http://io9.com/are-we-screwing-ourselves-by-transmitting-radio-signals-493800730
Interesting Article
Dave Chase
Interesting Article
Dave Chase
Are we asking for trouble or are we asking for help?
- Thread starter DaveChase
- Start date
Maybe both?
I science show I stream says no, and this is corroborated by some other folks, I think one of them is NASA; the reason being that our transmissions become nothing after a certain distance, and are essentially drowned out by other EMF from not just our sun, but other starts. I forget what distance it is, but it's not much compared to the solar system.
Never rear, Kang and gang are not watching us hapless humans via our TV transmissions of I Love Lucy, waiting for the time to strike. They're too busy trying to broadcast their presence to the rest of the galaxy and failing, just like us.
Never rear, Kang and gang are not watching us hapless humans via our TV transmissions of I Love Lucy, waiting for the time to strike. They're too busy trying to broadcast their presence to the rest of the galaxy and failing, just like us.
Not sure: we could be ringing the dinner bell or sending up a flare. Either way I'm ready to either welcome my new alien overlords or join the resistance.
I'd like to think that eventually we will have somebody show up that is better organized than the plethora of seeming hobby craft of disparate design and purpose that are the usual UFOs. And stop hacking up our cows, too. But I'm dunno if that will happen in my lifetime.
I'd like to think that eventually we will have somebody show up that is better organized than the plethora of seeming hobby craft of disparate design and purpose that are the usual UFOs. And stop hacking up our cows, too. But I'm dunno if that will happen in my lifetime.
The presence of signal in certain bands is actualyl detectable for several hundred LY with a 500m radio dish. The problem being that in those bands, the presence of signal will be noted - but the data carried will be lost due to multiple signals on the same frequency.
We have some 0.5MW and larger broadcast stations out there.
Mind you, a 30m dish can pick up a 25w transmission from about 100AU (1/630 LY) with no difficulty; the problem being that the Voyager has trouble aiming at earth accurately enough for it's narrow transmission angle... but that also has to do with a narrow beam transmission for that 25w transmitter...
Note that Arecibo has often been said to be able to pick up a cell phone (2W-3.6W) at jupiter... (~5AU)
I've seen estimates that range from detectable radio noise to 100LY (in what should be low amplitude bands) to ≤1LY. Actually getting signal instead of simply elevated noise is a whole 'nother matter. Think what happens when you get a good bounce day and pick up two FM radio stations on the same frequency - can't make out either, but can easily tell you're getting signal - Lots of noise!
We have some 0.5MW and larger broadcast stations out there.
Mind you, a 30m dish can pick up a 25w transmission from about 100AU (1/630 LY) with no difficulty; the problem being that the Voyager has trouble aiming at earth accurately enough for it's narrow transmission angle... but that also has to do with a narrow beam transmission for that 25w transmitter...
Note that Arecibo has often been said to be able to pick up a cell phone (2W-3.6W) at jupiter... (~5AU)
I've seen estimates that range from detectable radio noise to 100LY (in what should be low amplitude bands) to ≤1LY. Actually getting signal instead of simply elevated noise is a whole 'nother matter. Think what happens when you get a good bounce day and pick up two FM radio stations on the same frequency - can't make out either, but can easily tell you're getting signal - Lots of noise!
My thoughts too. "It's a cookbook!"
Hi,
I guess my thoughts here are that if you have something similar to a single cell phone call at Jupiter might stick out as unusual and would be one thing, but if you have tens/hundreds of thousands to millions of them then I'd wonder if the superposition of all these messages on top of one another wouldn't then still kind of come across as something akin to just more "noise".
A suden directional spike in noise is a strong indicator of something being unusual there. if you pick up 10^(-30)W/m^2 background, and from a given direction pick up 10^(-28)W/m^2 in a particular 0.01" arc, you've got a pretty good indicator that something interesting is there. Even if you can't make out the signals separately, the increased amplitude of the noise is EXACTLY what seti is looking for...
Tell that to the Mongols.
Occurs to me that it's an awful long way to go for a bunch of resources at the bottom of a gravity well. If they have the tech to make that trip, what could we have that they can't make for themselves or harvest without getting within a million kilometers of us, except maybe sunny beaches?
That's not true.
Naw, we kept some of ours. Of course, they probably have some very not nice things to say about us. Still if they get uppity we still have the guns, germs and steel that settled things last time.
