[karajorma]

I wasn't on about a race with FTL although that's possible too.

SETI have stated that they couldn't pick up even Earth's transmissions if they were on Alpha Centauri.

From the SETI website

If an extraterrestrial civilization has a SETI project similar to Project Phoenix, could they hear Earth?
In general, no. Most earthly transmitters are too weak to be detectable by Phoenix-type equipment at the distance of even the nearest star. The exceptions are some high-powered radars and the Arecibo broadcast of 1974 (which lasted for only three minutes). To detect "leakage" radiation similar to our own will require instruments that are many times more sensitive than what we now have.

So bang goes the theory that we can hear ET's microwave. He can make popcorn every day and we won't hear him.

In addition to that SETI is largely ignoring almost every frequency except the hydrogen band and a few other very narrow frequencies.  If ET isn't transmitting anything much on those bands we won't hear anything.

So we're back to the assumptions again. The only way we're going to hear ET with our current technology is if they choose to send out radio signals. You're assuming that the aliens are choosing to send out something on the narrow set of radio bands we choose to listen to.

[WMCoolmon]

Where did the Aliens come from? Nowhere in OUR neighborhood. Our light-horizon is 26 billion lightyears across, and nowhere in the local 100-200 thousand lightyear sphere is there a structured RF source.

How do we know 3000 years ago, 3010 light-years away, aliens didn't start making RF transmissions? Then they develop some FTL drive and come visit us.

Really, I don't think we're a good enough neighbor someone would travel for x-hundred years to meet us. Heck, we might not even rate a decade.

[karajorma]

I wouldn't even walk next door to meet half of the idiots on this planet

[mikhael]

What? SETI is the only transmission ever? We've NEVER blasted RF straight up? Aliens of sufficient ability to TRAVEL ACROSS SEVERAL LIGHTYEARS AT LEAST can't come up with a listening device to hear us?

Nah. I don't buy it.

[Grey Wolf]

I've always found it funny that people with low IQ in the middle of nowhere claim to be abducted by aliens and have surgery that doesn't show up as scars done to the,.

[karajorma]

Originally posted by mikhael
What? SETI is the only transmission ever? We've NEVER blasted RF straight up? Aliens of sufficient ability to TRAVEL ACROSS SEVERAL LIGHTYEARS AT LEAST can't come up with a listening device to hear us?

Nah. I don't buy it.

Now you're arguing the other side Mik. My arguements were all related to whether we could hear the aliens. That's about whether they can hear us.

Sure aliens with FTL would probably be able to detect us if they tried.  However if they have FTL they may have completely abandoned radio astronomy (or at least limited it to a degree that they won't hear us).  After all what's the point in building a giant radio telescope to listen to 4 year old signals from Sol when you can just go there in a couple of minutes? Maybe they only point radio telescopes at deep space where the signals are from far away enough to be a barrier to them.

However you're making an even bigger assumption. You're assuming the aliens care. We're dealing with an alien race here. You're assuming that the alien race would upon detecting us would do something that let us know that they had found us. They might not.

Like I said assumptions about the aliens technology and psychology.

[Ghostavo]

First thing first, if FTL is possible, wouldn't any travel near (relatively speaking) Earth leave like a detectable MASSIVE light spectrum burst behind?

Well, we may never know, but one thing is clear.....

"The truth is out there."

[Grey Wolf]

You mean like a sonic boom? Maybe. If a ship is travelling FTL, it has to be defying Einsteinian physics, or bypassing them. If it bypasses the speed restriction (see hyperspace/subspace and warp concepts), then I doubt it. If it is defying (and therefore standing Einsteinian physics on their ear) then who knows?

[castor]

Well, what do we know for sure about the basic structure of the universe?
Our best bet atm is the uber theoretic string theory, which has no practical proof at all.. (or does it?)

Pretty much everything/anything could FIT in the holes in our knowledge.

A strong oipinion here, on the way or the another would be mostly ego boosting.

(& sorry for the ego boosting above )

[IceFire]

So in conclusion: We don't know enough really about anything to be certain one way or another

[castor]

Well, yes  
We can observe, and draw our personal conclusions that apply on that moment in time.. for us.

The fact is, there is no fixed ground to stand on.

Thats how life has always been.

[jdjtcagle]

Aliens Exist

[YodaSean]

I didn't know Mexico had an airforce

[übermetroid]

Originally posted by YodaSean
I didn't know Mexico had an airforce

They strap rockets to there legs...  

[mikhael]

Originally posted by karajorma
Now you're arguing the other side Mik. My arguements were all related to whether we could hear the aliens. That's about whether they can hear us.

Well, its a two way street. RF goes both ways. The only real assumptions I make about aliens is that they if they're interested enough to come here and give anal probes, they're interested enough to do the fruity SETI thing themselves AND that if they're advanced enough to come here and visit, then they've gone through the whole SATURATE THE SKY WITH COMMUNICATIONS thing like we have.

Based on those two things and a basic knowledge of physics, there ain't no one but us in our end of the sky.

[Grey Wolf]

Or they could just not give a ****. They could hear us, think "That is an incredibly stupid race of sentients" and go back to doing whatever they were doing. Also, if they are 200 light years away, what if they stopped using RF 300 years ago? The signals would be past us, and we wouldn't even know.

[karajorma]

Originally posted by mikhael
Well, its a two way street. RF goes both ways.

I know but it's really hard to argue from both the alien and human perspectives at the same time so I tend to pick one for each post

Originally posted by mikhael
The only real assumptions I make about aliens is that they if they're interested enough to come here and give anal probes, they're interested enough to do the fruity SETI thing themselves AND that if they're advanced enough to come here and visit, then they've gone through the whole SATURATE THE SKY WITH COMMUNICATIONS thing like we have.

Based on those two things and a basic knowledge of physics, there ain't no one but us in our end of the sky.

Again you're making basic assumptions about the alien tech. I've already stated that SETI have said they couldn't detect Earth style RF leakage even from nearby stars. We haven't saturated the sky as you claim. The simple fact is that a species with a similar tech base on Alpha Centauri wouldn't be able to hear us. It's equally a fact that we wouldn't be able to hear them either.

Okay so that deals with an alien race with a similar tech base to ours. Lets now deal with an advanced civilisation.

 You're assuming that a more advanced race would saturate the sky with RF. Thats a prettty big assumption again. Why would they?
 If they have FTL travel who's to say they don't also have FTL comms? So that removes almost all the transmissions from any powerful RF source.

 All we're left with is alien microwaves and car engines and I doubt that no matter how powerful and advanced they are that an alien making popcorn is a sound you can hear 10,000LY away.

You're still making the assumption that we can pick up alien background noise. We can't. We'll hear aliens when they choose to point a transmitter in our direction and send a deliberate message.

[IceFire]

You never know...they may prefer giant city sized microwave machines for their mass production of popcorn...who knows, they are aliens

[Flipside]

They may have evoled on the dark side of a planet that permanently faces one side toward the star, and is about as far out as Mercury. In that case, it would be even harder for RF signals to get as far as Earth due to the stars magnetic interference They may use some kind of EM shielding to protect the hull that blocks RF output.

That's the fun thing about the Universe, it could be anything

[übermetroid]

I hope a big yellow thing does not show up to destroy eath to make a space freeway.