Unfortuanately, the shuttle program was based on some incorrect assumptions.
True.
First, it was assumed that their cost predictions for the shuttle would be accurate (they weren't, it costs far more per launch than predicted)
Yes, but that is mainly because the Shuttle takes much longer (both more person hours and elapsed) to turn around than originally predicted. If the Shuttle could launch every week, or even every month, then everything else being equal, the cost of the Shuttle would plummet from economies of scale. Indeed that is the primary concept of RLVs, but the Shuttle didn't manage to leverage this advantage, due to lack of funding leading to a shoddy design.
and secondly, the increase in payloads wanting taking to orbit wasn't predicted (there was a massive increase, IIRC)
I don't know where you get that from; increased launch rate wouldn't have increased the fixed costs, and fixed costs are the main cost point in the Shuttle program. But alas the Shuttle physically can't handle launching more often.
ESA and the russians aren't much competition right now...
Well, Arianespace owns most of the GEO satellite market where most commercial space launches go, and American launchers only launch vehicles that can't go on Ariane for one reason or another, so I don't really agree.
The russians will just keep cranking out 1960's era craft until the factories break down. Nothing wrong with 60's rockets, but we need to have modern designs and materials if we're going to lower the cost of space access.
Interestingly, the Russian hardware is cheaper than the Americans, even when you account for the lower wages in America. This is evidence that higher technology is not the answer and may well be counterproductive. The only trick that is needed for cheap space is to launch. Launch often. Launch really often. Economies of scale are bigger than every other known trick for reducing the cost of space, even put together. Of course the Russians use mass production techniques to build their rockets.
Why that would be like asking the United States if there were WMD in Iraq.
A better analogy would be to ask Britain's Tony Blair, because he told the house of parliament that there very definitely was WMDs there. At the moment it is looking like he lied. If proven, he may be for the high jump.
Anything which will seep through cast iron is not suitable for use on a motor vehicle, for what should be obvious safety reasons.
Oh pulllleeeeze you don't build a hydrogen engine out of cast iron!
I've driven around in plenty of aluminum block engines, aluminum and hydrogen are compatible materials (e.g. the space shuttle hydrogen filled tank is made from it).
The energy to split the hydrogen out of compounds must be coming from somewhere. How do you do it? Primarily with existing electric generation techniques - coal, nuclear, hydroelectric dams... there's no free lunch, and solar, wind, wave power have yet to demonstrate economic or even environmental viability despite Greenpeace and David Suzuki jumping up and down telling us to use them. So your non-pollutiong hydrogen car actually pollutes.
Let's get this straight. You're claiming that hydroelectric, nuclear and solar energy directly pollute? Huh? Sure when you build them, you might get some pollution depending on how you do it, but once you've built them; no.
NOx compounds are unstable at our temperatures and pressures, so eventually NOx compounds break down on their own.
Yes. And isn't this what a catalytic converter does?
Hydrogen burns extremely hot. What will the NOx emissions of a hydrogen engine be?
Depends. Just like with petrol engines you can change the mixure ratio of the combustion to change the combustion temperature. You can even inject water.
This could lose a lot of votes though, particularly if they ignore the comments they had via the web. Is this the poll tax of the Labour Party? Could they lose an election because of it? Probably not on it's own- but it could trigger an ireversible slide- Tony Blair already rammed through the Gulf War II, and that wasn't particularly popular either; if he does this as well he is creating a pattern, and one that can lose him the election.
I call BS. GM has hydrogen cars in the 200-250 mile range on a full tank today. They need to get 300 for the car to be practical.
Well, you're half right. The tanks can either be large or very heavy. Or both. Presumably the GM car is just very heavy. That's probably partly/mainly why they've got poor range. You've ignored the other points I made about hydrogen being a rotten fuel I notice.
There's a lot of productive work going on out there for hydrogen storage.
Yeah? Well, I'm real excited I can tell you. Wake me when it's practical, if I haven't died of old age.
