I read a report (in the la times, I think) that the analysis of the damage during the mission (that showed the damage from the foam was nothing to worry about) was just some hand-waiving analysys in an excel spreadsheet.
There is NO way anyone can do a reasonable analysis of damage from an impact in a freakin' spreadsheet. They probably just did something that amounted to fitting a curve to historical data and extrapolating... sheesh! And this was deemed reliable enough analysis that they didn't need to image the damaged area when they had a chance...
All of the avionics, the computer, etc. are on board the rover. The umbilical cables connect the rovers to sensors, solar panels, antennas, thrusters, etc on the cruise stage and on the descent stage.
As far as a rigid docking system... that sounds very unreliable to me. A cable will very reliable be connected when you need it to be connected and you can reliably cut the cable when you need to. Designing a rigid docking system seems like a very difficult problem if you want it to be reliable... and it seems like a waste of effort if you aren't reusing the system....
The problem isn't with the sytem to cut the umbilical anyway, the problem is with circuits that aren't supposed to be sending a signal through a severed wire... you don't know if two severed wires could touch each other or some other piece of metal. The solution is to not send a signal through the wire after its cut.
And most good software for the Mac comes from Shareware and Freeware developers,and I'd bet, though I couldn't verify, that the average size of those files isn't much more than 20MB.
If this catches on, it might replace the shareware market. Shareware is shareware because it is so expensive to distribute software through retail. Since this has no upfront costs, it's a good way for small-time developers to sell their software.
I don't know how big the cut Software-To-Go takes, but I bet its comparable to what various regestration services charge to register shareware.
If Apple does this right it might really help to make the Mac a mecca for small-time developers.
I saw a presentation when I was in grad school on the previous incarnation of the 747-laser. The big problem was the laser could only blow up the missle if its tanks were mostly full of fuel.
This is because missle fuel tanks are under high pressure so that the fuel can help form part of the structure for the missle to support the weight of the fuel. If a laser can weaken the walls of the fuel tank then the missle's structure will fail, and the missle will break up.
Anyway these lasers have to hit a missle right after it launches or else the tanks have lost too much pressure and the laser won't do any damage... the presenter defended this by saying you want to shoot down a missle close to launch anyway because you don't want the debris from the missle falling on any friendlies... and this is a good argument (the scuds shot down by patriots in gulf war I caused a lot of damage when they fell out of the sky).
I do have to wonder, though, if the missle launches can be detected and the missle targeted quickly enough for these lasers to work... and what about missles with solid rocket motors? I doubt the laser would be any good against these at all.
yeah, I was trying to make the point that PageRank, etc. are obvious ideas.... certainly a high school project written before the internet took off is pretty good evidence of that sort of thing being an obvious idea.
I thought patent's were supposed to be 'non-obvious', The idea behind PageRank is clearly obvious to anyone who's spent a little bit of time thinking about how to search the internet.
The implementation of PageRank is a much more complicated thing... and that is protected by copyright laws, etc. It's plain assinine to patent the idea.
I did a report with a freind in high school (1993) about cyberspace and how to 'map' cyberspace. In the paper we suggested that it should be mapped like a giant Venn diagram... this would be achieved by looking for key words in documents and modelling them like strings attracting each other... I think we even mentioned that www links could also be used as springs to pull similar documents together... (the only access to the web we had beck them was to telnet to a machine at cern which gave a lynx like interface, at the time mosaic only ran on x-windows and we didn't have access to any unix machines)
We could never get the scheme to work out... the main problem is figuring out how many dimensions such a space might have... and of course after that you have to run a massive prgram to put all of the "springs" into equilibrium...
But since when are "idea" patents about ideas that actually work? Would this paper be enough to prove that google's pagerank stuff wasn't a new idea and should never been given a patent. (I mean c'mon the basic idea behind Pagerank was pretty obvious, the hard part was getting it to work)
People who patent ideas like math or computer algorithms are slime balls. They are killing the free sharing of ideas that made the scientific revolution possible. Where would we be if Newton patented gravity and Calculus? If Einstien patented relativity would anyone even bother to learn all of the complexities of general realtivity?
