Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
×

Comment Re:I'm waiting for the doomsayers (Score 1) 610

However many of the uses convert electric energy to things like formulation of chemical bonds that require energy for creation.

By definition bond formation doesn't require energy but releases it, since "bond" is something that requires energy to break and energy must be conserved. It's setting up the preconditions for bond formation that requires energy, possibly less than is released when the bond forms.

Comment Re:symbols, caps, numbers (Score 1) 549

At one point when I was a system administrator and we only required 6-digit passwords changed every 90 days,

Why did you? Require the password to be changed periodically, I mean? The only thing it seems to accomplish is make sure the users will either pick weak passwords or resort to post-it notes.

Comment Re:Read below to see what Bennett has to say. (Score 1) 622

If you write your pin number on your ATM card are you not at least partially to blame when a thief finds the card and cleans out your account?

Certainly. But what if you didn't, and simply have an ATM card some malefactor manages to use to get money without your PIN due to bank's bad security? Because it seems like having your account cracked is closer to that.

Of course, a more important question is: does it matter? If I run a red light and drive over you, should I get off lighter because you didn't look both ways before crossing? Yes, you were dumb as hell, but does that mean that you deserved to die and if so, on what basis?

This is a question that we should put some serious thought into, since it has ripple effects on a lot of different areas of society.

Comment Re:Dear Scientists (Score 2) 66

Closing scene is the last few rocket ships barely escaping Earth as it disappears, with innumerable other rocket ships not making it.

Collapses, not disappears. The hole is hollowing out the insides of the planet, and when enough is gone, the no-longer-supported crust cracks into pieces that fall in as magma sprays everywhere. And of course we have terrible earthquakes and volcanic activity leading up to the final doom.

Obviously none of it has to be scientifically accurate, so pedants please don't start trying to pick the plot apart, because it's just too easy pickings.

Well, scientifically speaking the entire mass of the Earth would only create a hole the size of a centimeter or so, so it'd take a long time for the entire planet to plunge down that drain. The "superball of death", on the other hand, could easily trigger massive quakes and tides at every bounce due to the tidal forces, despite the hole itself being very small.

Comment Re:How Would Hawking Radiation Dissolve a Black Ho (Score 1) 66

How is the HR process not symmetric? Whatever would cause the dissolution of the black hole--how would the same process happening in reverse (matter falling into the black hole and anti-matter escaping) not cause equilibrium to be maintained?

Matter and anti-matter annihilating each other produces energy. That energy remains trapped in the hole, so it's mass is unchanged (energy = mass * lightspeed squared). So whether matter or anti-matter fall into the hole, its mass will grow.

What's happening with Hawking radiation is (AFAIK) that particles are actually ripples in a field - for example, a photon is a ripple in the electromagnetic field, and an electron is a ripple in the "electron field". If these ripples are well-formed waves they're said to be "real" and have measurable quantities, such as energy. Otherwise they're "virtual" particles. That's what's meant when they say electromagnetism works by exchanging virtual photons: charged particles cause disturbances in the electromagnetic field, which affect other charged particles.

Now, quantum mehcanics has a number of paired properties, where both members of the pair can't have an exact value at the same time. Position and momentum are perhaps the most famous such pair, but another is the value and rate of change of a field. That means that no field's value can be permanently zero, because then we'd know both the exact value (0) and exact rate of change (also 0). And because they can't be permanently 0 despite having to average to it, they must ripple randomly, a state of affairs often referred to as "quantum foam". Since particles are ripples in these fields, this process is usually depicted as a pair of virtual particles coming from nowhere, living for a while, and then meeting again and canceling each other out.

An interesting property of these virtual particle pairs is that if they receive at least as much energy as corresponds to the pair's rest mass, for example by being accelerated in a black hole's gravity field, they become "real". That is, random ripple turns into a well-defined wave that's not going to disappear, but is going to continue its existence as a real particle. According to current cosmological theories, this is how all matter originated, with the Big Bang acting as a source of energy. This is also how particle accelerators work: smash a stream of particles together hard, so the energy of the collision makes virtual particles materialize.

So what happens is that if a pair of virtual particles is brought to existence near the even horizon of a hole, one might fall in and the other fly away. The one flying outwards loses energy - it's rising against gravity, after all - but the one falling in gains more than enough to offset that, since it gets pulled harder and harder the farther it goes. So, the pair of particles as a whole gain energy, and if that energy exceeds the pair's rest mass the pair turns into real particles. Since energy must be conserved, it must come from somewhere, and the only available source is the black hole's mass, which is diminished as a result. The falling particle is basically carrying a bill with it, which negates some of the black hole's energy. And since it's the direction of gravity that determines which particle gets the bill, it's always the one falling into the hole, making the process asymmetric.

