fsh

86 ms·

1081.
by fsh 7y ago
This whole "open source voting machine" idea completely misses the point why electronic voting is a bad idea in the first place. The obvious attack against such a system is to secretly use different software or hardware in the mac
1082.
by fsh 7y ago
Quantum random number generators do exactly this and have been demonstrated and analyzed many times.
1083.
by fsh 7y ago
Any true non-local effect would however clash with the observation that the universe obeys the theory of relativity. Quantum mechanics can handle this by switching to quantum field theory, but non-local theories such an Bohmian mechanics ca
1084.
by fsh 7y ago
Nyquist-Shannon only deals with measurements of power spectral densities in sampled systems, not measurements in general. The resolution of measuring for instance the location of a particle in QM has nothing to do with Nyquist-Shannon and d
1085.
by fsh 7y ago
Banking has insurance against fraud and transactions are generally reversible.
1086.
by fsh 7y ago
Quite ironic that the chart (PNG by the way) does not even render in Firefox.
1087.
by fsh 7y ago
And the neutral is tied to (earth) ground. Otherwise all metal devices would shock you if you touched something earth referenced, such as a radiator, at the same time. Edit to clarify: In principle, only the voltage difference between Live
1088.
by fsh 7y ago
This section is plain wrong: "The ONLY purpose for the EGC (or green wire) is to clear a ground-fault (clearing a ground-fault means tripping a breaker or blowing a fuse) in the 'oh shit moments'. It has absolutely NOTHING to
1089.
by fsh 7y ago
The point is that non-relativistic quantum mechanics and therefore also Bohmian mechanics are wrong. They cannot even describe hydrogen atoms correctly! Solving this issue required developing relativistic quantum field theories. So far nobo
1090.
by fsh 7y ago
On the contrary, decades of experiments violating Bell's inequality have shown that the statement "Physics is real whether we observe it or not" can only be true if we abandon locality. Non-local interpretations of QM, such a
1091.
by fsh 7y ago
What do you mean by measurements being deterministic? In Haroche's cavity-QED experiments the outcome of each individual measurement is fundamentally random and cannot be predicted. Quantum mechanics (regardless of which interpretation
1092.
by fsh 7y ago
Because it doesn't take infinite time from our perspective. The object falling into the black hole experiences strong time dilation due to the extreme gravitational field, but that doesn't affect a remote observer.
1093.
by fsh 7y ago
Yes, this is called a "quantum non-demolition measurement" and has actually been done. One technique is to use highly excited atoms (Rydberg atoms) which are extremely sensitive to external electric fields. In this way, the field
1094.
by fsh 7y ago
As the article correctly states, photons have a finite mass that could in principle be measured by putting an optical cavity on a scale.
1095.
by fsh 7y ago
That's actually a very good point. Standard dielectric mirror coatings can easily handle tens of kW hitting a ~1cm spot.
1096.
by fsh 7y ago
These numbers show that the grid is already 95% efficient! It makes much more sense to improve the really inefficient parts, such as power plants and electricity consumers.
1097.
by fsh 7y ago
People seem to underestimate how efficient regular power lines are. The continent-spanning european power grid has a total transmission loss of about 6% using 19th century technology (transformers and copper wires). Modern high voltage DC l
1098.
by fsh 7y ago
Apparently they reached superconductivity at 3K. Hardly room temperature.
1099.
by fsh 7y ago
A standard 380 kV power line has a loss on the order of 1% per 100 km. Unless you want to span large continents, this doesn't seem like a big limitation at all.
1100.
by fsh 8y ago
No. The gross structure of an atom is only determined by the electrostatic interaction between the charge of the electrons and of the protons in the nucleus. The interaction between the magnetic moments of the electrons and of the nucleus (
1101.
by fsh 8y ago
The magnet inside your compass isn't charged either. Magnetic fields act on magnetic moments, not on charge (unless the charge is moving which gives you a Lorentz force).
1102.
by fsh 8y ago
Neutrons with low enough kinetic energy (< 300 neV) are reflected by some materials due to the so-called Fermi pseudo potential. These ultracold neutrons can therefore be stored in an actual bottle made from an appropriate material (such
1103.
by fsh 8y ago
In this case the author should make it very clear that what he is doing with the API doesn't make much sense. Judging from the comments, most readers seem to believe that he is describing a legitimate use-case for the machine. In fact,
1104.
by fsh 8y ago
I don't get what the author is trying to say. It should be obvious to any physicist that his "classical" algorithm for the Bragg grating is complete nonsense (as he now admits in the editor's note). Furthermore, he does
1105.
Quantum Computing: Dream or Nightmare? (1996) [pdf](wp.optics.arizona.edu)
1 points by fsh 8y ago|0 comments