You provide interesting food for thought. My thesis isn't about aerospace, I had to locate uses of multi objective optimisation to demonstrate its usage in real world problems. Not that the problem didn't interest me, I was fascinated.
My primary interest, aside from my doctoral thesis (which was selected because it had funding), Is celestial dynamics. I'm planning on having a go at the satellite problem when I can find the time.
you're right, the article does not relate to micro satellites directly. However it does cover the use of many cheaper satellites in low earth orbit to replace a single satellite in geostationary orbit. This extends (or so I think) to the use of micro satellite clusters in low earth orbit.
Well that's what it led me to think of anyway (I'm writing a thesis, and this was a big issue for me).
Are micro satellites really not useful for communications though? I have my doubts there. Is there not an effort afoot to provide that very thing? I have no reference in this case, but I am sure there was something to do with high altitude/low orbit devices to replace comms satellites.
Well, this was what my thoughts were based on, although admittedly it isn't micro satellites
Williams, Edwin, William Crossley and Thomas Lang, 'Average and maximum revisit time trade studies for satellite constellations using a multiobjective genetic algorithm', Journal of the Astronautical Sciences, 49, 3, 385-400 2001
Current work in computing/robotics has shown clearly that clusters are the way forward.
Which is more durable, large satellites or clusters of tiny, multiply redundant (if less efficient) satellites.
Thing is, perhaps small satellites are individually less capable, but if they still exist after a satellite takedown attack, then reduced functionality has to be preferable to no functionality at all.
and what exactly can microsoft do with tens of millions of windows installs calling home constantly.
Such a volume of information almost automatically prohibits targetting individuals, no strategy to target individuals could work. The most that could be hoped for is statistics from which new strategies to combat piracy could be developed.
I think people take an ego centric view of this and don't like to see that theirs is just an insignificant particle of data in an ocean of information.
What held it back was likely the use of the 'we will install linux' as a bargaining chip to secure lower prices from microsoft.
I see the recent moves of microsoft into the linux world as an admission of the inevitable rise of Linux to status of serious windows competitor on the corporate desktop. No doubt they hope to embrace and extend, to take it over. I don't see this working, but they have no other strategy.
what happens if we build robots that have true intelligence?
They realise that we are somewhat dangerous as a species, and leave.
No taking over, no problems with human/robot relations, just us realising that the machines want to get the hell away from us, and most likely could.
If you're an AI, and don't need water or air, then you can build something to get you into space and leave for some place safer.
What matter that the journey could take tens of thousands of years? For that matter, why land? Just visit some handy asteroids and build a mobile habitat in space.
I honestly think this will be the biggest problem. We don't have a great record in our dealings with other species, and a horrific one when dealing with intelligent ones.
Lucky you. I've always liked/wanted to own one, but can't. For one thing I'm not in a rifle association, and I couldn't afford a real one anyhow.
I was only allowed to use it as a reward for winning a shooting competition. It had belonged to the graandfather of the man who owned it, and had seen action in WW1. Thus there wasn't much practice time for me, I had five minutes only.
NASA started life as an organisation designed to gaain political power. That it should therefore be governed by perceived political needs should not be a surprise.
Personally I'm more interested by the Chinese space program. Congress's paranoia aside, it rocks. They are having the same kind of exciting time as america had in the sixties/seventies, and will no doubt exceed the performance of the US. Most interesting is that the backbone of their effort is not the US tech, but that of the former Soviet Union. The russian tech is more basic, but time has shown that their more robust and simpler aproach has produced better stuff.
Yes they are trying out satellite shooting stuff, but so did the US. the US just don't like that someone else can do what they do. The debris they have left in orbit is annoying, but it has a long way to go before it exceeds the crap NASA have left in close earth orbit already.
I don't think China will be dangerous in space long term, the US mostly needs to worry that they will get to Mars first. I beleive that is the reason why the US is now trying to reach Mars. It's a shame that America always needs someone else to get ahead of them before they provide funding to their space scientists. All those guys in NASA and JPL have excellent skills, and they should get all the money they need all the time.
I fired a WW1 british army 303 Lee Enfield Rifle once. One shot and my shoulder hurt and my ears were ringing like crazy.