If the Watson-Crick model was pure theory... i.e. if they never saw Franklin's work, her X-Ray diffraction results would have been hailed as confirming the theory, etc, etc... the irony is that in this scenario, Franklin would have gotten a lot more respect than she has gotten.
However, she did her work before Watson-Crick and she was sold out by her advisor who gave her experimental data to Watson without telling her. So what if she didn't think up the model based on her data, Watson did... and he didn't even acknowledge it!
Her experimental results lead to Watson and Crick's theory... and they didn't acknowledge it. That is a severe breach of scientific ethics. Just like Pete Rose isn't allowed in the Hall of Fame for his ethics breaches, Watson and Crick should have never gotten the Nobel prize.
If a photon has enough energy it can decay into a matter anti-matter pair. This has been observed for some time in particle collisions.
I do wonder if a black hole could "explode"... I'm not aware of any sort of explosion that could escape a black hole. however, black holes do slowly decay and radiate away mass as hawking showed... anyway I should prolly just read more of the thread
Purdue University is doing lots of work with Peroxide based rockets. Armadillo should contact the Aero/Astro dept. there to get some tips on how to aquire the stuff. Just call the number on their web page.
I think they couldn't get stuff above 80% because of transportation concerns... I believe that they were able to distill the 80% stuff up to higher concentrations. They've also developed catalysts that can be mixed with the peroxide as a colloid to get better performance.
Purdue has just rehabilitated an Apollo-era test facility to do some engine tests. When they get up to full swing, they'll probably have the best facility at a University. Armadillo might want to contact them about using their facility for tests.
If the Armadillo guys have halfway decent designs, I'm sure the Purdue people would love an excuse to light up a new engine.
Yeah, and this derivative stuff isn't that interesting either. It's just a simple ratio of the delta of a function value devided by the delta in its arguments... yeah there's some sort of ad hoc limit thing that says you can somehow make the devisor zero and still get a value... I mean, c'mon!....Just because a paper is simple and easy to understand doesn't mean its without value... I for one find this timescales stuff a very interesting insight...
I'm curious... details please. I'm not sure what you mean by a "Taylor series of the expression". Is it a power series? If so there's lots of cool things that can be done once you have a power series... including lagrange inversion...
Buying comm equipment that uses some "weirdass nasa protocol" is extra super expensive... besides they want different spacecraft to be able to relay data, especially at Mars. With IP a NASA rover can relay data to an ESA spacecraft and the ESA spacecraft can relay the data back to Earth.
The actual commands sent to spacecraft are still some weirdass NASA-only command set, and everything's encrypted, and you need to drop down a few hundred million for a tracking station to even have a shot at 'hacking' a spacecraft.... so I don't think this stuff is easy to hack.
If Konqueror doesn't use the Opera engine, will Opera drop linux support? Since they've released a Windows version, they must've gotten Microsoft to use the Opera engine in Explorer...
Yeah it sucks when Apple releases a free version of your App... but it would suck more if there were less Macs to sell your app to. Apple releasing a web browser was a very neccesary step for Apple to keep tha Mac platform alive and to try and take away the Wintel market share. The more mac users, the bigger the market for Mac developers.
Opera has a head start on Safari... instead of giving up, they could just try and out-innovate Safari they way Watson has out-innovated Sherlock.
What about allowing open access to the internals of your code and all of its objects along with documenting how it works without releasing the source?
Say the way the Cocoa Application kit works. All of the code is closed source, but any developer can use the objects in the application kit or write their own objects to replace ones that Apple wrote.
In principle any Cocoa application's objects can be accessed by any other app.... in essance every Cocoa app is a mini Application kit without the documentation.
This might be a way to open up your program for other developers to enhance and use in their own apps without giving away any of your source. This would work especially well with the free as in beer programs. (hey kids, download my super enhanced iPhoto that enhances the free iPhoto that you already have)
Apple could open up the objects in the iApps for third party developers and get many of the benefits they would get from open sourcing the apps without having to worry about someone porting the apps to a competing platform. Such a strategy could work well for other harware vendors like Sun or IBM.
yeah there are problems with this, but this might be a new middle-ground between open and closed source.
of course, a big problem is what if apple takes away the free app that the code you wrote depends on... maybe if that happens the developers that use the code that got yanked could get together and write an open source repcement (like Gnustep)
I bet the omnigroup's dev lists will be a good place to look also. If Omni's team is learning webcore it seems like there will be a lot of good stuff on the lists....
