Wait, what? No, that's not what I meant. It seemed the thread had diverged a bit from the OP, and your statement that you cannot "figure" acceleration without a reference point is patently false in the general case, so I took offense at your invocation of the Nobel Prize for something so simple. Forgive my juvenile use of sarcasm and capitalization, but I was merely defending a perceived slight to Newtonian physics.
I'm sure you remember from high school physics that there are two completely independent ways to compute acceleration: one using time and relative position, the other using force and mass. Any of those values can be directly measured in some cases, but in this case it is true that they are most likely tracking the satellite's position from afar and computing the force that would explain its trajectory over time. But if force and mass were measured, as they are in an accelerometer, and in fact could be on the spacecraft itself, no position reference would be required to compute your acceleration relative to the object's coordinate system.
I can go on to clarify that the statement "accelerating toward the sun" provides an external direction reference for the direction of the acceleration but not the velocity, leading once again to the conclusion that the word "deceleration" is inappropriate.
Dude, 6600 pounds is a really cheap payload. I'm surprised they can do anything with 3500 pounds now, that's like 10 bolts if you buy them from NASA.;);)
A large chunk of the inefficiency at NASA itself is caused by, you guessed it, privatization of capabilities and variable cost contracts. It wouldn't matter that the work was being done by contractors instead of civil servants if the companies actually had an incentive to be efficient, but they don't. SpaceX, unlike all the other contractors NASA uses, is offered fixed-price launches, meaning they bear 100% of the financial risk and have every incentive to be efficient. I can only see this as an improvement.
Actually, I'm more interested in the motive force produced by the radiation of all that energy in one direction. I forget the equations for the impulse imparted by a photon though, and we'd have to compare it with the force from the solar wind as well. Maybe I should RTFA and see if they did already.
Yes exactly, you have to know position and time to know acceleration, this is why every Wiimote has a super duper GPS receiver that can resolve centimeter positions while indoors, which is why they all cost $10000000000 and are regulated by the military. What's that you say? They're only $20 and imported from China? Maybe that's because they use an ACCELEROMETER which senses the FORCE applied to a MASS whenever it gets ACCELERATED, without ever needing to know position OR time.
Tell that to your face when it's planted on the floor of a Jupiter colony. Alternatively, amaze your friends and relatives by standing on the wall while your spaceship accelerates. Gravitational acceleration is no different from any other acceleration, only the magnitude and direction different.
Actually Deceleration would mean a reduction in speed ( |v| ), while Acceleration would mean a change in velocity ( v ). Since you're only decelerating if the magnitude of your velocity is reducing relative to a specific inertial reference frame, then Deceleration is a pretty specific case of acceleration.
Furthermore, to specify this acceleration as a deceleration, you must assume that the velocity is directly *away* from the sun, which is likely not the case. So even if you did specify the reference frame (relative to the sun) and the initial velocity (away from the sun but not necessarily in a straight line), you cannot call it a deceleration and still convey the fact that the force is toward the sun.
And by the way, having just attended a lecture on spacecraft thermal design, I can say this is a perfectly reasonable theory. The thermal radiators used to dissipate excess heat into space necessarily need to be placed on the "dark" side of the spacecraft so they don't absorb energy from the sun. That means that the photons that radiate exert a force on the spacecraft pushing it back toward the sun, regardless of what direction it is moving. When the probe gets far enough from the sun, at some point the radiated heat will exceed the solar flux (which thins out as 1/r^2), and the net force will be toward the sun.
Well, the U.S. government is only a fraction of SpaceX's business, albeit a significant fraction. They are government contracting at its best: providing a service the government needs to do its job (launching research satellites and astronauts) for a fixed price regulated by a more-or-less competitive market, and for a fraction of the cost it would be if the government did it themselves. That's not socialism in my book any more than having a government in the first place is socialism.
SpaceX is not like a lot of other space contractors (e.g. United Space Alliance) that only exist by and for government contracts--those guys only exist to shave profits off the top of what should be government operations, and have every incentive to *raise* costs rather than lower them.
What is wrong with letting the private sector do what they are best at--taking existing technology and refining it to the point of profitability?
You may have untintentionally set up a straw man. My present argument was against privatisation of space flight research, not for restricting the privilege of lucky entrepreneurs to spend money on fun projects which might then make them more money.
