he coffee dispenser at my office is usually up around 205 degrees, yet I don't see people running around with third degree burns...
Yet an office is a much safer environment to be carrying around dangerously hot liquids.
Think about it: if the liquid is hot enough to cause 3rd degree burns, is it prudent to give it to people strapped into a moving vehicle? I'd argue not.
Accidents happen, so it becomes necessary to take reasonable precautions. It's the same reason childrens' clothing manufacturers are required to add fireproofing: Duh, textiles burn. But the risk associated with children and fire is too great, so we take precautions.
Furthermore, ALL of the registrars I have ever dealt with have some sort of "comming soon" page used until the hostnames could be set up properly for the actual web sites.
This must only be if you're using them to provide your DNS services. There's no technical way for them to do it otherwise...
Every domain I've registered simply didn't exist before I registered it, and after I did they pointed the NS records for that domian to my servers. At no point did they even have the opportunity to create their own A records.
So I don't think we should be all high-and-mighty about Register.com not executing their registrar duties properly... we're criticizing their DNS-services division, which isn't special or sacred at all.
(We hold registrars themselves to a higher level, because they manage such an important commodity.)
question: Is that charge spoken of a static charge? If it is, how big is that charge compared to typical static charges?
A coulomb is just a certain number of electrons. Magnetic forces act on any charged particle in motion, so the units for the strength of a magnetic field are the amount of force on a certain number of charged particles moving at a certain speed.
How much is a coulomb? Besides saying that it's 16 billion billion (1.6e19) electrons, it's easier to think about what that amount of electrons will do:
If you raise one coulomb of electrons to 100 volts potential, and then let them pass through a light bulb over the course of one second, you would get 100 Watts of light+heat from that light bulb. To light the bulb continuously at that voltage, 1 coulomb per second of electrons needs to pass through it.
The handy name for coulombs per second, of course, is the ampere, or amp.
Really makes you think: some modern CPUs come close to using 100 watts of power, at, say, 3 volts. That's over 30 amperes of current, or somewhere on the order of 450 billion billion electrons being shoved through every second.
There really is no reason NOT to switch to hydrogen as an energy source.
Except, of course, that we don't have a ready, cheap supply of it, or a distribution network for it.
We can extract hydrogen fairly cheaply from natural gas, but it's still cheaper just to burn the gas...
No, right now, hydrogen is not an energy source! It is, however, a very nice energy transporter, and it might very well make environmental sense to replace all our internal combustion engines with hydrogen-burning ones, at least in urban areas.
All energy sources are dangerous, nuclear fission probably the most so. But a carefully designed, run, and monitored plant can be acceptably safe. Plus, fusion promises to be much safer than fission.
#2 will it pollute? Radiation is the 'obvious' one, but what about spent fuel? is it poisonous?
The odd unanswered question here is why so _few_ nutrons are produced compared to the heat generated. But even a few nutrons is enough of a problem that radioactive contamination of the surrounding equipment is a concern, just as it is for nuclear fission.
BUT, the nice thing about any kind of fusion is that there is no spent fuel. The hydrogen(deuterium) is consumed, and helium is produced. The helium is not radioactive or harmful in any way.
Anything exposed to the nutrons could become radioactive by absorbing those nutrons and transmuting into a radioactive element, but the amount of material involved is trivial compared to a fission reactor's spent fuel.
Now, if any tritium (H with two nutrons) is produced, its radioactivity could be harmful. If that is a problem, I'd imagine that it could be reliably captured and stored as waste.
#3 where will we get the fuel for this? It won't run on nothing.
Deuterium is a naturally occurring element. Granted, it is rare (about 1:4500 compared to protium, or regular hydrogen). But otherwise it is a pretty much unlimited resource. As long as your fusion process generates more power than your deuterium-separation process, your fuel is "free".
The first major auto manufacturer to come out with a significant improvement in fuel economy or type stands to make a killing in the market.
If someone comes up with a fabulous renewable energy source, and then can patent or otherwise control the market, they'd make a killing too. There is financial incentive to develop these technologies, which is why these companies are spending a lot on research.
A light bulb that lasts 20 years... could be sold for something like 10x the price of a regular light bulb. They'd sell like hotcakes, and make the company money. So, if they have one of these mythical things, they'd sell it. I don't buy this buried technology business without proof.