The Safari BETA may be less full featured than IE, but when it ships with new Macs I have a feeling that it will be on par with IE, just much, much faster.
I like Omniweb's features and if it was as fast as Safari and rendered as many pages as Safari I would pay for Omniweb (actually I've already paid for Omniweb).
Right now I'm using Safari and Mozilla as a backup for the few pages that safari can't handle. IE is just too slow on my G3 to be usable.
Faster Firewire + Rendezvous means now there is an easy and cheap way to set up a home network of Macs, Printers, Scanners, iPods, and whatever else Apple would like to sell.
I wasn't arguing your credentials... just that paragraph which was awfully troll-y. The review of gauss's law was for other slashdotters such as myself who's physics classes are in the distant past. Virtual cathode and virtual anode are not first year physics topics. (at least not at Purdue)
Yeah, keeping the grid from getting destroyed is a big problem in IEC fusion... I still argue that the ions are confined, in that with a perfect grid (that doesn't degrade) the ions won't leave the containment vessel. Anyway, that's just semantics.
Consider the electrons on the grid of an ion engine... aren't they confined to the grid electrostatically?...I guess with what you said that suggests that most fusion in an IEC device would occur rather close to the grid..
Since you've dropped your credentials, I have a fusion question for you.. what would be the problem of using particle beams (ala fermilab) to induce fusion by colliding the beams? It always seemed to me that fusion ought to be done dynamically rather than by confining and "squeezing".
Hall thrusters accelerate electrostatically. They just trap electrons in a magnetic field instead of using a grid. Arcjets use plasma to apply heat, are they a plasma engine?
If you exhaust a plasma you are limited in the densities that you can achieve. Ion engines and hall thrusters need to be very large to get higher thrust levels. I don't see how anything that exhausts a plasma can get thrust to weight ratios comparable to something that thermally heats a working fluid (like fusion or fission engines)....ok, maybe some large gossamer structure could get high T/W with plasma.
MHD and VASIMR engines don't exist yet. In theory they have promise... but so does IEC fusion.
P.S. Furthermore, a purely electrostatic confining potential is not allowed by Poisson's equation (the equation governing electrostatics), as is taught in any first year college physics class. The quick explanation is that Gauss's law implies the existance of a charge in the potential well. But if you are trying to make a trap to isolate a particle, that is exactly what you don't want in your well. For example, Penning traps use a combination of electrostatic confinement (confinement at the end-caps) and magnetic fields (radial confinement). However, I'll give them the benefit of the doubt as this appears to be relying on dynamic effects virtual cathode/anode effects. (Actually, much of the initial modeling of virtual cathodes was done by my thesis advisor in the 1960s.)
I admit that my electrodynamics are a little rusty, but this read like troll-nonsense. You can confine a charged particle with a simple electric field. Columb's law is still valid.
Here's a brief review of Guass's law: http://scienceworld.wolfram.com/physicsGauss sLaw.h tml and also some info about the spherical electric field (relevent to IEC): http://scienceworld.wolfram.com/physics/SphereElec tricField.html
So I charge up a sphere, and its equivalent to putting the whole charge at the center of the sphere... so Ions of the opposite charge will be attracted to the center of the sphere... but the charge is still physically on the outer surface of the sphere and the ions won't neutralize the charge.
Seems to me that If I have a charge of 30 electrons on my sphere, I can keep less than 30 protons trapped in the center if they have a low enough temperature. (Calculating the temperature to keep the protons under is beyond first year physics).
Magnetic fields are nice in that you can more easily confine higher temperature plasmas, but you can still confine these high temp plasmas with a strong enough E-field and a big enough sphere.
Slashdot Mirror
I read a report (in the la times, I think) that the analysis of the damage during the mission (that showed the damage from the foam was nothing to worry about) was just some hand-waiving analysys in an excel spreadsheet.
