Depends on how the system is configured. I once did this when my X session hung at work, expecting to be returned to XDM. Instead it just killed X and returned to the console. Ok, the console showed me a login prompt as well...:-) But that's only because I wasn't logged in at that console (nor was anyone else). And of course you could configure the system so that you don't show a login prompt on consoles at all;-)
No. Matter is, well, matter (i.e. electrons, protons, etc.). Energy is a property of matter/fields.
E=m*c^2?
The m here is "mass", not "matter". Again, mass is a property of matter. BTW, this equation holds only for matter at rest; generally it's E^2 = (mc^2)^2 + (pc)^2.
So shouldn't energy have turned back into matter at some point?
Normally matter and antimatter are produced in equal amounts. Note that antimatter has positive energy (and positive mass) as well.
Indeed, you need at least ten cores. One of the cores is already fully occupied with the intelligent spelling checker, while another one is constantly checking the grammar, and the third one is coordinatig those two, as well as doing some higher level analysis to improve their accuracy. The fourth core is occupied with doing the GUI, while the fifth one does content checks using internet ressources. The sixth core is occupied with auto-correcting the user's style, assisted by the seventh core which analyses the user's behaviour. The eighth core is responsible for optimizing the formatting of the text, while the nineth core cordinates all those other processes (well, except the first two which are coordinated by core 3). And of course you need at least one additional core top keep the OS itself running.
Wouldn't it be great if hardware was able to handle some of the things an OS is now used for, like memory (de)allocation? Or if we could tag memory according to type?
Hydrogen in its most compressed form is called a black hole:-) But even before that, the electrons would combine with the protons to form neutrons, so at that point it would stop being hydrogen. I'd guess compressing a free electron gas would finally result in a (charged) black hole as well.
Of course in practice you'll have a hard time to compress your hydrogen (and even more, the electron gas) that much.:-)
It depends on the material. Let's e.g. see what a gallon of electricity is in copper.
First, a gallon is 0,0038 m^3. Now copper has a free electron density of 8.47*10^28/m^3, and an electron has a charge of 1.6*10^-19 C. Multiplying this together means in copper, 1 gallon of electricity is 51 MC or about 14 kAh.
Even non-subscribers can see articles in the future. I thought the distinguishing feature would be that subscribers can see articles now which others only can only see in the future.
I guess they didn't want to bore the viewer with technical details, the book The Cuckoo's Egg does say the hacker used trojans in that manner.
The hacker used trojans to bore the viewer with technical details? I guess that's a new sort of DoS attack: Instead of attacking the computer, attack the people in front of it by giving technical details...:-)
Since a and b were explicitly declared as boolean (in the posting I answered to), the values cannot be anything but true or false. Indeed, if equality is meant to implement iff, it's actually a feature if a and b are implicitly converted to bool instead of (erroneously) comparing the actual non-bool values.
Well, actually you can derive all logical operations just from ?: and the constants true and false.
!a is the same as a?false:true a&&b is the same as a?b:false (even the shortcut behaviour is right!) a||b is the same as a?true:b (again, with the correct shortcut behaviour) a==b is the same as a?b:b?false:true a!=b is the same as a?b?false:true:b
Especially the latter ones are probably quite nice for IOCCC:-)
Good design by contract should ahve contracts behave properly with respect to inheritance (preconditions can only be weakened, and postconditions and invariants can only be strengthened) with contracts being inherited properly even in overidden methods.
You can get most of that in C++ by using the idiom of public non-virtual functions calling private virtual functions:
class Base { public:
int something(int whatever)
{ // check preconditions
int result = do_something(whatever); // check postconditions
} //... private:
virtual int do_something(int) = 0; //... };
Now everyone calling something(int) will get the checks defined on the base class, but the actual virtual function from the derived class. Derived classes cannot override the base class version, so calls through base class pointers/references will always use the base class checks, even if the derived class defines its own version with different checks. The only part that cannot be checked by the compiler is that derived classes don't weaken the post-conditions or strengthen the preconditions.
Well, it's quite easy to win energy by changing the frame of reference. Let's say I start with a frame of reference where earth is at rest. Now I accelerate a car to, say, 50 km/h. This needs some energy, which now is in the car in the form of kinetic energy (since this speed is hardly relativistic, the kinetic energy of the car is well approximated by 1/2 m v^2, where m is the mass of the car).
Ok, now I change my frame of reference, so that in my new frame of refernce, the car is at rest, and the earth moves at 50 km/h in the opposite direction. Now I've won a lot of energy, because the earth's mass, and thus the earth's kinetic energy at the same speed, is much larger than the car's. By taking a tiny amount of that won energy to accelerate the car even further, I can repeat that proocedure, thus producing as much energy as I want.:-)
Note to humour-impaired readers and moderators: It's funny, laugh!