Yeah right. So hydrogen must be used inspite of it being all of:
a) inefficient
b) incredibly expensive
c) dangerous
d) incredibly bulky
e) unsuitable for cars
f) unsuitable for aeroplanes
g) energy intensive to make (less than 20%)
Because it is 'environmentally friendly'. Um. No. Anyone of those things would preclude it's use, 6 bad things- you're out; dead. There's nothing unique about hydrogen- any sensible material made from solar energy is 'environmentally friendly'. Look, if you were to make ethanol using solar energy- you only need CO2 and water to make it in principle- then the material is a lot safer, easier to handle and energy dense- and not being a fossil fuel it doesn't contribute to global warning either.
I'm not so sure it's much good for battery replacement either- the volumetric efficiency sucks. It's looking at the moment like methanol is a better choice- it's far denser, has good power/weight and is easier to recharge. It's possibly a little safer in terms of stability and fire risk as well. Still, we'll see.
One of the main benefits of a hydrogen economy is that you can generate hydrogen cleanly and efficiently in places where there is a lot of sunshine (and access to water) and ship the hydrogen safely to places that need it.
No. For a few reasons:
a) making hydrogen from water is really inefficient (commercial production is done from methane, because it's wayyyy easier/cheaper/less energy)
b) shipping hydrogen around is at best a total nuisance. Hydrogen is incredibly voluminous, even in liquid form [14x less dense than water, 10x less dense than kerosene], (incidentally hydrogen takes a lot of energy to liquify), and difficult/dangerous. (Hydrogen embrittles most metals, escapes incredibly easily, is explosive, and diffuses incredibly quickly; liquid hydrogen has an annoying habit of condensing oxygen from the air- liquid oxygen forms dangerous explosives with quite a few common materials- such as tarmac- it's a contact explosive; you walk on it- well, you wouldn't want to).
Lots of people talk about hydrogen powered vehicles. With current technology (and nobody has done better in about 30 years of research), your fuel tank would have to be 10x bigger than it is now.
Once again, perishable fuel that is in limited supply on our planet.
Not very limited. The earth has huge methane deposits in the form of clathrates (methane contained in ice). There's more methane stored in clathrates than the total fossil fuel supply (oil and coal) by a factor of about 5.
However, Gamble said that non-Asian makers such as Nortel, Cisco, Nokia and others have supported IPv6 in their products for some years.
Ironically, Nortel owns 47.*.*.* (16 million addresses, and they probably only actually use a few tens of thousand at the very most); so they are part of the IPv4 problem. Something tells me, with all their IPv6 sales, they aren't about to give this up, atleast not without a fight, or alternatively, a lot of cash.
Currently P2P networks generally form almost entirely at random- you're as likely to connect to a server on the other side of the world as you are to connect to a server 5 feet away that has the same file. This means you use up bandwidth on all the links on all the machines inbetween. Clearly you can reduce the total amount of bandwidth used, and often latency and throughput, if you (mostly) go to local servers. Are you planning to include any strategies to help minimise this in Bittorrent?
And this is why I say that educating users is just about as important as implementing spam filtering technology. If people know that they are perpetuating a serious problem by replying to spam, then that's bad news for spammers.
The reason that spam works so well is that the proportion of idiots out there who either didn't attend the lesson, didn't believe the lesson, or didn't listen in the lesson is small, but significant. There's one born every minute as they say.
About another fact mentioned in the article: It said Paul Graham's filter extracts "the top 15 features that define them as spam." 15? I thought that most Bayesian filters use many more spam-defining features. Because I'd say that there are quite a few more. Just think of the many features that spam tends to have. But he says his filter works well. Interesting.
Actually, he wasn't that clear. His software picks the top 15 features that suggest it to be spam, or suggests it to be non spam, and then judges the spam on that. The Bayesian filters record literally thousands of 'rules' as you put it, it's just that at most only a specially chose subset of 15 apply to any one message. And his software works exceedingly well. My personal installation is running at well over 98% accuracy.
It's not exactly a scripting language. It's actually a very close cousin of 'forth'. It runs quite quickly, and doesn't particularly excel at text processing, which most scripting languages do.
