The superheated rock/iron vapour flying off is the reaction mass that supplies most of the deflection.
It will also send fantastic shockwaves into the asteroid and break it into pieces, some of which will hit Earth. That's why I said that using the mass of the asteroid itself as reaction mass is dangerous.
I once did some back-of-the-envelope calculations about deflecting asteroids with a physicist friend of mine.
Our presumed target was a 1 mile dinosaur killer that is about to hit Earth in a few months and we want to impart enough kinetic energy to change its trajectory so that by the time it reaches Earth it will miss it by a few thousand miles of safety margin.
Well, it turns out that it takes so much energy that even the biggest thermonuclear devices barely have enough energy to do it, even assuming we could convert it efficiently to kinetic energy.
A nuke going off in space is just a big flash. No real blast. You need some working mass to convert it to kinetic energy. Using the mass of the asteroid itself is dangerous because you don't want it to break into multiple fragments.
Here our calculations probably become much less accurate because we took some shortcuts and made some assumptions that may be way off, but the result we got is that we needed to send some tens of thousands of tonnes of working mass (e.g. water) along with the nuke to convert its energy to momentum with reasonable efficiency.
Needless to say, this is beyond our current launching capabilities.
Apple isn't doing this out of selfless motives. But the fact is, they're doing it. Pretty cool indeed.
I think that the coolness factor may have played a big part in Apple's reasons for this business move.
The hackers of the Open Source community are addicted to cool and will use this technology and exploit it to the maximum. I think this may have an even bigger effect than Sun's open sourcing of StarOffice because an office suite just doesn't have the same coolness factor. Sure, it's very important and the OpenOffice team have been doing a great work but it just doesn't scream "play with me!" to tinkerers and gadget freaks like this does...
I was using everyday terms. By "gravitationa pull" meant the force you call "weight", not acceleration.
This force really is proportional to the mass:
f = mass*g = volume*density*g = K*size^3*density*g where g is the Earth gravitational acceleration at sea level and K depends on the shape of the object (it's 1 for cubes).
Not necessarily. Gravitational pull is proportional to mass, drag is proportional to area. Mass grows at 3rd power, area at 2nd power. Therefore smaller objects fall more slowly in an atmosphere.
Most 5.1 channel mixes are done using simple pairwise panning between two adjacent speakers to place the sound sources around you. This may be OK for movie effects but not for capturing the spatial nuances of a recording venue.
Ambisonics is a true 3D audio recording format. It is composed of 4 components: X, Y, Z and W that may be captured by the Soundfield Microphone or synthesized by audio ray tracing of the virtual venue.
The four components of the Ambisonics B format are a mathematical decomposition of the 3D sound wavefront at a point in space and are not directly related to any particular speaker placement. It may be decoded using simple linear operations into any speaker configuration. The 3D fidelity of the playback will depend on the number and placement of the speakers.
Note that 5.1 audio is still just 2D. The equivalent Ambisonics format would require only the W, X and Y components. With an additional top speaker you could feel the height of the concert hall in an Ambisonics recording.
One of the problems with Ambisonics is the chicken-and-egg problem - lack of enough media and playback equipment.
The significance of this is that AC3 on CD-R could let more people experiment with Ambisonics - the W, X and Y channels will be pre-decoded to a typical 5.1 speaker placement configuration. The AC3 should probably be recorded at the maximum quality setting of 640kbps. The resulting disk can be played back on any home theater system.
The Z channel can be somehow also stored on the disk so an Ambisonics-aware decoder could get full 3D audio. 3 of the 5 channels can be linearly combined to get back the W, X and Y channel and together with the Z channel you can decode it to any speaker configuration.
There is one particular speaker configuration that makes Ambisonics much easier to understand: imagine 8 speakers at the points of a cube. The W channel is fed to all speakers in the same polarity. The X channel is fed to the 4 right speakers with positive polarity and 4 left speakers with negative polarity. The Y channel is fed to the 4 front speakers with positive polarity and 4 back speakers with negative polarity. By now you can probably guess how the Z channel is connected.
