Is this news article about quantum radar legit? [duplicate]
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Quantum entanglement as practical method of superluminal communication
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From https://www.digitaltrends.com/cool-tech/quantum-radar-stealth-aircraft/
In principle, a quantum radar functions like a regular radar — only
that instead of sending out a single beam of electromagnetic energy,
it uses two split streams of entangled photons. Only one of these
beams is sent out, but due to a quirk of quantum physics both streams
will display the same changes, despite being potentially miles apart.
As a result, by looking at the stream which remains back home it’s
possible to work out what has happened to the other beam.
Wouldn't this imply faster-than-light information transfer? Is there any way that the interactions of a remote particle can influence a local entangled particle?
quantum-mechanics photons quantum-information quantum-entanglement faster-than-light
asked Nov 16 at 18:49
Joel
193110
marked as duplicate by AccidentalFourierTransform, Kyle Kanos, Community♦ 2 days ago
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
up vote
7
down vote
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This question already has an answer here:
Quantum entanglement as practical method of superluminal communication
2 answers
From https://www.digitaltrends.com/cool-tech/quantum-radar-stealth-aircraft/
In principle, a quantum radar functions like a regular radar — only
that instead of sending out a single beam of electromagnetic energy,
it uses two split streams of entangled photons. Only one of these
beams is sent out, but due to a quirk of quantum physics both streams
will display the same changes, despite being potentially miles apart.
As a result, by looking at the stream which remains back home it’s
possible to work out what has happened to the other beam.
Wouldn't this imply faster-than-light information transfer? Is there any way that the interactions of a remote particle can influence a local entangled particle?
quantum-mechanics photons quantum-information quantum-entanglement faster-than-light
asked Nov 16 at 18:49
Joel
193110
marked as duplicate by AccidentalFourierTransform, Kyle Kanos, Community♦ 2 days ago
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
up vote
7
down vote
favorite
up vote
7
down vote
favorite
This question already has an answer here:
Quantum entanglement as practical method of superluminal communication
2 answers
From https://www.digitaltrends.com/cool-tech/quantum-radar-stealth-aircraft/
In principle, a quantum radar functions like a regular radar — only
that instead of sending out a single beam of electromagnetic energy,
it uses two split streams of entangled photons. Only one of these
beams is sent out, but due to a quirk of quantum physics both streams
will display the same changes, despite being potentially miles apart.
As a result, by looking at the stream which remains back home it’s
possible to work out what has happened to the other beam.
Wouldn't this imply faster-than-light information transfer? Is there any way that the interactions of a remote particle can influence a local entangled particle?
quantum-mechanics photons quantum-information quantum-entanglement faster-than-light
asked Nov 16 at 18:49
Joel
193110
This question already has an answer here:
Quantum entanglement as practical method of superluminal communication
2 answers
From https://www.digitaltrends.com/cool-tech/quantum-radar-stealth-aircraft/
In principle, a quantum radar functions like a regular radar — only
that instead of sending out a single beam of electromagnetic energy,
it uses two split streams of entangled photons. Only one of these
beams is sent out, but due to a quirk of quantum physics both streams
will display the same changes, despite being potentially miles apart.
As a result, by looking at the stream which remains back home it’s
possible to work out what has happened to the other beam.
Wouldn't this imply faster-than-light information transfer? Is there any way that the interactions of a remote particle can influence a local entangled particle?
This question already has an answer here:
Quantum entanglement as practical method of superluminal communication
2 answers
quantum-mechanics photons quantum-information quantum-entanglement faster-than-light
quantum-mechanics photons quantum-information quantum-entanglement faster-than-light
asked Nov 16 at 18:49
Joel
193110
asked Nov 16 at 18:49
Joel
193110
asked Nov 16 at 18:49
Joel
193110
asked Nov 16 at 18:49
Joel
193110
asked Nov 16 at 18:49
Joel
193110
193110
marked as duplicate by AccidentalFourierTransform, Kyle Kanos, Community♦ 2 days ago
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
marked as duplicate by AccidentalFourierTransform, Kyle Kanos, Community♦ 2 days ago
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
add a comment |
2 Answers
2
active
oldest
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up vote
17
down vote
accepted
Quantum radar is a real thing. The description is somewhat wrong.
In radar, you send out a beam of radio waves which get reflected, and you measure them when you come back to look at the objects they were reflected off of.
In quantum radar you send out a beam of radio waves, which are entangled with another beam. This first beam gets reflected. And when it comes back, you interfere them with the other beam to learn about the objects that reflected them.
So there's no faster-than-light transfer, because the beam comes back before you extract the information (just like conventional radar).
There are real theoretical advantages to using quantum radar, but it is also quite a bit more complicated to make it work. The article says that it's not clear whether this is a real device yet or whether it's still vaporware.
answered Nov 16 at 19:10
Peter Shor
8,7402255
Where do they keep the 2nd beam while the 1st is our exploring the sky? Does it just keep bouncing around in a bottle somewhere? If the wavelength is kilometers long, wont it dissipate before the 1st gets back?