Slashdot Mirror
Depends on how the system is configured. I once did this when my X session hung at work, expecting to be returned to XDM. Instead it just killed X and returned to the console. ... :-) But that's only because I wasn't logged in at that console (nor was anyone else). And of course you could configure the system so that you don't show a login prompt on consoles at all ;-)
Ok, the console showed me a login prompt as well
So all spelling mistakes on Slashdot are intentional?
No. Matter is, well, matter (i.e. electrons, protons, etc.). Energy is a property of matter/fields.
The m here is "mass", not "matter". Again, mass is a property of matter.
BTW, this equation holds only for matter at rest; generally it's E^2 = (mc^2)^2 + (pc)^2.
Normally matter and antimatter are produced in equal amounts. Note that antimatter has positive energy (and positive mass) as well.
Like Faraday's famous answer when asked by a politician what electricity was good for: "One day you will tax it."
Real hackers don't need a screen. If you need output, use the HDD LED.
Not really. When she found out that filling with matter would only get so far, she invented dark energy.
Really? Well, let me try:
but repetition makes it funny (+1 funny)
Indeed, you need at least ten cores. One of the cores is already fully occupied with the intelligent spelling checker, while another one is constantly checking the grammar, and the third one is coordinatig those two, as well as doing some higher level analysis to improve their accuracy. The fourth core is occupied with doing the GUI, while the fifth one does content checks using internet ressources. The sixth core is occupied with auto-correcting the user's style, assisted by the seventh core which analyses the user's behaviour. The eighth core is responsible for optimizing the formatting of the text, while the nineth core cordinates all those other processes (well, except the first two which are coordinated by core 3). And of course you need at least one additional core top keep the OS itself running.
Don't you think the number of transistors you need is roughly proportional to the number of cores?
And I always thought the point of solid state HDDs were that they don't move!
You mean, like Lisp machines?
They will be capable of running Duke Nukem Forever. :-)
Hydrogen in its most compressed form is called a black hole :-) But even before that, the electrons would combine with the protons to form neutrons, so at that point it would stop being hydrogen.
:-)
I'd guess compressing a free electron gas would finally result in a (charged) black hole as well.
Of course in practice you'll have a hard time to compress your hydrogen (and even more, the electron gas) that much.
What will happen if Apple Records starts to offer Podcasts (under that name) for some of their music?
Seems to have been a really bad marketing move by Ballmer. And I always thought the one thing Microsoft were really good in was marketing!
Matrix?
Battery reloaded!
It depends on the material. Let's e.g. see what a gallon of electricity is in copper.
First, a gallon is 0,0038 m^3. Now copper has a free electron density of 8.47*10^28/m^3, and an electron has a charge of 1.6*10^-19 C. Multiplying this together means in copper, 1 gallon of electricity is 51 MC or about 14 kAh.
SCNR
Even non-subscribers can see articles in the future. I thought the distinguishing feature would be that subscribers can see articles now which others only can only see in the future.
I'm sure it was an accident. As a good slashdotter he just wanted to help the slashdot effect, and unexpectedly the article showed up ... :-)
The hacker used trojans to bore the viewer with technical details? I guess that's a new sort of DoS attack: Instead of attacking the computer, attack the people in front of it by giving technical details
Since a and b were explicitly declared as boolean (in the posting I answered to), the values cannot be anything but true or false. Indeed, if equality is meant to implement iff, it's actually a feature if a and b are implicitly converted to bool instead of (erroneously) comparing the actual non-bool values.
Well, actually you can derive all logical operations just from ?: and the constants true and false.
:-)
!a is the same as a?false:true
a&&b is the same as a?b:false (even the shortcut behaviour is right!)
a||b is the same as a?true:b (again, with the correct shortcut behaviour)
a==b is the same as a?b:b?false:true
a!=b is the same as a?b?false:true:b
Especially the latter ones are probably quite nice for IOCCC
You can get most of that in C++ by using the idiom of public non-virtual functions calling private virtual functions:Now everyone calling something(int) will get the checks defined on the base class, but the actual virtual function from the derived class. Derived classes cannot override the base class version, so calls through base class pointers/references will always use the base class checks, even if the derived class defines its own version with different checks. The only part that cannot be checked by the compiler is that derived classes don't weaken the post-conditions or strengthen the preconditions.
Well, it's quite easy to win energy by changing the frame of reference. Let's say I start with a frame of reference where earth is at rest. Now I accelerate a car to, say, 50 km/h. This needs some energy, which now is in the car in the form of kinetic energy (since this speed is hardly relativistic, the kinetic energy of the car is well approximated by 1/2 m v^2, where m is the mass of the car).
:-)
Ok, now I change my frame of reference, so that in my new frame of refernce, the car is at rest, and the earth moves at 50 km/h in the opposite direction. Now I've won a lot of energy, because the earth's mass, and thus the earth's kinetic energy at the same speed, is much larger than the car's. By taking a tiny amount of that won energy to accelerate the car even further, I can repeat that proocedure, thus producing as much energy as I want.
Note to humour-impaired readers and moderators: It's funny, laugh!
Shouldn't emergency stopping be quite easy to achieve by switching the hovering mechanism off?