"However, if you provide a continual thrust that everywhere is greater than the local acceleration due to Earth's gravity, you will never fall back down."
*cough* If you're providing continual thrust to counteract the acceleration due to earth's gravity YOU HAVEN'T ESCAPED GRAVITY!
You have when you get out of the potential well, which under the above situation you will eventually do. You will eventually reach a point where the upward velocity is greater than the local escape velocity, and it's bye-bye blue world. At no point have you had to attain a speed equal to the escape velocity at the surface, which is the claim you and TG are erroneously making.
By your logic, a helicopter has escaped the earth's gravity. It produces a constant thrust which keeps it in "orbit" or as it accelerates vertically away from the earth, it's "escaped".
A helicopter does nothing of the sort, and nowhere have I claimed explicitly or otherwise that it would. For a start, a helicopter is usually not in a single orbit. Of course, any motion could be described as a sum over many orbits. The helicopter has not escaped the potential well due to the Earth, so it has not escaped the Earth's gravity. The difference between the helicopter situation and that of a rocket is this: what happens when you switch the engine off? A helicopter goes smack back into the planet, a successfully launched rocket will carry on at some constant velocity away from the planet (or would do, if some git hadn't put the Sun there. In fact it starts orbiting that).
Somehow you must attain that velocity relative to the earth which dictates the energy required to escape the earth's gravity.
That is not necessary at all. The only situation in which your argument is even in appropriate scope is that not of a continually thrusting body such as a rocket, but that of a body that has gained momentum through an initial impulse. That is, a projectile. I'm afraid to say that Verne's "De la terre a la lune" is inaccurate in supposing that this is how astronauts are launched into space (though it is a riveting read). You are making the assumption that the body is essentially (resistive forces notwithstanding) moving in a single orbit from the beginning, and trying to derive the condition for which this orbit is unbounded. That isn't how we throw rockets into space.
sucking away the Earth's atmosphere[...](prior to sucking away the atmosphere)
We merely assume that atmospheric resistive forces may be neglected to arrive at an appropriate order-of-magnitude estimate for certain properties, because it simplifies the equation of motion. No-one's suggesting that the atmosphere needs to be removed;-). You can calm back down now.
My karma's probably blown now for this post but I have a thing for truth....
The truth has a tendency to be true, unlike your post. Let me just give my background for disclosure - I'm a rocket scientist.
#1. YOu are simply incoprrect when you say that you do NOT have to reach 25,000 (or Mach 25 as you out it) to escape Earth's gravity because of the *engines* on a craft sigh). In point of fact you simply DO.
No, you don't. If you were blasted off from the surface of the Earth at Mach 25 and the atmosphere didn't exist, then (to use the kind of lax definition of infinity that us physicists are proud of) you'd come to rest at infinity and wouldn't fall back into the Earth. However, if you provide a continual thrust that everywhere is greater than the local acceleration due to Earth's gravity, you will never fall back down. You could achieve this at a constant velocity of 1m/s if you liked, by suitable modification of the thrust.
#2. You are incorrect when you say it's "trivially easy" to build up speed outside the atmosphere. Newton's laws still hold whether inside or outside the atmosphere...and you STILL have to carry the reaction mass up there somehow.
To go forward in space, throw something backward. To go forward in the atmosphere, throw enough stuff backward to push enough air out of the way. It's easier in space - as you don't have to overcome resistive drag (unless the solar wind is non-negligible) then the same acceleration can be had for less driving force - the net force is the same yes. This means you can take it easy, and do something like throwing photons or ions out of the back of your spaceship.
The rest of your post is (unfortunately) just a layperson's opinion about physics and I'm sorry but a rather poor opinion at that.
As opinions go, it was just as valid as anyone else's. As statements of physical understanding go, it was superior to yours.
That's very very true. The difference between the NeXTstations and the TurboStations was amazing - same 25MHz to 33MHz speed bump. Of course, the difference between OpenStep on a 25MHz 68040 and on a Pentium 100 was even more impressive:-).
Granted, in this situation it's not the best solution but there are areas in which FWRAID is a valid option. I wouldn't want to stream my pr0n films^W^WiMovie projects from such a system, but for doing a nightly sync backup of the internal disk it's fine. I expect that for the/Users on developer, desktop publishing or some other systems it's a good-enough-and-cheap-enough option to be considered. Further, don't forget that FW800 can be bumped up to 3.2G/s just through firmware updates on the controller and the target devices - it was designed with that scalability in mind. I expect that FW3200 would be more than adequate for RAID hosting in many scenarios.:-)
External FireWire bunch-o'-disks + software RAID or FC connection to XServe RAID unit or PCI-X SCSI card + bunch-o'-disks = G5 RAID storage. And no need to heat up the insides of your G5.
