Jump to content
Science Forums

The Inverse Doppler Effect: Ece Researchers Add To The Bylaws Of Physics


C1ay

Recommended Posts

What if the speed of light is a constant only most of the time? What if gravity sometimes pushed instead of pulled? Scientists are increasingly asking what would seem like far-out questions regarding the laws and rules of physics after discovering conditions and materials where the rules don't quite apply.

 

Take the Doppler effect.

 

The Doppler effect is in use everywhere, everyday. Police use it to catch speeders. Satellites use it to track space debris and air-traffic controllers use it to monitor aircraft. The Doppler effect explains why the pitch changes from high to low when a police siren passes you on the street. As the siren moves toward you, it is catching up to and compressing the sound waves it produces, thus the higher pitch. When it passes, the sound expands to fill the increasing space between you and the noise. The sound waves are longer and the pitch is lower.

 

The inverse Doppler effect is not something you can hear, but understanding it could one day lead to important advances in optics and communications equipment.

 

Predicted in the 1940s, the inverse Doppler effect was first observed in 2003 by British researchers Nigel Seddon and Trevor Bearpark using an experimental magnetic, nonlinear transmission line sketched out by Avenir Belyantsev and Alexander Kozyrev in 2000. This nonlinear transmission line is a synthetic structure that allows electromagnetic waves to propagate along it in a new fashion.

 

In the experiment, a pulse of current fed into the line acts as the moving "siren" or shockwave. It generates a radio frequency (RF) signal but as the pulse recedes, the spacing between the peaks and troughs in the waves tighten rather than loosen: the inverse of the Doppler effect. That's just the opposite of what happens with sound waves when a siren passes you.

 

Reporting in the May 20 issue of the journal Physics Review Letters, University of Wisconsin-Madison Research Associate Alexander Kozyrev and Electrical and Computer Engineering Professor Dan van der Weide prove how an RF signal moving through this special transmission line can reverse itself and fall in sync with the shockwave in order to realize the inverse Doppler effect. They demonstrated that the shift arises from a complex and remarkable spatial structure of waves propagating along the line.

 

Normally consisting of only one spatial period, the considered system exhibits multiple spatial periods enabled by the periodicity of the nonlinear transmission line structure. Their explanation may point the way toward making materials in which this new effect can operate.

 

"There are now emerging a whole class of experiments, and theories to back them up, that involve the creation of materials that support electromagnetic wave propagation in ways that are not observed in nature," van der Weide says. "In other words, it's turning nature on its head. Some might ask, 'If you can only do this in artificial material, what good is it?' The answer is that we might be able to create materials that could support this type of effect for light or other electromagnetic waves. The larger point is that physicists are starting to challenge what were thought to be the basic laws of nature."

 

In 1968, Russian theorist V.G. Veselago predicted that materials could be engineered to interact with their environment in the opposite of how natural materials react. In 2000, researchers at the University of California-San Diego (UCSD) confirmed this, creating what's known as the first "left-handed" material.

 

In nature, all materials appear to obey the "right-hand rule." If the fingers of the right hand represent the waves' electric field, and if the fingers curl around to the base of the hand, representing the magnetic field, then the outstretched thumb indicates the direction of the flow of power. But the UCSD team created material that caused fields to move to the left even though the electromagnetic energy moved to the right. Light waves produced by such material should also produce an inverted Doppler effect. Van der Weide's group, in collaboration with researchers at MIT and the University of Delaware, is also exploring left-handed media.

 

"This is kind of the tip of the iceberg in terms of discovering things that we've held to be inviolable. We're finding they can, in fact, be violated under certain conditions," van der Weide says. "Can we build structures that would support that kind of thing? The answer appears to be yes."

 

Source: University of Wisconsin-Madison

Link to comment
Share on other sites

I like your comment about gravity Pushing. I have just released a book call Particle Mechanics the Theory of Energy States. One of my main new theories is that gravity is a particle and it pushes everything it goes through until it reaches the object it is going to. This is my first posting at this web site. I could not believe that someone else was going down the same path that I have been on for several years. I would recommend you read my book. You will not look at gravity the same way. You will not look at waves the same way and you will see the doppler effect isn't what you think it is.

 

I have a web site at ParticleMechanics.com with more information. I have been busy writing for the last several years. Now I intend to do lots of posting.

 

Understanding gravity is one of the keys to unlocking how the universe works!

Link to comment
Share on other sites

I like your comment about gravity Pushing. I have just released a book call Particle Mechanics the Theory of Energy States. One of my main new theories is that gravity is a particle and it pushes everything it goes through until it reaches the object it is going to. This is my first posting at this web site. I could not believe that someone else was going down the same path that I have been on for several years. I would recommend you read my book. You will not look at gravity the same way. You will not look at waves the same way and you will see the doppler effect isn't what you think it is.

 

I have a web site at ParticleMechanics.com with more information. I have been busy writing for the last several years. Now I intend to do lots of posting.

 

Understanding gravity is one of the keys to unlocking how the universe works!

Are we talking about an aether here? The concept is quite old if we are. It does seem to be making a comeback of sorts however, and I'm really interested to see just where all these new ways of breathing life into an old concept will take us.

Link to comment
Share on other sites

No it's not aether. This is a different look at what is behind all the forces. There is something there. For example, there is a particle that causes the sound vibration. The sound particle in my theory is 3 diminsional. Sound is commonly viewed as a 2 diminsional wave. Waves are viewed by their heights and the distances between the troughs or pitch and frequencey.

 

So, a lot of wave theories are a 2D look at a 3D phenomenon. The doppler effect is based on 2D. When you take my 3D look at things the inverse doppler effect is not hard to see or understand.

 

Now about aether. Aether was considered to be the medium for light to propagate through. Light does not need that. Gravity doesn't need it either. Sound does need a medium to go through. The doppler effect is something used with Sound. Trying to apply it to light gets some strange and interesting results.

 

I think I may start my own articles.

Link to comment
Share on other sites

I like your comment about gravity Pushing. I have just released a book call Particle Mechanics the Theory of Energy States. One of my main new theories is that gravity is a particle and it pushes everything it goes through until it reaches the object it is going to. This is my first posting at this web site. I could not believe that someone else was going down the same path that I have been on for several years. I would recommend you read my book. You will not look at gravity the same way. You will not look at waves the same way and you will see the doppler effect isn't what you think it is.

 

I have a web site at ParticleMechanics.com with more information. I have been busy writing for the last several years. Now I intend to do lots of posting.

 

Understanding gravity is one of the keys to unlocking how the universe works!

Welcome to Hypography. FWIW, these are not my comments. This is a news release from the University of Wisconsin at Madison. It can be found here. I did find the material to be thought provoking and that is why I posted it here.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...