Non-addtictive cigarette indeed... they wouldn't sell very well, since your customer base is addicted to, well, the addictive drug in tobacco. So if you sell cigarettes without that drug, it wouldn't satsfy the needs/wants of your customers. No conspiracy.
To sum it up, I wouldn't worry too much about it. It's not like anyone really wants your porn anyway:]
And you weren't bothered at all by the extra traffic generated by CodeRed or slammer?
Network security is something that affects the entire network -- any compromized host is a bad thing. Worms can only work if there are vulnerable hosts waiting.
I don't worry about Grandma's port collection being compromised... I worry that Grandma's machine will be hijacked to send out worms and spam.
Think of the (as beer) as a casting operation to the free word
Of course! It's not clear until it's expressed as a computer science concept, naturally.
It still doesn't feel natural to me, since I can't think of a case where the sense of "free" isn't implicitly understood. In most cases it's an object that is free(beer). Of course, you could talk about it being free(libre) to do something or other... but that would be anthropomorphizing an inanimate object, and they hate it when you do that.
Except, of course, (duh!) the concept of free(freedom/speech) software. Aha. Now I get it. Thanks to the Wikipedia article for spelling that out for me.
And finally, how can someone who has such a low slashdot ID not have picked these things up?
That why it was such a stupid question. I've been here since 1996... and the free beer has confused me for all 7 years.
The rest of it I understand a bit better, though I'm always curious about the etymologies of these things.
This is a stupid question: where on earth did that phrase come from? Beer isn't free, is it? Have I been ripped off all along?
Is there a/. culture FAQ out there somewhere that documents this, the "in Soviet Russia [object] [verb] [subject]" thing, and the "1. xxx, 2. ?, 3. Profit!" spiel?
It's the difference between being held up by a balloon (you still weigh the same and feel gravity) and being in orbit (you feel weightlessness since you're in freefall).
The reason that an orbit works is that you're falling to the ground just as fast as the gravity is pulling you, but you're traveling forward so fast that "down" is now behind you. Your forward speed and the effect of gravity cancel each other out, and you stay at the same height above the surface.
The key is that in an orbit, nothing is "holding you up", which is why you feel weightlessness.
And, of course, it is actually impossible to use a balloon to get up to any orbital height -- by definition if there's enough atmosphere to keep a balloon afloat, there's enough to slow down any fast-moving object such that it falls out of orbit.
Sometimes it's difficult to make an envelope that is sufficiently strong, has four times the volume, and doesn't weigh any more...
Better make that two times the volume: Hydrogen is diatomic, so the total atomic weight of the H2 molecule is 2. Helium is an atomic gas, with its atomic weight of 4.
Round numbers, of course.
Just a little bit more food for thought: the duterium isotope of hydrogen wieghs just as much as helium, in gas form.
$100 Switch (Retail) + 9% Tax = $109
$90 Switch (Same Switch Online From Another State) + $5 SH = $95
Funny, that. Legally, at least in Minnesota, the sales tax applies even if the company selling you the goods doesn't collect it for you. In such cases Minnesota calls it a use tax, and you're supposed to fill out a form and send the state a check.
Obviously, this doesn't happen often... and for the few hundred dollars worth of stuff I order from out of state, I'm only cheating the state out of $20 or so.
I understand, though, that trying to purchase big-ticket items like cars or boats, the state's more likely to notice and cause a fuss if you don't send them their share.
I'm surprised that given budget shortfalls that they don't try harder to collect this tax.
I still wish that there would be JUST an income tax. Get all the smart people together and figure out what the fair rate is, tax me, and BE DONE with it. No property tax, car fees, sales tax, etc.
Except that, of course, the digital signature only indicates that it came from a machine with your private key. No proof that you signed and sent the message.
What's to prevent a well-written virus from doing what it takes to hijack your private key, and digitally sign copies of itself to all your friends?
Granted, that'd be a long shot -- but it's well within the realm of possibility.
Southwest Ohio is not in the "after" picture at all -- you can see a pretty obvious border at the edge of the satellite sweep.
The more interesting question is why a major city like Toronto is so dark. Is there just substantially more backup-power used in some of the other cities, many of which still show up brightly. Or is all that light from a greater number of cars? New Yorkers standing outside shining flashlights upwards?:)
And the final consideration: Clouds? There are some cities up in Maine that must be covered by clouds in the "before" picture. Do we know for sure the rest of the region was cloud-free?
