The Aliens are Silent because They're Dead

It's my opinion that most really advanced aliens would be impossible to detect if they wanted to remain hidden as to not disrupt our natural evolution. The prime directive might be something most intelligent benevolent species adhere to and it makes a lot of sense to me.
Why would they show themselves now? We are obviously not a stable or mentally prepared as a whole to accept we are not alone yet.
The technology that we have now is beyond the comprehension of people who lived 1000 years ago and if aliens who could be millions of years more advanced than us would poses technology that we can't even comprehend.
Our best chance would be to make contact with a predatory race which wouldn't end well for us or if we advanced enough to make contact a viable option to an advanced race. Also we could eventually find a signal as I do believe seti and other space scanning methods are our best chance.
I'd bet millions that we are not alone.

Well I don't believe that we are the last of the Mohicans, I rather find it more as assumable that extraterrestrials are either below the transmitting age . And those who are far ahead of radio transmitting technology, something we can't even decipher if we could hear it..

So that makes us in between the galactic evolution.
By the time we found another way to communicate over long distance, we can hear the first incoming radio signals and we will probably the ones who are invisible to them.

And what about regions of space where radio signals not even can penetrate, I've heard someone talk about that some waves can't even go through dark matter ?

.

originally posted by: 0bserver1
Well I don't believe that we are the last of the Mohicans, I rather find it more as unable that extraterrestrials are either below the transmitting age . And those who are far ahead of radio transmitting technology, something we can't even decipher if we could hear it..

So that makes us in between galactic evolution.
By the time we found another way to communicate over long distance, we can hear the first incoming radio signals and we will probably the ones who are invisible to them

A signal from a star 20,000 LY away would have been sent 20,000 years ago. There's a large enough population of stars that we could possibly get a signal if it happened within the last 700,000 years or so because we have a large sample of stars within that range of light years.

Of course, someone has to be there and they have to send a high gain signal (not television or radio) on a directed broadcast that was either purposefully or accidentally aimed our way.

So even in the best possible case, it's unlikely still that we will ever receive anything we can verify as a legitimate signal.

Harte

originally posted by: HarteA signal from a star 20,000 LY away would have been sent 20,000 years ago. There's a large enough population of stars that we could possibly get a signal if it happened within the last 700,000 years or so because we have a large sample of stars within that range of light years.

Of course, someone has to be there and they have to send a high gain signal (not television or radio) on a directed broadcast that was either purposefully or accidentally aimed our way.

So even in the best possible case, it's unlikely still that we will ever receive anything we can verify as a legitimate signal.

Harte

IF a signal was "sent" even within a few short light years, it would be very unlikely that it could/would be interpreted as "intelligent. This is mostly due to the way Radio Astronomy works.

You try to speak of a "signal" that is not radio or TV, yet the only "signals" we are capable of receiving at that great distances are electromagnetic in nature, or in a more common terminology; radio.

The problem with electromagnetic radiation is the way it propagates, and the "signal", or strength thereof decreasing at as an inverse square. Such a signal sent from Earth, using the best and most powerful of Masers extant today, would not reach Alpha Centauri intact. While the signal would reach those 4 light years, it would be far too weak to receive in a normal manner, even with the very best of high gain antenna.

The solution to receiving these weak signals, and what is commonly done by Radio Astronomers, is a sort of summation over short periods of time. This has the effect of amplifying the signal to a level that can be detected by today's electronics. Unfortunately, this process destroys any intelligence (data) impressed onto the original signal Thus, signals from deep space can never be recognized as artificial, and possessing data of any form.

As a result of this "space" seems quiet, even if it is not.

originally posted by: tanka418

originally posted by: HarteA signal from a star 20,000 LY away would have been sent 20,000 years ago. There's a large enough population of stars that we could possibly get a signal if it happened within the last 700,000 years or so because we have a large sample of stars within that range of light years.

Of course, someone has to be there and they have to send a high gain signal (not television or radio) on a directed broadcast that was either purposefully or accidentally aimed our way.

So even in the best possible case, it's unlikely still that we will ever receive anything we can verify as a legitimate signal.

Harte

IF a signal was "sent" even within a few short light years, it would be very unlikely that it could/would be interpreted as "intelligent. This is mostly due to the way Radio Astronomy works.

You try to speak of a "signal" that is not radio or TV, yet the only "signals" we are capable of receiving at that great distances are electromagnetic in nature, or in a more common terminology; radio.