– Chloe
yesterday
1
@Chloe: this is presumably one of the things that makes building these things difficult. For a demonstration system, you could just bounce it off something you made specially for this purpose. For a real, portable, system maybe you could store it in optical fibers. (From wikipedia, it looks like you need to start with visible or near-infrared frequencies to produce the entanglement, after which you convert to microwave frequencies.)
– Peter Shor
yesterday
add a comment |
up vote
2
down vote
Yes. See https://en.wikipedia.org/wiki/Quantum_radar.
The particles retain their entanglement at large separations.
This question discusses the issue of whether this implies faster-than-light information transfer:
Quantum entanglement faster than speed of light?
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
answered Nov 16 at 19:10
G. Smith
2,302310
2
Peter Shor’s answer is much better than mine, and I have voted for his.
– G. Smith
Nov 16 at 19:34
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
17
down vote
accepted
Quantum radar is a real thing. The description is somewhat wrong.
In radar, you send out a beam of radio waves which get reflected, and you measure them when you come back to look at the objects they were reflected off of.
In quantum radar you send out a beam of radio waves, which are entangled with another beam. This first beam gets reflected. And when it comes back, you interfere them with the other beam to learn about the objects that reflected them.
So there's no faster-than-light transfer, because the beam comes back before you extract the information (just like conventional radar).
There are real theoretical advantages to using quantum radar, but it is also quite a bit more complicated to make it work. The article says that it's not clear whether this is a real device yet or whether it's still vaporware.
answered Nov 16 at 19:10
Peter Shor
8,7402255
Where do they keep the 2nd beam while the 1st is our exploring the sky? Does it just keep bouncing around in a bottle somewhere? If the wavelength is kilometers long, wont it dissipate before the 1st gets back?
– Chloe
yesterday
1
@Chloe: this is presumably one of the things that makes building these things difficult. For a demonstration system, you could just bounce it off something you made specially for this purpose. For a real, portable, system maybe you could store it in optical fibers. (From wikipedia, it looks like you need to start with visible or near-infrared frequencies to produce the entanglement, after which you convert to microwave frequencies.)
– Peter Shor
yesterday
add a comment |
up vote
17
down vote
accepted
Quantum radar is a real thing. The description is somewhat wrong.
In radar, you send out a beam of radio waves which get reflected, and you measure them when you come back to look at the objects they were reflected off of.
In quantum radar you send out a beam of radio waves, which are entangled with another beam. This first beam gets reflected. And when it comes back, you interfere them with the other beam to learn about the objects that reflected them.
So there's no faster-than-light transfer, because the beam comes back before you extract the information (just like conventional radar).
There are real theoretical advantages to using quantum radar, but it is also quite a bit more complicated to make it work. The article says that it's not clear whether this is a real device yet or whether it's still vaporware.
answered Nov 16 at 19:10
Peter Shor
8,7402255
Where do they keep the 2nd beam while the 1st is our exploring the sky? Does it just keep bouncing around in a bottle somewhere? If the wavelength is kilometers long, wont it dissipate before the 1st gets back?
– Chloe
yesterday
1
@Chloe: this is presumably one of the things that makes building these things difficult. For a demonstration system, you could just bounce it off something you made specially for this purpose. For a real, portable, system maybe you could store it in optical fibers. (From wikipedia, it looks like you need to start with visible or near-infrared frequencies to produce the entanglement, after which you convert to microwave frequencies.)
– Peter Shor
yesterday
add a comment |
up vote
17
down vote
accepted
up vote
17
down vote
accepted
Quantum radar is a real thing. The description is somewhat wrong.
In radar, you send out a beam of radio waves which get reflected, and you measure them when you come back to look at the objects they were reflected off of.
In quantum radar you send out a beam of radio waves, which are entangled with another beam. This first beam gets reflected. And when it comes back, you interfere them with the other beam to learn about the objects that reflected them.
So there's no faster-than-light transfer, because the beam comes back before you extract the information (just like conventional radar).
There are real theoretical advantages to using quantum radar, but it is also quite a bit more complicated to make it work. The article says that it's not clear whether this is a real device yet or whether it's still vaporware.
answered Nov 16 at 19:10
Peter Shor
8,7402255
Quantum radar is a real thing. The description is somewhat wrong.
In radar, you send out a beam of radio waves which get reflected, and you measure them when you come back to look at the objects they were reflected off of.
In quantum radar you send out a beam of radio waves, which are entangled with another beam. This first beam gets reflected. And when it comes back, you interfere them with the other beam to learn about the objects that reflected them.
So there's no faster-than-light transfer, because the beam comes back before you extract the information (just like conventional radar).