The OP is arguing about diverting government money to "the free market", or something, as if SpaceX's profit-based implementation efforts are a substitute for NASA's research efforts (worse, he may be suggesting that one proper function of government is to channel money to private corporations). It's part of a wider philosophical obsession with applying capitalism everywhere that has resulted in the privatisation, stagnation and price-gouging of various industries and services since the early '80s.
Yes, I may have misinterpreted your comment a little. I detected some disdain in your comment about government projects being starved before privatization, etc., and then assumed that you were arguing against privatization in general because of that. I agree with everything you have said.
So? What is wrong with letting the private sector do what they are best at--taking existing technology and refining it to the point of profitability? It's not trivial work, and we need it done just as much as we need the research in the first place. I think we've pretty well proven that the current system of government funding is incapable of actually producing an efficient production program.
Besides, the minute the space shuttle became a "production" vehicle, the progress stopped. It should never have been elevated to that status; the shuttle was an incomplete and half-baked idea from the start and should have been the first in a long list of modern spacecraft experiments by NASA. Instead, we were stuck with a boondoggle program in need of justification, hence Hubble and the space station. All worthy enterprises, but could have been so, so much cheaper if the shuttle had been refined for another 10 years--or changed completely--before production.
IMHO, the real test is to see if we can jump-start the real research in NASA while simultaneously promoting private-sector production development of existing technologies. And no, a Constellation-style (read: Apollo-style) heavy-lift rocket does not constitute real research. That too can be left to the private sector. I've said it a million times, Constellation was squarely on track to become just as expensive and unreliable as the shuttle--that "$9b wasted" was a drop in the bucket compared to what the program would have cost in the long run. The real research is in ion & plasma drives, space elevators, and planetary exploration vehicles, etc.
Yeah, we'll get patent reform all right...for the trolls, by the trolls. The America Invents act will make it easier than ever for a patent troll to actually steal an idea before it's patented, get the patent, and then win in court when they sue the original inventor.
Unfortunately, that is why we're all so depressed about patents (and many other things as well). It's because the status quo is one thing, but if Congress goes near it they can only make it worse.
At least they air any truths at all, which is more than can be said for most news outlets. And no, they don't air what you call "inconvenient truths"--if they are actually falsehoods. For example, on the Dianne Rehm show about vaccines and autism, she deliberately did not bring anyone from the "other side" because they have been so thoroughly proven false. To give falsehoods like that airtime would be irresponsible journalism, yet it is perpetrated every day by mainstream media "covering the controversy".
Well I'm assuming that the guy who makes a living telling investors whether their prospects' patents are unique (and thus valuable) knows more on the subject than I do. The point, I thought, was that even if they are legally distinguishable, the amount of "value added" is so little from one to the next that it's hard to consider them new inventions. All it does is make any one application infringe on even more patents.
Another amusing quote was of a software engineer who said he has four patents in his name, and he doesn't have a clue what they mean. By the time the lawyers were done with them, it was all gobbledegook to the person who invented them. That just seems wrong to me.
Yeah, the guy from Intellectual Ventures said there were two cases, TWO CASES out of their 35,000 patents, that had actually been licensed to manufacturers. And he couldn't even remember what industry they were involved in, much less which patents. When their entire spiel is that they "take languishing ideas and put them to good use", that is a pretty piss poor record.
I listened to the whole thing live streaming from my NPR station. I was interested to hear that almost everything considered "common knowledge" here on Slashdot held up under their scrutiny. They visited a company that makes software to find duplicate patents, and they said that about 30% of patents granted are duplicates of the same idea. They also said that the one case Intellectual Ventures gives as their "poster child" of an "inventor whose idea was being used illegally until IV came along" actually had over 5500 duplicates granted in the same time frame (nevermind all the prior art that existed). That one patent, by the way, was traced to a patent troll company that is obligated to give Intellectual Ventures a cut of their revenue from it...and the creator of the patent is trying to sue them, IIRC. So much for "encouraging innovation by helping poor inventors".
Another interesting statistic is that they cited polls claiming that 80% of software engineers say patents hurt their business and creativity. I know we've been repeating this to each other for years, but it's nice to see it backed up every now and then.
I'm curious how much of that research that companies do actually makes it to the light of day. Granted, university research is frequently stuck behind journal paywalls as well, but is there any comparison to be made? How much research that doesn't result in a patent actually gets published for others to use?