The problem with electromagnetic radiation is the way it propagates, and the "signal", or strength thereof decreasing at as an inverse square. Such a signal sent from Earth, using the best and most powerful of Masers extant today, would not reach Alpha Centauri intact. While the signal would reach those 4 light years, it would be far too weak to receive in a normal manner, even with the very best of high gain antenna.

The solution to receiving these weak signals, and what is commonly done by Radio Astronomers, is a sort of summation over short periods of time. This has the effect of amplifying the signal to a level that can be detected by today's electronics. Unfortunately, this process destroys any intelligence (data) impressed onto the original signal Thus, signals from deep space can never be recognized as artificial, and possessing data of any form.

As a result of this "space" seems quiet, even if it is not.

Actually, it could be received, if there was enough gain.
By "radio," I mean radio station broadcasts. The portion of the EM spectrum we call radio is fairly low power, but the gain can be vastly increased by using a directional transmitter. Also, frequencies used for radar extent up to thousands of times the strength of the kind of "radio" I was talking about.

And radar is used to map extraterrestrial bodies.

If a culture in the Alpha Centauri system was mapping a moon with radar, and the moon happened to be between us and them, then we would be able to receive that signal.

High powered radar doesn't include any info though, so we'd be hard pressed to establish it was an artificial signal.

If that same culture was stupid enough to be sending out such signals to advertise their presence, on the other hand, they would include information so that receivers would know it was an artificial signal.

This is why I implied (or tried to) that any signal would have to be purely accidentally (radar) or purposefully aimed at us (radar with information) or we could never receive it.

Harte

Published today in Live Science.

The first evidence of alien life may be recorded as a hologram.

Scientists have detected microbes in Greenland sea ice using a specially built digital holographic microscope, suggesting that the instrument could have similar success on icy moons in the outer solar system, if any of them harbor life.

Indeed, the holographic microscope could theoretically make a contribution to NASA's mission to the Jupiter moon Europa, which the agency plans to launch by the mid-2020s, the instrument's developers say.

How Holograms Could Aid Alien Life Hunt

originally posted by: Harte
Actually, it could be received, if there was enough gain.

Do you know how "gain" works? Do you know where this "gain" comes from?

By "radio," I mean radio station broadcasts. The portion of the EM spectrum we call radio is fairly low power, but the gain can be vastly increased by using a directional transmitter. Also, frequencies used for radar extent up to thousands of times the strength of the kind of "radio" I was talking about.

Yes, I know...I've worked with such equipment n my lifetime. But even at 10's of megawatts, the signal strength falls off very rapidly...as I said "inverse square". So even with a high gain antenna, or even using a maser (an RF equivalent to a laser) the signal would be lost in noise after traveling light years. At this point it would only be the impressed data that distinguishes the signal from any other naturally produced emission.

And radar is used to map extraterrestrial bodies.

Yep they sure do...over short distances. however the issues here are more than simply signal strength loss, there are also time constraints involved.

If a culture in the Alpha Centauri system was mapping a moon with radar, and the moon happened to be between us and them, then we would be able to receive that signal.

High powered radar doesn't include any info though, so we'd be hard pressed to establish it was an artificial signal.

Actually, high powered radars do include data impressed on the carrier. This data can be used to identify and validate a return. This helps defend against Electronic Countermeasures, and Deception. It also makes it possible to receive that return even if it is buried in noise...it would allow for the reception, and use of very weak signals. But such technology doesn't work with Astronomy.

If that same culture was stupid enough to be sending out such signals to advertise their presence, on the other hand, they would include information so that receivers would know it was an artificial signal.

This is why I implied (or tried to) that any signal would have to be purely accidentally (radar) or purposefully aimed at us (radar with information) or we could never receive it.

Harte

As I said, in Radio Astronomy they use a system that "sums" the signal over time; this provides that "gain" you were talking about (in addition to what the antenna provides), and allows very weak signals to be received. Unfortunately, this process destroys all information that may have been carried by the signal...so even IF you managed to receive that alien signal...you wouldn't be able to recognize it as an artificial / intelligent signal. It would appear just as any other naturally produced emission; a part of the background.

originally posted by: tanka418

originally posted by: Harte
Actually, it could be received, if there was enough gain.

Do you know how "gain" works? Do you know where this "gain" comes from?

By "radio," I mean radio station broadcasts. The portion of the EM spectrum we call radio is fairly low power, but the gain can be vastly increased by using a directional transmitter. Also, frequencies used for radar extent up to thousands of times the strength of the kind of "radio" I was talking about.