There is NO way anyone can do a reasonable analysis of damage from an impact in a freakin' spreadsheet. They probably just did something that amounted to fitting a curve to historical data and extrapolating... sheesh! And this was deemed reliable enough analysis that they didn't need to image the damaged area when they had a chance...
Houston, YOU have a problem!
All of the avionics, the computer, etc. are on board the rover. The umbilical cables connect the rovers to sensors, solar panels, antennas, thrusters, etc on the cruise stage and on the descent stage.
As far as a rigid docking system... that sounds very unreliable to me. A cable will very reliable be connected when you need it to be connected and you can reliably cut the cable when you need to. Designing a rigid docking system seems like a very difficult problem if you want it to be reliable... and it seems like a waste of effort if you aren't reusing the system....
The problem isn't with the sytem to cut the umbilical anyway, the problem is with circuits that aren't supposed to be sending a signal through a severed wire... you don't know if two severed wires could touch each other or some other piece of metal. The solution is to not send a signal through the wire after its cut.
if two wires accidentally touch there could be a short even with a non-conductive blade
And most good software for the Mac comes from Shareware and Freeware developers,and I'd bet, though I couldn't verify, that the average size of those files isn't much more than 20MB.
If this catches on, it might replace the shareware market. Shareware is shareware because it is so expensive to distribute software through retail. Since this has no upfront costs, it's a good way for small-time developers to sell their software.
I don't know how big the cut Software-To-Go takes, but I bet its comparable to what various regestration services charge to register shareware.
If Apple does this right it might really help to make the Mac a mecca for small-time developers.
I saw a presentation when I was in grad school on the previous incarnation of the 747-laser. The big problem was the laser could only blow up the missle if its tanks were mostly full of fuel.
This is because missle fuel tanks are under high pressure so that the fuel can help form part of the structure for the missle to support the weight of the fuel. If a laser can weaken the walls of the fuel tank then the missle's structure will fail, and the missle will break up.
Anyway these lasers have to hit a missle right after it launches or else the tanks have lost too much pressure and the laser won't do any damage... the presenter defended this by saying you want to shoot down a missle close to launch anyway because you don't want the debris from the missle falling on any friendlies... and this is a good argument (the scuds shot down by patriots in gulf war I caused a lot of damage when they fell out of the sky).
I do have to wonder, though, if the missle launches can be detected and the missle targeted quickly enough for these lasers to work... and what about missles with solid rocket motors? I doubt the laser would be any good against these at all.
yeah, I was trying to make the point that PageRank, etc. are obvious ideas.... certainly a high school project written before the internet took off is pretty good evidence of that sort of thing being an obvious idea.
I thought patent's were supposed to be 'non-obvious', The idea behind PageRank is clearly obvious to anyone who's spent a little bit of time thinking about how to search the internet.
The implementation of PageRank is a much more complicated thing... and that is protected by copyright laws, etc. It's plain assinine to patent the idea.
I did a report with a freind in high school (1993) about cyberspace and how to 'map' cyberspace. In the paper we suggested that it should be mapped like a giant Venn diagram... this would be achieved by looking for key words in documents and modelling them like strings attracting each other... I think we even mentioned that www links could also be used as springs to pull similar documents together... (the only access to the web we had beck them was to telnet to a machine at cern which gave a lynx like interface, at the time mosaic only ran on x-windows and we didn't have access to any unix machines)
We could never get the scheme to work out... the main problem is figuring out how many dimensions such a space might have... and of course after that you have to run a massive prgram to put all of the "springs" into equilibrium...
But since when are "idea" patents about ideas that actually work? Would this paper be enough to prove that google's pagerank stuff wasn't a new idea and should never been given a patent. (I mean c'mon the basic idea behind Pagerank was pretty obvious, the hard part was getting it to work)
People who patent ideas like math or computer algorithms are slime balls. They are killing the free sharing of ideas that made the scientific revolution possible. Where would we be if Newton patented gravity and Calculus? If Einstien patented relativity would anyone even bother to learn all of the complexities of general realtivity?
If the Watson-Crick model was pure theory... i.e. if they never saw Franklin's work, her X-Ray diffraction results would have been hailed as confirming the theory, etc, etc... the irony is that in this scenario, Franklin would have gotten a lot more respect than she has gotten.