But I thought that one pill makes you larger, one pill makes you small, and the ones that mother gives you don't do anything at all! Just ask the rabbit, when he's ten feet tall.
That's certainly true of the G3 iMac - you just pop the case open and unscrew the caddy. I actually wrote about that in my/. journal not so long ago, so take a look if you're interested. The G4 iMac, OTOH, is a completely different kettle of bricks. Opening that up to do anything other than remove the airport card is a bit of a task, and if you need to change the fan then you've got to empty all of the components out of the case, then put them all back in the right order (applying thermal paste as you go).
Linux is not a panacea, although it does everything I personally need and more, but it is being adopted in far too many places simply because it's ABM (Anything But Microsoft).
An interesting assertion. Although I think that a large factor in Linux's adoption is that it came about at The Right Time(TM); just as it was becoming a useful OS the.com bubble burst, and all the companies who had Solaris, IRIX, AIX etc. machines suddenly found themselves in need of an upgrade but without any money. How does one stay in UNIX without shelling out any capital? Enter the penguin.
The actual situation is likely to be a combination of my suggestion and yours, with a bit of something that neither of us have mentioned thrown in:-)
I was using the term in a sociological context, bub.
The name's grahamlee. I was using a word from the english language and taking it to mean that which is its accepted meaning. It's even written as such in the dictionaries.
BTW, since you're so well versed in engineering and it's terminology I'm sure you know that all computers built since the dawn of time (computing) to this day are said to use a "Von Neumann architecture"?
That's a load of rubbish; all computers since the dawn of time have certainly not been exclusively von Neumann computers (as distinct from von Neumann machines, of course). Note all of the computers that employ the Harvard architecture. And I doubt you can conveniently ignore those unless you never ever intend to use a DSP (ever). The Harvard architecture is named after the Harvard Mark I (a.k.a. IBM ASCC), and one of its programmers was a certain Grace Hopper. She went on to big things, you know.
Von Neumann was a mathematical genius, the father of the modern computational model and the original pioneer of game theory.
You mean Neumann János? [I'm not happy that a paid-for title should necessarily be honoured.] I wonder whether he was able to see the word 'nonzero' written down without trying to invent a new meaning for it....probably. Anyway, the achievements or otherwise of a Hungarian mathematician have little bearing on your version of the word nonzero's definition, which of course comes from the Old French / Latin prefix "non-" and the Arabic "çifr". Not that your definition isn't necessarily valid in some field, I'm sure it is. It's just that the previous (c. 1879) definition already has a lot of inertia everywhere else, because people know that that is what the word means.
Only if you restrict your definition of 'nonzero' to that in game theory, not that which is in wide use in engineering, physics and mathematics. And I wasn't discussing game theory at all. The more general meaning of the word 'nonzero' is "that which is not zero". Which is indeed what the etymology of the word would apply.
I think it's probably just fair to say that the number of Linux-scriptkiddie wannabies is as nonzero as the number of Windows-scriptkiddie wannabies, and that a trivial piece of code guaranteed to crash any Linux/x86 system is attractive to any number of scriptkiddies. They just chose to crash someone else's machine instead of their own - I went for trying it out on the latter and have since modified the kernel on that machine.
Note though that the phrase "lame free-shell provider" is not attributable to the author of TFASA, who does go on to say "this is illegal in most parts of the world and strongly discouraged". That phrase was probably passed on to them by some skiddie who wanted to go "hey look at me i am so l33t it's unbelievable i can like read gcc-bug and everything!!!11".
That truly is a mighty console collection, although it's clear that this auction probably has better retro value, and is more affordable. Tis pity it's bigger than my house...:-(.
Some of ID's development was contracted out to The Omni Group, who did their stuff on NeXTSTEP. You haven't lived until you've played Doom and Doom II on a 33MHz MC68040:-)
The G5 iMac-replacements had better be headless and Apple had better create a low-budget display alternative - if both of these are fulfilled then I'll place an order for 35 of the headless units ASAP. Unfortunately, I expect iSteve to be all for the "easy enough for my mother to use" route, and make the new Macs all-in-ones again - even though iMac sales are lagging atm.