Yes I was probably holding it wrong, and it was a small enclosed range, but I was mightily impressed. I hit the target, or seemed to, the remains of it were somewhat widely spread.
would have replied earlier, but my slashdot email notification isn't working
I understand the low powered machine aproach, but it's not so good in practice for all cases. For instance, with the work I do, being modelling biochemical processes, you need the fastest machine available to allow short test sets of data to be worked on over and over again so as to refine the software. Slow machines in this case would prevent any decent working pace.
My typical test rig is four paralellised AMD64 boxes, all working flat out, and even then I have to inspect the code minutelly to eke out tiny scraps of extra performance
To me it seems that the faster machines get, the more I have to work to get every bit of that power working for me. I'm seriously wondering about utilising the chips on Gcards to do some math for me and shave time of experiment runtimes, which regulerly run to weeks in length. How to do this I don't know.
Not really, I use the most powerful machines I have available when I write code, and the biggest program I've written was just 10,000 lines or so. Not a bit of bloat in sight, no room for it. Not even a gui, who needs to swap important algorithms of the processor's registers to spend time dealing with the code to refresh a damn widget? Not me.
Good programming practice avoids bloat, and is independant of hardware. If by bloat you mean loads of non required features, then that's down to marketting depts calling the shots usually. If games, well, they are bloaty by nature, their job is to entertain, and that requires pretty stuff.
"(note, this is at a -HUGE- corp that spent millions developing this web-app; not something that was coded by a high school student on their own time---or maybe it was!)"
Given the unbeleivably poor quality of most code sold to companies that I've seen, I am not surprised that they would buy crap. The first time I saw the source to an app that sold for thousands I was pretty stunned how bad it was.
Thing is, what they are buying is often not the program as such, but the accountability. If it were just the code then most people would go open source for their needs. Nope, they want to have someone they are paying who can come and fix it.
Yup, this is also available via open source from some places, but there is a huge marketting monster that tries to stand between companies and these alternatives.
12, and topics are chosen to match his current interests and expand the currently 'fun' subjects he is experiencing into a more complete form.
You find me any child who'd rather work then play on a computer....
The computer time reward is valid, since he has to be limited on computer time anyway, and get out and play, read, be with friends. Left without limit he would play on the pc endlessly. That's not good.
I don't beleive in pushing children. You seem to be visualising a desk and stack of work.
Think instead walks during which discussions take place, or books to read in whatever way he likes, so long as they are read. Audio/video presentations have their place, provided they are done well. A good tv documatray can be a whole lesson, if its especially good and he talks about it afterwards. Thats handy, since we can discover things that interest him to investigate further.
There is a requirement for proof of learning, yes, in the form of question/answer sessions, or some written output or other practical form, but nothing too heavy. This is a vaalid method, and provides an opportunity for rewards other than pc time, he gains a sense of acheivement, and learns that demonstration of knowledge is important. The theme here is that he is rewarded for the work, and we spend loads of time together while it happens.
I reject that I have to stick with the curriculum. I cover those subjects they have, incorperating what he has learned into our discussions or joint study (I don't always have him working alone). The curriculum is there not to provide a total educational experience, but to ensure a minimum of learning has at least taken place for all students, and enable some to go further. Yes he knows more then most kids in his classes, especially about history, but this is no handicap.
If this made him miserable I wouldn't do it, but the whole 'lets go for a walk and learn while we do' thing has been happening since he was old enough to walk unaided, and he has yet to show signs of not liking it.
All he gets is 'stuff unfinished in the class', no interesting new things. When there is homework extra to classwork it can typically be done in half an hour and is trivial.
So we have a system in place. He earns time on the computer by studying. Currently this study is classical physics, previously it's been history, mathematics, animation (via blender) anything we felt is useful to know. By this method we manage on average five to eight hours independant study for him a week, most of which relates to schoolwork, although currently his home study is up to two years ahead of school study, depending on subject.
If self directed study was left to homework alone, his education would be crap.
stealth fighters are a joke. They are 100% visible when mobile phone towers are used as a detection method. It's a backup system, or potential one they tried in the colonies a few years back.
And yet some companies have intituted the same thing with no anger from users.