As other people have pointed out, it's useful to have a fairly powerful language in a printer since it allows the printer to adapt the printed stuff to the paper size and so forth (no pun intended).
Another language that is very closely related is pdf; as I understand it, it's pretty much postscript with a few cludges on the side to make it run faster.
The difference between an Applet and an application is often fairly trivial; relatively small changes to the application can enable it to run in the web browser window.
I assume this was intended as a joke, but I may as well point out that unless a program is not an applet, unless it implements the interface Applet
It's usually fairly easy to add the extra interface though. I've written Java that runs as both; at the same time if you want.
Yeah, just one roundabout (aka 'traffic circle') down. Actually, did I say one? I meant one hundred- almost 6 feet.
I got a better idea, forget ants how about...
on
Ant Farm PC
·
· Score: 2, Funny
Bees!
Think about it. Bees don't like their hive to get too hot, cos then they all die. So, if it does they station a whole bunch of workers on the outside and get them to flap their little chitinous wings to cool it all down. It's a self cooling case!
Admittedly the bees buzzing all the time might be louder than an overclocked AMD with an ill chosen fan, but you have to admit; it would be a unique case mod. And you get honey!
So, is a self-cooling-honey producing-beehive case a great idea or what?
Re:Don't worry about your firmware upgrades
on
802.11g Slows Down
·
· Score: 1
Yeah, it doesn't surprise me at all. I mean 802.11b is obstensibly 11 Mbit/s, but in practice you are lucky to get 3.5Mbit/s. Scaling everything up by 54/11 = ~5 times, so you'd expect to get just about 20Mbit/s.
Last time I checked, citizens of an EU country don't need a visa for a stay in the USA of up to 90 days, even if they're working.
Really? No, I don't think that's right.
If you have a Business Visa then maybe (sounds like these guys didn't). If you have a Tourist Visa (which people from the EU usually routinely get given), then you are NOT supposed to work at all. The immigration officers have a certain amount of discretion (presumably based on guidelines), but that's all. The guidelines vary somewhat over time though, and I suspect that this may be part of the problem.
Ok, let's get this straight. A bunch of journalists try to enter America without the proper paperwork, and get this, they get locked up and then deported! What a tyrannical government! It's an outrage I tell you! An outrage!
I've never done any fibre channel, but SONET is very not novel, and in fact it is a dying dinosaur. The only reason it is so widespread is tradition, and the ethernet has caught up bigtime; and is much, much cheaper.
If I was a telephone company I would be looking at buying only VOIP equipment and run it on private LANs with plenty of bandwidth. No SONET at all.
Slashdot Mirror
True.
First, it was assumed that their cost predictions for the shuttle would be accurate (they weren't, it costs far more per launch than predicted)
Yes, but that is mainly because the Shuttle takes much longer (both more person hours and elapsed) to turn around than originally predicted. If the Shuttle could launch every week, or even every month, then everything else being equal, the cost of the Shuttle would plummet from economies of scale. Indeed that is the primary concept of RLVs, but the Shuttle didn't manage to leverage this advantage, due to lack of funding leading to a shoddy design.
and secondly, the increase in payloads wanting taking to orbit wasn't predicted (there was a massive increase, IIRC)
I don't know where you get that from; increased launch rate wouldn't have increased the fixed costs, and fixed costs are the main cost point in the Shuttle program. But alas the Shuttle physically can't handle launching more often.
Well, Arianespace owns most of the GEO satellite market where most commercial space launches go, and American launchers only launch vehicles that can't go on Ariane for one reason or another, so I don't really agree.
The russians will just keep cranking out 1960's era craft until the factories break down. Nothing wrong with 60's rockets, but we need to have modern designs and materials if we're going to lower the cost of space access.
Interestingly, the Russian hardware is cheaper than the Americans, even when you account for the lower wages in America. This is evidence that higher technology is not the answer and may well be counterproductive. The only trick that is needed for cheap space is to launch. Launch often. Launch really often. Economies of scale are bigger than every other known trick for reducing the cost of space, even put together. Of course the Russians use mass production techniques to build their rockets.