However, she did her work before Watson-Crick and she was sold out by her advisor who gave her experimental data to Watson without telling her. So what if she didn't think up the model based on her data, Watson did... and he didn't even acknowledge it!
Her experimental results lead to Watson and Crick's theory... and they didn't acknowledge it. That is a severe breach of scientific ethics. Just like Pete Rose isn't allowed in the Hall of Fame for his ethics breaches, Watson and Crick should have never gotten the Nobel prize.
If someone makes 90% of a discovery why does someone who fills in the last 10% get all of the credit?
If a photon has enough energy it can decay into a matter anti-matter pair. This has been observed for some time in particle collisions.
I do wonder if a black hole could "explode"... I'm not aware of any sort of explosion that could escape a black hole. however, black holes do slowly decay and radiate away mass as hawking showed... anyway I should prolly just read more of the thread
Purdue University is doing lots of work with Peroxide based rockets. Armadillo should contact the Aero /Astro dept. there to get some tips on how to aquire the stuff. Just call the number on their web page.
I think they couldn't get stuff above 80% because of transportation concerns... I believe that they were able to distill the 80% stuff up to higher concentrations. They've also developed catalysts that can be mixed with the peroxide as a colloid to get better performance.
Purdue has just rehabilitated an Apollo-era test facility to do some engine tests. When they get up to full swing, they'll probably have the best facility at a University. Armadillo might want to contact them about using their facility for tests.
If the Armadillo guys have halfway decent designs, I'm sure the Purdue people would love an excuse to light up a new engine.
Yeah, and this derivative stuff isn't that interesting either. It's just a simple ratio of the delta of a function value devided by the delta in its arguments... yeah there's some sort of ad hoc limit thing that says you can somehow make the devisor zero and still get a value... I mean, c'mon! ....Just because a paper is simple and easy to understand doesn't mean its without value... I for one find this timescales stuff a very interesting insight...
(If anyone is curious, I can supply the details.)
I'm curious... details please. I'm not sure what you mean by a "Taylor series of the expression". Is it a power series? If so there's lots of cool things that can be done once you have a power series... including lagrange inversion...
Buying comm equipment that uses some "weirdass nasa protocol" is extra super expensive... besides they want different spacecraft to be able to relay data, especially at Mars. With IP a NASA rover can relay data to an ESA spacecraft and the ESA spacecraft can relay the data back to Earth.
The actual commands sent to spacecraft are still some weirdass NASA-only command set, and everything's encrypted, and you need to drop down a few hundred million for a tracking station to even have a shot at 'hacking' a spacecraft.... so I don't think this stuff is easy to hack.
If Konqueror doesn't use the Opera engine, will Opera drop linux support? Since they've released a Windows version, they must've gotten Microsoft to use the Opera engine in Explorer...
Yeah it sucks when Apple releases a free version of your App... but it would suck more if there were less Macs to sell your app to. Apple releasing a web browser was a very neccesary step for Apple to keep tha Mac platform alive and to try and take away the Wintel market share. The more mac users, the bigger the market for Mac developers.
Opera has a head start on Safari... instead of giving up, they could just try and out-innovate Safari they way Watson has out-innovated Sherlock.
What about allowing open access to the internals of your code and all of its objects along with documenting how it works without releasing the source?
Say the way the Cocoa Application kit works. All of the code is closed source, but any developer can use the objects in the application kit or write their own objects to replace ones that Apple wrote.
In principle any Cocoa application's objects can be accessed by any other app.... in essance every Cocoa app is a mini Application kit without the documentation.
This might be a way to open up your program for other developers to enhance and use in their own apps without giving away any of your source. This would work especially well with the free as in beer programs. (hey kids, download my super enhanced iPhoto that enhances the free iPhoto that you already have)
Apple could open up the objects in the iApps for third party developers and get many of the benefits they would get from open sourcing the apps without having to worry about someone porting the apps to a competing platform. Such a strategy could work well for other harware vendors like Sun or IBM.
yeah there are problems with this, but this might be a new middle-ground between open and closed source.
of course, a big problem is what if apple takes away the free app that the code you wrote depends on... maybe if that happens the developers that use the code that got yanked could get together and write an open source repcement (like Gnustep)
Omniweb uses Objective-C and Cocoa. A main benefit of Objective-C is supposed to be that the code is modular and switching out objects is easy.
