The biggest problems are (1) fuel for the outbound and return trip (2) how to land the craft that has humans in it and (3) how to get off the planet again. Mars' atmosphere is too thin for parachutes, and the gravity is too heavy to use conventional chemical thrusters to brake the landing all the way down (which isn't possible anyways due to the mass of the fuel you would have to haul all the way from Earth with those "cryogenic" thrusters).
1) Multiple launches to orbit with fuel. Yes, you have boiloff on the way there, while parked in Martian orbit, and on the return trip. However you have to remember the darkness of space has a temperature of several degrees Kelvin, so if you can shield from the sun, earth and Mars you are in pretty good shape to minimize boiloff.
2) You can use parachutes. The martian atmosphere does exist, its ~1% of earth atmosphere. So you need a bigger parachute along with rocket augmentation. Think of a lunar lander with parachutes. Lunar gravity is 1/6 earth gravity, and Martian gravity is aproximately 1/3. So it's only two times as bad as the moon. Rocket powered descent is feasible, and augmented with a parachute it can be made even more feasible.
3) Again, think of the lunar lander. Theres no reason why you can't have a two or three staged vehicle, use the first one on descent and launch off the second/third stage. Again, 1/3 g makes the problem a lot easier. The rocket equation scales with g.
It's not just engineering, there are basic scientific barriers.
Multiple launches gets you as much mass as you want to LEO. Landing and launching from mars is **Easier** than launching and landing from the earth. Mars, while not trivial, is completely possible. We could have done it with the Saturn V if we really wanted to, a beefier LEM and a spacelab-type module with a rocket stage slapped on it for the trip there and back. Descend on the LEM, explore, ascend, dock and come home. Would take multiple launches, but completely feasible, according to Zubrin (Note: I'm a huge Zubrin skeptic, but he has a few useful data points).
The point is that even putting a tiny computer in lead is amazingly expensive, propellant-wise, due to the additional dead mass you need to loft to orbit (IIRC, to stop the heavy particles, you are talking **feet** of lead, not inches). So it is wiser to go with older, "rad-hardened" hardware that doesn't require shielding whatsoever. It doesn't really matter, the computational requirements for orbital corrections and system observation are pretty low, so it really doesn't matter - in 2004 the Shuttle cockpit was 'upgraded' to 386's.
Maybe even for checking that the in-house keyboard and drivers didn't infringe on Lancor's IP?
That's why they have these nifty things called patents. They lay out a company's claims. If you can read through the patent and determine that you don't infringe (having a lawyer at this step might help), then you are home free. There is no need to purchase the product in question. In fact its nothing but trouble as this debacle will now show.
All I'm saying is that time line does look very suspicious.
LANCOR's lawsuit alleges that OLPC purchased two KONYIN Multilingual Keyboard models (KONYIN Nigeria Multilingual Keyboard and KONYIN United States Multilingual Keyboard) with the express purpose of illegally reverse engineering the source codes for use in OLPC's XO Laptops.
The real problem here is the way Firefox handles the plugins. Or rather does not.
IE uses a plugin interface to deal with QuickTime. As such, it has a standard framework which does some bounds checking and can find buffer overflows like this one and kill a plugin (or iexplore.exe if necessary) preventing damage.
Firefox just passes parameters on to an external program.
Pick your poison, you can probably make justifications for either, but to me the IE method makes more sense. It's embedded content, it should be handled as a plugin to the parent application. You are a programmer, I'm sure you are familiar with the concepts of parents and children:). I'm a programmer too... I have to sanitize my inputs and sanitize my outputs. When I call functions that aren't mine I have to make sure that they are doing what they should be doing, not wreaking havoc on my computer, and in a sense that's exactly what this comes down to, taking responsibility for a child process.
It isn't a firefox problem, but then again, it isn't an IE problem because Internet Explorer has some buffer overflow protection which prevents further execution.
Glass half empty, half full type thing. Of course, Quicktime is causing the problem, but would you rather have a browser that arbitrarily trusts the plugin, or does some bounds checking?
The reason scientific computing requires such huge amounts of processing power is that scientists are writing the code.