But then again, the actual math is beyond me, so I could be completely wrong here.

Comment What Is Your Relationship with Microsoft & Ora (Score 5, Interesting) 187

You were a valuable unbiased source of information on software patents and patent litigation. Particularly the German court's struggle with them. However it came to light -- in a rather surprising way -- that you were paid or possibly employed by Microsoft and Oracle. I have heard much about this and it often casts a negative light on your blogging but I would like to hear your side of these relationships. I can conceivably understand how you could accept money that furthers your ideals but it is difficult to comprehend how I can be assured this does not influence your writing, position, selected details and bias. Are you able to lay my concerns to rest?

Comment Re:Dear Scientists (Score 2) 66

Dear Scientists, Please stop trying to create black holes. I would prefer not waking up in the middle of some random night feeling a tug on my body and seconds later falling into the aforementioned black hole to my death.

Why hasn't this been made into a movie already?!?

A black hole created at, say, Large Hadron Collider, would fall into Earth's center and then continue onto the other side, rising to the surface only to fall again, in an essentially chaotic orbit, snapping a person here and another there, slowly growing as it ate Earth's innards like a hookworm, surrounded by a growing spiral of white-hot remains of its feast. It's perfect material for a horror movie, or a disaster one, or an artistic one, a monster movie, or a Michael Bay explosion fest.

Comment Re:Mimicking a theory, not a phenomenon (Score 1) 66

The production of Hawking radiation in a gravitational black hole relies (and relies only) on the presence of a horizon.

Does it? Because from what I've understood, it's caused by virtual particles getting sufficient energy from interaction with a field to become real particles, and even horizon is simply the boundary above which particles so produced can escape. If so, then any strong enough field should produce Hawking radiation - for example, a strong enough electric field would produce a stream of electrons and positrons moving in the opposite directions.

Comment Re:There is no need to panic (Score 1) 421

And it is still correct. There is no need to panic. Ebola gets WAY more press than the severity of the actual risk justifies.

Reiterating a claim is no evidence for it.

First off, ebola is NOT "highly contagious". It's actually rather hard to get. Unless you have been in direct contact with the sweat, blood, tears, feces or other bodily fluids of a symptomatic ebola patient then you have nothing to worry about.

You do realize this puts it one step beneath airborne pathogens like the flu, right?

It is incorrect that "every" pathogen has to potential to become a "deadly and highly contagious disease". Go talk to an infectious disease doctor and they will tell you that the biology of most viruses and bacteria prevents them from ever becoming a threat to humans. It's actually quite hard for that to happen even in a rapidly mutating virus which ebola is not.

Ebola is, however, already past that hurdle. It has crossed the species boundary and is adapted enough to its new human hosts to overcome the immune system in most cases. All that remains is slight tweaking of the exact parameters of symptoms to optimize spreading.

What you are suggesting is almost as unlikely as all the air in the room suddenly deciding to be on just one side of the room because, hey, it's theoretically possible.

Either you have no idea of the magnitudes of probabilities involved or are lying for rethorical reasons. Either way, your absurd exaggeration accomplishes nothing.

Comment Re:For those who said "No need to panic" (Score 2) 421

No, there is no need to panic. Get a grip on your fantasies.

You know, I've heard that many times now, yet Ebola continues spreading. And every new case gives it new opportunities to evolve further. So perhaps it would be better to panic and spend some serious dough to crush the outbreak while it's still possible, rather than wait for it to turn into the doomsday scenario a deadly and highly contagious disease has every potential to become?

Comment Re:They really need to pardon Snowden... (Score 1) 228

Again, the big mistake they made was in not shaming noisy holier then thou types that are often either misrepresenting or simply misinformed about the nature of the world.

Really? Because it seems that it was the NSA that made a grave miscalculation about "the nature of the world". All this talk about "holier than thou" is trying to assert that people are wrong to react like they do, as opposed to how you think they should. And to paper over this cognitive dissonance, you insist this is evidence of their hypocrisy, not you being wrong.

Your masters are still fighting the Cold War, and refuse to admit the world is changing. You aren't doing any favours to them by letting them stay delusional. The wakeup call will get louder and ruder the more times it needs to be repeated.

Comment Re:Research (Score 3, Insightful) 165

Unfortunately, low reportage is correlated with a mass of social ills (increase corruption for one), so I suspect this development is not welfare-improving in the long run.

Except that newspapers, having long since been consolidated into massive cartels, don't have any interest in reporting social ills, since the owners of those cartels benefit from the status quo. Why would I pay Murdoch for his propaganda?

Slashdot Top Deals

Suggest you just sit there and wait till life gets easier.

Working...