Wouldn't using the resulting hot gasses/radiation from a nuclear reactor provide a smoother, more efficient burn?
Smoother? Yes. More efficient? definitely not.
Specific impulse depends on exhaust velocity. Exhaust velocity depends on temperature. The maximum achievable temperature for a nuclear thermal rocket is limited by the reactor construction materials to a few thousand degrees. With an Orion rocket, even if it loses a significant percentage of of thrust sideways the temperature is still orders of magnitude higher.
This is a design by Robert Zubrin for a rocket that produces a continous atomic blast using water with a high concentration of Uranium or Plutonium salts.
Just in case it wasn't clear - this is done only once to introduce a new terminal into the wireless network. A strong key is generated and stored in the machine. This is the equivalent of plugging the cable into an RJ45 socket.
"Wire Equivalent Privacy"
If an authenticated machine falls into the wrong hands (stolen laptop) it can be used to connect to the system. To protect against this a password or other means of authentication may be required for each new connection. Stealing a machine AND guessing a single password is much harder than driving by with any wireless equipped machine and trying to guess any password.
Passwords suck. More precisely, people suck at making and memorizing passwords. Here's an idea for secure authnentication without passwords:
I set up my wireless card until I can see the ID string of the network. I don't have any access yet.
I start the authentication client and type in a descriptive name for my machine.
I call the system administrator on the phone.
The system administrator sees my authentication request with the associated description and authorizes it.
That's all.
Why is it secure? The actual shared secret is generated by Diffie-Hellman key exchange or other method that is secure against sniffing. Theoretically it is vulnerable to a man-in-the-middle attack but in practice it is difficult to perform on a broadcast medium like wireless. Even if it is practical it is impossible to do it silently without raising suspicion - the attack attempts will be clearly visible on the list of authentication requests and the request must be authorized manually.
Get an industrial RF module that works in the 433 or 868 european unlicensed bands. These lower frequencies penetrate walls much better.
No, they are not as fast as WiFi. Most of them are around 19200 but I've seen some that run at 1 mbps. The lower bandwidth improves sensitivity and increases the range significantly.
Is MySQL an Oracle replacement in all circumstances? Absolutely not, but very often Oracle is wholly unnecessary for many of the tasks it's purchased for.
Claude Shannon hacking Las Vegas in the 60s.
on
MIT vs. Las Vegas
·
· Score: 2
Check out this amazing article about the first wearable computer built by Claude Shannon and Edward Thorp to predict roulette results.
I once saw an amazing demonstration on an Apple II: two 8 bit D/A converters were connected to the low and high bits of the address bus and fed to an oscilloscope in X/Y mode.
It was easy to see loops, interrupts and other program patterns and most importantly, deviations from these patterns.
Remember that this is based on observations of Quasars. There are several alternative theories to explain the apparent red shift of Quasars. Here's one of them.
These theories claim that Quasars are much closer and less bright than currently assumed. Needless to say, if any of these alternative theories are correct the speed of light may not need any adjustments, after all.
I assume you mean the reality of you wanting to make more money. You will have to do that within the limits of existing laws, whether you agree with them or not. There are lots of laws I don't agree with but trademark law is not one of them.
Are we going to call it Pink Cap? Or XXX XXXX? Or Pontific Linux 7.3[opensoars.com]?
It seems you have answered your own question.
"Pontific Linux is a verbatim copy of Red Hat Linux 7.3. Red Hat is a registered trademark of Red Hat inc."
And if so, how are customers going to easily know what they are getting?
That's your problem. Spend the time and effort to build your own reputation capital.
So patent laws promote innovation in the marketplace
It's interesting to discuss whether patents create an overall economic benefit for society - but that is not my point. Economic benefit is not everything. Patents and copyrights do not promote freedom. Trademarks do, with some reasonable tradeoffs.
There is no such thing as the "freedom" to make money with a business model based on government backed violence to limit another individual's freedom. It may be justified in some cases but you should always keep in mind that it's a compromise, an an inalienable right.
