As other/.ers pointed out: "HTML is not a programming language". HTML lacks loops and is therefore not turing complete.
I wonder what you meant with 'HTML', probably JavaScript?
This is a possibility though I would really stick with scheme. Scheme is IMHO: - one of the smallest languages available (write your own interpreter/compiler --> it's no problem and covered in the book mentioned below!) - *VERY* expressive. Forget Python/Java whatever. In Scheme you have everything. Build your own syntax using macros. You will probably 'stay-ahead' of every other language forever. Well that has also drawbacks - As some have said: Scheme is and will remain the language of the future;) - It lacks syntax. No weird structures to learn.
Maybe you should use the book "Structure and Implementation of Computer Programs" instead? It covers every basic aspect of programming today in a very simple way.
Well, ask an eastern german about that! The STASI was quite good at not only spying, but also 'database management'. Ironically, this now turns on the people who were responsible for it, because the records are also good for lawsuits.
After all they were not able to control the people any longer in 1989, but this secret service is considered the reason why the eastern german government lasted that long (aside from soviet union support etc.).
IANAKH (kernel hacker), but IMHO this *can* make a difference. Because the application which queries for available memory gets only the value "free RAM+cached disk blocks" back.
So with this approach, you can constrain the hunger of applications for RAM because they will notice that there is not too much. The RAM you allocated for the RAM disk swap partition does not count!
Of course, there would be better ways to get this behaviour;)
Well, no, the earth will not be 'destroyed'. But if you think a nuclear strike would almost be harmless, please read this: http://www.johnstonsarchive.net/nuclear/nuc learwar 1.html.
Nice prospects, eh?
And, what few people realize, it would be no problem for a nation that has the facilities to produce hydrogen bombs to produce the ultimative doomsday device. According to Wikipedia et.al., the soviets were so afraid of their own 100MT design that they NEVER REALLY TESTED IT WITH FULL YIELD!
Hydrogen bombs can be scaled up arbitrarily. This makes it possible to easily reach the energy of a major asteroid impact. Yes, enough to destroy the world.
Saying that nukes are simply 'bigger bombs' is just stupid.
Today's P2P apps have no notion of "friends". Everyone is a foreigner to everyone. Making available material can more or less clearly be called "publishing".
But what happens if you have a P2P app that copies files only between friends, friends you did manually enter into the system? What happens if you request a file from your friend but which originates from your friend's friend? What happens if you forward requests from friends?
This shows IMHO, that either the concept 'fair use' or 'private/non-commercial copyright violation' is outdated.
Disclaimer: This is only to spawn more discussion, not to promote copyright violation!
No, the grandparent is right. The maximum you can get is thermal radiation equilibrium, i.e. surface temperature=sun's temperature. And 6kK is too less to start fusion.
While your geometrical arguments seem intuitive, they contain a fallacy. If the surface you concentrate the rays on to get hotter than the sun, the surface would radiate back to the sun, with is clearly impossible.
No. The compiler/the OS should make it possible to switch on bounds checking for C/C++ code. You would have benefits from both sides:
- code can be run fast if neccessary (local intranet where everyone is trusted) - code can be run secure if neccessary, with switched on bounds checking.
Apparently, your post is controversial. So I have a (harmless, no gasoline involved) plan to test it:
1. Get a cellular phone, find out the frequency of it. Calculate the wavelength lambda=c/f. 2. Make 2 pieces of installation copper wire, each slightly less than lambda/4 long. 3. Get an old glow lamp, a lamp which is uses instead of a LED in older household equipment. 4. Solder the glow lamp to the two pieces of copper wire, let the wires have an angle of 180. That's the field strength indicator. If the lamp lits, the voltage across the antenna is >90V and would be sufficient to start a fire under certain conditions (admitted, this a rule of thumb). 5. Switch on the cell phone, hold the dipole parallel to it, move it around, watch the lamp.
I tried this already with two phones, without success.
Uh oh, you're comparing apples with oranges [Yes, I know the joke about apples and oranges being comparable..]
15.75MJ/kg is the *calorific value* of cornflakes. You have to add oxygen to get that energy out of them. Not so with TNT, gun powder, or batteries. The energy is readily available and there only needs to be a trigger to release it.
Cornflakes mixed with nitrate as the oxygen supply would surely be explosive. Cornflakes dust in air would also be explosive.
