a question just for fun--- never gotten a "good" answer----

[Catbrain]

Here is my questions----
Why is the impedance of space (like outer space) 377 ohms ?
Impedance is a "material" property. Why should the vacuum of space show an impedance to propagation of EM waves ?
how does vacuum come to have an X-C and an X-L ?

and before you use the answer that "the equations predict it" ---- no-- I say that is a circular answer. This question is conceptual and i am looking for a conceptual answer. How does "nothing" have measurable physical electrical properties ?

after I hear some possible answers-- i will reveal what I believe it the explanation.......

PS-- I remember reading a story about the early space flight engineers--- they made radios to go on the first deep space missions.
They discovered that they were not getting the expected transmit power back at the receiving stations. After a while of studying the problem they discovered that their spacecraft antennas were operating mismatched to their environment. (vacuum)
So that kind of shows that the 377 ohms wasn't predicted at all by science--- even if they claim NOW--- that it was.

 

[merlin]

Where did you get free space has an impedance? There is such a thing as space loss but nothing to do with impedance.
Any antenna with an impedance of X, it won't change in a vacuum.
Voyager 1, IE: is about 164.7 AU (1.531E+10 miles) into interstellar space, its 20 watt signal is so weak it takes a vast array of huge satellite antennas just to hear it at all.

 

[Omega-TI]

Space is not a pure vacuum, there are some hydrogen atoms in every cubic foot, more around solar systems. I know this also sounds bizarre, but electromagnetic waves (radio) actually travel a tad slower speed in our atmosphere. While math always appears perfect on paper, sometimes nature creeps in and over great distances those hydrogen atoms might have a negligible but hardly measurable or verifiable effect. Now @merlin was right on with the main and verifiable and reproducible explanation which can be seen (for easier understanding) in the illustration below.

 

[Catbrain]

yes--- we are taking into account the inverse square law for radiation. Thats not in question
I have read in many places that the vacuum of space has a characteristic impedance of 377 ohms.

as to hydrogen gas in space---- its concentration would be so small as to be immeasurable by electrical means
--- it is probably only detectable by optical means that can span across several light years and accumulate a sum
total change over that kind of distance. so we cant really blame 377 ohms on hydrogen. I would say 'space" is a more pure vacuum that we can make (under normal circumstances) in the laboratory. Most common lab vacuum systems dont go much below 10x-6 ...... and i think deep space would be way lower than that. (once you get suitably away from earth's atmosphere. )

below is the very first google hit on that question-----

AI Overview
Learn more…Opens in new tab

The impedance of free space, often referred to as the "characteristic impedance" of free space, is approximately 377 ohms.


Explanation:

• Definition:
  Impedance of free space represents the relationship between the electric and magnetic fields of an electromagnetic wave propagating through a vacuum.
  
  
  
• Calculation:
  This value is calculated using the permeability and permittivity of free space, with the formula: √(μ₀/ε₀).
  
  
  
• Approximation:
  While the exact value is closer to 376.73 ohms, it's commonly rounded to 377 ohms for practical purposes.
  

Key points:

• Symbol: The impedance of free space is often represented by the symbol "Z₀".
  
  
  
• Application: This value is crucial in antenna design and electromagnetic wave propagation calculations.

 

[Catbrain]

So we are back to the question that seems to have no answer (or any answer that makes sense---)
how does "nothing" (vacuum) show a characteristic impedance --- when that is a material property ?
when there is nothing there to have any physical properties....... hence the confounding nature of the question----

 

[Omega-TI]

Well this is out of my sphere of knowledge and I'm man enough to admit it. Resistance without measurable attenuation is not something I can get my head around.

 

[Catbrain]

hint-----
these two things that they teach--- are not even self consistent ----- that is--- "nothing" ---- no physical matter--- has measurable physical properties. The only conclusion I can draw is that what they have taught us is not correct. I understand that this next comment is a magic rabbithole--- but i DID say this was for fun------
Go and look up the Pais patent on the web and read what it says. This is the so-called Navy UFO patent.
(yes I know I just lost most of you there with the eye rolls-- )
i believe this patent has a direct bearing on the first question I threw out there.

in a related development-- in an area mostly forgotten to modern physicists---- in the last 10 years-- some scientists have gotten positive results for the michaelson-Morley experiment first done shortly after the turn of the century. (about the same time Einstein was doing his thing-- or just before----)
The M-M experiment was a search for an invisible medium of propagation for light waves. They referred to this invisible medium as "the either". Many scientists ---NOW---incorrectly believe (or were taught) that there is no medium.
That is not correct. It was never disproven-- only that everyone had gotten negative results trying to prove it.
But it is said that now that we have lasers and very sophisticated optics--- they have gotten a positive result.

think about what this means relative to my first question.......