First, thanks so much for your wonderfully informative posts to/. Do you know of any links to more information about the day-to-day issues of power plants? I'd love to read more about the issues involved in synching power grids and balancing loads, maintaining the strict frequency requirements etc., what happens if only one phase is knocked out...
One thing I wonder about regarding suddenly-decreasing loads: You describe what sounds like 3.6GW of heat energy produced by the nuclear reactions, all converted to steam. That stem passes through turbines, which capture 1.2GW, and the rest is all vented as heat waste.
Why can't these plants just vent un-needed steam pressure if loads suddenly decrease, keeping the generators turning at the reduced load? Is it just impossible to vent 1/3 more heat?
How does a power market like France's, at 80% nuclear, deal with changing demand and outages?
I still think that a 100% nuclear grid would be a worthy goal... I wonder what other considerations would have to be made in that case.
Slashdot Mirror
Cloak and dagger is right...
I first read this as "automated fileless wire transfers", which could only mean some sort of computer bank fraud.
(Who would'a thunk that the brain could do Spoonerisms while reading?)
- Peter
he coffee dispenser at my office is usually up around 205 degrees, yet I don't see people running around with third degree burns...
Yet an office is a much safer environment to be carrying around dangerously hot liquids.
Think about it: if the liquid is hot enough to cause 3rd degree burns, is it prudent to give it to people strapped into a moving vehicle? I'd argue not.
Accidents happen, so it becomes necessary to take reasonable precautions. It's the same reason childrens' clothing manufacturers are required to add fireproofing: Duh, textiles burn. But the risk associated with children and fire is too great, so we take precautions.
- Peter
Furthermore, ALL of the registrars I have ever dealt with have some sort of "comming soon" page used until the hostnames could be set up properly for the actual web sites.
This must only be if you're using them to provide your DNS services. There's no technical way for them to do it otherwise...
Every domain I've registered simply didn't exist before I registered it, and after I did they pointed the NS records for that domian to my servers. At no point did they even have the opportunity to create their own A records.
So I don't think we should be all high-and-mighty about Register.com not executing their registrar duties properly... we're criticizing their DNS-services division, which isn't special or sacred at all.
(We hold registrars themselves to a higher level, because they manage such an important commodity.)
- Peter
Yeah... Gravity really gets you down sometimes.
- Peter
I know... sorry. I'll immediately go cancel this account and get me a new one past the half-billion mark. That'll teach me. :)
- Peter
it's a C&C joke. A funny one at that.
Could you explain it for us poor ingorant saps?
- Peter
question: Is that charge spoken of a static charge? If it is, how big is that charge compared to typical static charges?
A coulomb is just a certain number of electrons. Magnetic forces act on any charged particle in motion, so the units for the strength of a magnetic field are the amount of force on a certain number of charged particles moving at a certain speed.
How much is a coulomb? Besides saying that it's 16 billion billion (1.6e19) electrons, it's easier to think about what that amount of electrons will do:
If you raise one coulomb of electrons to 100 volts potential, and then let them pass through a light bulb over the course of one second, you would get 100 Watts of light+heat from that light bulb. To light the bulb continuously at that voltage, 1 coulomb per second of electrons needs to pass through it.
The handy name for coulombs per second, of course, is the ampere, or amp.
Really makes you think: some modern CPUs come close to using 100 watts of power, at, say, 3 volts. That's over 30 amperes of current, or somewhere on the order of 450 billion billion electrons being shoved through every second.
- Peter
There really is no reason NOT to switch to hydrogen as an energy source.
Except, of course, that we don't have a ready, cheap supply of it, or a distribution network for it.
We can extract hydrogen fairly cheaply from natural gas, but it's still cheaper just to burn the gas...
No, right now, hydrogen is not an energy source ! It is, however, a very nice energy transporter, and it might very well make environmental sense to replace all our internal combustion engines with hydrogen-burning ones, at least in urban areas.
- Peter
Not happy with the stories on /.? Have you submitted any yourself?
Do your part to help. Complaining doesn't fix anything...
- Peter
#1 is it safe?
All energy sources are dangerous, nuclear fission probably the most so. But a carefully designed, run, and monitored plant can be acceptably safe. Plus, fusion promises to be much safer than fission.