Red Hat is not trying to make anyone's life more difficult. They are just doing what they are required to do by law if they want to keep their trademark.
Considering that their trademark is just about the only thing they own (they give away everything else under the GPL) I'd say they have the right and duty to defend it. You can distribute copies of their distribution - just don't call it Red Hat.
On a more philosophical note - I wouldn't mind living in a world without copyright or patent laws. Neither of them protects my rights to be free from violence or fraud. On the contrary - patents and copyrights are a deal with the government to use the force of the courts underwritten by police violence to go after people who are doing something that doesn't harm anyone.
But trademark is different - it serves an important role in protecting me from fraud. How can trust in a vendor be built without a means of identifying his products that has some protection from fraud? It doesn't seem practical to put this burden on me as a customer. This tradeoff between two freedoms is therefore justified.
If I install an unlicensed ("pirated") copy of commercial software can I sue the vendor if it causes damage to my system? I have not agreed to any shrink-wrap or click-wrap license.
Same here - installing LILO requires *copying* it to your hard disk. You are granted the right to do it under a specific license which includes the "thou shalt not sue" clause. If you sue you are in violation of the license and should be treated no differently than someone who installs "warez" and violates the license by not paying. He can't sue the vendor.
(Or perhaps he can, but is likely to be countersued for copyright infringement? IANAL)
It would be in character if ICANN went through before Friday and labelled all of their documents "confidential". These guys are crooks just like the people at Enron and Global Crossings.
What strikes me as odd is why an organization like this should have *any* documents labelled as confidential.
Slashdot Mirror
The superheated rock/iron vapour flying off is the reaction mass that supplies most of the deflection.
It will also send fantastic shockwaves into the asteroid and break it into pieces, some of which will hit Earth. That's why I said that using the mass of the asteroid itself as reaction mass is dangerous.
I once did some back-of-the-envelope calculations about deflecting asteroids with a physicist friend of mine.
Our presumed target was a 1 mile dinosaur killer that is about to hit Earth in a few months and we want to impart enough kinetic energy to change its trajectory so that by the time it reaches Earth it will miss it by a few thousand miles of safety margin.
Well, it turns out that it takes so much energy that even the biggest thermonuclear devices barely have enough energy to do it, even assuming we could convert it efficiently to kinetic energy.
A nuke going off in space is just a big flash. No real blast. You need some working mass to convert it to kinetic energy. Using the mass of the asteroid itself is dangerous because you don't want it to break into multiple fragments.
Here our calculations probably become much less accurate because we took some shortcuts and made some assumptions that may be way off, but the result we got is that we needed to send some tens of thousands of tonnes of working mass (e.g. water) along with the nuke to convert its energy to momentum with reasonable efficiency.
Needless to say, this is beyond our current launching capabilities.
Apple isn't doing this out of selfless motives. But the fact is, they're doing it. Pretty cool indeed.
I think that the coolness factor may have played a big part in Apple's reasons for this business move.
The hackers of the Open Source community are addicted to cool and will use this technology and exploit it to the maximum. I think this may have an even bigger effect than Sun's open sourcing of StarOffice because an office suite just doesn't have the same coolness factor. Sure, it's very important and the OpenOffice team have been doing a great work but it just doesn't scream "play with me!" to tinkerers and gadget freaks like this does...
Actually, you're right. You can't see water vapor either. Only the condensed droplets.
Thanks.
The pictures show wisps of nitrogen evaporating from the jar sitting on top of the CPU
You can't see the evaporating nitrogen. The wisps are droplets of water condensed from water vapor in the air by the low temperature.
I was using everyday terms. By "gravitationa pull" meant the force you call "weight", not acceleration.
This force really is proportional to the mass:
f = mass*g = volume*density*g = K*size^3*density*g where g is the Earth gravitational acceleration at sea level and K depends on the shape of the object (it's 1 for cubes).
Nobody needs to turn in any grave.