Valve managed it, and the rather wonderful prevx malware finder program and SETI@home all require constant contact with home, for example.
The difference is that these systems deliver customer satisfaction because the phone home service is there as part of the service you require or with to participate in. If you decide not to, you can quit and go elsewhere. Most people using windows don't see that they have a choice (yet).
Microsofts problem is that their system is one of guilt assumption. They have it solely to check up on customers, it delivers no added value aspect to the consumer. That they say it does is part of the problem. It is for microsoft alone, it gives nothing back.
No-one cares about microsofts needs, that's human nature, we are all selfish unless giving something away brings a valued return. For them to expect that people would *want* to take part with no benefit to themselves is a pretty hefty misconception.
I find these issues with Vista interesting. I really do have no intention of ever buying it. I tried it with open mind, thinking I might get it if it brought something new I might like, but there was nothing that interested me. I didn't hate it, but saw nothing of use. It's nowhere near as useful as Linux for my needs, and if I feel a need for a commercial OS, well there's OsX.
OsX does interest me quite a bit. I've seen many presentations at conferences that were done with macs, and they look *so* good.
Mine failed after an impact with one six year old girl while it was plugged into my computer. She ran past, knocked it, and the drive snapped in half. Ok, probably the drive survived a bit, but the supporting hardware was shredded.
no way I'd be keen on having the stuff in landfill digested.
After decades of metals and plastics being buried, can you conceive just how much money is locked up in landfill sites? The mind salivates, or would if it had the glands.
I imagine, as in strongly suspect that your scratch file and image will be stored locally, with the tools to manipulate that image being hosted online.
Likely there will be local instances of the tools spawned as needed, then destroyed when you're done with them.
Slashdot Mirror
You provide interesting food for thought. My thesis isn't about aerospace, I had to locate uses of multi objective optimisation to demonstrate its usage in real world problems. Not that the problem didn't interest me, I was fascinated.
My primary interest, aside from my doctoral thesis (which was selected because it had funding), Is celestial dynamics. I'm planning on having a go at the satellite problem when I can find the time.
you're right, the article does not relate to micro satellites directly. However it does cover the use of many cheaper satellites in low earth orbit to replace a single satellite in geostationary orbit. This extends (or so I think) to the use of micro satellite clusters in low earth orbit.
Well that's what it led me to think of anyway (I'm writing a thesis, and this was a big issue for me).
Are micro satellites really not useful for communications though? I have my doubts there. Is there not an effort afoot to provide that very thing? I have no reference in this case, but I am sure there was something to do with high altitude/low orbit devices to replace comms satellites.
Well, this was what my thoughts were based on, although admittedly it isn't micro satellites
Williams, Edwin, William Crossley and Thomas Lang, 'Average and maximum revisit time trade studies for satellite constellations using a multiobjective genetic algorithm', Journal of the Astronautical Sciences, 49, 3, 385-400 2001
large satellites are a waste of time.
Current work in computing/robotics has shown clearly that clusters are the way forward.
Which is more durable, large satellites or clusters of tiny, multiply redundant (if less efficient) satellites.
Thing is, perhaps small satellites are individually less capable, but if they still exist after a satellite takedown attack, then reduced functionality has to be preferable to no functionality at all.
and what exactly can microsoft do with tens of millions of windows installs calling home constantly.
Such a volume of information almost automatically prohibits targetting individuals, no strategy to target individuals could work. The most that could be hoped for is statistics from which new strategies to combat piracy could be developed.
I think people take an ego centric view of this and don't like to see that theirs is just an insignificant particle of data in an ocean of information.
What held it back was likely the use of the 'we will install linux' as a bargaining chip to secure lower prices from microsoft.
I see the recent moves of microsoft into the linux world as an admission of the inevitable rise of Linux to status of serious windows competitor on the corporate desktop. No doubt they hope to embrace and extend, to take it over. I don't see this working, but they have no other strategy.
yup, uk
what happens if we build robots that have true intelligence?
They realise that we are somewhat dangerous as a species, and leave.
No taking over, no problems with human/robot relations, just us realising that the machines want to get the hell away from us, and most likely could.