A better analogy would be to ask Britain's Tony Blair, because he told the house of parliament that there very definitely was WMDs there. At the moment it is looking like he lied. If proven, he may be for the high jump.
Oh pulllleeeeze you don't build a hydrogen engine out of cast iron!
I've driven around in plenty of aluminum block engines, aluminum and hydrogen are compatible materials (e.g. the space shuttle hydrogen filled tank is made from it).
The energy to split the hydrogen out of compounds must be coming from somewhere. How do you do it? Primarily with existing electric generation techniques - coal, nuclear, hydroelectric dams... there's no free lunch, and solar, wind, wave power have yet to demonstrate economic or even environmental viability despite Greenpeace and David Suzuki jumping up and down telling us to use them. So your non-pollutiong hydrogen car actually pollutes.
Let's get this straight. You're claiming that hydroelectric, nuclear and solar energy directly pollute? Huh? Sure when you build them, you might get some pollution depending on how you do it, but once you've built them; no.
NOx compounds are unstable at our temperatures and pressures, so eventually NOx compounds break down on their own.
Yes. And isn't this what a catalytic converter does?
Hydrogen burns extremely hot. What will the NOx emissions of a hydrogen engine be?
Depends. Just like with petrol engines you can change the mixure ratio of the combustion to change the combustion temperature. You can even inject water.
It's hard to say, probably not. But even a reduced majority can have a chilling effect on the more way-out tendencies of governments.
Well, if they ignore these comments I will be; I was one of the ones that sent in a comment via this particular website.
This could lose a lot of votes though, particularly if they ignore the comments they had via the web. Is this the poll tax of the Labour Party? Could they lose an election because of it? Probably not on it's own- but it could trigger an ireversible slide- Tony Blair already rammed through the Gulf War II, and that wasn't particularly popular either; if he does this as well he is creating a pattern, and one that can lose him the election.
Well, you're half right. The tanks can either be large or very heavy. Or both. Presumably the GM car is just very heavy. That's probably partly/mainly why they've got poor range. You've ignored the other points I made about hydrogen being a rotten fuel I notice.
There's a lot of productive work going on out there for hydrogen storage.
Yeah? Well, I'm real excited I can tell you. Wake me when it's practical, if I haven't died of old age.
a) inefficient
b) incredibly expensive
c) dangerous
d) incredibly bulky
e) unsuitable for cars
f) unsuitable for aeroplanes
g) energy intensive to make (less than 20%)
Because it is 'environmentally friendly'. Um. No. Anyone of those things would preclude it's use, 6 bad things- you're out; dead. There's nothing unique about hydrogen- any sensible material made from solar energy is 'environmentally friendly'. Look, if you were to make ethanol using solar energy- you only need CO2 and water to make it in principle- then the material is a lot safer, easier to handle and energy dense- and not being a fossil fuel it doesn't contribute to global warning either.
I'm not so sure it's much good for battery replacement either- the volumetric efficiency sucks. It's looking at the moment like methanol is a better choice- it's far denser, has good power/weight and is easier to recharge. It's possibly a little safer in terms of stability and fire risk as well. Still, we'll see.
Perhaps the post surprised them in some way, and yet they could see the sense. Or; don't know.
Either way, I may well lose mod points with metamoderation.
No. For a few reasons:
a) making hydrogen from water is really inefficient (commercial production is done from methane, because it's wayyyy easier/cheaper/less energy)
b) shipping hydrogen around is at best a total nuisance. Hydrogen is incredibly voluminous, even in liquid form [14x less dense than water, 10x less dense than kerosene], (incidentally hydrogen takes a lot of energy to liquify), and difficult/dangerous. (Hydrogen embrittles most metals, escapes incredibly easily, is explosive, and diffuses incredibly quickly; liquid hydrogen has an annoying habit of condensing oxygen from the air- liquid oxygen forms dangerous explosives with quite a few common materials- such as tarmac- it's a contact explosive; you walk on it- well, you wouldn't want to).