 

[trentbob]

yes--- we are taking into account the inverse square law for radiation. Thats not in question
I have read in many places that the vacuum of space has a characteristic impedance of 377 ohms.

as to hydrogen gas in space---- its concentration would be so small as to be immeasurable by electrical means
--- it is probably only detectable by optical means that can span across several light years and accumulate a sum
total change over that kind of distance. so we cant really blame 377 ohms on hydrogen. I would say 'space" is a more pure vacuum that we can make (under normal circumstances) in the laboratory. Most common lab vacuum systems dont go much below 10x-6 ...... and i think deep space would be way lower than that. (once you get suitably away from earth's atmosphere. )

below is the very first google hit on that question-----

AI Overview
Learn more…Opens in new tab

The impedance of free space, often referred to as the "characteristic impedance" of free space, is approximately 377 ohms.


Explanation:

• Definition:
  Impedance of free space represents the relationship between the electric and magnetic fields of an electromagnetic wave propagating through a vacuum.
  
  
  
• Calculation:
  This value is calculated using the permeability and permittivity of free space, with the formula: √(μ₀/ε₀).
  
  
  
• Approximation:
  While the exact value is closer to 376.73 ohms, it's commonly rounded to 377 ohms for practical purposes.

Key points:

• Symbol: The impedance of free space is often represented by the symbol "Z₀".
  
  
  
• Application: This value is crucial in antenna design and electromagnetic wave propagation calculations.

Welcome to radio reference, I see you just joined this month.

Interesting thread!😄

 

[MUTNAV]

hint-----
these two things that they teach--- are not even self consistent ----- that is--- "nothing" ---- no physical matter--- has measurable physical properties. The only conclusion I can draw is that what they have taught us is not correct. I understand that this next comment is a magic rabbithole--- but i DID say this was for fun------
Go and look up the Pais patent on the web and read what it says. This is the so-called Navy UFO patent.
(yes I know I just lost most of you there with the eye rolls-- )
i believe this patent has a direct bearing on the first question I threw out there.

in a related development-- in an area mostly forgotten to modern physicists---- in the last 10 years-- some scientists have gotten positive results for the michaelson-Morley experiment first done shortly after the turn of the century. (about the same time Einstein was doing his thing-- or just before----)
The M-M experiment was a search for an invisible medium of propagation for light waves. They referred to this invisible medium as "the either". Many scientists ---NOW---incorrectly believe (or were taught) that there is no medium.
That is not correct. It was never disproven-- only that everyone had gotten negative results trying to prove it.
But it is said that now that we have lasers and very sophisticated optics--- they have gotten a positive result.

think about what this means relative to my first question.......

I'm pretty sure that the ether was taught and thought about even more than a generation ago.

I HAVE also wondered if radio things (antennas?) were matched to 377 ohms, if they would work better.
It would be interesting to see if there was a way or reducing the impedance... Who knows, maybe it would get rid of the faster than light limit

Thanks
Joel

 

[dlwtrunked]

Here is my questions----
Why is the impedance of space (like outer space) 377 ohms ?
Impedance is a "material" property. Why should the vacuum of space show an impedance to propagation of EM waves ?
how does vacuum come to have an X-C and an X-L ?

and before you use the answer that "the equations predict it" ---- no-- I say that is a circular answer. This question is conceptual and i am looking for a conceptual answer. How does "nothing" have measurable physical electrical properties ?

after I hear some possible answers-- i will reveal what I believe it the explanation.......

PS-- I remember reading a story about the early space flight engineers--- they made radios to go on the first deep space missions.
They discovered that they were not getting the expected transmit power back at the receiving stations. After a while of studying the problem they discovered that their spacecraft antennas were operating mismatched to their environment. (vacuum)
So that kind of shows that the 377 ohms wasn't predicted at all by science--- even if they claim NOW--- that it was.