Re:less wires = more ecologically friendly
on
Wiring a Neighborhood?
·
· Score: 2, Interesting
Uh oh, this will trigger the anti wireless crowd. Electromagnetic waves cause headaches, bad energy fields, weird auras and let my cat run around wildly:)
Your absolutely right, especially for more powerful high voltage supplies. But you have to consider that a flash capacitor charging circuit is not all that powerful. And a bleeding resistor may impact performance quite a bit. It's safer, yes.
Yes, and that is IMHO not absurd. Recent advancements in rechargeable technology get the energy stored per mass unit into the region of chemical explosives. According to various source (google), cell phone batteries have around 165Wh/kg, approx 0.6MJ/kg. TNT has 4GJ/ton, i.e. 4MJ/kg. Now consider the mass of a common laption LiIon battery...
Sorry, my fault. I meant: "If your flashlight operates at around 400V.". You're right, the capacity halves (for two equal caps). But the voltage rating doubles and you do not really want caps exploding in front of your face!
Yeah, capacitors on slashdot once again:) But beware that this is really dangerous. I touched a flash capacitor some time ago, 40uF@400V are not really nice. 200uF@600V and I can assure you that you will fly across the room, hopefully surviving the shock. I have several 1uF@10kV caps, and I don'T dare to charge them to > 3kV (LOUD, risk of EMI, some PC failures already because of cap discharges)
Because this is all too destructive, here is a nice modification (I TAKE NO RESPONSIBILITY!!): Leave the connection to the flash tube intact. Increase the capacity of the HV cap. Add capacitors salvaged from other cameras, or as a very cheap alternative, from PC power supplies. Check the voltage rating. Often, they're rated at 800uF@200V, if your flash light operates around 200V, connect two of them in series (+ -)(+ -).
You can get nice, very *bright* flashes with this method. Do not add to much or the flash time will explode.
Problems here: - NEVER touch power supply caps, they can store 10x - 20x the energy of flash caps. Lethal! - Discharge the CAPs from the power supplies before salvaging. - Discharge the unit after use with an *isolated* gripper, better yet, a high-wattage resistor (few kOhms) hold by an *isolated* gripper.
Someone said that more that more than 10 joule are dangerous, but I think you should not set an upper bound for harmless capacitors.
PS. Someone told me that you have to drink much liquid after an electric shock. Because it removes toxic products from your body which could result in kidney failure or so. Maybe the medicine-studying/.ers know more? But... better don't let this happen!
IMHO, this is not so clear. You have to take into account that processing the food you ate as the energy source for bicycling also costs fossil fuels. Although I think you can safely count yourself to the 'green' side if you carefully select what you eat, a unconvicable carnivore could maybe exceed the amount of fuels needed to power the electro-bike with the amount to process his/her meat. Maybe. I didn't do the calculations here, but one has to be at least careful.
Ahh, I was sure that this "Green transportation" thing would spawn quite a few comments. But as astounding as it sounds, electricity-powered vehicles *can* be 'greener' than directly fossil-fuel powered. Why?
If you consider nuclear power as a 'green' energy source, it's easy. Some do, I'm personally not sure...:)
If you don't: 1. A certain amount of electricity is from renewable fuels already. 2. The energy conversion efficiency is greater in power plants (about 42%) than in combustion engines (about 25%) and the conversion efficiency of an electro motor is good (about 90%). 3. Waste heat from power plants can be used (for efficiencies up to 60%)
Of course, one has to throw the building energy costs for the power plant, the motor cycle etc. into the equations. And there is bio diesel... Oh yeah and you have to take into account the fuel logistics. And, and,...:) Obviously, a difficult question to decide.
Ok, having my ham license, I'll try to explain this *fact* (you *can* transmit gigabits/second over hundreds-of-mega-hertz-channels) in simple terms:
Let's look at a soundcard. For simplicty, let's only look at one channel with the settings: 44KHz sampling rate, 8 bit per sample.
According to _nyquist's sampling theorem_, the maximum frequency you can sample with your soundcard is the sampling rate/2=22KHz. In other words, the bandwidth (in physical terms, on the frequency axis, here is a source of confusion!) of your signal is 22KHz, you could e.g. lift your soundcard's output with a carrier into the radio frequency range. For example, it may occupy the range from 1,000 KHz to 1,022Khz in the electromagnetic spectrum. [Admitted, with popular modulation methods, you'll get sidebands and similar things, but these are not of interest here].