Lots of people talk about hydrogen powered vehicles. With current technology (and nobody has done better in about 30 years of research), your fuel tank would have to be 10x bigger than it is now.
Not very limited. The earth has huge methane deposits in the form of clathrates (methane contained in ice). There's more methane stored in clathrates than the total fossil fuel supply (oil and coal) by a factor of about 5.
Ironically, Nortel owns 47.*.*.* (16 million addresses, and they probably only actually use a few tens of thousand at the very most); so they are part of the IPv4 problem. Something tells me, with all their IPv6 sales, they aren't about to give this up, atleast not without a fight, or alternatively, a lot of cash.
Currently P2P networks generally form almost entirely at random- you're as likely to connect to a server on the other side of the world as you are to connect to a server 5 feet away that has the same file. This means you use up bandwidth on all the links on all the machines inbetween. Clearly you can reduce the total amount of bandwidth used, and often latency and throughput, if you (mostly) go to local servers. Are you planning to include any strategies to help minimise this in Bittorrent?
The reason that spam works so well is that the proportion of idiots out there who either didn't attend the lesson, didn't believe the lesson, or didn't listen in the lesson is small, but significant. There's one born every minute as they say.
About another fact mentioned in the article: It said Paul Graham's filter extracts "the top 15 features that define them as spam." 15? I thought that most Bayesian filters use many more spam-defining features. Because I'd say that there are quite a few more. Just think of the many features that spam tends to have. But he says his filter works well. Interesting.
Actually, he wasn't that clear. His software picks the top 15 features that suggest it to be spam, or suggests it to be non spam, and then judges the spam on that. The Bayesian filters record literally thousands of 'rules' as you put it, it's just that at most only a specially chose subset of 15 apply to any one message. And his software works exceedingly well. My personal installation is running at well over 98% accuracy.
No, I would never do that, and don't ever accuse me again, I am very offended. YHBT.
As other people have pointed out, it's useful to have a fairly powerful language in a printer since it allows the printer to adapt the printed stuff to the paper size and so forth (no pun intended).
Another language that is very closely related is pdf; as I understand it, it's pretty much postscript with a few cludges on the side to make it run faster.
You're correct in an anal, trivial, boring sense.
The difference between an Applet and an application is often fairly trivial; relatively small changes to the application can enable it to run in the web browser window.
I assume this was intended as a joke, but I may as well point out that unless a program is not an applet, unless it implements the interface Applet
It's usually fairly easy to add the extra interface though. I've written Java that runs as both; at the same time if you want.
Yeah, just one roundabout (aka 'traffic circle') down. Actually, did I say one? I meant one hundred- almost 6 feet.
Think about it. Bees don't like their hive to get too hot, cos then they all die. So, if it does they station a whole bunch of workers on the outside and get them to flap their little chitinous wings to cool it all down. It's a self cooling case!
Admittedly the bees buzzing all the time might be louder than an overclocked AMD with an ill chosen fan, but you have to admit; it would be a unique case mod. And you get honey!
So, is a self-cooling-honey producing-beehive case a great idea or what?
Yeah, it doesn't surprise me at all. I mean 802.11b is obstensibly 11 Mbit/s, but in practice you are lucky to get 3.5Mbit/s. Scaling everything up by 54/11 = ~5 times, so you'd expect to get just about 20Mbit/s.
Really? No, I don't think that's right.
If you have a Business Visa then maybe (sounds like these guys didn't). If you have a Tourist Visa (which people from the EU usually routinely get given), then you are NOT supposed to work at all. The immigration officers have a certain amount of discretion (presumably based on guidelines), but that's all. The guidelines vary somewhat over time though, and I suspect that this may be part of the problem.
Ok, let's get this straight. A bunch of journalists try to enter America without the proper paperwork, and get this, they get locked up and then deported! What a tyrannical government! It's an outrage I tell you! An outrage!
If I was a telephone company I would be looking at buying only VOIP equipment and run it on private LANs with plenty of bandwidth. No SONET at all.