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saviornt's avatar
saviornt
Protege
12 years ago

Any quantum geeks here?

Soo, I've been at this for awhile now, and would like a pair of second eyes on this. I'll list the subject matters first, then the theoretical situation afterwards (which may not be so theoretical in the next 15 years.. ie: 2030 and the different Mars missions:

Quantum Entanglement (http://en.wikipedia.org/wiki/Quantum_entanglement)
Binary (http://en.wikipedia.org/wiki/Binary_code)
Digital Communications (http://en.wikipedia.org/wiki/Data_transmission)
Ion Propulsion (http://dawn.jpl.nasa.gov/mission/ion_prop.asp)
Ion Potential Maximum Speeds (http://physics.stackexchange.com/questions/12346/ion-drive-propulsion-top-speed)
Theory of Relativity (http://en.wikipedia.org/wiki/Theory_of_relativity)
Time Dilation (http://en.wikipedia.org/wiki/Time_dilation)
Theoretical "Warp" Drive (http://goo.gl/X9FBXw)

Ok, read the above, then come back to this post.


Well then, I presume if you were not familiar with the subjects, you are now. Let's talk first about propulsion systems. The current designs and fuel limitations of ion drives are fairly elementary at this point (considering maximum possible velocity of ion-based particle drives, which is 1/3 the speed of light). For a second, let us imagine that we created a propulsion drive, ion-based or not, that could reach, say.. 1/10 the speed of light, which is well below the stated maximum potential. Keep this 1/10th the speed of light in mind.

Now, let us talk about time dilation. In space, we have 2 observers. A) The Earth, and B) The astronauts. The faster the astronauts go, the slower time goes for them. So, at our not-so-imaginary 1/10th the speed of light, they will experience a pretty good amount of dilation, right? That was rhetorical, sorry.

Ok, propulsion and time are out of the way, now, let us move on to the next, more interesting topic of quantum entanglement. At the most basic of explanations, you have 2 particles. When particle A changes, particle B changes as well, at the same time, no matter the distance. Now then.. let's talk about change!

Digital communications and binary, 1's and 0's, allowing us to communicate digitally. Wait, wut? When computer A transmits a 1, computer B receives a 1, same with the 0's. Of course, with no lag whatsoever, the speed of the communication is still limited by the medium it is transmitted on, ie: fiber, copper, gold.

Let's mix and match.. digital comm's and quantum entanglement. Now, we have a means of having communications which happens instantly, now matter where the two people are. Instant porn, yay!

With me so far? Good. Let's move onto the question at hand then I suppose.

We enter into a new age. We are now a Type 1 civilization (inter-planetary species), well on the way to becoming a Type 2 civilization (Alpha Centari, here we come!) We have created a propulsion system capable of going 1/10th the speed of light. We have mastered (I'm coining this term here), quantum communications. We launch.

A few days into the launch, we get news stating that our spaceship has crashed into a asteroid. Oh no's.. right? Remember, we are experiencing time faster than the astronauts are. The moment we hear of their death, they are still alive. :shock:

Quantum communications gentlemen. Instant, I mean, instant communication. We, on earth, send out a distress message to the astronauts, which, to us, are dead. They receive the communication, and avert their course. Now, they are no longer in danger. They do not crash into the asteroid.

So, now.. grandfather paradox. What happens?

The only way I can see for that to NOT happen is to fully develop an actual spacetime warping engine, and hope to hell some nutjob doesn't set off the antimatter here on earth.

Am I way out in left field here? What are your thoughts and opinions on the subject?

9 Replies

  • All that reading is hard to do, can't I watch some outer limits episodes instead?

    I have watched a lot of larry krauss on youtube, and maybe I am wrong, probably so, but he seems to be saying that within maybe 250 years we will have expanded as much as possible, that to expand anymore would require more resources than we could harvest from our entire solar system, much less planet earth. This was in context to information processing I believe. That seems very dim, only 250 years left? He talked about how the universe was forever expanding, it was not stable and not going to deflate back in on itself from some theories.
  • Quantum teleportation still happens at a speed of light.

    Sorry, bro, but someone had to break it to you.
  • dahZee's avatar
    dahZee
    Honored Guest
    In addition to the above, quantum entanglement cannot be used to transmit any sort of information. That's the whole nature of quantum entanglement. If you observe it, it changes. Basic quantum theory.
  • "dahZee" wrote:
    In addition to the above, quantum entanglement cannot be used to transmit any sort of information. That's the whole nature of quantum entanglement. If you observe it, it changes. Basic quantum theory.


    "wikipedia" wrote:
    Birgit Dopfer's experiment

    Although such communication is prohibited in the thought experiment described above, some argue that superluminal communication could be achieved via quantum entanglement using other methods that don't rely on cloning a quantum system. One suggested method would use an ensemble of entangled particles to transmit information,[3] similar to a type of quantum eraser experiments.[4][5][6]

    Birgit Dopfer, a student of Anton Zeilinger's, has performed an experiment which seems to make possible superluminar communication through an unexpected collective behaviour of two beams of entangled photons, one of which passes through a double-slit, utilising the creation of a distance interference pattern as bit 0 and the lack of a distance interference pattern as bit 1 (or vice versa), without any other classical channel.[4][7] Since it is a collective and probabilistic phenomenon, no quantum information about the single particles is cloned and, accordingly, the no cloning theorem remains inviolate. Physicist John G. Cramer at the University of Washington is attempting to replicate Dopfer's experiment and demonstrate whether or not it can produce superluminal communication.
  • "dahZee" wrote:
    In addition to the above, quantum entanglement cannot be used to transmit any sort of information. That's the whole nature of quantum entanglement. If you observe it, it changes. Basic quantum theory.


    But isn't QE needed to copy from one to the other? Why wouldn't "rewriting" one change the other?
  • "us11csalyer" wrote:

    But isn't QE needed to copy from one to the other? Why wouldn't "rewriting" one change the other?

    Even if it turns out that it's possible to reverse wave function collapse, forcing a particular spin state breaks entanglement.

    Peejle