The author of the article probably never heard of the DVD-Audio format and means "the audio format most commonly used on Video DVDs" i.e. AC3.
With Sony's aggressive marketing of SACD most of us will probably never hear of the superior DVD-Audio format either...
A meteorite might go a bit faster
Not necessarily. Gravitational pull is proportional to mass, drag is proportional to area. Mass grows at 3rd power, area at 2nd power. Therefore smaller objects fall more slowly in an atmosphere.
Most 5.1 channel mixes are done using simple pairwise panning between two adjacent speakers to place the sound sources around you. This may be OK for movie effects but not for capturing the spatial nuances of a recording venue.
Ambisonics is a true 3D audio recording format. It is composed of 4 components: X, Y, Z and W that may be captured by the Soundfield Microphone or synthesized by audio ray tracing of the virtual venue.
The four components of the Ambisonics B format are a mathematical decomposition of the 3D sound wavefront at a point in space and are not directly related to any particular speaker placement. It may be decoded using simple linear operations into any speaker configuration. The 3D fidelity of the playback will depend on the number and placement of the speakers.
Note that 5.1 audio is still just 2D. The equivalent Ambisonics format would require only the W, X and Y components. With an additional top speaker you could feel the height of the concert hall in an Ambisonics recording.
One of the problems with Ambisonics is the chicken-and-egg problem - lack of enough media and playback equipment.
The significance of this is that AC3 on CD-R could let more people experiment with Ambisonics - the W, X and Y channels will be pre-decoded to a typical 5.1 speaker placement configuration. The AC3 should probably be recorded at the maximum quality setting of 640kbps. The resulting disk can be played back on any home theater system.
The Z channel can be somehow also stored on the disk so an Ambisonics-aware decoder could get full 3D audio. 3 of the 5 channels can be linearly combined to get back the W, X and Y channel and together with the Z channel you can decode it to any speaker configuration.
There is one particular speaker configuration that makes Ambisonics much easier to understand: imagine 8 speakers at the points of a cube. The W channel is fed to all speakers in the same polarity. The X channel is fed to the 4 right speakers with positive polarity and 4 left speakers with negative polarity. The Y channel is fed to the 4 front speakers with positive polarity and 4 back speakers with negative polarity. By now you can probably guess how the Z channel is connected.
Wouldn't using the resulting hot gasses/radiation from a nuclear reactor provide a smoother, more efficient burn?
Smoother? Yes. More efficient? definitely not.
Specific impulse depends on exhaust velocity. Exhaust velocity depends on temperature. The maximum achievable temperature for a nuclear thermal rocket is limited by the reactor construction materials to a few thousand degrees. With an Orion rocket, even if it loses a significant percentage of of thrust sideways the temperature is still orders of magnitude higher.
This is a design by Robert Zubrin for a rocket that produces a continous atomic blast using water with a high concentration of Uranium or Plutonium salts.
Nuke Your Way to the Stars
Just in case it wasn't clear - this is done only once to introduce a new terminal into the wireless network. A strong key is generated and stored in the machine. This is the equivalent of plugging the cable into an RJ45 socket.
"Wire Equivalent Privacy"
If an authenticated machine falls into the wrong hands (stolen laptop) it can be used to connect to the system. To protect against this a password or other means of authentication may be required for each new connection. Stealing a machine AND guessing a single password is much harder than driving by with any wireless equipped machine and trying to guess any password.
Passwords suck. More precisely, people suck at making and memorizing passwords. Here's an idea for secure authnentication without passwords:
I set up my wireless card until I can see the ID string of the network. I don't have any access yet.
I start the authentication client and type in a descriptive name for my machine.
I call the system administrator on the phone.
The system administrator sees my authentication request with the associated description and authorizes it.
That's all.
Why is it secure? The actual shared secret is generated by Diffie-Hellman key exchange or other method that is secure against sniffing. Theoretically it is vulnerable to a man-in-the-middle attack but in practice it is difficult to perform on a broadcast medium like wireless. Even if it is practical it is impossible to do it silently without raising suspicion - the attack attempts will be clearly visible on the list of authentication requests and the request must be authorized manually.