Some things do not have simple answers. Start with there are two different kinds of impedance--sometimes one is called characteristic impedance and the other intrinsic impedance. You (and others) are confusing these. there is no simple way to explain but you might look at LearnEMC - EMC Question of the Week: June 6, 2022
You might also read If free space impedance is 377 ohms, does it mean that impedance of receiving antenna should be 377 ohms for receiving maximum power? Wha...

 

[wtp]

is this the cause of self discharge on my rechargeable batteries ?
they have a 377 ohm invisible resistor connected to them ...?

i do like the idea of 377 ohm antennas.

 

[RFI-EMI-GUY]

Where is Coyote Frostbite when we need her?

 

[buddrousa]

Coyote Frostbite doing what all do this time of year gathering fruits and nuts for winter.

 

[kb1fua]

Well this is out of my sphere of knowledge and I'm man enough to admit it. Resistance without measurable attenuation is not something I can get my head around.

likewise! ☕

 

[Catbrain]

DLWtrunked------

I just read all 3 "explanations" of how vacuum can have a finite impedance.
NONE of it answered the question. All but one just sidestepped the situation - factually speaking.
One commenter suggested that vacuum must not be empty. ( I agree 100% )

The idea (theory) of self propagation of EM waves---- is lacking from a common sense point of view.
if we are in vacuum-- and vacuum is "nothingness"----- then how can a E field induce a current to create a corresponding B field-- when there is nothing to induce into ? Some of the "explainers" state that the two fields are stored as potential energy on the off cycle. So where --- pray-- is that potential stored if there is now matter in vacuum. ??? I contend that science can not answer where potential energy is physically stored in many cases.
when you lift a 1 pound weight from the floor to a table--- there is PE stored. Where is it stored ???? science tells us it is stored as gravitational potential energy. oK----- where is that PE stored ?????? You also never get an answer there either. That question -- in my mind---- is linked to the 377 ohm question. i think the same invisible soup we call vacuum--- is responsible for both things. so our task seems to be to figure out how to disassemble vacuum and see what's in there. so how do we do that ?

 

[MUTNAV]

Even in a vacuum there are gravitational and magnetic fields. I think a redefinition of vacuum is appropriate, maybe something like an absence of matter?

Thanks
Joel

 

[Catbrain]

Joel--- that's kind of how its defined now in college text books. As "nothing" -- no matter.

There is a concept referred to as "action at a distance". which is a way to describe a force which propagates over a distance where no intermediate agent of that force is detected or seen. it was named that In Newton's day.
they couldn't explain it so they named it that. Today --- we REALLY have no better explanation than Newton had.
we just do not wish to admit it. Science is a pompous ass. Why are there forces associated with electric fields ?
well they answer--- because opposite charges attract---- well-- why should electric charges attract or repel ?
Then we are back to the same point---- we never really explain that - we just say that it is true without attempting to say why. This is what makes physics somewhat dishonest--- from the view of someone trying to understand it.
we have all these advances concepts that are built on top of foundations that we don't even admit we don't understand. That doesn't mean the house above the foundation is right or wrong---- but if the goal of physics is to understand the nature of the universe---- it seems like we miss the mark by not figuring out the very first part that everything else got built on top of.

like gravity. when we lift the weight and PE goes "somewhere " -- and is stored somehow. and somehow the universe's book keeping never looses that information. The weight can sit for 1000 years and the when the table breaks-- the universe knows how much energy goes back into the weight. So to my thinking --- that has to mean that when we first lifted the weight-- we changed the "state" of a hidden system somehow associated with the weight. That change of state -- rearranged something into a higher configuration---- and when the weight drops-- that configuration reverts back to its original configuration. I think that whatever is hiding inside vacuum--- is the matrix of virtual particles which control all the forces- such as gravity, electric, magnetic - strong and weak nuclear and many more lesser ones. and let me throw out a curve ball and suggest that prayer may be just another "wave" in one of these virtual particles. Perhaps our psychic ability might be another one. I suspect the concept we know as "matter" may just be a particular configuration of these virtual particles. we see that matter can turn into energy and vice versa. and even potential energy can convert to matter. mother nature is giving us hints-- but we are not looking....... as usual.....

 

[bill4long]

Why is the impedance of space (like outer space) 377 ohms ?

The true impedance of free space is 42.

Don't ask me how I know.