Now, let's see how much data will be transferred (in bits per second) through your soundcards output. As defined, each sample has 8 bits, this means that you have to provide 22Khz*8 bits=176 kilobits*hertz=kilobits per second to your soundcard's analog-to-digital converter. If the signal will be sent over a radio antenna, 176 kilobits per second will go through the 'ether'. In a 22KHz wide channel! If you would have no noise at all in your system, you could receive and decode the signal at the other end and you would receive this stream of 176 kilobits per second. This is clearly more than the 22KHz channel width. Now of course, every real signal path injures every signal and you will get a non-infinite signal-to-noise ratio. This will constrain the amount of data you can transmit.
BTW, I think there is (like this 600 year moore law mentioned recently on slashdot) also a limit for the amount of data you could push through the electromagnetic spectrum - constrained by ionization effects (f low, but already reachable value).
> tax on media,... IMHO a lot better than house searches because you could have copied music! If it comes to taxes (or fees), everyone starts screaming. Oh no, this is against freedom because it is against the free market.
But if very basic rights, the sanctities of the home, secrecy of telecommunications, etc. erode, it is 'understandable', because it is theft of property. Oh noo!
Heh. It's even more complicated. The photon does not hit at a single point... because it hits some atom and excites it. And since Mr. de Broegli, atoms are also weird fuzzy things because every mass has a wavelength.
Which leads to the planck length and if there are any 'point's in the universe at all. Which leads to the question: If there are any points, are there coordinates?
Yeah, thought about that, but for me the question remains. The "free will is an imagination" argument is circular and a too-simple answer, I think. What's this imagination?
Broadening from the free will to the 'self':
How comes that this (imaginated?) free self only sees *one* universe? Or, in other words, now, in the present, what decided why did you take exactly the way you took in the past?
I think this relates to Feynman's path integral quite a bit.
Slashdot Mirror
As other /.ers pointed out: "HTML is not a programming language".
;)
HTML lacks loops and is therefore not turing complete.
I wonder what you meant with 'HTML', probably JavaScript?
This is a possibility though I would really stick with scheme. Scheme is IMHO:
- one of the smallest languages available (write your own interpreter/compiler --> it's no problem and covered in the book mentioned below!)
- *VERY* expressive. Forget Python/Java whatever. In Scheme you have everything. Build your own syntax using macros. You will probably 'stay-ahead' of every other language forever. Well that has also drawbacks - As some have said: Scheme is and will remain the language of the future
- It lacks syntax. No weird structures to learn.
Maybe you should use the book "Structure and Implementation of Computer Programs" instead?
It covers every basic aspect of programming today in a very simple way.
Well, ask an eastern german about that!
The STASI was quite good at not only spying, but also 'database management'.
Ironically, this now turns on the people who were responsible for it, because the records are also good for lawsuits.
After all they were not able to control the people any longer in 1989, but this secret service is considered the reason why the eastern german government lasted that long (aside from soviet union support etc.).
But apparently, /.ers worry about muggers.
;)
Over 500 posts so far and still growing quickly, still the first entry on the front page...
A new hall of fame entry?
Well, I hope this post helps to reach that goal
IANAKH (kernel hacker), but IMHO this *can* make a difference. Because the application which queries for available memory gets only the value "free RAM+cached disk blocks" back.
;)
So with this approach, you can constrain the hunger of applications for RAM because they will notice that there is not too much. The RAM you allocated for the RAM disk swap partition does not count!
Of course, there would be better ways to get this behaviour
Well, no, the earth will not be 'destroyed'. But if you think a nuclear strike would almost be harmless, please read this:c learwar 1.html.
http://www.johnstonsarchive.net/nuclear/nu
Nice prospects, eh?
And, what few people realize, it would be no problem for a nation that has the facilities to produce hydrogen bombs to produce the ultimative doomsday device. According to Wikipedia et.al., the soviets were so afraid of their own 100MT design that they NEVER REALLY TESTED IT WITH FULL YIELD!
Hydrogen bombs can be scaled up arbitrarily. This makes it possible to easily reach
the energy of a major asteroid impact. Yes, enough to destroy the world.
Saying that nukes are simply 'bigger bombs' is just stupid.
But can you prove that your ISP is using such methods of traffic shaping? Can you even see it clearly?
I also thought about this.
