Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×

Comment Re:DC is more dangerous (Score 1) 466

i was talking about a more local electrical arrangement

but yes, long distance, that's a complicated topic, what distance are you really talking about and what other interconnections do you need? dc does have advantages in many cases, especially very long distance

but now we are very far away from the topic of a guy charging his laptop and running some LED lights

The advantage of AC has always been that it is easy to change the voltage up and down with a transformer; DC requires more equipment and some losses to convert.

That being said, transferring AC power between separate grids requires making sure the phase of the power transmitted matches from the two grids (so that the power from the two grids doesn't cancel or ring), which is difficult and expensive. This is not a problem for DC, so DC lines are used in cases such as where power is transferred from another grid to increase the capacity of an existing grid, or between countries that use different frequency power.

Capacitance between the AC phases (usually 3 phases are transmitted at once over a line) or between the line and the surrounding soil or water causes losses that are not a problem with DC. Therefore, undersea high voltage lines tend to be DC.

Overall line loss is also lower per 1,000 km, so very long distance transmission lines sometimes use DC.

http://www.quora.com/When-and-...

Comment Re:DC is more dangerous (Score 1) 466

thank you, dc genuinely has greater fire hazard implications than ac

as for health, it is a bit more nuanced and complex than i said:

Direct current (DC), because it moves with continuous motion through a conductor, has the tendency to induce muscular tetanus quite readily. Alternating current (AC), because it alternately reverses direction of motion, provides brief moments of opportunity for an afflicted muscle to relax between alternations. Thus, from the concern of becoming "froze on the circuit," DC is more dangerous than AC.

However, AC's alternating nature has a greater tendency to throw the heart's pacemaker neurons into a condition of fibrillation, whereas DC tends to just make the heart stand still. Once the shock current is halted, a "frozen" heart has a better chance of regaining a normal beat pattern than a fibrillating heart. This is why "defibrillating" equipment used by emergency medics works: the jolt of current supplied by the defibrillator unit is DC, which halts fibrillation and gives the heart a chance to recover. ...

One of the reasons that AC might be considered more dangerous is that it arguably has more ways of getting into your body. Since the voltage alternates, it can cause current to enter and exit your body even without a closed loop, since your body (and what ground it's attached to) has capacitance. DC cannot do that. Also, AC is quite easily stepped up to higher voltages using transformers, while with DC that requires some relatively elaborate electronics. Finally, while your skin has a fairly high resistance to protect you, and the air is also a terrific insulator as long as you're not touching any wires, sometimes the inductance of AC transformers can cause high-voltage sparks that break down the air and I imagine can get through your skin a bit as well.

http://physics.stackexchange.c...

Comment DC is more dangerous (Score 5, Insightful) 466

this experiment is fine if you're doing little LED lights and laptops, but if you're running something like air conditioning or a washing machine you're building a fire hazard and a mortality risk

the decision to use AC over DC was not random nor taken lightly, there are many factors involved (heck, it was a major engineering, corporate, and PR war between Edison and Westinghouse: https://en.wikipedia.org/wiki/... ), but the right decision was made

for our modern world where some people only care about their laptop and smartphone, it does indeed seem silly and wasteful to convert to AC then back to DC, especially if you've ever tried charging electronics in a car. but there are of course many other uses for electricity, and the navel gazing small electronics crowd is but a minor topic

but i do see a time in the future as more people use local solar and other renewables, that a small DC subsystem is made available in the house for electronics like computers

Comment Re:Yeah, great (Score 1) 205

the adult film industry has exploitative parts, yes

so shut down those parts

don't stand against the entire industry

there are plenty of men and women who get into it as a empowerment ego rush, or even just because of the money, but never are in a position because they are forced to do something. it's always a freely chosen choice for them

there also naive kids who are tricked into situations which are basically rape and brutality for pennies. so find those assholes and jail them as the shitbags they are

Comment Re:Pure Rubbish! (Score 1) 205

the existence of a progression indicates an impulse which exists independently

the mere creation of a police dept, for example, does not mean martial law is somehow inevitable. this is fear addled ignorance

the slippery slope is a simple logical fallacy like all the others, asking us to trust to fear instead of reason

anyone who depends upon the concept of a slippery slope in the construction of their argument can immediately be dismissed as invalid, unworthy of consideration, and a fearmongering fool

Comment Re:Yeah, great (Score 3, Insightful) 205

is this the evidence you are referring to?

