th glitch on some regular
basis, I'd expect anyone monitoring the pulsar would notice.

JS I like it! Much better than my own idea of actually changing the
JS beam in some way. Presumably no-one's actually seen this yet?

People have certainly see pulsar glitches. (Indeed, there is a famous
one from the Vela pulsar on Christmas Day or Christmas Eve in the
1970s.) I don't think that anybody has seen glitches occurring on a
regular basis. I would think there would be considerable interest if
something like this were found because pulsar glitches are typically
taken to be probes of the internal structure of a neutron star.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

Jonathan,

Your right, bad mistake on my part.

Wasn't it Joseph Lazio who wrote:

If I had the capability, I'd try to make the pulsar do something
unusual. One thing to try would be to try to shoot an asteroid (or
something) at an isolated pulsar so that the pulsar would "spin up" a
bit. Pulsars typically slowly spin down, and isolated pulsars should
not, in general, spin up. Of course, the result might look a lot like
a pulsar "glitch," in which the pulsar pulse period changes by a small
amount. In that case, I'd try to shoot asteroids in at a regular rate
so that the pulsar would "glitch" on a regular basis. After the 4th
or 5th glitch on some regular basis, I'd expect anyone monitoring the
pulsar would notice.

We might well notice, but it wouldn't take long for someone to come up
with a theory that explains how regular glitches might be caused by
natural mechanisms.

There are pulsars that regularly speed up and slow down slightly, and
the explanation for that involves the suggestion that there are planets
orbiting the pulsar.

--
Mike Williams
Gentleman of Leisure

"Rob Dekker" wrote in message .com...
wrote in message
oups.com...

You mentioned on one of my other post's how gamma radiation wouldn't
be used as a communication method, which I agree on. What I was
implying was that gamma radiation could be sign of either antimatter or
fusion type drive, the only two types of energy sources that are
powerful enough for interstellar travel.

That's indeed not a bad idea. I did not think of that.
So you mean that some gamma-ray's might actually be the 'exhaust'
of some alien space ship. Interesting.

Do you dare to speculate on the 'signature' of such an exhaust ?
I mean, how could we differentiate it from any natural gamma-ray's ?

Mike Harris has written a couple of papers on this type of search:
http://adsabs.harvard.edu/cgi-bin/np...1829338ea23899

On the detectability of antimatter propulsion spacecraft
Authors: Harris, M. J.
Journal: Astrophysics and Space Science (ISSN 0004-640X), vol. 123,
no. 2, June 1986, p. 297-303. (Ap&SS Homepage)

Abstract
It is shown that the NASA Gamma-Ray Observatory will be able to detect
large interstellar spacecraft at distances up to about 300 pc by the
gamma-ray emission from the propulsion system alone. The distance
limit is set by the possibility of recognizing such objects by their
proper motions.

http://adsabs.harvard.edu/cgi-bin/np...1829338ea23899

In message , Joseph Lazio
writes
"JS" == Jonathan Silverlight
id writes:

JS In message , Joseph Lazio
JS writes

RD Sorry for not catching that. So, how do you modulate the signal
RD of a pulsar at-will ?

If I had the capability, I'd try to make the pulsar do something
unusual. One thing to try would be to try to shoot an asteroid
(...) at an isolated pulsar so that the pulsar would "spin up"
a bit. Pulsars typically slowly spin down, and isolated pulsars
should not, in general, spin up. Of course, the result might look
a lot like a pulsar "glitch," in which the pulsar pulse period
changes by a small amount. In that case, I'd try to shoot
asteroids in at a regular rate so that the pulsar would "glitch" on
a regular basis. After the 4th or 5th glitch on some regular
basis, I'd expect anyone monitoring the pulsar would notice.

JS I like it! Much better than my own idea of actually changing the
JS beam in some way. Presumably no-one's actually seen this yet?

People have certainly see pulsar glitches. (Indeed, there is a famous
one from the Vela pulsar on Christmas Day or Christmas Eve in the
1970s.) I don't think that anybody has seen glitches occurring on a
regular basis. I would think there would be considerable interest if
something like this were found because pulsar glitches are typically
taken to be probes of the internal structure of a neutron star.

