Forgot your password?
typodupeerror

Comment: Doesn’t match with the reported facts. (Score 3, Interesting) 436

by qubex (#46492833) Attached to: Malaysian Flight Disappearance 'Deliberate'

That’s a valid (and fairly chilling) reference, but insofar as the two tracking systems/transponders were deactivated at different times and deliberately it seems quite obvious that nothing of a sudden or accidental nature occurred - at least not at the outset of the episode. Of course something catastrophic or at the very least final must have occurred later on because well aeroplanes don’t stay aloft indefinitely.

Comment: Conservation of Energy. (Score 1) 193

by qubex (#46183597) Attached to: New Type of Star Can Emerge From Inside Black Holes, Say Cosmologists

Let’s take your scenario: a proton/anti-proton pair of virtual particles pops into existence from the quantum vacuum near the event horizon and the anti-proton spirals into the black hole, meaning that the proton no longer has it’s antiparticle to annihilate against. (Clearly we’re talking about energy in terms of mass-energy terms here.)

OK, the original virtual-particle pair ‘borrowed’ energy from the vacuum; that debt must be paid back because the universe’s energy must be conserved. If the energy can no longer be ‘returned’ by annihilating the virtual particles, the ‘energy debt’ must be subtracted from the mass-energy of the black hole. This, essentially, is the process of Hawking radiation that causes a black hole to evaporate: it’s kind of like cosmic repo-men demanding dues from the black hole. The universe wants to be made whole and it gets it’s due from wherever it can. If the repo-men can’t find you and repossess your unpaid television, they annoy your old folks instead.

Here’s where the quantum-information question arises: is there any ‘information’ contained in that debt repayment? The classical view says ‘no’: it’s just the right amount of mass-energy, but all other parameters are random (spin, charge, bla bla bla). Quantum mechanics cannot accept that and insists that the information must be expressed as energy radiating with exactly the right characteristics. As if the dollars extracted from your parents must also, in some sense, carry a hint of that TV you haven’t paid for.

Comment: The turning point of Stalingrad (Score 1) 110

by qubex (#46178707) Attached to: Second World War Code-cracking Computing Hero Colossus Turns 70

It was thanks to American manpower and equipment that the allies successfully opened a second front by invading Sicily in the summer of 1943 (and later a third front by invading Normandy in 1944), thus drawing away German forces that might’ve otherwise been directed towards the Eastern Front with possibly decisive effect. Stalingrad might’ve been a momentary (though expensive) setback for the German war effort if it weren’t for the fact that they never again had sufficient troops available to concentrate on the problem. And this, of course, is because of American intervention in the European war.

Comment: At least I substantiated my opinion. (Score 1) 110

by qubex (#46178625) Attached to: Second World War Code-cracking Computing Hero Colossus Turns 70

At least I substantiated my opinion with a summary of key points an opponent would need to successfully address if he were (to my satisfaction, anyway) argue the opposite case. The original poster’s statement was an unsubstantiated bolt from the blue stated with almost religious fervour and conviction.

As for national pride: I’m a hybrid european, half british and half italian. I am certainly not in the habit of promoting the USA and it’s foreign policy. But merit must be given when merit is due: the USA saved our continental asses. And we must be forever grateful for that, whatever the motive might’ve been or might be said to have been.

Comment: Correct. (Score 4, Informative) 110

by qubex (#46172393) Attached to: Second World War Code-cracking Computing Hero Colossus Turns 70

The Colossus was useless at decrypting Enigma traffic: that was handled by the electronic bombes.

Colossus was constructed to break Lorenz/Tunny traffic: a much more advanced system designed for encrypting teleprinter five-bit Baudot-code teleprinter transmissions. Dilettantes will harp on Tunny’s greater number of rotors, but it was a far more radical departure than might at first appear. As many subsequent stream-ciphers, Tunny XORed cleartext to a cryptostream. Amongst other things, that meant that there was no restriction against a character in the ciphertext being the same as the corresponding character in the cleartext, a flaw which allowed skilled cryptographers to infer what might, conceivably, be contained within a given stretch of text.

Two sets of ‘wheels’ were summed independently to a five-bit cleartext word. One set was advanced on every word and one advanced only if another wheel’s value was !FALSE (this wheel itself advanced on every word). This meant, amongst other things, that sometimes part of the keystream did not increment, and this in turn had a discernible effect upon the statistical distribution of the difference between successive ciphertext words.

Reconstructing the keystream from these distributions is how Tunny was broken, and that is the task that Colossus was designed to automate. (Mumbling about Colossus’ Turing-Completeness is fundamentally ill-posed, as no machine has the infinite memory capacity envisioned by Turing. I will however emphasise that Colossus lacked a stored program facility, a concept that was only developed much later.)

Comment: There would have been no victory without the resou (Score 4, Informative) 110

by qubex (#46172205) Attached to: Second World War Code-cracking Computing Hero Colossus Turns 70

That’s a totally dubious opinion misstated as fact.

Without American materiel (lend/lease ships, tanks, bomber aircraft) and manpower (D-Day landings, continental fighting, naval convoys) the war effort would have been almost inevitably lost. This does not mean that the UK mightn’t have eked out a long-term stalemate and perhaps even an uneasy truce, but the defeat of Nazi Germany would have been out of the question. What ultimately defeated Germany was not the war on two fronts, but an expensive, resource-intensive war on two fronts that exceeded the country’s ability to regenerate. Without the virtually bottomless reserves of resources provided by the USA, the USSR would have been eventually brought to heel, and the West would have followed suit.

The USA was pivotal.

Comment: Re:So more enthalpy=more life? (Score 2) 185

by qubex (#46058383) Attached to: A Thermodynamics Theory of the Origins of Life

Clearly the original poster intended to signify a to-be-defined set of “usable” chemicals. It is clear to everybody versed in even rudimentary chemistry that a concentration of noble gasses would not give rise to life for the simple reason that though concentrated they do not react. Thus the expected reactivity of the chemicals under consideration becomes a key concern. The building blocks of life as we know it (carbon, oxygen, nitrogen, & cetera) is a pretty reactive bunch of stuff.

I expect professor English has already formalised this (fairly trivial) observation in his work. If that is not the case, it could no doubt be effortlessly included. I do not believe it to be a profound point. I especially resist the tendency Slashdot users often display of building straw-men absurd logical reductions.

At these prices, I lose money -- but I make it up in volume. -- Peter G. Alaquon

Working...