No, this is not a correct analysis. You have to break it up into all 512 possible outcomes and then calculate the probability for each. So one of the possibilities is that all engines will work, that has a probability of (35/36)^9 or 77.6%. There are 9 possible ways that one engine could fail. Each possibility has a probability of (1/36)^1*(35/36)^8 or 2.2%. If you multiply that by the 9 single engine failure possibilities you get a probability of 20.0% that exactly one engine will fail. So if a successful flight can have either no engines or one engine fail the probability is 77.6% + 20.0% = 97.6%. Does that make sense?
They have had 1 in 4 rockets with a defective engine, 1 in 16 could on average have TWO defective engines.
I'm not sure if you're serious or not, but I got a good laugh out of that one. Please elaborate on your calculation technique if you'd like me to point out what's wrong with it.
You can not take the failure rate of a single engine and work that way.
That may or may not be true. You'd need to see at least one multi-engine failure before you can reasonably conclude that one engine can cause another to fail. Once they've done about 100 launches, you can see if single engine failures occur about 20% of the time and double engine failures occur 2% of the time. If that's the ratio, you can reasonably assume engine failures are not related to each other. As far as explosions go, they do have firewalls in place to prevent an explosion in one engine from cascading to other engines. Each engine operates independently, so there's no reason to assume that a failure in one engine will cause failures in others. At this point, it looks like a failure in one engine will not cause failures in the others, since only a single engine failed during this launch.
They have 9 engines in the first stage of each rocket and that multiplies the chances of failure.
Nope, if they had a single engine their failure rate would be about 2.8%. With 9 engines, and the ability to operate with one engine out, their failure rate would be 2.4%. So the failure rate is actually reduced.
They've launched 4 Falcon 9 rockets. One engine has failed, so that's an observed failure rate of 1/36 or about 3%. The means the odds of 0 or 1 engine failing (a successful launch) is 97.6% and the odds of more than one failing is 2.4% assuming the currently observed rate is representative of the actual rate. 2.4% would be an excellent failure rate for any rocket launch system. In fact, no one has achieved a failure rate that low. And bear in mind this rate includes 3 experimental launches and only one production launch. Of course, a launch failure can be brought about by more than just engine failures, so 2.4% is really a minimum and other factors which haven't yet manifested themselves would add to it.
Space X is saying that this is probably a failure in the aerodynamic structure of the rocket, not the rocket engine itself. If that's the case, the above statistical analysis is invalid because it assumes no interdependency in engine failures. A structural failure could lead to more than one engine failing. It would also be problematic in assessing the future failure rate because the engine configuration is going to change in their 1.1 version. The outer engines will be circularly arranged in future versions while in current versions they're arranged in a square.
People's brains are not especially good at identifying objects above the horizon. We typically determine the size and distance of distant objects with visual cues because our stereoscopic vision is limited to close range. For example, we are able to determine the distance of a person because we know (generally) how big a person is. If there's something next to him, we can then know it's size (by comparing it's apparent size to the apparent size of the person) and distance (it's about the same distance as the person). But in the absence of these visual cues, we are unable to determine the size and distance (as well as a host of related factors such as velocity and acceleration) of objects. Moreover, even the color of objects is determined by visual cues, since we color correct images to account for differences in lighting.
This leads to a lot of difficulty in identifying objects in the sky. Since flying objects are not arranged in a plane, we can't use their position in relation to the horizon to approximate their distance. Nevertheless, we often do. The moon seems to be much larger when it's near the horizon because we assume objects near the horizon are much farther away (the moon also appears larger due to atmospheric distortion, but this effect is minor).
Isn't this exactly what Edison and Ford did? Edison didn't invent electricity, or the lightbulb. Ford did not invent the Automobille. What they did was popularize these technologies by refining them and making them more practical, and yes, marketing them.
We don't want to contribute to your health care when you are a brain damaged vegetable for the rest of your life.
Then don't!