Today's P2P apps have no notion of "friends". Everyone is a foreigner to everyone. Making available material can more or less clearly be called "publishing".
But what happens if you have a P2P app that copies files only between friends, friends you did manually enter into the system? What happens if you request a file from your friend but which originates from your friend's friend? What happens if you forward requests from friends?
This shows IMHO, that either the concept 'fair use' or 'private/non-commercial copyright violation' is outdated.
Disclaimer: This is only to spawn more discussion, not to promote copyright violation!
> The government can buy ad space in the papers?
Whatever, this is called pillory and comes straight out of the middle ages!
And this for ***P2P***. Unbelievable.
No, the grandparent is right. The maximum you can get is thermal radiation equilibrium, i.e. surface temperature=sun's temperature. And 6kK is too less to start fusion.
While your geometrical arguments seem intuitive, they contain a fallacy. If the surface you concentrate the rays on to get hotter than the sun, the surface would radiate back to the sun, with is clearly impossible.
No. The compiler/the OS should make it possible to switch on bounds checking for C/C++ code. You would have benefits from both sides:
- code can be run fast if neccessary (local intranet where everyone is trusted)
- code can be run secure if neccessary, with switched on bounds checking.
BTW. There is bounds checking code in GCC!
Apparently, your post is controversial. So I have a (harmless, no gasoline involved) plan to test it:
1. Get a cellular phone, find out the frequency of it. Calculate the wavelength lambda=c/f.
2. Make 2 pieces of installation copper wire, each slightly less than lambda/4 long.
3. Get an old glow lamp, a lamp which is uses instead of a LED in older household equipment.
4. Solder the glow lamp to the two pieces of copper wire, let the wires have an angle of 180. That's the field strength indicator. If the lamp lits, the voltage across the antenna is >90V and would be sufficient to start a fire under certain conditions (admitted, this a rule of thumb).
5. Switch on the cell phone, hold the dipole parallel to it, move it around, watch the lamp.
I tried this already with two phones, without success.
Uh oh, you're comparing apples with oranges [Yes, I know the joke about apples and oranges being comparable..]
15.75MJ/kg is the *calorific value* of cornflakes. You have to add oxygen to get that energy out of them. Not so with TNT, gun powder, or batteries. The energy is readily available and there only needs to be a trigger to release it.
Cornflakes mixed with nitrate as the oxygen supply would surely be explosive. Cornflakes dust in air would also be explosive.
Uh oh, this will trigger the anti wireless crowd. :)
Electromagnetic waves cause headaches, bad energy fields, weird auras and let my cat run around wildly
Tell me, did you really wire your own home that way?
Seems like the nerd's dream come true.
Your absolutely right, especially for more powerful high voltage supplies. But you have to consider that a flash capacitor charging circuit is not all that powerful. And a bleeding resistor may impact performance quite a bit. It's safer, yes.
Yes, and that is IMHO not absurd. Recent advancements in rechargeable technology get the energy stored per mass unit into the region of chemical explosives. According to various source (google), cell phone batteries have around 165Wh/kg, approx 0.6MJ/kg. TNT has 4GJ/ton, i.e. 4MJ/kg. Now consider the mass of a common laption LiIon battery ...
Sorry, my fault. I meant: "If your flashlight operates at around 400V.". You're right, the capacity halves (for two equal caps). But the voltage rating doubles and you do not really want caps exploding in front of your face!
Yeah, capacitors on slashdot once again :)
/.ers know more?
But beware that this is really dangerous. I touched a flash capacitor some time ago, 40uF@400V are not really nice. 200uF@600V and I can assure you that you will fly across the room, hopefully surviving the shock. I have several 1uF@10kV caps, and I don'T dare to charge them to > 3kV (LOUD, risk of EMI, some PC failures already because of cap discharges)
Because this is all too destructive, here is a nice modification (I TAKE NO RESPONSIBILITY!!):
Leave the connection to the flash tube intact. Increase the capacity of the HV cap. Add capacitors salvaged from other cameras, or as a very cheap alternative, from PC power supplies.
Check the voltage rating. Often, they're rated at 800uF@200V, if your flash light operates around 200V, connect two of them in series (+ -)(+ -).
You can get nice, very *bright* flashes with this method. Do not add to much or the flash time will explode.
Problems here:
- NEVER touch power supply caps, they can store 10x - 20x the energy of flash caps. Lethal!