I knew natural glitches had been seen - they've even formed the basis of
an SF novel, Robert Forward's "Starquake".
Perhaps I'm being pessimistic, but I fear that absence of evidence
really is evidence of absence for anything on this scale at the present
(our present). Which doesn't rule out more modest transmitters, or
glitches still to be seen, a thousand years from now..

"Rob Dekker" wrote in message om...
"10of100" wrote in message m...
Hello group,

I have some ideas and questions I wanted to ask, please be kind with
your replies if any as I am new to this group and not sure if this has
been batted around before.


Welcome ! We are always kind in this newsgroup )
The purpose of this newsgroup is to exchange ideas, and share thoughts, and ask/answer questions about this fascinating new branch
of science.
Similar ideas come up every now and then, but this one "message-in-a-bottle" idea has not yet been discussed in depth.

Last April (just before Rob arrived?) there was brief thread about a
NASA scientist, Scot Stride who is proposing in solar system searches

http://www.setileague.org/editor/stride2.htm

An online article in Astrobiology Magazine - Can SETI Probe for
Probes? at

http://www.astrobio.net/news/article919.html

was an interview with Scot Stride of NASA's Jet Propulsion Laboratory:

"Summary: Just as our own robots reach out beyond the solar system,
searching for life elsewhere may well involve hailing some kind of
space
artifact in our own neighborhood. At least one style of life search is
about looking for the technological evidence of life, rather than its
wet biology."

(and Scot Stride happened to reference a hypothesis by me that
resulted from old threads I've posted in this newsgroup, which
summarized appears on my website at
http://www.geocities.com/exosearch/i...hypothesis.htm and is called
SETI Candidates at Saturn? )

....snip...

Now, the shere number of potential target star systems is (in my opinion) what also kills the "message in a bottle" approach.
What is the cost of sending out 1billion probes across the galaxy ?


Will that be in Euros or the giant stone coins of the Yap islanders?
:^) The hypothetical cost may not be relevant because we are
interpreting this from an anthropocentric perspective. Who can
guesstimate what motivates a potentially infinite variety of
civilizations expanding into the cosmos? What concepts do
self-repairing or self-replicating machine probes have of money and
time? To them it will be an issue of - Are the materials available?
What is mission-critical? Also, what are the implications of
nano-technology on propagation of machines (low-mass, low energy
requirements, low material inputs.) One can literally litter the
universe with the chaff of technology. Additionally, are some
space-worthy microbes DNA coded with their maker's signature and
propagating throughout the universe? When talking about a "message in
a bottle" there are lots of different kinds and sizes of bottles, this
can dramatically affect the economics, or from a machine's point of
view, 'the efficiencies' of transmission. What is the purpose of the
bottle, to investigate a star system? To communicate with other
civilizations? If they don't care about message transmission times on
human life-span scales, then perhaps there are no economic issues,
especially if you are a Type II or III civilization. Also, the amount
of power (and the cost of it) I can harness myself today is immensely
more than a similar person could have harnessed 100 years ago. What
will be at the fingertips of a child of a type II civilization?

These things should be quite sophisticated, with lots of intelligence, because they need to operate totally autonomous :
At 1000 or 10,000LYs from home, there is no 'remote-control' possible.

Borrowing a little from a previous post (by me) I don't think it is
beyond
current day technology for a probe to be fully autonomous. As noted
elsewhere, the astronomer Ronald Bracewell proposed (over 40 years
ago) that it would be easier, cheaper and more productive for a
civilization to send
automatic probes to the stars. Recent work seems to support this
hypothesis.

Additionally, I selectively quote Isaac Asimov from the 1978 book
'Extraterrestrial Civilizations' - "We can imagine advanced
civilizations sending out very advanced probes..." although he felt
there would be a limit to
the complexity because because of the long mission times of millions
of years and the second law of thermodynamics and the uncertainty
principle. He also said "...If we go to an extreme, we might imagine
a crew of advanced robots as intelligent as human beings, for
instance, exploring the Universe as human beings themselves could
not..." (humans couldn't because of the radiation threat,
mission-time, expense etc.) although he felt that the robot probes
would be purposefully limited in intelligence because they might be
subject to the same psychological problems that might befall humans.