What is it with conservative Americans? Some even still believe that car seat belts are a conspiracy against their precious, but largely imaginary, freedoms.
It's hardly reasonable to say that just because the government has eroded most of our freedoms we shouldn't complain about it. Actually, that's downright silly.
Also, I'm an anarchist, so me not supporting these laws was a foregone conclusion. If you don't like it, you don't have to agree with it.
Why not simply write a law prohibiting people from engaging in any dangerous recreational activity? Bicycle accidents are a tiny fraction of recreationally acquired injuries. Surely your ability to enjoy a dangerous recreational activity is less important than our precious taxpayer money.
Would you sign a waiver that would prevent the government or insurance company from providing any assistance if you had an accident while you were playing football?
Do you realize that I have no say in whether or not the government "mandates" health care coverage for me? This is a blanket excuse in which social programs can be used to justify literally any encroachment on personal choice. Any assumed health care costs are totally hypothetical. Accidents are caused by carelessness every day! A socialized healthcare plan that excepted care for injuries caused by accidents in which carelessness was a contributing factor would not be a socialized health care plan.
The risks of many types of accidents can be reduced by wearing proper personal protective equipment. For example, accidents in the shower (which are much more common) could be prevented by wearing a harness attached to the ceiling. Injuries related to bicycling are a relatively small fraction of our overall health care costs, and a relatively small fraction of the injuries caused by accidents. Special attention (other than education about the benefits of wearing helmets) is simply not warranted in this because it is not really an exceptional case.
I post online at my regular level of rudeness. While in person many find me to be an insufferable jackass, online I come across as a perfect gentleman.
I find it hilarious that so many people have posed this question to me. How many people do you suppose are opposed to helmet laws, but in favor of seat-belt laws? Probably not many.
The thing is, most people care about their personal safety. So if it's really reasonable for them to do something to protect their safety, they will do it. If I'm going on a serious bike-ride, I will probably wear a helmet. If I'm just riding down the block, probably not. But other people have other reasons for their behavior. I don't see why I'd drive without wearing a seatbelt, but that doesn't mean someone else might not have a reason to. In either case, you don't need to compel someone to do these things because there's already a good reason to do them. When I see signs that say "click it or ticket" or something similar, I just have to laugh. As if I would find the risk of getting a ticket more compelling than the risk of colliding with my windshield in the event of an accident!
In reality, laws such as these seem like they're meant to foster a society of thoughtlessness. As if our compliance with a set of rules is more important than our ability to think and make decisions for ourselves. That's not a society I want to live in. Theses laws encourage that kind of society, so I don't like them.
The real problem is that I'm an adult and I can decide for myself whether or not I will wear a helmet. The government doesn't need to make this decision for me.
The moon is only about 1 light second away from the earth, and yet our most powerful terrestrial and orbiting telescopes are not powerful enough to resolve the spacecraft we've landed on the moon. Without dramatically improved technology, or technology working on completely different principles, it's hard believe you'd be able to detect and track a space vessel that's more than a few light-seconds distant, even with an incredibly massive array. Especially if it was designed to be hard to detect. So I don't buy the idea that you can't hide in space, and if you want to launch a surprise attack in space, you'd still realistically need advanced knowledge of your targets location. Though it's true that you'd be on them before they ever saw it coming. There are stealth aircraft that can achieve this result today.
One thing that often seems wrong is the pace of space combat. Lasers move at the speed of light, and if you have FTL, there's no way you'd resist putting it on a missile. Those factors come together to mean a space battle would be over before the loosing side even realized it had begun.
It's true that ships need to be refit at regular intervals, but spacecraft seem to have more longevity. There are space probes which have been in operation continuously for 35 years with no maintenance whatsoever. Nevertheless, with the exception of Battlestar Galactica (which ends with the ship breaking it's back), most Sci-Fi shows do seem to show spaceships being refit from time to time. So it's not like they are showing that logistics don't exist or aren't an issue, as much as they don't want to boor people to death with meaningless imagined details.