Yes, I know...I've worked with such equipment n my lifetime. But even at 10's of megawatts, the signal strength falls off very rapidly...as I said "inverse square". So even with a high gain antenna, or even using a maser (an RF equivalent to a laser) the signal would be lost in noise after traveling light years. At this point it would only be the impressed data that distinguishes the signal from any other naturally produced emission.

The inverse-square law applies, yes, but directional broadcasts increase the power of the signal without increasing energy input.

Maser is a general term. Using a high frequency maser with a high energy input would result in a higher probability of reception. In other words, it depends on the maser.

But also importantly it depends on the Earth being in exactly the right spot for the right amount of time and that we be searching in the given frequency of the signal. These factors have as great an impact on any successful reception as hypothesized transmitters would have.

Some of the microwaves we receive from space start out around 20 Gw. That's not Jiggawatts.

Harte

originally posted by: intrptr
a reply to: vethumanbeing

vhb: the creators had to produce billions of various life forms; including the most advanced: the mammal.

intrptr: If the Universe is Infinite and Eternal, then the 'creators' have had an infinite amount of time to develop life, lonnng before they ever put it here.

Infinite means "possibilities" to construct more possibilities to then again construct (it builds upon itself like a fractal form); as its *learning* as it creates/produces something from nothing. Add information acquired by trial and error, 'binary code' becomes DNA as living matter.

intrptr: Your proposing that this earth is the first such 'petri dish', pretty arrogant. How could you possibly know that, having never left here or been anywhere else?

This Earth IS the first petri dish experiment EVER to produce the variety of lifeforms/ecosystems/weather patterns in a very heavy 3D environment. I will leave the rest of your question to your own imagination to answer.

originally posted by: Harte
Some of the microwaves we receive from space start out around 20 Gw. That's not Jiggawatts.

Harte

1.21 jiggawatts?!!! 1.21 jiggawatts? Great Scott!
-- Dr. Emmet Brown

originally posted by: Harte

Some of the microwaves we receive from space start out around 20 Gw. That's not Jiggawatts.

Harte

Most signals received from space originate within a star...so, the power is a wee bit more than mere gigawatts. And most of those are rather weak.

We don't have a telescope that can detect what gases make up the atmosphere of an exoplanet or even get color pictures of an exoplanet. The moment life started producing photosynthesis it could be detected in our atmosphere, which is a pretty big time frame to be detected by aliens.

originally posted by: game over man
We don't have a telescope that can detect what gases make up the atmosphere of an exoplanet or even get color pictures of an exoplanet. The moment life started producing photosynthesis it could be detected in our atmosphere, which is a pretty big time frame to be detected by aliens.

Actually, we do have telescopes that can detect the gasses in an exoplanet.

By using a spectrometer attached to even a small telescope and waiting for the exoplanet to transit its star. Then hoping for a somewhat rare event; microlensing, we can get a spectroscopic "reading" of an exoplanet. Requires a bit of luck, but quite possible.

originally posted by: game over man
We don't have a telescope that can detect what gases make up the atmosphere of an exoplanet or even get color pictures of an exoplanet. The moment life started producing photosynthesis it could be detected in our atmosphere, which is a pretty big time frame to be detected by aliens.

I think life itself (simple life) may be common. Therefore, an alien finding signs of "just life" in our atmosphere may not be that meaningful to aliens who have the ability to easily analyze the spectra of at atmospheres. They may find it all the time, and not find that anything worth necessarily following up on (if they had the ability to follow up). If plant life is common, then they may not find an atmosphere that indicates plant life to be something exciting. It may be a "ho-hum" finding that happens all the time.

The thing they may need to detect if they want to know if intelligent life is on a planet is industrial gasses in the atmosphere. In the case of Earth, the light from those industrial gasses has only reached the stars that are maybe only a few hundred light years away from us.

Maybe they can detect the fires made by hunter-gathers or the fires in the first settlements at the beginnings of our civilization, in which case that light from our atmosphere that may show the fires of our ancestors could be much farther out -- maybe 50,000 light years.

But the light from our atmosphere that shows signs of a technological civilization has only gone a few hundred light years out from us to only a fraction of the galaxy. It's not like the entire galaxy can detect that light.

Thankyou to the learned responses to this question of radio signals.
I'm a Trog, but I've learnt quite a lot, thx.