I'll grant you that, to a point. I'm a Mechanical/aerospace engineer, I've only had 1 formal course in C++ although I've been programming C++ since I was 12, and BASIC for years before that. I don't consider myself a computer scientist by any means. However, you need to look at the problems we are solving. Regardless of how elegant your code is, you will be pegging a processor for days or even weeks at a time. When you are trying to solve a CFD grid for heat transfer coefficients on something like a missile or Ares, you are going to have multi-million node meshes, integrating several differential equations at each node. Optimize away, your bottleneck is still going to be the processor.
Believe it or not engineers **do** integrate with CS types every now and then... a good friend of mine went to school as a CS, and up to a few months ago before I switched companies, he worked across the hall from me, taking engineer's algorithms and implementing it in code.
As someone who does scientific computing, I say bunk! My primary bottleneck is still the processor. FTA:
Too much R&D time and money goes into processor speed when other issues remain under-addressed. For example, could data not be handled a bit better? What about smarter ways of tagging data? The semantic web initiative runs along these sorts of lines, so where is the hardware-based equivalent?
Sure, tagging and controlling data is important, but far from difficult, and with well-written programs a good suite of visualization tools is relatively easy. Give me some speed, dammit! Why should I have to wait for my slot on the cluster when I could have the power right here under my desk?
It isn't a brain backup device, it's a little recorder that you wear around your neck. It takes snapshots throughout the day and records sound. The software on the computer also allows for archival of various documents, etc. Stuff gets associated and it essentially becomes a surrogate memory.
A good, extensive writeup can be found in Fast Company. The original article is over half a year old and this idea from Gordon Bell has been known for years: he started working on this project in 1995.
Bunch of drama queens on slashdot talking about "omgz vaporware" "Microsoft doign what neuroscience cant? omgz" Read the goddamned article, not the FUD summary.
Back where I used to work they had a diskless computer cluster similar to this. A master node held the disk image, and when each computer booted up it would request the disk image from the master node and put it on a RAM disk. No hard drive, floppy or CD-ROM drive on the cluster. Once they booted up they got their image with their tasks, started running the tasks, etc.
If any node was having problems, all they had to do was flip a switch. If it came back up, great, if not pull it offline and see what failed.
Hopefully the facility you're in has proper emergency ventilation measures, adequate room size, properly constructed doors, and protective equipment to avoid this scenario, but you still don't want to be in the room if it happens if you can help it... Cryogenic gasses are seriously dangerous. Don't underestimate them or treat them lightly.
I'm an Aerospace Engineer. I'm fairly familiar with the properties of cryogenic oxygen:)
The first thing you do, is you NEVER store a LOX dewar inside an enclosed area. You store it outside. When it vents, it vents into the atmosphere. You have a mixer outside which expands and mixes the LOX with the NOX. OUTSIDE. With proper feedback the appropriate breathing ratio can be attained. It's insulated so you don't lose that nice cool chill. Only when the mix is appropriate do you vent it into your server room. Otherwise, dump it outside... it's nitrogen and oxygen, the primary constituents of the atmosphere.
LOX is dirt cheap. Pennies a pound by the tanker. There are many people who have small dewars at home that they own for medical purposes (migraines, cluster headaches, lung issues, etc.). There are even guys I know who make liquid rocket engines as a hobby, and have LOX dewars in their backyard. The handling of it is well known, to the point where oxygen is becoming a viable commercial industry (some have called it the next bottled water). With proper handling there is no reason to be intimidated.
$20k/year doesn't even buy rent and health insurance. For one person. Let alone someone trying to support a family.
Bullshit. I was in college with my new wife of a year and a half and our first son. I was working part time under $10 an hour and my wife stayed at home with our son - this was important to us. Guess what? We made it just fine, without credit card debt, and I was purchasing health insurance and long-term life insurance out of my own pocket. It's amazing to me how many people think they need $40k+ a year to 'scrape by'. We were doing it on a quarter of that.