That said, he's probably right there's a huge disincentive to building vary large spacecraft. If you had a large number of smaller ones, it'd provide you with better capabilities, and you could keep them spread out so they wouldn't be as vulnerable to attack.
If you don't want to see information about someone, you can delete them from your friends list. Though if their account were no longer changing, you'd never see updates from them anyway. It's unlikely you'd see Facebook presenting the information you've suggested since it would be really tacky and a PR nightmare.
The present generation doesn't keep physical or even digital photo albums the same way past generations did. If you automatically delete this stuff, you will delete important historical information. You would likely be doing it against the will of a persons living relatives and friends, and against the wishes of the deceased at the time of their death. It's senseless, and there's no compelling reason for such a sweeping measure.
I don't want my Facebook deleted in the event of my death! My friends would lose all of the photos I posted of them! And all the comments and links and everything I posted on their timelines. And what if they want to come back years later and reminisce about old times. There are lots of reasons living customers might want to look at the information. Wouldn't it be better to freeze the account?
How did they ever think they could get away with this?! If I were deciding the penalty, I'd probably take them for all they're worth. They were blatantly violating the ruling! They obviously aren't expecting the court to take this seriously.
But hey, go right ahead kid, show yourself to be a true dweed and insist on using words by their most strict interpretation, it will warn everyone that you are someone who hasn't any social skills whatsoever. I would warn you to now go try to order soil to fill your kids sandbox but I think it is safe to assume you never will be in that situation.
Doctor, heal thy self.
The saying I posted is just a funny way of saying "hey, this stuff (the dirt) is important."
I wasn't trying to be pedantic. I used to work at an environmental engineering company, and I noticed that the geologists and environmental scientists didn't like it when I referred to soil samples as dirt. One once said to me "I didn't spend 6 years in college to study dirt." I looked it up and it turns out they were right. These nasa scientists aren't studying dirt. Saying that implies what they're doing is less important than it actually is. Even if it's not on mars, the soil covering the earth is very important to us, and many people make studying it their live's work.
Slashdot Mirror
I'm pretty sure the word flaw should be in quotation marks in this context.
No, this is not a correct analysis. You have to break it up into all 512 possible outcomes and then calculate the probability for each. So one of the possibilities is that all engines will work, that has a probability of (35/36)^9 or 77.6%. There are 9 possible ways that one engine could fail. Each possibility has a probability of (1/36)^1*(35/36)^8 or 2.2%. If you multiply that by the 9 single engine failure possibilities you get a probability of 20.0% that exactly one engine will fail. So if a successful flight can have either no engines or one engine fail the probability is 77.6% + 20.0% = 97.6%. Does that make sense?
I'm not sure if you're serious or not, but I got a good laugh out of that one. Please elaborate on your calculation technique if you'd like me to point out what's wrong with it.
That may or may not be true. You'd need to see at least one multi-engine failure before you can reasonably conclude that one engine can cause another to fail. Once they've done about 100 launches, you can see if single engine failures occur about 20% of the time and double engine failures occur 2% of the time. If that's the ratio, you can reasonably assume engine failures are not related to each other. As far as explosions go, they do have firewalls in place to prevent an explosion in one engine from cascading to other engines. Each engine operates independently, so there's no reason to assume that a failure in one engine will cause failures in others. At this point, it looks like a failure in one engine will not cause failures in the others, since only a single engine failed during this launch.
Nope, if they had a single engine their failure rate would be about 2.8%. With 9 engines, and the ability to operate with one engine out, their failure rate would be 2.4%. So the failure rate is actually reduced.