If you can travel interstellar, getting up/down the gravity well is likely a non-issue; you'd need to have solved that issue. Unless, of course, you've "Tunnel in the Sky" style FTL travel.
If the only interstellar is sublight generation ships, it's likely that anybody going plans on landing at the far end of their trip, because it's extremely unlikely that they're making a round trip. And building a ship capable of STL interstellar in anything resembling a reasonable time means drives that are weapons of mass destruction. And such a ship is likely large enough that it could carry a relatively decent skyhook with, and/or manufacture one from an asteroid.
We'd have probably a couple years warning; the weapon of mass destruction drive would be a new and tiny star-in-motion from either the midpoint flip, or the deceleration start point if not under acceleration the whole time; 1G, that's about two years with dilation.
Because ...
One of the problems we face with space travel now is that everything economy-wise is down here, so we look for anything we send up to benefit us down here in some manner. Much the same happened with the early colonization of the Americas.
However, there may come a tipping point, if you have a good cheap energy source and master the trick of providing a reliable and continuous source of air, water, food, and waste management in space, where "up there" gets big enough that there starts being an economy among the various space-living whatevers. At that point, the only value we down here have to them up there is that we're a several-billion-person economy to sell things into. We down here would do well to master the gravity well issue if we want to remain a valued trading partner, but there's also a possible future where that doesn't happen, where - for whatever reason - the fix isn't found and the space-based economy finds it more profitable to trade among themselves than to pay the extra costs involved in lifting goods up from Mama Earth in exchange for their own work product.
I can remember when fusion was the "next big thing," and it's remained the "next big thing", just barely out of reach, for the past 60-plus years. It's not inconceivable that realizing one of our clever ideas for accessing space more efficiently from down here could prove equally or more elusive.
Let those who are accustomed to living out their lives in space head out to other stars, and it is likely that their first priority on arriving in a new system is not going to be to settle the local earth-like gravity well.
See remark above. We value this dirtball, and it's a very pleasant dirtball. However, that doesn't mean that someone who was born and raised to something else, whose father and maybe grandfather was born and raised to something else, is going to suddenly have a passionate desire to live under open sky on a dirtball once he gets there. There might be a few percent who are bold adventurers, but we're kind of a conservative bunch, proportionally - my money says the bulk of them stay in the ship and start building more ships.
That being said, I don't see the "invaders" being eager to pick a fight with the locals at the bottom of the gravity well. The adventurers among them can make their own decisions, maybe they'll get a bit of a helping hand, perhaps an occasional blunt hint to the locals about who holds the high ground and who shouldn't be messed with, but I figure most are going to concentrate the bulk of their resources on what they're already familiar with. They aren't going to give much thought to the local yokels unless the yokels try to interfere in some way with what they're doing.
Our biggest and most likely threat, to be honest, is someone shows up and starts harvesting resources from the rest of the system while we sit down here unable to say two words about it.
Then I'd say our best defense is to be out there settling in and competing for the resources they want, or it's going to be Reservation Earth for us.
Hi,
I'd suspect that would only be true if the garbled mix of multiple overlaid signals sticks out from the background noise. If, however, all these different signals mix together so that the sum total of them ends up looking like random static it would seem that they could easily be lost in the noise.
A potential analogy might be trying to determine if the noise you here in the distance at night is coming from a large group of people involved in multiple independent conversations in the distance or whether this 'noise" is the result of other natural sources, such as animals, wind or other atmospheric effects such as thunder, rain, and/or sleet and hail, and associated noises such as the creaking of trees and such straining in the wind, etc.
In the bands in question, a 100x increase in signal, even meaningless signal, is significant, tho'.
Keep in mind: SETI isn't actually looking for DATA coming across. They're looking for a steady above background tone - they don't care if it's people, traffic, or critters, to use your analogy - all that matters is it's 100x louder than wind across the landscape and directionally localized.
Once you HAVE such a signal, the odds are good that it's a world. You can then do some BIG antennae (2-9 sq km), make an interferometer, and record what you can, then see if you can attempt to take and figure out some actual data from the signal mush.
Hmmm I thought I had tried that, must have mistyped the tags or something. OK here goes, I won't give away the ending but what I write will reveal some of the mysteries presented at the start of the book.
Spoiler: