A layman question about signals....

No not the amazingly awesome Rush album, but all detectable forms of energy. I have always found this topic fascinating ever since I was kid in the early 80s trying to get a better picture on the TV by moving the antenna around. I have a relatively broad question that I'm hoping someone will be able to answer if not point me in the right direction. I have attempted a vast Google search and it has certainly helped, but I'm thinking there are so many sciences involved, that the form of question I'm choosing is half the problem in that it is too broad a question. So having thought about it, ATS seems like a pretty efficient way as people have a tendency to understand what you're trying to get at.

In a nutshell, exactly how many ways are there to "listen" or detect an energy? I know we can detect electromagnetism, light, sound, radiation, but if one were to create a list of every possible "type" of signal or detectable energy there is, how big would it be? What spurred on the question was wondering what type of energy were we observing when SETI picked up the "Wow Signal". Another example albeit likely fictitious are EVP Ghost signals and how many individuals in that community are convinced that entities are somehow able to utilize radio waves. How many ways are there to "listen" for anything that could intentionally or unintentionally reach our "reality" for lack of a better term?

The more I try to grasp things like String Theory, the more I am wondering anything in one dimensional reality could possibly be detected in another and if so, how?

I know that SETI (from what I have read) focuses on a specific band of (Radio?) frequencies.

a reply to: BS_Slayer

Nicknamed the “Wow!” signal, this was a brief burst of radio waves detected by astronomer Jerry Ehman who was working on a SETI project at the Big Ear radio telescope, Ohio. The signal was, in fact, so remarkable that Ehman circled it on the computer printout, writing “Wow!” in the margin — and unintentionally giving the received radio signal the name under which it would become famous.

news.discovery.com...

SETI searches for patterns in radio noise on various frequency bands.
There have also been some efforts at searching in optical wavelengths.
It doesn't make sense to search for sound signals across space.

a reply to: BS_Slayer

There are numerous forms of energy along with numerous ways for us to detect each of them.

It would be a very long list.

The "Wow!" signal was electromagnetic in nature (IE Radio),

What is it we should be looking for? Well it depends on what it is you want to look for. Some things you would not look for, like Phage stated: Sound. Space is not a good medium for sound waves to travel through as they best travel through gases, liquid and solids.

The other thing to consider is our ability to detect something. If an ET civilization is using some form of FTL communication, chances are we are not going to be able to detect it if we don't know how they are doing it.

Detecting electromagnetic energy is a good bet because it covers all sorts of things (Radio, TV, Radars) and even if ET out there is not actively sending out messages, we might actually pick up the usage of the above from their daily lives (IF that energy has had enough time to reach us, since it travels at the speed of light, a ET world 1,000 lightyears away that has only had those things for the past 200 years means none of their signals will have reached us yet).

Indeed, as I understand it sound uses air to travel, therefore there is no sound in space. I guess I'm wondering if there are other means of sending a communication, or merely picking up activity that is normally not accessible. Quantum entanglement for example, which I will not attempt to define but suggests that what is done to one particle will affect another. I wonder if it is possible that it could be used as a means of communication. Perhaps we can not locate the parallel particle to one we are manipulating, but maybe we could detect one that is being manipulated by something else. Odd that we focus on radio waves within SETI activity, seems like there would be some type of communication format that is more efficient.

a reply to: Phage

a reply to: eriktheawful

Thank you kindly - Out of curiosity, is there anything naturally occurring in nature that travels faster than the speed of light?

a reply to: BS_Slayer

Not that we know of.

I know CERN got all excited as they thought they had detected something doing just that, but it turned out to be a problem with their equipment.

So for now (at least for us) the speed of light is still the big speed limit in the sky.

When we refer to these signals, we are refering to the very wide spectrum of electromagnetic frequencies. Which includes, sound, light, and radiation. They are basically all the same thing, Vibration. We as humans are limited by our sense organs, and can only percieve a miniscule section of this spectrum. One section of this spectrum appears to us as sound. As this frequency increases in speed we see visible light. As it speeds up more, it gets into the infrared, microwaves and then radio waves respectively. Further along and we get what we call radiation, like x-rays and gamma rays. All of which we cannot percieve without technology. This technology is based on chemistry and physics. We find a substance that naturally reacts to these frequencies, and we study how it reacts and changes when it encounters them. By studying this data we can see that these reactions are perfectly predictable.

Lets take a ribbon microphone for example. Your vocal cords produce waves in the frequency we percieve as sound. These waves are carried by our atmosphere and physically move a tiny ribbon of conductive metal. As the metal is vibrated by your voice, it is making an electronic connection every time it makes a full cycle of vibration (hertz). As it vibrates it makes a tiny electronic click. Every click is proportional to the clicks caused by the vibration of your vocal cords. When you put all the clicks together in order, it is an exact copy of the sounds coming from your cords.

Think of a vinyl album under a needle. If you turn it slow enough, you can hear the single clicks as the needle passes over the ridges and nothing as it falls into the valley or as it climbs the next ridge.

Light and radiation work in a very similar way.

Hope that helps.



a reply to: BS_Slayer

a reply to: BS_Slayer

In a nutshell, exactly how many ways are there to "listen" or detect an energy?

The known Electromagnetic Spectrum is the energy thingy you are asking about. It charts all the known energies of the spectrum that we can measure.

The color part is what we see with our eyes. If the whole known spectrum was a roll of film a thousand miles long, the color we see with our eyes would be one inch wide.

I'm sure Phage can provide a more accurate description than my "from memory' attempt to give it some scale.

a reply to: Woodcarver

When we refer to these signals, we are refering to the very wide spectrum of electromagnetic frequencies. Which includes, sound, light, and radiation.

No. Sound is nothing like electromagnetic radiation.

We as humans are limited by our sense organs, and can only percieve a miniscule section of this spectrum. One section of this spectrum appears to us as sound. As this frequency increases in speed we see visible light. As it speeds up more, it gets into the infrared, microwaves and then radio waves respectively.

No. Radio is lower frequency than microwave. Microwave is lower frequency than infrared. Infrared is lower frequency than the visible spectrum. And sound has nothing to do with them because sound is not electromagnetic radiation. Electromagnetic radiation propagates at the speed of light. Sound does not.

These waves are carried by our atmosphere and physically move a tiny ribbon of conductive metal. As the metal is vibrated by your voice, it is making an electronic connection every time it makes a full cycle of vibration (hertz). As it vibrates it makes a tiny electronic click. Every click is proportional to the clicks caused by the vibration of your vocal cords.

No. Sound is an analog phenomenon, not digital.

Light and radiation work in a very similar way.

No, they don't. Sound cannot travel in a vacumn.

Kudos OP for tackling a subject with seemingly no technical bounds. I think the "no sound in space" statement could be qualified somewhat.

There is no sound in pure space. Space though is often impure and sound from the many high energy sound sources in space can propagate for some distance. Sound in nebulous space for instance can travel quite effectively. Accelerometers aboard orbiting satellites have detected sound waves from high energy events on Earth which manage to propagate via the few particles which make up what's left of our atmosphere at those distances. Astronomers have measured sounds in space indirectly by detecting the electromagnetic energy liberated from materials by sound waves. An extreme example of this would be jets from quasars impinging on nebula gases and producing an acoustically active boundary area.

This does relate to SETI. Decades ago it was theorised that a spacecraft travelling near the speed of light, while interacting with the thin compilation of particles along its path would produce a massive shockwave at its bow, analogous to the way a jet creates a shockwave at mach speeds. The shockwave could be detected indirectly by the electromagnetic energy it liberated when interacting with other particles in space.

I realise I may be summoning the semantics zombies, but the topic bears relevance here.

Yes phage is correct sound is not in the EM spectrum. I should not have included it. I also mixed up the radio and infrared.

But my description of a ribbon microphone is spot on and i am not describing sound as digital.


Also light and higher forms of radiation do work similarly. His last correction is not what i said.

Thanks anyways for correcting me.

a reply to: Phage

originally posted by: BS_Slayer
In a nutshell, exactly how many ways are there to "listen" or detect an energy? I know we can detect electromagnetism, light, sound, radiation, but if one were to create a list of every possible "type" of signal or detectable energy there is, how big would it be?

The question's a bit vague, and the way you phrase it leads me to think you might be a bit foggy on the physics definition of energy. You should understand that the "new age"/spiritual/theosophic use of the term is intentionally misleading and doesn't correspond to the concept physics uses for that term. So when you see a post about "spirit energy" "life energy" "ghost energy" "he gives off negative energy" etc, that doesn't mean what I would mean if I said something was capable of providing a few hundred Joules of electrical energy.

What spurred on the question was wondering what type of energy were we observing when SETI picked up the "Wow Signal".

That would be radio, or EM energy.

Another example albeit likely fictitious are EVP Ghost signals and how many individuals in that community are convinced that entities are somehow able to utilize radio waves.

That would be "woo" or fictitious energy. I'm at a loss to understand why death equips the life-impaired with a radio transmitter that somehow only functions if the receiver scans rapidly through radio noise. Other than a sort of audio pareidolia, of course.

The more I try to grasp things like String Theory, the more I am wondering anything in one dimensional reality could possibly be detected in another and if so, how?

I know that SETI (from what I have read) focuses on a specific band of (Radio?) frequencies.

If there are alternate realities, you won't be able to communicate with them anyway.