No big screen TV's, no Wii's XBOX's, or PlayStations, we didn't go out to eat every dinner, we only had one car, a one-bedroom apartment in a decent enough part of town but we got by just fine. Instead, we learned to enjoy each other's company, enjoy the great outdoors, and cook good food from raw ingredients. If you learn to manage your resources, $7.50 an hour is workable for a young family of three. Not easy but a great and valuable experience.
That bit about not being able to take it down for repair, well, that's going to make it into some future book on industrial design.
Pray tell, short of covering the solar array from view of the sun, how do you stop solar cells from generating electricity? It is a passive electricity generating device, not an active one (like a fuel cell or a conventional gas-powered generator). As long as it has a sufficient view factor of a light source, it generates electricity.
has there ever been an occasion where it was accused of doing something anti-competitive and turned out to be innocent?
Yes!
Look up at the first thread, where it was claimed that they were paying off Paramount to drop Blue-Ray. It was actually a false rumor by a Blue-Ray fanboy. link.
I bought a top of the line processor and quadrupled my RAM the beginning of last year - not for video gaming (although it sure didn't hurt, I play occasionally not very hardcore anymore) but to do scientific computing for my thesis. I did a 6DOF model of a guided bullet, with this spiffy guidance model. 500 monte carlo runs took about 2 hours. I needed to do a ton of sets. All in all, my entire master's dissertation worth of sets took about a month worth of running 16 hours a day on a dual-core machine. And of course I had to do a lot of pre-emptive runs to determine the domain of my problem, etc.
I still do a lot of scientific computing at home - 6DOF's, playing with CFD, etc. There are plenty of 'hobbyists' out there who can keep a CPU pegged more often than its not...
Slashdot Mirror
The biggest problems are (1) fuel for the outbound and return trip (2) how to land the craft that has humans in it and (3) how to get off the planet again. Mars' atmosphere is too thin for parachutes, and the gravity is too heavy to use conventional chemical thrusters to brake the landing all the way down (which isn't possible anyways due to the mass of the fuel you would have to haul all the way from Earth with those "cryogenic" thrusters).
1) Multiple launches to orbit with fuel. Yes, you have boiloff on the way there, while parked in Martian orbit, and on the return trip. However you have to remember the darkness of space has a temperature of several degrees Kelvin, so if you can shield from the sun, earth and Mars you are in pretty good shape to minimize boiloff.
2) You can use parachutes. The martian atmosphere does exist, its ~1% of earth atmosphere. So you need a bigger parachute along with rocket augmentation. Think of a lunar lander with parachutes. Lunar gravity is 1/6 earth gravity, and Martian gravity is aproximately 1/3. So it's only two times as bad as the moon. Rocket powered descent is feasible, and augmented with a parachute it can be made even more feasible.
3) Again, think of the lunar lander. Theres no reason why you can't have a two or three staged vehicle, use the first one on descent and launch off the second/third stage. Again, 1/3 g makes the problem a lot easier. The rocket equation scales with g.
It's not just engineering, there are basic scientific barriers.
Multiple launches gets you as much mass as you want to LEO. Landing and launching from mars is **Easier** than launching and landing from the earth. Mars, while not trivial, is completely possible. We could have done it with the Saturn V if we really wanted to, a beefier LEM and a spacelab-type module with a rocket stage slapped on it for the trip there and back. Descend on the LEM, explore, ascend, dock and come home. Would take multiple launches, but completely feasible, according to Zubrin (Note: I'm a huge Zubrin skeptic, but he has a few useful data points).
The point is that even putting a tiny computer in lead is amazingly expensive, propellant-wise, due to the additional dead mass you need to loft to orbit (IIRC, to stop the heavy particles, you are talking **feet** of lead, not inches). So it is wiser to go with older, "rad-hardened" hardware that doesn't require shielding whatsoever. It doesn't really matter, the computational requirements for orbital corrections and system observation are pretty low, so it really doesn't matter - in 2004 the Shuttle cockpit was 'upgraded' to 386's.
Maybe even for checking that the in-house keyboard and drivers didn't infringe on Lancor's IP?