Question,.... If someone light years away, purposefully or by accident, aimed a radio signal at Planet Earth for say, 2 hours, then stopped......
Would/could it be something as simple as, the Moon being in direct "Line of Fire" of the signal, or one of our sensitive Radio Telescopes is just about to enter the "Other Side" of the signal direction, due to the Earth revolving every 24 hrs, that, the signal transmitted by the "Others" may Never even be detected by our instruments, as they are not pointing in the right direction at exactly the right time? Even If a signal was actually sent.
Is it such a "Hit or Miss" operation?.
Is it really worth "listening" then?
Have we put instruments on the Moon for "Listening"?

Our part of the Galaxy could be teaming with intelligent life, and we may indeed never hear them, even if they used technology that we could receive, except by amazing remote chance........Depressing in a way really.

originally posted by: Soylent Green Is People

originally posted by: game over man
We don't have a telescope that can detect what gases make up the atmosphere of an exoplanet or even get color pictures of an exoplanet. The moment life started producing photosynthesis it could be detected in our atmosphere, which is a pretty big time frame to be detected by aliens.

I think life itself (simple life) may be common. Therefore, an alien finding signs of "just life" in our atmosphere may not be that meaningful to aliens who have the ability to easily analyze the spectra of at atmospheres. They may find it all the time, and not find that anything worth necessarily following up on (if they had the ability to follow up). If plant life is common, then they may not find an atmosphere that indicates plant life to be something exciting. It may be a "ho-hum" finding that happens all the time.

The thing they may need to detect if they want to know if intelligent life is on a planet is industrial gasses in the atmosphere. In the case of Earth, the light from those industrial gasses has only reached the stars that are maybe only a few hundred light years away from us.

Maybe they can detect the fires made by hunter-gathers or the fires in the first settlements at the beginnings of our civilization, in which case that light from our atmosphere that may show the fires of our ancestors could be much farther out -- maybe 50,000 light years.

But the light from our atmosphere that shows signs of a technological civilization has only gone a few hundred light years out from us to only a fraction of the galaxy. It's not like the entire galaxy can detect that light.

Our telescope will do the same... James Webb Space Telescope

But the James Webb Space Telescope (JWST), which has been proposed as a successor to the Hubble Space Telescope for launch in 2018 and will study the universe in infrared wavelengths, could give us a first glimpse into the atmospheres of Earth-like exoplanets.

I think you're underestimating the chance of discovering alien life...there are sightings all the time, they're covered up and denied.

a reply to: game over man

On the contrary. I think life might be common elsewhere, and there's a good chance that we will be able to detect signs of life processes in the atmospheres of exoplanets within the next couple of decades.

What I said in my post above is that while finding signs of just "life" in the spectrum of light from an exoplanet atmosphere may end up being relatively common someday, it might be more difficult to detect the signs of intelligent life.

So, maybe an alien 10,000 ly away can detect signs of just "life" in the 10,000 year old light from the atmosphere of Earth, but to that alien, just finding "life" (not necessarily intelligent life, but just life) be so common that they don't think it's a big deal, and won't bother trying to contact Earth.

a reply to: Soylent Green Is People

We won't be making contact either...sending out a signal could potentially bring problems. If we did happen to detect an atmosphere like ours with pollution, we would probably send a probe in that direction to study it and not be discovered by the intelligent life. Who knows if these discoveries will ever be made public.

If the atmospheres on Venus and Mars didn't change and there was obvious life there, society would have such a different and optimistic outlook on searching for intelligent ET.

Mutation allowed the human brain to change overtime...imagine brains of animals on alien planets mutated in a more advanced way?

a reply to: game over man

Mutation allowed the human brain to change overtime...imagine brains of animals on alien planets mutated in a more advanced way?

Evolution isn't really about advancement though. It's about survival in changing environments. Sharks have been around for a whole lot longer than humans have, by an evolutionary standard it would seem that they are more advanced. Intelligence is not a requirement for survival. Obviously.

If there's no aliens...then who has been buzzing our aircraft and missile bases( Including deactivating minuteman missiles) for the last 70+ years, messing with our population for WHO KNOWS WHAT REASON? Either show yourselves or get the hell away from our planet.

And please, while 90% of UFO sightings, aircraft incidents, landings, abductions and encounters are BS or can be explained by natural phenomenon, secret projects, mass hysteria and crazy ass people, there's enough incidents of official govt reporting and documentation dating back to the late 40s that declare that SONETHING is out there.

Just had to put my two cents out there.