They've launched 4 Falcon 9 rockets. One engine has failed, so that's an observed failure rate of 1/36 or about 3%. The means the odds of 0 or 1 engine failing (a successful launch) is 97.6% and the odds of more than one failing is 2.4% assuming the currently observed rate is representative of the actual rate. 2.4% would be an excellent failure rate for any rocket launch system. In fact, no one has achieved a failure rate that low. And bear in mind this rate includes 3 experimental launches and only one production launch. Of course, a launch failure can be brought about by more than just engine failures, so 2.4% is really a minimum and other factors which haven't yet manifested themselves would add to it.
Space X is saying that this is probably a failure in the aerodynamic structure of the rocket, not the rocket engine itself. If that's the case, the above statistical analysis is invalid because it assumes no interdependency in engine failures. A structural failure could lead to more than one engine failing. It would also be problematic in assessing the future failure rate because the engine configuration is going to change in their 1.1 version. The outer engines will be circularly arranged in future versions while in current versions they're arranged in a square.
People's brains are not especially good at identifying objects above the horizon. We typically determine the size and distance of distant objects with visual cues because our stereoscopic vision is limited to close range. For example, we are able to determine the distance of a person because we know (generally) how big a person is. If there's something next to him, we can then know it's size (by comparing it's apparent size to the apparent size of the person) and distance (it's about the same distance as the person). But in the absence of these visual cues, we are unable to determine the size and distance (as well as a host of related factors such as velocity and acceleration) of objects. Moreover, even the color of objects is determined by visual cues, since we color correct images to account for differences in lighting.
This leads to a lot of difficulty in identifying objects in the sky. Since flying objects are not arranged in a plane, we can't use their position in relation to the horizon to approximate their distance. Nevertheless, we often do. The moon seems to be much larger when it's near the horizon because we assume objects near the horizon are much farther away (the moon also appears larger due to atmospheric distortion, but this effect is minor).
Your ISP would pay for it. It would be a value-added feature.
Isn't this exactly what Edison and Ford did? Edison didn't invent electricity, or the lightbulb. Ford did not invent the Automobille. What they did was popularize these technologies by refining them and making them more practical, and yes, marketing them.
I read that the writer of the screenplay didn't finish reading the book. It was too depressing.
Then don't!
It's hardly reasonable to say that just because the government has eroded most of our freedoms we shouldn't complain about it. Actually, that's downright silly.
Also, I'm an anarchist, so me not supporting these laws was a foregone conclusion. If you don't like it, you don't have to agree with it.
That's not up to me. . .
There shouldn't be laws requiring people to wear seat-belts.
Then why are they doing it?
Why not simply write a law prohibiting people from engaging in any dangerous recreational activity? Bicycle accidents are a tiny fraction of recreationally acquired injuries. Surely your ability to enjoy a dangerous recreational activity is less important than our precious taxpayer money.
Would you sign a waiver that would prevent the government or insurance company from providing any assistance if you had an accident while you were playing football?
Do you realize that I have no say in whether or not the government "mandates" health care coverage for me? This is a blanket excuse in which social programs can be used to justify literally any encroachment on personal choice. Any assumed health care costs are totally hypothetical. Accidents are caused by carelessness every day! A socialized healthcare plan that excepted care for injuries caused by accidents in which carelessness was a contributing factor would not be a socialized health care plan.
The risks of many types of accidents can be reduced by wearing proper personal protective equipment. For example, accidents in the shower (which are much more common) could be prevented by wearing a harness attached to the ceiling. Injuries related to bicycling are a relatively small fraction of our overall health care costs, and a relatively small fraction of the injuries caused by accidents. Special attention (other than education about the benefits of wearing helmets) is simply not warranted in this because it is not really an exceptional case.
I post online at my regular level of rudeness. While in person many find me to be an insufferable jackass, online I come across as a perfect gentleman.
Sure, they just won't let you pump your own gas.
I find it hilarious that so many people have posed this question to me. How many people do you suppose are opposed to helmet laws, but in favor of seat-belt laws? Probably not many.