That's why they have these nifty things called patents. They lay out a company's claims. If you can read through the patent and determine that you don't infringe (having a lawyer at this step might help), then you are home free. There is no need to purchase the product in question. In fact its nothing but trouble as this debacle will now show.
All I'm saying is that time line does look very suspicious.
when you purchase your competitor's product
fta:
LANCOR's lawsuit alleges that OLPC purchased two KONYIN Multilingual Keyboard models (KONYIN Nigeria Multilingual Keyboard and KONYIN United States Multilingual Keyboard) with the express purpose of illegally reverse engineering the source codes for use in OLPC's XO Laptops.
The real problem here is the way Firefox handles the plugins. Or rather does not.
:). I'm a programmer too ... I have to sanitize my inputs and sanitize my outputs. When I call functions that aren't mine I have to make sure that they are doing what they should be doing, not wreaking havoc on my computer, and in a sense that's exactly what this comes down to, taking responsibility for a child process.
IE uses a plugin interface to deal with QuickTime. As such, it has a standard framework which does some bounds checking and can find buffer overflows like this one and kill a plugin (or iexplore.exe if necessary) preventing damage.
Firefox just passes parameters on to an external program.
Pick your poison, you can probably make justifications for either, but to me the IE method makes more sense. It's embedded content, it should be handled as a plugin to the parent application. You are a programmer, I'm sure you are familiar with the concepts of parents and children
YOU FAIL! NO SOUP FOR YOU!
It isn't a firefox problem, but then again, it isn't an IE problem because Internet Explorer has some buffer overflow protection which prevents further execution.
Glass half empty, half full type thing. Of course, Quicktime is causing the problem, but would you rather have a browser that arbitrarily trusts the plugin, or does some bounds checking?
The reason scientific computing requires such huge amounts of processing power is that scientists are writing the code.
... a good friend of mine went to school as a CS, and up to a few months ago before I switched companies, he worked across the hall from me, taking engineer's algorithms and implementing it in code.
I'll grant you that, to a point. I'm a Mechanical/aerospace engineer, I've only had 1 formal course in C++ although I've been programming C++ since I was 12, and BASIC for years before that. I don't consider myself a computer scientist by any means. However, you need to look at the problems we are solving. Regardless of how elegant your code is, you will be pegging a processor for days or even weeks at a time. When you are trying to solve a CFD grid for heat transfer coefficients on something like a missile or Ares, you are going to have multi-million node meshes, integrating several differential equations at each node. Optimize away, your bottleneck is still going to be the processor.
Believe it or not engineers **do** integrate with CS types every now and then
That's what she said.
There is more to computing than processor speed
As someone who does scientific computing, I say bunk! My primary bottleneck is still the processor. FTA:
Too much R&D time and money goes into processor speed when other issues remain under-addressed. For example, could data not be handled a bit better? What about smarter ways of tagging data? The semantic web initiative runs along these sorts of lines, so where is the hardware-based equivalent?
Sure, tagging and controlling data is important, but far from difficult, and with well-written programs a good suite of visualization tools is relatively easy. Give me some speed, dammit! Why should I have to wait for my slot on the cluster when I could have the power right here under my desk?
have you seen the Quad Laser? :)
"There is no escape" "Yeah!" "OH SHIT! It's going backwards!"
Sounds about right. Middle class is in the 25ish% tax bracket, and most of us have mortgages and other things which reduce our tax liability.
It isn't a brain backup device, it's a little recorder that you wear around your neck. It takes snapshots throughout the day and records sound. The software on the computer also allows for archival of various documents, etc. Stuff gets associated and it essentially becomes a surrogate memory.
A good, extensive writeup can be found in Fast Company. The original article is over half a year old and this idea from Gordon Bell has been known for years: he started working on this project in 1995.
Bunch of drama queens on slashdot talking about "omgz vaporware" "Microsoft doign what neuroscience cant? omgz" Read the goddamned article, not the FUD summary.
Back where I used to work they had a diskless computer cluster similar to this. A master node held the disk image, and when each computer booted up it would request the disk image from the master node and put it on a RAM disk. No hard drive, floppy or CD-ROM drive on the cluster. Once they booted up they got their image with their tasks, started running the tasks, etc.