From my limited experience with Objective-C, I don't think switching renedring engines will be that big a deal for Omniweb.
I bet the omnigroup's dev lists will be a good place to look also. If Omni's team is learning webcore it seems like there will be a lot of good stuff on the lists....
The Safari BETA may be less full featured than IE, but when it ships with new Macs I have a feeling that it will be on par with IE, just much, much faster.
I like Omniweb's features and if it was as fast as Safari and rendered as many pages as Safari I would pay for Omniweb (actually I've already paid for Omniweb).
Right now I'm using Safari and Mozilla as a backup for the few pages that safari can't handle. IE is just too slow on my G3 to be usable.
Put it does block pop-up ads!
Faster Firewire + Rendezvous means now there is an easy and cheap way to set up a home network of Macs, Printers, Scanners, iPods, and whatever else Apple would like to sell.
thinksecret is a good place to go for accurate rumors... http://www.thinksecret.com/news/mwsf03apple.html
I wasn't arguing your credentials... just that paragraph which was awfully troll-y. The review of gauss's law was for other slashdotters such as myself who's physics classes are in the distant past. Virtual cathode and virtual anode are not first year physics topics. (at least not at Purdue)
...I guess with what you said that suggests that most fusion in an IEC device would occur rather close to the grid..
Yeah, keeping the grid from getting destroyed is a big problem in IEC fusion... I still argue that the ions are confined, in that with a perfect grid (that doesn't degrade) the ions won't leave the containment vessel. Anyway, that's just semantics.
Consider the electrons on the grid of an ion engine... aren't they confined to the grid electrostatically?
Since you've dropped your credentials, I have a fusion question for you.. what would be the problem of using particle beams (ala fermilab) to induce fusion by colliding the beams? It always seemed to me that fusion ought to be done dynamically rather than by confining and "squeezing".
Hall thrusters accelerate electrostatically. They just trap electrons in a magnetic field instead of using a grid. Arcjets use plasma to apply heat, are they a plasma engine?
...ok, maybe some large gossamer structure could get high T/W with plasma.
If you exhaust a plasma you are limited in the densities that you can achieve. Ion engines and hall thrusters need to be very large to get higher thrust levels. I don't see how anything that exhausts a plasma can get thrust to weight ratios comparable to something that thermally heats a working fluid (like fusion or fission engines).
MHD and VASIMR engines don't exist yet. In theory they have promise... but so does IEC fusion.
P.S. Furthermore, a purely electrostatic confining potential is not allowed by Poisson's equation (the equation governing electrostatics), as is taught in any first year college physics class. The quick explanation is that Gauss's law implies the existance of a charge in the potential well. But if you are trying to make a trap to isolate a particle, that is exactly what you don't want in your well. For example, Penning traps use a combination of electrostatic confinement (confinement at the end-caps) and magnetic fields (radial confinement). However, I'll give them the benefit of the doubt as this appears to be relying on dynamic effects virtual cathode/anode effects. (Actually, much of the initial modeling of virtual cathodes was done by my thesis advisor in the 1960s.)
s sLaw.h tml and also some info about the spherical electric field (relevent to IEC): http://scienceworld.wolfram.com/physics/SphereElec tricField.html
I admit that my electrodynamics are a little rusty, but this read like troll-nonsense. You can confine a charged particle with a simple electric field. Columb's law is still valid.
Here's a brief review of Guass's law:
http://scienceworld.wolfram.com/physicsGaus
So I charge up a sphere, and its equivalent to putting the whole charge at the center of the sphere... so Ions of the opposite charge will be attracted to the center of the sphere... but the charge is still physically on the outer surface of the sphere and the ions won't neutralize the charge.
Seems to me that If I have a charge of 30 electrons on my sphere, I can keep less than 30 protons trapped in the center if they have a low enough temperature. (Calculating the temperature to keep the protons under is beyond first year physics).
Magnetic fields are nice in that you can more easily confine higher temperature plasmas, but you can still confine these high temp plasmas with a strong enough E-field and a big enough sphere.