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Physicist Trying To Send a Signal Back In Time
phil reed writes "University of Washington physicist John Cramer is attempting to send a signal back through time."
From the article: "We're going to shoot an ultraviolet laser into a (special type of) crystal, and out will come two. lower-energy photons that are entangled," Cramer said.
For the first phase of the experiment, to be started early next year, they will look for evidence of signaling between the entangled photons. Finding that would, by itself, represent a stunning achievement. Ultimately, the UW scientists hope to test for retrocausality — evidence of a signal sent between photons backward in time.
The test will involve sending one of the photons down 10 miles of fiber optic cable, delaying it by 50 microseconds, then testing a quantum-mechanical aspect of the delayed photon. Due to quantum entanglement, the non-delayed photon would need to reflect the measurement made 50 microseconds later on the delayed photon. In order for this to happen, some kind of signal would need to be sent 50 microseconds back in time from the delayed photon to the non-delayed photon. (Confusing? Quantum physics is like that.)
I have a question: Is it legal to use a timetravel device to chea^H^H^H^Haid in winning the lottery?
IANAP, but when I studied some basic quantum theory, I thought that one of the issues that arose in the EPR/Bell research was that in order for entanglement to be valid, it could not be used to transmit information, except via quantum teleportation, which has strong limitations due to being a classical information channel. Does anyone care to clarify for me?
From what I can understand the backwards-in-time measurement requires communication from one entangled photon to the other. This would allow faster-than-light communication which is the first thing you think of when you hear about entanglement. I thought it was well established that this was impossible since measuring one photon destroys the entanglement and you can never tell if you sent the signal or received it.
Can anyone explain how this experiment is different, and would it also allow for ftl comms?
Karma police, I've given all I can, it's not enough, I've given all I can, but we're still on the payroll.
http://en.wikipedia.org/wiki/Ronald_Malett
The importance of both of these projects is that if you can send photons back in time, you can send signals back in time, and send messages. For years people have wondered about temporal paradoxes and how they may be resolved. With a system such as these, paradoxes can be tested. We'll finally have an answer to the Grandfather paradox.
Even with paradoxes such as this, a temporal communication device would have incredible application. The scientist in the article might only be working with a few microseconds, but it sounds like that if you have a long enough fiber optic cable, you can send a signal as far back as you want. You might not be able to, say use it to prevent someone from having a fatal accident, since if the accident never happened, you would have never sent the message. But there are many useful applications, especially in forewarning events beyond human control. What if we knew exactly when and where every earthquake and hurricane was going to hit in a particular year? What if we knew rainfall patterns in advanced and could plan for draught ahead of time?
You wouldn't be able to use it to prevent the next 9/11, but you could probably use a temporal communicator to prevent the next hurricane Katrina disaster. The hurricane or earthquake will still devastate the city, but that doesn't mean there has to be anyone in it at the time.
Wouldn't we know if the test was successful before we actually conducted it?
I heard this Cramer physicist dude on the radio the other night. He's deadly serious, and he's for real. He's also looking to get financing for building a time machine for sending tiny bits of information back in time (and he's getting a fair amount, too). You'd need a transmitter and a receiver. What would it be worth to find out that the Challenger mission was going to end badly (that was one of his examples)?
My biggest fear would be that the system works, and we start getting messages from 5 years from now 8 years from now, but ten years from now...nothing.
You are welcome on my lawn.
Holy cow, the ice is getting thinner as I go along here.
Aw, what the hell, let 'er rip:
The moment we (present) invent it, they (future) will already have it, so we might be in for a barrage of information the moment we go online.
But who's to say what their agenda will be? They might be military or corporate totalitarians in disguise, leading us right into their paws. By what evidence can we trust what they tell us? Or why would we assume that it's in their best interest to warn us to change course, which might lead to their eventual non-existence?
Referring to my previous post, where I mention keeping the dialogue open to different points in the future. Could we possibly detect if time hackers are intercepting and blocking the lines, then transmiting us misinformation? Before believing in a utopian future, we must proyect past and present trends to generally visualize a future, and by these standards, how can we trust potential power-hungry bastards ten generations down the line? The future will have its' own agenda, and it might be completely opposed to our own. We might not be welcome in their future.
Here's another: what if the Karl Rove of 2005 could have a conversation with the Karl Rove of November 2006? After all, those in power will be among the first to gain access to the technology. Or maybe a Pentagon general in charge of the project will find a way to make himself into an emperor for life. Temptations will be humongous.
Now, working under the assumption that the future is relatively benevolent, somebody will have to make incredibly harsh decisions. In order to save a billion lives a hundred years down the line, who's willing to make a decision that permits the destruction of cities or nations? The death of ten or a hundred million people in the current generation? It's more than likely that the invention of a temporal communications network may diminish the worth of the individual, who becomes an abstraction that serves the species, or something more petty: an ism.
