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#1 2003-09-10 10:27:36

Registered: 2001-09-20
Posts: 6,278

Re: Messages across the void - An idea...

[color=#000000:post_uid0]So I was thinking... yeah, I know, a dangerous proposition, but I want to see how feasible an idea it might be.

This idea of E.T. in the black of night, of somehow communicating across the vast distances of time and space, struck me last night. How could they do it? Better yet, how could [b:post_uid0]we[/b:post_uid0] do it?

Now, I don't claim to be an astrophysicist, or know all that much about how the science of the universe works. But I was thinking, if [b:post_uid0]we[/b:post_uid0] wanted to send a signal, and be heard, what would be the best way to do it. Now, when I was a kid, I remember camping out in good old mother nature. I remember lying on my back in some meadow, with a flashlight, shining it up into the pitch black heavens above.

I always wondered how long it would take for my flashlight light to reach another planet. I would stare up at the sky and wonder if far away, some E.T., on their own camping trip, in their own meadow, was doing the same thing.

Well, enough of memory lane, with me so far?

I was thinking, if I was an alien race, and I wanted to communicate with another alien race, that might or might not be there, and even if they were, my species could be long dead by the time they received the message, and long after the machines our race had built had stopped working, which sent messages, and listened to messages; I might do something that I [b:post_uid0]knew[/b:post_uid0] would outlive me and my race.

So what is it I might do?

Shine a flashlight into the universe!

Not a machine, but an orbital perturbation around my home sun that would communicate mathematically- something like Morse code.

Right now, we are detecting extra-solar planets in other solar systems. We do this by more or less measuring the shadows created by planets moving in front of their sun. So the sun, which would last billions of years becomes the flashlight battery- sending our message out to the rest of the universe for well near forever.

An orbital perturbation would last nearly as long, and could be set up in such a way as to block the sun and create the message- even after my species is long dead, or moved on.

As far as I know, no one has, or is even capable of, examining this idea as a means of communication. i don't know if it's even a very good idea.

But still, i always wondered if the twinkling stars were just someone with a flashlight, flashing it on and off into the night.

Wouldn't that be something? Well, enough for now.   big_smile[/color:post_uid0]


#2 2003-09-14 06:06:38

Shaun Barrett
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Messages across the void - An idea...

[color=#000000:post_uid4]Hi Clark,
    Unless I misunderstand you, you're talking about a series of vast, carefully spaced 'shutters' orbiting the Sun, which would produce a dimming of the sunlight in a particular pattern.(?)
    This would be an enormous technological challenge because the objects interrupting the light would have to be so big to make an appreciable difference to the Sun's apparent brightness. In addition, since you want these objects to go on producing this Morse-Code-like signal long after our civilisation is dead and gone, their orbits would need to be stable over geological time. For that, you either have to place them at stable Lagrangian Points or you have to equip them with long-lived computer-controlled thruster systems which will constantly monitor and correct the objects' positions.
    The latter is not desirable since technology fails over long periods due to wear and tear. And if you use stable Lagrangian points, then you are no longer at liberty to determine the form of the message since your objects must be placed at points dictated by the vagaries of orbital mechanics. Interruptions to the Sun's light made by objects at such well-known natural positions relative to planetary bodies, could easily be interpreted by an alien civilisation (in another star system) as caused by accumulations of ordinary debris and not a signal of intelligent manufacture.

    Another drawback to orbiting 'signallers' of the kind I think you're suggesting, is that they're only visible at or near the plane of the ecliptic, or whatever plane you choose to orbit them in. I don't know how many inhabited star systems you'll miss out on signalling simply because, from their vantage point, your objects fail to interrupt our star's light.
    On the other hand, I recognise that this will be a problem with any directional signal used by any civilisation.

    As an illustration of the size range we're talking about for your obscuring objects, let's consider Jupiter, which is about 1/10th the diameter of the Sun. Observers in a far-flung planetary system, which just so happens to be on the plane of the ecliptic, will see our Sun dim by just 1% as Jupiter passes between it and them.
    How much dimming is required before an observer is certain it's not being caused by a patch of interstellar dust? How large are you prepared to make your 'shutters'?

    Just a few thoughts.   ???[/color:post_uid4]

The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner


#3 2003-09-14 10:35:39

From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Messages across the void - An idea...

[color=#000000:post_uid0]Clark: Now let me get this straight: You want to "perturbate' my one-and-only Sun...? Well you can forget it--Jupiter undoubtedly has been doing this for you. Go on out there and play around with it, if you want, but leave the Sun alone, eh?[/color:post_uid0]


#4 2003-09-14 14:00:54

Free Spirit
Registered: 2003-06-12
Posts: 167

Re: Messages across the void - An idea...

[color=#000000:post_uid0]Clark, there's no need to "shutter the sun" to send easily seen light signals across the vast blackness of space.   See the Harvard Optical SETI site.  Manipulating the brightness of the sun might not be very effective anyway because it could be mistaken for a variable star which naturally adjust their brightness levels, sometimes very dramatically.  Here's the intro paragraph at the Optical SETI site:

A high-intensity pulsed laser, teamed with a moderate sized telescope, forms an efficient interstellar beacon. Using only "Earth 2000" technology, we could build such a laser transmitter. To a distant observer in the direction of its slender beam, it would appear (during its brief pulse) a thousand times brighter than our sun.
Beginning October 19, 1998 we have been searching for such intense laser pulses, transmitted deliberately in our direction by another civilization in order to initiate communication across interstellar distances. [/quote:post_uid0][/color:post_uid0]

My people don't call themselves Sioux or Dakota.  We call ourselves Ikce Wicasa, the natural humans, the free, wild, common people.  I am pleased to call myself that.  -Lame Deer


#5 2003-09-15 09:30:20

Registered: 2001-09-20
Posts: 6,278

Re: Messages across the void - An idea...

[color=#000000:post_uid0]So it's a bad idea.  tongue  big_smile

Ah well.[/color:post_uid0]


#6 2003-09-28 04:14:44

From: india
Registered: 2003-09-14
Posts: 169

Re: Messages across the void - An idea...

[color=#000000:post_uid0]SETI is good idea.[/color:post_uid0]


#7 2004-01-14 23:54:46

From: USA
Registered: 2004-01-09
Posts: 1,409

Re: Messages across the void - An idea...

[color=#000000:post_uid0]I think SETI is a bad idea.  I'm not against the search for other intelligent life but the chance of finding the exact frequency of an alien transmission is not good. Electromagnetic radiation (Radio waves included) spreads out as it travels so the amount of energy needed to create a focused beam would be enormous, I don't know how high but it's way up there, and the chances of it hitting something the size of the earth, actually the aricebo dish is virtually impossible.[/color:post_uid0]


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