#2 will it pollute? Radiation is the 'obvious' one, but what about spent fuel? is it poisonous?
The odd unanswered question here is why so _few_ nutrons are produced compared to the heat generated. But even a few nutrons is enough of a problem that radioactive contamination of the surrounding equipment is a concern, just as it is for nuclear fission.
BUT, the nice thing about any kind of fusion is that there is no spent fuel. The hydrogen(deuterium) is consumed, and helium is produced. The helium is not radioactive or harmful in any way.
Anything exposed to the nutrons could become radioactive by absorbing those nutrons and transmuting into a radioactive element, but the amount of material involved is trivial compared to a fission reactor's spent fuel.
Now, if any tritium (H with two nutrons) is produced, its radioactivity could be harmful. If that is a problem, I'd imagine that it could be reliably captured and stored as waste.
#3 where will we get the fuel for this? It won't run on nothing.
Deuterium is a naturally occurring element. Granted, it is rare (about 1:4500 compared to protium, or regular hydrogen). But otherwise it is a pretty much unlimited resource. As long as your fusion process generates more power than your deuterium-separation process, your fuel is "free".
- Peter
Conspiracy! Fear! Uncertainty! Doubt!
Nah, I don't buy it.
The first major auto manufacturer to come out with a significant improvement in fuel economy or type stands to make a killing in the market.
If someone comes up with a fabulous renewable energy source, and then can patent or otherwise control the market, they'd make a killing too. There is financial incentive to develop these technologies, which is why these companies are spending a lot on research.
A light bulb that lasts 20 years... could be sold for something like 10x the price of a regular light bulb. They'd sell like hotcakes, and make the company money. So, if they have one of these mythical things, they'd sell it. I don't buy this buried technology business without proof.
Non-addtictive cigarette indeed... they wouldn't sell very well, since your customer base is addicted to, well, the addictive drug in tobacco. So if you sell cigarettes without that drug, it wouldn't satsfy the needs/wants of your customers. No conspiracy.
- Peter
There are actually much better technologies for doing anything Morse code claims to do now.
You're misunderstanding what "Morse claims to do".
PSK31 is a superior mode, but I defy you to copy or send in that mode without the aid of computer equipment.
Morse is still an important human readable mode.
It's sort of like arguing that kids shouldn't have to learn multiplication and long division because there are calculators.
The phonetic alphabet (alpha, bravo, charlie etc.) is another important "code" that most people don't bother to learn any more.
- Peter
To sum it up, I wouldn't worry too much about it. It's not like anyone really wants your porn anyway :]
And you weren't bothered at all by the extra traffic generated by CodeRed or slammer?
Network security is something that affects the entire network -- any compromized host is a bad thing. Worms can only work if there are vulnerable hosts waiting.
I don't worry about Grandma's port collection being compromised... I worry that Grandma's machine will be hijacked to send out worms and spam.
- Peter
The Germans didn't plow through the Maginot Line, they went around it, plowing through Belgium and the Netherlands.
So always wear pants while surfing the web -- don't let hackers get at your netherlands.
- Peter
Think of the (as beer) as a casting operation to the free word
/. culture... :)
Of course! It's not clear until it's expressed as a computer science concept, naturally.
It still doesn't feel natural to me, since I can't think of a case where the sense of "free" isn't implicitly understood. In most cases it's an object that is free(beer). Of course, you could talk about it being free(libre) to do something or other... but that would be anthropomorphizing an inanimate object, and they hate it when you do that.
Except, of course, (duh!) the concept of free(freedom/speech) software. Aha. Now I get it. Thanks to the Wikipedia article for spelling that out for me.
And finally, how can someone who has such a low slashdot ID not have picked these things up?
That why it was such a stupid question. I've been here since 1996... and the free beer has confused me for all 7 years.
The rest of it I understand a bit better, though I'm always curious about the etymologies of these things.
I have now also found a good explanation of the Soviet Russia bit, attributing it to Yakov Smirnoff.
And thanks to "glivings" for explaining that the whole "profit" thing comes from a SouthPark episode.
Now I'm just waiting for someone to write their PhD dissertation on
- Peter
Yeah, but what would a cloud weigh ON THE MOON!
Huh?
HUH?
- Peter
Wait...wait... slow down...