An example on a smaller scale that might hit home: What if the message we get from 2056 is: UNPLUG THE INTERNET! NOW!
Man, this is getting weirder and weirder.
Lil' Thindime, lilting a lacrimose lament, krashes the kwaint konfines of Kokonino Kounty
If, as has been suggested, you need a transmitter and a receiver, the quantum messages might already be out there, we just can't read them. Kind of like sending a book back a hundred thousand years and being surprised that Neanderthals don't get the warning.
That's like saying in 1870 that radio waves are impossible because nobody's received any. There weren't any receivers then. Or like saying neutrinos didn't exist before there were detectors for them. It's quite possible that the as soon as we have something that can receive such messages it'll be flooded with spam from the future.
Anyway, I've thought about time travel rather more than anyone probably should, if you're interested. I address that point and a lot of others.
PHEM - party like it's 1997-2003!
I decided I would send myself information from the future. I never got anything, so I figured it didn't work. So why would I waste my time and money on a project that already failed?
IANAP.
;)
The problem is that there appear to be 2 or 3 (maybe more?) going models of what time is. One says that time isn't a dimension, all that is exists is now, there is no before or after. The human mind tricks us into thinking otherwise do to memory.
Another states that time is linear, where if we send something into the past, we alter the present. So far as I understand, this has been more or less ruled out.
The third states that there are infinitely parallel universes with every possibly outcome occurring simultaneously (string theory?) and that the universe has many more dimensions than three or four, possibly ten or more dimensions.
So that's the real catch. If someone cuts down a tree in the forest, sends it to the past, and it falls in another dimension, no one is ever around to hear it....wait, where was I going with that?
Karma: Chameleon (mostly due to the fact that you come and go).
Okay, I can't believe I'm about to make a Dragonball Z reference here, but I am. :\
:P
For those not familiar with the series:
http://en.wikipedia.org/wiki/Mirai_Trunks
Oddly, DBZ is one of the few series that deals with time travel of the idea that the present can't be altered by travelling into the past. The brief synopsis is that in the near future, a pair of androids appear and kill all of those powerful enough to stop them, and more or less wipe out the human race. The reason no one was powerful enough to stop them was two-fold - one, no one saw it coming, and two, the one man that might have been strong enough to stop them died before they arrived from a virus that attacks the heart. There was no cure for this virus, but in the future one was created. Mirai Trunks (or Future Trunks if you will) a time machine to go into the past with a cure for that man, and to warn those who were killed that in 3 years the androids would appear. The man lived, and they all prepared for the next 3 years to stop the android threat. When Trunks returned to his own time, everyone was still wiped out. The man still died from the virus. Trunks then travelled back to a point 3 years later and even helped fight and defeat the androids. When he returned to his own time, the man was STILL dead, the androids were still running around, and everyone was still wiped out. He then proceeded to defeat the androids in his own time.
Just thought it was related and interesting, albeit horribly geeky.
Karma: Chameleon (mostly due to the fact that you come and go).
And if you can control the spin of Particle A, you can transfer data to the observer of particle B.
WIth 1 particle you could transmit(applied loosly here) morse code. If it is computer controlled, even just ussing a type of mose code, you could transfer data infinite distance near instantaniously.(The computer flipping particle A would take a small amout of time to determine how long until the next flip).
Of course, more particles means more information.
I suspect that if time travel is possible, there would need to be a 'reciever' portal, and it would have to be built before the first 'sender' portal.
The Kruger Dunning explains most post on
The way "linked" particles work is that if you measure a property (say, spin) of the two particles, the measurements will be the same. The interpretation is that when you make one measurement, some information is transmitted to the other particle so that when it is measured the results will be the same. The "transmission" is said to be instantaneous (in whose reference frame?). The value of the property being a hidden variable is another interpretation.
Anyway, I dimly recall being told that there is a proof that such linked particles cannot be used to transmit a message
Funny, I learned this as:
There once was a lady named Bright,
who traveled much faster than light.
She left one day, in a relative way,
and returned on the previous night.
But the original is so:
There was a young lady named Bright
Whose speed was far faster than light;
She set out one day,
In a relative way
And returned on the previous night.
followed by:
To her friends said the Bright one in chatter,
"I have learned something new about matter:
My speed was so great,
Much increased was my weight,
Yet I failed to become any fatter!"
Ah, synoptic limericks!
Leben Sie jetzt die Fragen.
What stops the photon from chaning its state while it is traveling through the fiber optic cable?
I often have trouble remembering which way is out of bed in the morning.