furthermore there's many different kinds of porn

there is indeed porn which is rape fantasy or porn which treats the woman brutally

there is also porn which is entirely respectful and almost romantic

there is also porn which shows a woman or women treating a man like shit

i submit the type of porn someone chooses is a reflection of their own predilections, so if they gravitate towards porn which subjugates and brutalizes women, that's about their organic character that existed before viewing that kind of porn

if you put me in front of gay porn, made me watch it constantly since a young age, would i be gay? i submit i would be quite bored, and never get aroused, and never become gay

you have one stilted prejudicial view of only one sector of porn, and think it applies to all porn, and you call this "evidence"

you're a troll or a moron on this topic. either way, you fail, and you reneed to rethink your position, it is intellectually invalid

Comment Re:Building a censorship infrastructure (Score 1) 205

building a police department allows for martial law

are you filled with the same irrational fear and loathing about the existence of police, a completely necessary component for society to function?

Furthermore, I vehemently oppose any moral judgment, moral policing, and censorship.

then you are an immature and naive person. all freedoms have limits. mainly when and where those freedoms impinge on the freedoms of others. my freedom to get a good night's sleep, your freedom to listen to loud music at 2 AM. my freedom to speed on the highway, your freedom to not be killed by a speeding douchebag

there is content, like child porn, whose creation is only possible with the denial of freedom to someone else, a child, who can not consent in an informed way to sex. therefore, censoring child porn is the extension of freedom, not the destruction of it

Comment Re:Yeah, great (Score 1) 205

There is also evidence that a lot of exposure to Porn, especially at a young age is detrimental to brain development, especially respect for women. And that respect for women is one of the key differentiators between an advanced society.

yeah, that's complete laughable nonsense. there is no magic substance in media that creates disrespect. disrespect is a function of a person's low character. putting that on media is a lame attempt at avoiding personal responsibility

i would like to see this "evidence" you refer to, as it sounds like a hilarious pile of crap

Comment Re:Yeah, great (Score 4, Insightful) 205

there are societies in this world where women are treated legally as little more than property

the west is only beginning to emerge from this barbarity, as "mens rights" morons like yourself illustrate, misogyny still exists

but to answer your scenario:

if a woman is going to try to victimize me, my first defense is a valid judge of character and never getting involved with an evil harpy in the first place

but if i am socially clueless and lack the insight that will protect me from getting invovled with a vile woman, she's going to victimize me anyway, even if she lives in a medieval sharia law society as you somehow believe it should be: poison me, assassinate my character with gossip, harm our children, etc.

there are evil people in this world

some are men. some are women

fight the evil shitbags of the world, not women. not men

to react to the very notion of women's rights as wrong simply marks you as a socially inept loser

i'm sorry your experience with some women has been so bad. but now you're constructing an artificial fantasy about how you interact with the opposite sex that only means you will be forever victimized in the way you fear. it's really only a testament to your weak mental faculties your own poor character

Comment Re:Building a censorship infrastructure (Score 1) 205

how hard do you think it is for someone who controls all of the circuits to block a webpage?

additionally, we already block, with complete legal and moral legitimacy, child porn sites, phishing sites, etc.

the "infrastructure" you refer to is not really difficult. and in fact already exists for completely valid reasons

so this argument "if we block porn, political opinions are next" is complete slippery slope fear based bullshit

if you want a winning argument, focus on the kind of govt that would do such a thing, not the red herring "oh noes teh infrastruture!" failed weak argument

Comment Re:Yeah, great (Score 5, Insightful) 205

i would never think a country like britain would fall victim to this sort of censorial nonsense, and it is a troubling development

however, i don't buy the argument it is because of feminism

you need to understand that feminism there is the older valid causes against the maltreatment of women and the removal of their rights. which used to be far worse in the west. and is indeed still a major problem in the world, especially in areas like india and islamic countries

but the kind of feminism you seem to be reacting to isn't really feminism at all, it is instead this sort of clueless teenaged reactive naval gazing by immature clowns

kind of like how dismantling all governmental protections against abuses by large market players is called "libertarianism" in the usa. while actual genuine libertarianism of the original european sort has to do with social issues. real valid libertarians are interested in legalizing marijuana, not freeing plutocrats from paying their fair share of taxes

so like the word "libertarian" in the usa has been hijacked corrupted and rendered invalid by a plutocrat agenda, so to have a few headcases coopted the word "feminist" and advanced truly nutty causes that only mark the believer in those causes as having some sort of psychological or social deficiency

furthermore, for you to react to these fringe idiots, and believe what they stand for is actual feminism, just means you have been horribly trolled. snap out of it, you've been fooled

real, valid feminism is a very important ideology in this world, against the very real and very evil treatment of women in many parts of this world

Slashdot Top Deals

All seems condemned in the long run to approximate a state akin to Gaussian noise. -- James Martin

Working...