Get an industrial RF module that works in the 433 or 868 european unlicensed bands. These lower frequencies penetrate walls much better.
No, they are not as fast as WiFi. Most of them are around 19200 but I've seen some that run at 1 mbps. The lower bandwidth improves sensitivity and increases the range significantly.
Is MySQL an Oracle replacement in all circumstances? Absolutely not, but very often Oracle is wholly unnecessary for many of the tasks it's purchased for.
Check out this amazing article about the first wearable computer built by Claude Shannon and Edward Thorp to predict roulette results.
I once saw an amazing demonstration on an Apple II: two 8 bit D/A converters were connected to the low and high bits of the address bus and fed to an oscilloscope in X/Y mode.
It was easy to see loops, interrupts and other program patterns and most importantly, deviations from these patterns.
Remember that this is based on observations of Quasars. There are several alternative theories to explain the apparent red shift of Quasars. Here's one of them.
These theories claim that Quasars are much closer and less bright than currently assumed. Needless to say, if any of these alternative theories are correct the speed of light may not need any adjustments, after all.
I meant a CD, of course.
Take a look at H. Peter Anvin's SuperRescue - it's a full Red Hat system on a floppy. It uses zisofs compression to fit it all on a single CD.
I guess what it really comes down to is reality.
I assume you mean the reality of you wanting to make more money. You will have to do that within the limits of existing laws, whether you agree with them or not. There are lots of laws I don't agree with but trademark law is not one of them.
Are we going to call it Pink Cap? Or XXX XXXX? Or Pontific Linux 7.3[opensoars.com]?
It seems you have answered your own question.
"Pontific Linux is a verbatim copy of Red Hat Linux 7.3. Red Hat is a registered trademark of Red Hat inc."
And if so, how are customers going to easily know what they are getting?
That's your problem. Spend the time and effort to build your own reputation capital.
So patent laws promote innovation in the marketplace
It's interesting to discuss whether patents create an overall economic benefit for society - but that is not my point. Economic benefit is not everything. Patents and copyrights do not promote freedom. Trademarks do, with some reasonable tradeoffs.
There is no such thing as the "freedom" to make money with a business model based on government backed violence to limit another individual's freedom. It may be justified in some cases but you should always keep in mind that it's a compromise, an an inalienable right.
Red Hat is not trying to make anyone's life more difficult. They are just doing what they are required to do by law if they want to keep their trademark.
Considering that their trademark is just about the only thing they own (they give away everything else under the GPL) I'd say they have the right and duty to defend it. You can distribute copies of their distribution - just don't call it Red Hat.
On a more philosophical note - I wouldn't mind living in a world without copyright or patent laws. Neither of them protects my rights to be free from violence or fraud. On the contrary - patents and copyrights are a deal with the government to use the force of the courts underwritten by police violence to go after people who are doing something that doesn't harm anyone.
But trademark is different - it serves an important role in protecting me from fraud. How can trust in a vendor be built without a means of identifying his products that has some protection from fraud? It doesn't seem practical to put this burden on me as a customer. This tradeoff between two freedoms is therefore justified.
If I install an unlicensed ("pirated") copy of commercial software can I sue the vendor if it causes damage to my system? I have not agreed to any shrink-wrap or click-wrap license.
Same here - installing LILO requires *copying* it to your hard disk. You are granted the right to do it under a specific license which includes the "thou shalt not sue" clause. If you sue you are in violation of the license and should be treated no differently than someone who installs "warez" and violates the license by not paying. He can't sue the vendor.
(Or perhaps he can, but is likely to be countersued for copyright infringement? IANAL)
It would be in character if ICANN went through before Friday and labelled all of their documents "confidential". These guys are crooks just like the people at Enron and Global Crossings.
What strikes me as odd is why an organization like this should have *any* documents labelled as confidential.