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Comment: Re:Time delay - info from the future? (Score 1) 465

by ByteSlicer (#39793227) Attached to: Quantum Experiment Shows Effect Before Cause

if two atoms are entangled, changing the state in one affects the other, right?

In a way, yes. But not in a way that most people think this works.

In order for two particles to be entangled, there has to exist sufficient uncertainty about the entangled (quantum) property, for example the polarization angle of a photon.

You could entangle two photons in such a way that their polarization angles are always at a 90 degree angle (simple case, but other correlations are possible, like 40% chance it will be 30 degrees and 60% it will be 60 degrees -- just making up numbers here).

As long as they are entangled, you have no way of knowing what the polarization angle of each photon is. Once you measure the angle of one photon, you will know that the other one will be at an 90 degree angle once someone measures it too.

The reason you can't use this to transmit information FTL is that you can't control what angle you will measure. So in this regard, you cannot "change the state in one". The person/sensor at the other end will just measure a stream of photons with random angles, and they'll only know of the entanglement after you send them your results (slower than light) to compare.

The interesting part is that the (random) angles of both photons are in superposition until you measure one, at which point they become fixed (wavefunction collapse). So in that regard, measuring does change something. The reason we know this, is because the statistics of the results differ from the classical case where both photons had a fixed but unknown angle to begin with (but the numbers match perfectly with the quantum/superposition case).

Comment: Re:When will they add... (Score 1) 172

by ByteSlicer (#38918257) Attached to: Google Starts Scanning Android Apps
There already is a firewall in android, it's built in the kernel, and just needs a frontend.
Personally, I use DroidWall as a frontend for iptables. Is free and works great.
The funny thing is, I use it mainly to restrict data from leaving my phone, since a lot of apps nowadays insist on having internet access, and can't be trusted with my personal data. A nice side effect of this is that is also blocks ads.

Comment: Re:Oracle and Java (Score 1) 372

by ByteSlicer (#38661880) Attached to: Oracle's Latest Java Moves Draw Industry Ire

which is a good thing, because the source code was lost when my old laptop died

Try http://java.decompiler.free.fr/ .
It usually produces compilable source code from class files. For non-obfuscated code the sources often look exactly like the originals (minus the comments). Also, it can convert a whole jar to a source zip at once.

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