So, they may be purposefully limited in intelligence, but not lack the
ability to reconnoiter and make mission-critical decisions.

Indeed, if they exist, it is probable (as you know) that a probe will
be thousands, millions or even billions of years advanced over
current-day Earth technology!

They need to be brought up to speed after lauch, which costs a lot of energy, then withstand an extremely long journey through
unknown space (a million years at 1% of light speed, more speed costs exponential amounts more energy) .
After arrival, they need to slow down, know how to manouver into an unknown star system, position themselves, bring their equipment
on-line, map the planets in the star system, collect all data that home needs to know (including signs of (intelligent) life), and
they need a powerfull transmitter to send their findings back.

This assumption is for probes, but if the purpose is as a
communication via a space relic, than the mission parameters are
somewhat less restrictive.


If ET is extremely sophisticated in space-travel, and technology, and they can actually build and lauch and control such a probe for
a rock-bottom $1M (2004 Earth money), then to target 1billion stars would still require $1,000Trilllion. Way more expensive than a
radio or optical beacon. And if they don't send out many probes, then we have a low probability of being visited (same
problem/reasoning as with the beacon signals).

I dont know about you, but I believe that only a 'colonizing' civilisation could afford that. That would be a 'class I'
civilisation, and they won't need to send probes out that far, since they already expanded (or are expanding) through the galaxy on
colonisation ships. And if that civilisation has colonisation ships and mastered interstellar travel, then there is nothing in their
way to flood the galaxy in a whimsical 100M years or so. They should have been here already. So that's back to the Fermie paradox.

So message-in-a-bottle is way too expensive for a single-planet civilisation (and certainly much more expensive than a beacon), and
otherwize it should come from a civilisation which already covers the entire galaxy with colonies.

This last was a leap of faith that is not based in facts. Nobody
knows what it will cost (or even if cost is an issue) but the certain
issues are efficiency and effectiveness. It may be that a
civilization decides that radio is not as effective or effecient as
putting a relic/monolith on a tidally locked moon, nobody knows
because THEIR economics and rationales are unknown.

Also, one may want to read
A SEARCH FOR ALIEN ARTIFACTS ON THE MOON - ALEXEY V. ARKHIPOV
http://it.utsi.edu/~spsr/articles/iau_symp.html
and
EARTH-MOON SYSTEM AS A COLLECTOR OF ALIEN ARTEFACTS by the same author
at
http://it.utsi.edu/~spsr/articles/jbis1.html


Borrowing from yet another post (by me) awhile back I had posted what
I thought might be logical/obvious places to look for a relic
"message-in-a-bottle" (that wants to be found) such as:

Looking at the center of craters, which besides being a nature's
bulls-eye, seems to afford one the opportunity to eliminate a heck of
alot of terrain.

Look atop central crater peaks (are they geologically unstable
regarding landslides, especially if you land an object on it?),

Select craters based on greatest crater depth and/or central peak
height,

Look at craters with the greatest floor brightness contrast to nearby
highlands ratio (in particular one crater on the moons far side seems
to stand out greatly from all of the others, Tsiolkovsky crater, it is
filled with a maria-type basalt that greatly contrasts with the
highlands, and it has a well defined central peak area, and wouldn't
be detected until an Earth civilization could go into space to see it.
I've seen some pretty close images but not close enough to rule out a
large relic.)

Look instead on crater floors near central peaks because the crater
walls afford better meteoroid protection than being at the crater
peak?

Look for relics at the center of gravitational field anomalies, which
on the moon's visible face, the strongest of which seems to be at the
center of Mare Imbrium?

Use lunar-chemical cartography surveys (of the future) to search for
anomolies (what those anomolous chemical elements would be I don't
know yet.

Where can I find radio-surveys of the moon? Anybody done magic SETI
freq. searches on the moon (sounds like an EME moon-bounce SETI League
thing to me, but I don't know anybody there, anything online about
this.)

Does the Moon's light spectra have any spikes in chemical or energy
levels that seem extra-ordinary? (Artificially added spectra changes
from a distance or direct broadcast from the surface?)