Just that the server on which the off-site information is maintained has melted, in trying to serve the 60,000-ish requests per hour that slashdot generates.
I'll agree with that - I've been with NeXT->Rhapsody->OS X for a while now, and the G5 is the first workstation since the black slab with me want goodness included. Well, I briefly wanted an Ultra 5 but they became old hat quite quickly. I don't think the same will be true of any of the G5 systems:-)
Slashdot Mirror
You have when you get out of the potential well, which under the above situation you will eventually do. You will eventually reach a point where the upward velocity is greater than the local escape velocity, and it's bye-bye blue world. At no point have you had to attain a speed equal to the escape velocity at the surface, which is the claim you and TG are erroneously making.
A helicopter does nothing of the sort, and nowhere have I claimed explicitly or otherwise that it would. For a start, a helicopter is usually not in a single orbit. Of course, any motion could be described as a sum over many orbits. The helicopter has not escaped the potential well due to the Earth, so it has not escaped the Earth's gravity. The difference between the helicopter situation and that of a rocket is this: what happens when you switch the engine off? A helicopter goes smack back into the planet, a successfully launched rocket will carry on at some constant velocity away from the planet (or would do, if some git hadn't put the Sun there. In fact it starts orbiting that).
That is not necessary at all. The only situation in which your argument is even in appropriate scope is that not of a continually thrusting body such as a rocket, but that of a body that has gained momentum through an initial impulse. That is, a projectile. I'm afraid to say that Verne's "De la terre a la lune" is inaccurate in supposing that this is how astronauts are launched into space (though it is a riveting read). You are making the assumption that the body is essentially (resistive forces notwithstanding) moving in a single orbit from the beginning, and trying to derive the condition for which this orbit is unbounded. That isn't how we throw rockets into space.
We merely assume that atmospheric resistive forces may be neglected to arrive at an appropriate order-of-magnitude estimate for certain properties, because it simplifies the equation of motion. No-one's suggesting that the atmosphere needs to be removed ;-). You can calm back down now.
The truth has a tendency to be true, unlike your post. Let me just give my background for disclosure - I'm a rocket scientist.
No, you don't. If you were blasted off from the surface of the Earth at Mach 25 and the atmosphere didn't exist, then (to use the kind of lax definition of infinity that us physicists are proud of) you'd come to rest at infinity and wouldn't fall back into the Earth. However, if you provide a continual thrust that everywhere is greater than the local acceleration due to Earth's gravity, you will never fall back down. You could achieve this at a constant velocity of 1m/s if you liked, by suitable modification of the thrust.
To go forward in space, throw something backward. To go forward in the atmosphere, throw enough stuff backward to push enough air out of the way. It's easier in space - as you don't have to overcome resistive drag (unless the solar wind is non-negligible) then the same acceleration can be had for less driving force - the net force is the same yes. This means you can take it easy, and do something like throwing photons or ions out of the back of your spaceship.
As opinions go, it was just as valid as anyone else's. As statements of physical understanding go, it was superior to yours.
That's very very true. The difference between the NeXTstations and the TurboStations was amazing - same 25MHz to 33MHz speed bump. Of course, the difference between OpenStep on a 25MHz 68040 and on a Pentium 100 was even more impressive :-).
Granted, in this situation it's not the best solution but there are areas in which FWRAID is a valid option. I wouldn't want to stream my pr0n films^W^WiMovie projects from such a system, but for doing a nightly sync backup of the internal disk it's fine. I expect that for the /Users on developer, desktop publishing or some other systems it's a good-enough-and-cheap-enough option to be considered. Further, don't forget that FW800 can be bumped up to 3.2G/s just through firmware updates on the controller and the target devices - it was designed with that scalability in mind. I expect that FW3200 would be more than adequate for RAID hosting in many scenarios. :-)
I think not sir. I think they might have been influenced by the very chart that they ripped off.
External FireWire bunch-o'-disks + software RAID or FC connection to XServe RAID unit or PCI-X SCSI card + bunch-o'-disks = G5 RAID storage. And no need to heat up the insides of your G5.
That's not true. Slashdot posts UnixWare product information at no charge to SCO, to whit this very article.
If I did, they would collapse into a single state and be useless as quantum computers.
" The pills won't make your penis larger."
But I thought that one pill makes you larger, one pill makes you small, and the ones that mother gives you don't do anything at all! Just ask the rabbit, when he's ten feet tall.