The thing is, most people care about their personal safety. So if it's really reasonable for them to do something to protect their safety, they will do it. If I'm going on a serious bike-ride, I will probably wear a helmet. If I'm just riding down the block, probably not. But other people have other reasons for their behavior. I don't see why I'd drive without wearing a seatbelt, but that doesn't mean someone else might not have a reason to. In either case, you don't need to compel someone to do these things because there's already a good reason to do them. When I see signs that say "click it or ticket" or something similar, I just have to laugh. As if I would find the risk of getting a ticket more compelling than the risk of colliding with my windshield in the event of an accident!
In reality, laws such as these seem like they're meant to foster a society of thoughtlessness. As if our compliance with a set of rules is more important than our ability to think and make decisions for ourselves. That's not a society I want to live in. Theses laws encourage that kind of society, so I don't like them.
The real problem is that I'm an adult and I can decide for myself whether or not I will wear a helmet. The government doesn't need to make this decision for me.
But fighters themselves would be of little use.
The moon is only about 1 light second away from the earth, and yet our most powerful terrestrial and orbiting telescopes are not powerful enough to resolve the spacecraft we've landed on the moon. Without dramatically improved technology, or technology working on completely different principles, it's hard believe you'd be able to detect and track a space vessel that's more than a few light-seconds distant, even with an incredibly massive array. Especially if it was designed to be hard to detect. So I don't buy the idea that you can't hide in space, and if you want to launch a surprise attack in space, you'd still realistically need advanced knowledge of your targets location. Though it's true that you'd be on them before they ever saw it coming. There are stealth aircraft that can achieve this result today.
One thing that often seems wrong is the pace of space combat. Lasers move at the speed of light, and if you have FTL, there's no way you'd resist putting it on a missile. Those factors come together to mean a space battle would be over before the loosing side even realized it had begun.
It's true that ships need to be refit at regular intervals, but spacecraft seem to have more longevity. There are space probes which have been in operation continuously for 35 years with no maintenance whatsoever. Nevertheless, with the exception of Battlestar Galactica (which ends with the ship breaking it's back), most Sci-Fi shows do seem to show spaceships being refit from time to time. So it's not like they are showing that logistics don't exist or aren't an issue, as much as they don't want to boor people to death with meaningless imagined details.
That said, he's probably right there's a huge disincentive to building vary large spacecraft. If you had a large number of smaller ones, it'd provide you with better capabilities, and you could keep them spread out so they wouldn't be as vulnerable to attack.
If you don't want to see information about someone, you can delete them from your friends list. Though if their account were no longer changing, you'd never see updates from them anyway. It's unlikely you'd see Facebook presenting the information you've suggested since it would be really tacky and a PR nightmare.
The present generation doesn't keep physical or even digital photo albums the same way past generations did. If you automatically delete this stuff, you will delete important historical information. You would likely be doing it against the will of a persons living relatives and friends, and against the wishes of the deceased at the time of their death. It's senseless, and there's no compelling reason for such a sweeping measure.
I don't want my Facebook deleted in the event of my death! My friends would lose all of the photos I posted of them! And all the comments and links and everything I posted on their timelines. And what if they want to come back years later and reminisce about old times. There are lots of reasons living customers might want to look at the information. Wouldn't it be better to freeze the account?
How did they ever think they could get away with this?! If I were deciding the penalty, I'd probably take them for all they're worth. They were blatantly violating the ruling! They obviously aren't expecting the court to take this seriously.
Doctor, heal thy self.
The saying I posted is just a funny way of saying "hey, this stuff (the dirt) is important."
I wasn't trying to be pedantic. I used to work at an environmental engineering company, and I noticed that the geologists and environmental scientists didn't like it when I referred to soil samples as dirt. One once said to me "I didn't spend 6 years in college to study dirt." I looked it up and it turns out they were right. These nasa scientists aren't studying dirt. Saying that implies what they're doing is less important than it actually is. Even if it's not on mars, the soil covering the earth is very important to us, and many people make studying it their live's work.