Beyond radar

[gubbi]

Beyond radar

Quantum illumination may one day let us get lots of data via hyper-long-distance systems

Imagine two photons, basic units of light that are infinitesimally small. Scientists shoot one photon into the sky. The other they keep in the lab. The photon in the sky strikes an airliner or a satellite. Almost immediately, the scientists pick up the flying object’s location. How do they know their sliver of light has hit a target miles away? They can tell by comparing one photon to the other.

It’s an exotic concept called quantum illumination, an outgrowth of quantum physics now under study by scientists at Raytheon BBN Technologies in Cambridge.

“We’ve learned about quantum physics in the lab. Now we ask ourselves, ‘Can we translate the most crucial ideas into the practical domain?’ ’’ said a Boston University physics professor, Alexander Sergienko.

The process is similar to radar, where electromagnetic waves rebound off objects to create an image of something so far away the naked eye can’t see it. But because of quantum physics, the smaller photon delivers far more data far more quickly and efficiently, scientists said.

A quantum radar could conceivably carry more data than, say, a traditional radar, because of the different qualities photons express as both particles and waves.

Read entire article at the link provided.


Interesting concept. With development of Quantum Radars, stealth just becomes a more deadly and practical terminology. Move over AESA, say hello to Photons!

 

[Archdemon]

Beyond radar

Quantum illumination may one day let us get lots of data via hyper-long-distance systems



Read entire article at the link provided.


Interesting concept. With development of Quantum Radars, stealth just becomes a more deadly and practical terminology. Move over AESA, say hello to Photons!

AESA uses photons

 

[gubbi]

AESA uses photons

?? What? Explanation, I demand.

 

[President Camacho]

AESA uses photons

My eyes do that too. Both of them -

Edit on seriousness:

But the work is nonetheless on the verge of yielding long-awaited applications for groundbreaking concepts developed a century ago by giants like Albert Einstein, scientists said.

Albert Einstein was as much a foreigner to the Quantum Mechanics as you are..

Both the photons are in different Hilbert's space. The possibility of determining one photon's space-time position will defy the laws of Relativity.

And Relativity is a concept proven with experiments. Whereas, Quantum Physics is not. I think the people involved in this experiments are 'determined' to fail.

The most important part:

Imagine two photons, basic units of light that are infinitesimally small. Scientists shoot one photon into the sky. The other they keep in the lab. The photon in the sky strikes an airliner or a satellite. Almost immediately, the scientists pick up the flying object’s location. How do they know their sliver of light has hit a target miles away? They can tell by comparing one photon to the other.

The part I bold and underlined, shall be changed to "Subsequently". So much about grammatical and political correctness.

 

[Archdemon]

?? What? Explanation, I demand.

electromagnetic spectrum is photons energy level spectrum.

 

[Archdemon]

My eyes do that too. Both of them -

Indeed, but unlike eyes AESA and many other radars uses T/R, our eyes are only R, passive radars

 

[below_freezing]

I use photons as well, every day. Many aspects of quantum physics are indeed proven, such as band gap in semiconductors, Fermi gas theory of metals and the resultant theory of conduction, among other things, are observed in nature. The photoelectric effect is a typical quantum phenomena.

That said this experiment will fail. Other concepts in quantum physics, outside of solid state physics and quantum chemistry, have never been experimentally determined. Originally, quantum theory was used to describe the properties of matter alone, never meant to be extrapolated to information. Not only that, practical aspects such as keeping a photon stationary, detection of a stationary photon without destroying it, and figuring out the vast array of changes that can accompany a photon's reflection are all immense hurdles.

 

[Thomas]

Beyond radar

Quantum illumination may one day let us get lots of data via hyper-long-distance systems



Read entire article at the link provided.


Interesting concept. With development of Quantum Radars, stealth just becomes a more deadly and practical terminology. Move over AESA, say hello to Photons!

I see one problem, Photons can be trapped and manipulated.

Slow and Stopped Light in Metamaterials | Mendeley

"We demonstrate the deceleration of guided electromagnetic waves propagating along an adiabatically tapered negative-refractive-index metamaterial heterostructure and show that light can ideally be brought to a complete halt. It is analytically shown that, in principle, this method simultaneously allows for broad bandwidth operation (since it does not rely on group index resonances), large delay-bandwidth products (since a wave packet can be completely stopped and buffered indefinitely) and high, almost 100 % in/out-coupling efficiencies. The halting of a monochromatic field component travelling along the heterostructure is demonstrated on the basis of a wave analysis and confirmed in a pertinent ray analysis, which unmistakably illustrates the trapping of the associated light-ray and the formation of a double light-ray cone (optical clepsydra) at the point where the ray is trapped. This method for trapping photons conceivably opens the way to a multitude of hybrid optoelectronic devices to be used in quantum information processing, communication networks and signal processors and may herald a new realm of combined metamaterials and slow light research"

 

[below_freezing]

A common misunderstanding. The photons continue propagating at the speed of light. The wave envelope's speed, the group velocity, can be slowed down.

 

[no_name]

And Relativity is a concept proven with experiments. Whereas, Quantum Physics is not. I think the people involved in this experiments are 'determined' to fail.

Quantum physics are as much proven by experiments as Relativity. Except that in the case of quantum domain the participants of the experiment will influences the outcome result of the experiment itself which is something that they cannot avoid. The wave-particle duality is one example - photons can behave like particle or waves depends on what the scientists are trying to 'prove' in their experimental setup. In otherwords the results from the experiment are influenced by what the scientists are 'intended' to find out.

What this means is that among other things these experiments don't have inherent objectivity.

 

[Thomas]

once a photon is slowed down it converts to energy correct?

 

[Developereo]

A common misunderstanding. The photons continue propagating at the speed of light. The wave envelope's speed, the group velocity, can be slowed down.

True. Photons always travel exactly at the speed of light.
In a non-vacuum, a travelling photon is absorbed by another particle, and then re-emitted. The denser the material, the more often this absorption/reemission happens, slowing down the effective propagation speed of the radiation energy.

By some estimates, a quantum of energy emitted at the sun's core takes a million years to reach the surface, from where it takes 8:20 minutes to reach the Earth.

As for this quantum illumination, the technical and theoretical challenges are immense but these people are clearly not idiots. They know relativity better tha most of us. It will be fascinating to see how this develops.

 

[casual]

electromagnetic spectrum is photons energy level spectrum.

don't get confused. AESA measures wavelengths.

from what i understand this new Quantum illumination measures photons.

 

[Vinod2070]

once a photon is slowed down it converts to energy correct?

What do you mean by energy? What is energy in this context?

Did you mean it gets absorbed by some material and increases the kinetic energy of electrons?

 

[farhan_9909]

why photon travel so fast?