That's certainly true of the G3 iMac - you just pop the case open and unscrew the caddy. I actually wrote about that in my /. journal not so long ago, so take a look if you're interested. The G4 iMac, OTOH, is a completely different kettle of bricks. Opening that up to do anything other than remove the airport card is a bit of a task, and if you need to change the fan then you've got to empty all of the components out of the case, then put them all back in the right order (applying thermal paste as you go).
An interesting assertion. Although I think that a large factor in Linux's adoption is that it came about at The Right Time(TM); just as it was becoming a useful OS the .com bubble burst, and all the companies who had Solaris, IRIX, AIX etc. machines suddenly found themselves in need of an upgrade but without any money. How does one stay in UNIX without shelling out any capital? Enter the penguin.
The actual situation is likely to be a combination of my suggestion and yours, with a bit of something that neither of us have mentioned thrown in :-)
The name's grahamlee. I was using a word from the english language and taking it to mean that which is its accepted meaning. It's even written as such in the dictionaries.
That's a load of rubbish; all computers since the dawn of time have certainly not been exclusively von Neumann computers (as distinct from von Neumann machines, of course). Note all of the computers that employ the Harvard architecture. And I doubt you can conveniently ignore those unless you never ever intend to use a DSP (ever). The Harvard architecture is named after the Harvard Mark I (a.k.a. IBM ASCC), and one of its programmers was a certain Grace Hopper. She went on to big things, you know.
You mean Neumann János? [I'm not happy that a paid-for title should necessarily be honoured.] I wonder whether he was able to see the word 'nonzero' written down without trying to invent a new meaning for it....probably. Anyway, the achievements or otherwise of a Hungarian mathematician have little bearing on your version of the word nonzero's definition, which of course comes from the Old French / Latin prefix "non-" and the Arabic "çifr". Not that your definition isn't necessarily valid in some field, I'm sure it is. It's just that the previous (c. 1879) definition already has a lot of inertia everywhere else, because people know that that is what the word means.
Only if you restrict your definition of 'nonzero' to that in game theory, not that which is in wide use in engineering, physics and mathematics. And I wasn't discussing game theory at all. The more general meaning of the word 'nonzero' is "that which is not zero". Which is indeed what the etymology of the word would apply.
I think it's probably just fair to say that the number of Linux-scriptkiddie wannabies is as nonzero as the number of Windows-scriptkiddie wannabies, and that a trivial piece of code guaranteed to crash any Linux/x86 system is attractive to any number of scriptkiddies. They just chose to crash someone else's machine instead of their own - I went for trying it out on the latter and have since modified the kernel on that machine. Note though that the phrase "lame free-shell provider" is not attributable to the author of TFASA, who does go on to say "this is illegal in most parts of the world and strongly discouraged". That phrase was probably passed on to them by some skiddie who wanted to go "hey look at me i am so l33t it's unbelievable i can like read gcc-bug and everything!!!11".
Haha. Nice try, but it's not my auction to sell and The Tube probably isn't the sort of interface you want to be creating Beowulfs on.
Yeah, and that's my neighbour :-). Looks like I might get to play with this stuff after all...
That truly is a mighty console collection, although it's clear that this auction probably has better retro value, and is more affordable. Tis pity it's bigger than my house... :-(.
Merde, more like.
Yeah, that's the same game although the original was a little more, well, crap. :-)
Some of ID's development was contracted out to The Omni Group, who did their stuff on NeXTSTEP. You haven't lived until you've played Doom and Doom II on a 33MHz MC68040 :-)
What about Donkey on the original IBM PC, which was distributed as source? That was written by Gates, in part and was MS software.
Or there's this.
The G5 iMac-replacements had better be headless and Apple had better create a low-budget display alternative - if both of these are fulfilled then I'll place an order for 35 of the headless units ASAP. Unfortunately, I expect iSteve to be all for the "easy enough for my mother to use" route, and make the new Macs all-in-ones again - even though iMac sales are lagging atm.
Just that the server on which the off-site information is maintained has melted, in trying to serve the 60,000-ish requests per hour that slashdot generates.
I meant for the "me want" to be in quotes, and indeed used the HTML quot; symbol. It didn't show up.
I'll agree with that - I've been with NeXT->Rhapsody->OS X for a while now, and the G5 is the first workstation since the black slab with me want goodness included. Well, I briefly wanted an Ultra 5 but they became old hat quite quickly. I don't think the same will be true of any of the G5 systems :-)