There are real theoretical advantages to using quantum radar, but it is also quite a bit more complicated to make it work. The article says that it's not clear whether this is a real device yet or whether it's still vaporware.
answered Nov 16 at 19:10
Peter Shor
8,7402255
edited yesterday
answered Nov 16 at 19:10
Peter Shor
8,7402255
answered Nov 16 at 19:10
Peter Shor
8,7402255
answered Nov 16 at 19:10
Peter Shor
8,7402255
8,7402255
Where do they keep the 2nd beam while the 1st is our exploring the sky? Does it just keep bouncing around in a bottle somewhere? If the wavelength is kilometers long, wont it dissipate before the 1st gets back?
– Chloe
yesterday
1
@Chloe: this is presumably one of the things that makes building these things difficult. For a demonstration system, you could just bounce it off something you made specially for this purpose. For a real, portable, system maybe you could store it in optical fibers. (From wikipedia, it looks like you need to start with visible or near-infrared frequencies to produce the entanglement, after which you convert to microwave frequencies.)
– Peter Shor
yesterday
add a comment |
Where do they keep the 2nd beam while the 1st is our exploring the sky? Does it just keep bouncing around in a bottle somewhere? If the wavelength is kilometers long, wont it dissipate before the 1st gets back?
– Chloe
yesterday
1
@Chloe: this is presumably one of the things that makes building these things difficult. For a demonstration system, you could just bounce it off something you made specially for this purpose. For a real, portable, system maybe you could store it in optical fibers. (From wikipedia, it looks like you need to start with visible or near-infrared frequencies to produce the entanglement, after which you convert to microwave frequencies.)
– Peter Shor
yesterday
Where do they keep the 2nd beam while the 1st is our exploring the sky? Does it just keep bouncing around in a bottle somewhere? If the wavelength is kilometers long, wont it dissipate before the 1st gets back?
– Chloe
yesterday
Where do they keep the 2nd beam while the 1st is our exploring the sky? Does it just keep bouncing around in a bottle somewhere? If the wavelength is kilometers long, wont it dissipate before the 1st gets back?
– Chloe
yesterday
1
1
@Chloe: this is presumably one of the things that makes building these things difficult. For a demonstration system, you could just bounce it off something you made specially for this purpose. For a real, portable, system maybe you could store it in optical fibers. (From wikipedia, it looks like you need to start with visible or near-infrared frequencies to produce the entanglement, after which you convert to microwave frequencies.)
– Peter Shor
yesterday
@Chloe: this is presumably one of the things that makes building these things difficult. For a demonstration system, you could just bounce it off something you made specially for this purpose. For a real, portable, system maybe you could store it in optical fibers. (From wikipedia, it looks like you need to start with visible or near-infrared frequencies to produce the entanglement, after which you convert to microwave frequencies.)
– Peter Shor
yesterday
add a comment |
up vote
2
down vote
Yes. See https://en.wikipedia.org/wiki/Quantum_radar.
The particles retain their entanglement at large separations.
This question discusses the issue of whether this implies faster-than-light information transfer:
Quantum entanglement faster than speed of light?
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
answered Nov 16 at 19:10
G. Smith
2,302310
2
Peter Shor’s answer is much better than mine, and I have voted for his.
– G. Smith
Nov 16 at 19:34
add a comment |
up vote
2
down vote
Yes. See https://en.wikipedia.org/wiki/Quantum_radar.
The particles retain their entanglement at large separations.
This question discusses the issue of whether this implies faster-than-light information transfer:
Quantum entanglement faster than speed of light?
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
answered Nov 16 at 19:10
G. Smith
2,302310
2
Peter Shor’s answer is much better than mine, and I have voted for his.
– G. Smith
Nov 16 at 19:34
add a comment |
up vote
2
down vote
up vote
2
down vote
Yes. See https://en.wikipedia.org/wiki/Quantum_radar.
The particles retain their entanglement at large separations.
This question discusses the issue of whether this implies faster-than-light information transfer:
Quantum entanglement faster than speed of light?
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
answered Nov 16 at 19:10
G. Smith
2,302310
Yes. See https://en.wikipedia.org/wiki/Quantum_radar.
The particles retain their entanglement at large separations.
This question discusses the issue of whether this implies faster-than-light information transfer:
Quantum entanglement faster than speed of light?
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
answered Nov 16 at 19:10
G. Smith
2,302310
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
edited Nov 16 at 19:50
AccidentalFourierTransform
24.5k1366121
24.5k1366121
answered Nov 16 at 19:10
G. Smith
2,302310
answered Nov 16 at 19:10
G. Smith
2,302310
answered Nov 16 at 19:10
G. Smith
2,302310
2,302310
2
Peter Shor’s answer is much better than mine, and I have voted for his.
– G. Smith
Nov 16 at 19:34
add a comment |
2
Peter Shor’s answer is much better than mine, and I have voted for his.
– G. Smith
Nov 16 at 19:34
2
2
Peter Shor’s answer is much better than mine, and I have voted for his.
– G. Smith
Nov 16 at 19:34
Peter Shor’s answer is much better than mine, and I have voted for his.
– G. Smith
Nov 16 at 19:34
add a comment |