- Discharge the CAPs from the power supplies before salvaging.
- Discharge the unit after use with an *isolated* gripper, better yet, a high-wattage resistor (few kOhms) hold by an *isolated* gripper.
Someone said that more that more than 10 joule are dangerous, but I think you should not set an upper bound for harmless capacitors.
PS. Someone told me that you have to drink much liquid after an electric shock. Because it removes toxic products from your body which could result in kidney failure or so. Maybe the medicine-studying
But... better don't let this happen!
IMHO, this is not so clear. You have to take into account that processing the food you ate as the energy source for bicycling also costs fossil fuels.
Although I think you can safely count yourself to the 'green' side if you carefully select what you eat, a unconvicable carnivore could maybe exceed the amount of fuels needed to power the electro-bike with the amount to process his/her meat. Maybe. I didn't do the calculations here, but one has to be at least careful.
Ahh, I was sure that this "Green transportation" thing would spawn quite a few comments. But as astounding as it sounds, electricity-powered vehicles *can* be 'greener' than directly fossil-fuel powered.
:)
... :) Obviously, a difficult question to decide.
Why?
If you consider nuclear power as a 'green' energy source, it's easy. Some do, I'm personally not sure...
If you don't:
1. A certain amount of electricity is from renewable fuels already.
2. The energy conversion efficiency is greater in power plants (about 42%) than in combustion engines (about 25%) and the conversion efficiency of an electro motor is good (about 90%).
3. Waste heat from power plants can be used (for efficiencies up to 60%)
Of course, one has to throw the building energy costs for the power plant, the motor cycle etc. into the equations. And there is bio diesel...
Oh yeah and you have to take into account the fuel logistics. And, and,
Arggh. /. ate my less-than- and greater-than- signs!
Ok, having my ham license, I'll try to explain this *fact* (you *can* transmit gigabits/second over hundreds-of-mega-hertz-channels) in simple terms:
Let's look at a soundcard. For simplicty, let's only look at one channel with the settings: 44KHz sampling rate, 8 bit per sample.
According to _nyquist's sampling theorem_, the maximum frequency you can sample with your soundcard is the sampling rate/2=22KHz. In other words, the bandwidth (in physical terms, on the frequency axis, here is a source of confusion!) of your signal is 22KHz, you could e.g. lift your soundcard's output with a carrier into the radio frequency range. For example, it may occupy the range from 1,000 KHz to 1,022Khz in the electromagnetic spectrum. [Admitted, with popular modulation methods, you'll get sidebands and similar things, but these are not of interest here].
Now, let's see how much data will be transferred (in bits per second) through your soundcards output. As defined, each sample has 8 bits, this means that you have to provide 22Khz*8 bits=176 kilobits*hertz=kilobits per second to your soundcard's analog-to-digital converter. If the signal will be sent over a radio antenna, 176 kilobits per second will go through the 'ether'. In a 22KHz wide channel!
If you would have no noise at all in your system, you could receive and decode the signal at the other end and you would receive this stream of 176 kilobits per second. This is clearly more than the 22KHz channel width. Now of course, every real signal path injures every signal and you will get a non-infinite signal-to-noise ratio. This will constrain the amount of data you can transmit.
BTW, I think there is (like this 600 year moore law mentioned recently on slashdot) also a limit for the amount of data you could push through the electromagnetic spectrum - constrained by ionization effects (f low, but already reachable value).
> tax on media, ...
IMHO a lot better than house searches because you could have copied music!
If it comes to taxes (or fees), everyone starts screaming. Oh no, this is against freedom because it is against the free market.
But if very basic rights, the sanctities of the home, secrecy of telecommunications, etc. erode, it is 'understandable', because it is theft of property. Oh noo!
Heh. It's even more complicated. The photon does not hit at a single point... because it hits some atom and excites it.
And since Mr. de Broegli, atoms are also weird fuzzy things because every mass has a wavelength.
Which leads to the planck length and if there are any 'point's in the universe at all. Which leads to the question: If there are any points, are there coordinates?
Yeah, thought about that, but for me the question remains. The "free will is an imagination" argument is circular and a too-simple answer, I think. What's this imagination?
Broadening from the free will to the 'self':
How comes that this (imaginated?) free self only sees *one* universe? Or, in other words, now, in the present, what decided why did you take exactly the way you took in the past?
I think this relates to Feynman's path integral quite a bit.