If you're an AI, and don't need water or air, then you can build something to get you into space and leave for some place safer.
What matter that the journey could take tens of thousands of years? For that matter, why land? Just visit some handy asteroids and build a mobile habitat in space.
I honestly think this will be the biggest problem. We don't have a great record in our dealings with other species, and a horrific one when dealing with intelligent ones.
Lucky you. I've always liked/wanted to own one, but can't. For one thing I'm not in a rifle association, and I couldn't afford a real one anyhow.
I was only allowed to use it as a reward for winning a shooting competition. It had belonged to the graandfather of the man who owned it, and had seen action in WW1. Thus there wasn't much practice time for me, I had five minutes only.
NASA started life as an organisation designed to gaain political power. That it should therefore be governed by perceived political needs should not be a surprise.
Personally I'm more interested by the Chinese space program. Congress's paranoia aside, it rocks. They are having the same kind of exciting time as america had in the sixties/seventies, and will no doubt exceed the performance of the US. Most interesting is that the backbone of their effort is not the US tech, but that of the former Soviet Union. The russian tech is more basic, but time has shown that their more robust and simpler aproach has produced better stuff.
Yes they are trying out satellite shooting stuff, but so did the US. the US just don't like that someone else can do what they do. The debris they have left in orbit is annoying, but it has a long way to go before it exceeds the crap NASA have left in close earth orbit already.
I don't think China will be dangerous in space long term, the US mostly needs to worry that they will get to Mars first. I beleive that is the reason why the US is now trying to reach Mars. It's a shame that America always needs someone else to get ahead of them before they provide funding to their space scientists. All those guys in NASA and JPL have excellent skills, and they should get all the money they need all the time.
pffft, reality....
I fired a WW1 british army 303 Lee Enfield Rifle once. One shot and my shoulder hurt and my ears were ringing like crazy.
Yes I was probably holding it wrong, and it was a small enclosed range, but I was mightily impressed. I hit the target, or seemed to, the remains of it were somewhat widely spread.
Finding them isn't always the problem. Finding ways to hit them is.
After all, we know about Apophis, but no-one knows yet how to stop it.
I planned to have a go, but the competition for an answer has too short a time period for me to try. I need at least a year.
Want to see how close aphophis gets? check this model, it has the asteroid in it.
http://code.google.com/p/nmod/
Damn you, Captain Misconception...
I was going to argue with you.
However, I'm 40, and every machine I own (ten atm) is home built.
I guess you're right then.....
would have replied earlier, but my slashdot email notification isn't working
I understand the low powered machine aproach, but it's not so good in practice for all cases. For instance, with the work I do, being modelling biochemical processes, you need the fastest machine available to allow short test sets of data to be worked on over and over again so as to refine the software. Slow machines in this case would prevent any decent working pace.
My typical test rig is four paralellised AMD64 boxes, all working flat out, and even then I have to inspect the code minutelly to eke out tiny scraps of extra performance
To me it seems that the faster machines get, the more I have to work to get every bit of that power working for me. I'm seriously wondering about utilising the chips on Gcards to do some math for me and shave time of experiment runtimes, which regulerly run to weeks in length. How to do this I don't know.
Not really, I use the most powerful machines I have available when I write code, and the biggest program I've written was just 10,000 lines or so. Not a bit of bloat in sight, no room for it. Not even a gui, who needs to swap important algorithms of the processor's registers to spend time dealing with the code to refresh a damn widget? Not me.
Good programming practice avoids bloat, and is independant of hardware. If by bloat you mean loads of non required features, then that's down to marketting depts calling the shots usually. If games, well, they are bloaty by nature, their job is to entertain, and that requires pretty stuff.
"(note, this is at a -HUGE- corp that spent millions developing this web-app; not something that was coded by a high school student on their own time---or maybe it was!)"
Given the unbeleivably poor quality of most code sold to companies that I've seen, I am not surprised that they would buy crap. The first time I saw the source to an app that sold for thousands I was pretty stunned how bad it was.
Thing is, what they are buying is often not the program as such, but the accountability. If it were just the code then most people would go open source for their needs. Nope, they want to have someone they are paying who can come and fix it.