And borrowing from yet another previous post, I proposed several ideas
for looking for probes and relics:

How would you look for a radio-silent Voyager-like craft if it were
passing through your system? Radar, or some type of active EM
illumination maybe?

How do you find a radar-stealthed vehicle? Irradiate it with EM
radiation outside of it's design parameters (i.e. don't use radar, use
U.V.,
IR, X-rays etc.) And of course there is a whole legal aspect of
trying to do
this that might become problematic, especially if you find a way to
illuminate
the Mach 8 Aurora spyplane by accident.

How would you look for a radio-live probe? Radio Direction Finding
RDF would be conducted using dedicated antennas, receivers, operators
familiar with RDF techniques (including wave propagation theory) maps,
plotting
methods, and they would of course have knowledge of common RDF errors.
There
would be 3 RDF sites for terrestrial searches, uniform plotting
methods,
uniform reporting methods, central controlling authority for
coordination, and
of course evaluating results and compiling a database of those
results.
I know of no civilian entity that is dedicated to searching for ETI
probes
using RDF. Intercepting radio traffic is also a touchy state-security
issue.
Spaceborne RDF could be conducted from multiple spacecraft with
similar format of the above.

Systematic analysis of the data from asteroid search programs for ETI
probes via looking for peculiar light curves, trajectories or suddenly
missing asteroids that might betray the presence of an ETI probe. Are
any dedicated researchers granted money to examine data for asteroids
that exibit peculiar, anatural shapes? Maybe a deep pockets ETI probe
research institute could help asteroid search programs with a portion
of their budgets for a larger telescope for higher resolution surveys
of smaller objects.

Is there a way to capture or look for micro or nanoprobes that might
deployed
on Earth? (Anybody looked inside of an MRI scanner for stuck ETI
probes lately? :-)

Ping each planet with Arecibo at the "magic" freqs. and see if there
is a
response from an automated ETI probe. This would include both faces
of each
moon and terrestrial planet and multiple pings for the giant planets
in case
there was an orbiting probe initially blocked by the pinged planet.

Do any high resolution spectra of any terrestrial bodies indicate
bizarre
alloys in any particular crater? (relic puddles)

Could a Spy Sat placed in orbit around the moon detect
Apollo/Pathfinder-sized relics. Is there a quick image analysis method
that could help zero in on these types of relics? Apply this
methodology to ETI relic probe searches.

What types of coordinated scientific searches can be conducted on the
googleplex-bytes of new data from various astronomical surveys to look
for
evidence of ETI probes?

I'll cut it here.

Seek and ye shall find, Jason H.

Personally, I would suggest going by what we know. We know that where
there's life there is a food chain, one form of life feeds off of
another. Predator and prey, which derives the 'Survival of the fittest'
instinctual bases, we can likely assume this fundemental approach take
place in other parts of the universe. Another intelligence would most
likely see things in this perspective. Thats one factor, another is,
based on what we know, interstellar travel no matter how advanced, when
all things are relative, is costly and very energy intensive. These are
just two factors that weigh in on interstellar exploration, we can have
a limited guess at what an intelligence will do under these
constraints. We can assume that each interstellar probe launched will
be maximized for the amount of scientific return due to launch and
energy costs. Launches would be in-frequent, most exploration would be
via passive devices like telescopes and other devices that listen for
different type of radiation, electromagnetic or otherwise. Finding a
probe in our own solar system would be most likely a one in a ten
billion shot or higher. I think this is a good thing though. If we take
in account of what I said about 'survival of the fittest' , only two
things that would give an advanced intelligent race enough motive to
spend time and cost to do interstellar travel 'en mass' would be
something that jeapordized their survival on a large scale (think home
sun going nova, etc.).
Now taking this into account, any ET intelligence who can manage this
feat, would be detrimental to any other ET intelligent life (think us)
as they would have resources and energy capabilities that are vastly
beyond ours. Even if they were peaceful such an ET could easily
eliminate us out from an economic and social perspective (again think
Aztecs meeting the Spaniards).
And of course they may be motivated by the extreme side of the predator
and prey thing and want to be the ultimate predator.
Of course all of this is based on what we know today, if tomorrow we
discover an easy and cheap way to travel from solar system to solar
system, this whole hypothesis would change.