If any node was having problems, all they had to do was flip a switch. If it came back up, great, if not pull it offline and see what failed.
Hopefully the facility you're in has proper emergency ventilation measures, adequate room size, properly constructed doors, and protective equipment to avoid this scenario, but you still don't want to be in the room if it happens if you can help it... Cryogenic gasses are seriously dangerous. Don't underestimate them or treat them lightly.
:)
... it's nitrogen and oxygen, the primary constituents of the atmosphere.
I'm an Aerospace Engineer. I'm fairly familiar with the properties of cryogenic oxygen
The first thing you do, is you NEVER store a LOX dewar inside an enclosed area. You store it outside. When it vents, it vents into the atmosphere. You have a mixer outside which expands and mixes the LOX with the NOX. OUTSIDE. With proper feedback the appropriate breathing ratio can be attained. It's insulated so you don't lose that nice cool chill. Only when the mix is appropriate do you vent it into your server room. Otherwise, dump it outside
LOX is dirt cheap. Pennies a pound by the tanker. There are many people who have small dewars at home that they own for medical purposes (migraines, cluster headaches, lung issues, etc.). There are even guys I know who make liquid rocket engines as a hobby, and have LOX dewars in their backyard. The handling of it is well known, to the point where oxygen is becoming a viable commercial industry (some have called it the next bottled water). With proper handling there is no reason to be intimidated.
Liquid oxygen?
The boiloff is a little bit worse but the stuff is almost as cheap as dirt. A mix of LOX and NOX would be breathable and not risk explosion.
$20k/year doesn't even buy rent and health insurance. For one person. Let alone someone trying to support a family.
Bullshit. I was in college with my new wife of a year and a half and our first son. I was working part time under $10 an hour and my wife stayed at home with our son - this was important to us. Guess what? We made it just fine, without credit card debt, and I was purchasing health insurance and long-term life insurance out of my own pocket. It's amazing to me how many people think they need $40k+ a year to 'scrape by'. We were doing it on a quarter of that.
No big screen TV's, no Wii's XBOX's, or PlayStations, we didn't go out to eat every dinner, we only had one car, a one-bedroom apartment in a decent enough part of town but we got by just fine. Instead, we learned to enjoy each other's company, enjoy the great outdoors, and cook good food from raw ingredients. If you learn to manage your resources, $7.50 an hour is workable for a young family of three. Not easy but a great and valuable experience.
Now tell me a way to cover 138 m^2 of solar array with what you have on station ... now.
That bit about not being able to take it down for repair, well, that's going to make it into some future book on industrial design.
Pray tell, short of covering the solar array from view of the sun, how do you stop solar cells from generating electricity? It is a passive electricity generating device, not an active one (like a fuel cell or a conventional gas-powered generator). As long as it has a sufficient view factor of a light source, it generates electricity.
has there ever been an occasion where it was accused of doing something anti-competitive and turned out to be innocent?
Yes!
Look up at the first thread, where it was claimed that they were paying off Paramount to drop Blue-Ray. It was actually a false rumor by a Blue-Ray fanboy. link.
GET OFF MY FRONTIER!!! young whippersnappers ....
with a SHARPIE!
I bought a top of the line processor and quadrupled my RAM the beginning of last year - not for video gaming (although it sure didn't hurt, I play occasionally not very hardcore anymore) but to do scientific computing for my thesis. I did a 6DOF model of a guided bullet, with this spiffy guidance model. 500 monte carlo runs took about 2 hours. I needed to do a ton of sets. All in all, my entire master's dissertation worth of sets took about a month worth of running 16 hours a day on a dual-core machine. And of course I had to do a lot of pre-emptive runs to determine the domain of my problem, etc.
...
I still do a lot of scientific computing at home - 6DOF's, playing with CFD, etc. There are plenty of 'hobbyists' out there who can keep a CPU pegged more often than its not
eh. Don'tchaknow. Come'n over to der farm und veesconsin, and we can tip der cows!
So much for the right to a fair and speedy trial...
It's a right the incriminated must invoke.