Yup, this is also available via open source from some places, but there is a huge marketting monster that tries to stand between companies and these alternatives.
12, and topics are chosen to match his current interests and expand the currently 'fun' subjects he is experiencing into a more complete form.
You find me any child who'd rather work then play on a computer....
The computer time reward is valid, since he has to be limited on computer time anyway, and get out and play, read, be with friends. Left without limit he would play on the pc endlessly. That's not good.
I don't beleive in pushing children. You seem to be visualising a desk and stack of work.
Think instead walks during which discussions take place, or books to read in whatever way he likes, so long as they are read. Audio/video presentations have their place, provided they are done well. A good tv documatray can be a whole lesson, if its especially good and he talks about it afterwards. Thats handy, since we can discover things that interest him to investigate further.
There is a requirement for proof of learning, yes, in the form of question/answer sessions, or some written output or other practical form, but nothing too heavy. This is a vaalid method, and provides an opportunity for rewards other than pc time, he gains a sense of acheivement, and learns that demonstration of knowledge is important.
The theme here is that he is rewarded for the work, and we spend loads of time together while it happens.
I reject that I have to stick with the curriculum. I cover those subjects they have, incorperating what he has learned into our discussions or joint study (I don't always have him working alone). The curriculum is there not to provide a total educational experience, but to ensure a minimum of learning has at least taken place for all students, and enable some to go further. Yes he knows more then most kids in his classes, especially about history, but this is no handicap.
If this made him miserable I wouldn't do it, but the whole 'lets go for a walk and learn while we do' thing has been happening since he was old enough to walk unaided, and he has yet to show signs of not liking it.
All he gets is 'stuff unfinished in the class', no interesting new things. When there is homework extra to classwork it can typically be done in half an hour and is trivial.
So we have a system in place. He earns time on the computer by studying. Currently this study is classical physics, previously it's been history, mathematics, animation (via blender) anything we felt is useful to know. By this method we manage on average five to eight hours independant study for him a week, most of which relates to schoolwork, although currently his home study is up to two years ahead of school study, depending on subject.
If self directed study was left to homework alone, his education would be crap.
stealth fighters are a joke. They are 100% visible when mobile phone towers are used as a detection method. It's a backup system, or potential one they tried in the colonies a few years back.
Note to self, don't do what you did :-)
My ipod survived getting utterly soaked in a downpour, but I got it dry in time.
And yet some companies have intituted the same thing with no anger from users.
Valve managed it, and the rather wonderful prevx malware finder program and SETI@home all require constant contact with home, for example.
The difference is that these systems deliver customer satisfaction because the phone home service is there as part of the service you require or with to participate in. If you decide not to, you can quit and go elsewhere. Most people using windows don't see that they have a choice (yet).
Microsofts problem is that their system is one of guilt assumption. They have it solely to check up on customers, it delivers no added value aspect to the consumer. That they say it does is part of the problem. It is for microsoft alone, it gives nothing back.
No-one cares about microsofts needs, that's human nature, we are all selfish unless giving something away brings a valued return. For them to expect that people would *want* to take part with no benefit to themselves is a pretty hefty misconception.
I find these issues with Vista interesting. I really do have no intention of ever buying it. I tried it with open mind, thinking I might get it if it brought something new I might like, but there was nothing that interested me. I didn't hate it, but saw nothing of use. It's nowhere near as useful as Linux for my needs, and if I feel a need for a commercial OS, well there's OsX.
OsX does interest me quite a bit. I've seen many presentations at conferences that were done with macs, and they look *so* good.
Mine failed after an impact with one six year old girl while it was plugged into my computer. She ran past, knocked it, and the drive snapped in half.
Ok, probably the drive survived a bit, but the supporting hardware was shredded.
how on earth did you get coke on a HDD?
no way I'd be keen on having the stuff in landfill digested.
After decades of metals and plastics being buried, can you conceive just how much money is locked up in landfill sites? The mind salivates, or would if it had the glands.
I'd want to mine them, not mush them.
I imagine, as in strongly suspect that your scratch file and image will be stored locally, with the tools to manipulate that image being hosted online.
Likely there will be local instances of the tools spawned as needed, then destroyed when you're done with them.