Water? has Weight? But they look fluffy!
Next you're going to try to tell me that the very air we breathe has weight, too. Bah. Silliness.
- Peter
Are there any other free (as beer) solutions?
/. culture FAQ out there somewhere that documents this, the "in Soviet Russia [object] [verb] [subject]" thing, and the "1. xxx, 2. ?, 3. Profit!" spiel?
This is a stupid question: where on earth did that phrase come from? Beer isn't free, is it? Have I been ripped off all along?
Is there a
- Peter
It's the difference between being held up by a balloon (you still weigh the same and feel gravity) and being in orbit (you feel weightlessness since you're in freefall).
The reason that an orbit works is that you're falling to the ground just as fast as the gravity is pulling you, but you're traveling forward so fast that "down" is now behind you. Your forward speed and the effect of gravity cancel each other out, and you stay at the same height above the surface.
The key is that in an orbit, nothing is "holding you up", which is why you feel weightlessness.
And, of course, it is actually impossible to use a balloon to get up to any orbital height -- by definition if there's enough atmosphere to keep a balloon afloat, there's enough to slow down any fast-moving object such that it falls out of orbit.
- Peter
Sometimes it's difficult to make an envelope that is sufficiently strong, has four times the volume, and doesn't weigh any more...
Better make that two times the volume: Hydrogen is diatomic, so the total atomic weight of the H2 molecule is 2. Helium is an atomic gas, with its atomic weight of 4.
Round numbers, of course.
Just a little bit more food for thought: the duterium isotope of hydrogen wieghs just as much as helium, in gas form.
- Peter
$100 Switch (Retail) + 9% Tax = $109
$90 Switch (Same Switch Online From Another State) + $5 SH = $95
Funny, that. Legally, at least in Minnesota, the sales tax applies even if the company selling you the goods doesn't collect it for you. In such cases Minnesota calls it a use tax, and you're supposed to fill out a form and send the state a check.
Obviously, this doesn't happen often... and for the few hundred dollars worth of stuff I order from out of state, I'm only cheating the state out of $20 or so.
I understand, though, that trying to purchase big-ticket items like cars or boats, the state's more likely to notice and cause a fuss if you don't send them their share.
I'm surprised that given budget shortfalls that they don't try harder to collect this tax.
I still wish that there would be JUST an income tax. Get all the smart people together and figure out what the fair rate is, tax me, and BE DONE with it. No property tax, car fees, sales tax, etc.
Should I start holding my breath?
- Peter
Except that, of course, the digital signature only indicates that it came from a machine with your private key. No proof that you signed and sent the message.
What's to prevent a well-written virus from doing what it takes to hijack your private key, and digitally sign copies of itself to all your friends?
Granted, that'd be a long shot -- but it's well within the realm of possibility.
- Peter
Does anyone else find it ironic that the Rotten Library is such a good source of information?
Or did they do that just to get back at various places that would ordinarily block access to rotten.com?
- Peter
Southwest Ohio is not in the "after" picture at all -- you can see a pretty obvious border at the edge of the satellite sweep.
:)
The more interesting question is why a major city like Toronto is so dark. Is there just substantially more backup-power used in some of the other cities, many of which still show up brightly. Or is all that light from a greater number of cars? New Yorkers standing outside shining flashlights upwards?
And the final consideration: Clouds? There are some cities up in Maine that must be covered by clouds in the "before" picture. Do we know for sure the rest of the region was cloud-free?
- Peter
First, thanks so much for your wonderfully informative posts to /. Do you know of any links to more information about the day-to-day issues of power plants? I'd love to read more about the issues involved in synching power grids and balancing loads, maintaining the strict frequency requirements etc., what happens if only one phase is knocked out...
One thing I wonder about regarding suddenly-decreasing loads: You describe what sounds like 3.6GW of heat energy produced by the nuclear reactions, all converted to steam. That stem passes through turbines, which capture 1.2GW, and the rest is all vented as heat waste.
Why can't these plants just vent un-needed steam pressure if loads suddenly decrease, keeping the generators turning at the reduced load? Is it just impossible to vent 1/3 more heat?
How does a power market like France's, at 80% nuclear, deal with changing demand and outages?
I still think that a 100% nuclear grid would be a worthy goal... I wonder what other considerations would have to be made in that case.
- Peter