The difference is even greater because in the winter, there is less sunlight to do the heating. The savings during the summer win hands down. If the power goes out, the color of the roof is not going to make an appreciable difference--unless maybe you sleep in the attic. Never heard of anybody doing that.
All other comments aside, I'm curious what makes you think a Harvard architecture (separate program and data memory) would be transparent to users. I've used Harvard architecture microcontrollers extensively, so I know how secure that can make it. I also know that the minute you want to transmit a program using another program, i.e. downloading a program from the internet or even a software update, you have to make a bridge between data and program memory. If that bridge is transparent, there may as well be no distinction to begin with. The best you could do is have a popup that says "program y wants to make this code executable. Allow?" And then it's no different from the Unix "execute" permission, a tried and true technology that Windows only somewhat emulates.
The Republicans have gone so far right that they are dragging the rest of us with them. Almost daily, President Obama is championing proposals first brought by Republicans less than two years ago, only to be jeered off the stage by today's ultra-conservatives. It's like following in the wake of a glacier, lots of good bits to pick up, but no way to stop it from moving down the mountain (before it hits the sea and disintegrates).
I have heard it naked expressed that the real purpose of NASA is to make sure certain DOD contractors make a profit.
And I've heard that the NASA divisions of certain DOD contractors never turn a profit. They only do it for shits and giggles, somewhere to stick people without a contract, and can charge enough in contract overage to cover their costs.
In other words, and to be blunt, building things shovels money into the pockets of politically well connected contractors. Running things, not so much.
No argument there.
However, the flip side of this is that it is much easier to shut down a not-yet-built program, than to shut down an existing one. So, the Hubble Space Telescope (which is still functioning well, and could probably be kept going for decades), is viewed as obsolete, and is shut down by NASA managers. The Webb (which is not intended for on-orbit servicing, and so will only last 5 years or so), is beloved by NASA managers, but is an obvious target for cost-cutters in the Congress. What's worse to me is that, if it is funded and launched, it will probably be late, and will die well before any replacement, thus causing huge gaps in our ability to observe from above the atmosphere.
The only reason Hubble kept going was because of the shuttle servicing missions. It cost about $2b to make. For the price of the five servicing missions (>$4b) we could have built and launched several new telescopes with the same or better upgraded technology and much less risk. The only reason it was designed to be serviced was as a manned spaceflight experiment and to give the ill-conceived space shuttle something to do.
I think that end-of-lifing of the Hubble ST is a major strategic blunder by NASA - just try getting that money re-established now. As far as what is to be done, I am not sure. I wish that we would stop electing so many bought and paid for politicians, though. That would be a start.
The reason Hubble is being decommissioned is because the shuttle is being decommissioned (because it is too costly and dangerous) and can no longer service it, not because it is obsolete. And they aren't going to throw a working telescope out, they're going to wait until it breaks again and then not fix it.
So...you're saying we should eliminate most of the government *except* NASA? Is that the one thing out of everything the private sector can't do? Just curious because I totally wasn't expecting that from a Ron Paul supporter. Most libertarians say things like "sell it off" or "starve it to make it more efficient". And yes, I did just skim through severalpages on the subject.
How is this profiling? It's not like they are predicting who will commit a crime, they're only predicting where crime will be highest. That makes perfect sense, because you want to station your officers where they will do the most good.
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Wait, what? No, that's not what I meant. It seemed the thread had diverged a bit from the OP, and your statement that you cannot "figure" acceleration without a reference point is patently false in the general case, so I took offense at your invocation of the Nobel Prize for something so simple. Forgive my juvenile use of sarcasm and capitalization, but I was merely defending a perceived slight to Newtonian physics.
I'm sure you remember from high school physics that there are two completely independent ways to compute acceleration: one using time and relative position, the other using force and mass. Any of those values can be directly measured in some cases, but in this case it is true that they are most likely tracking the satellite's position from afar and computing the force that would explain its trajectory over time. But if force and mass were measured, as they are in an accelerometer, and in fact could be on the spacecraft itself, no position reference would be required to compute your acceleration relative to the object's coordinate system.
I can go on to clarify that the statement "accelerating toward the sun" provides an external direction reference for the direction of the acceleration but not the velocity, leading once again to the conclusion that the word "deceleration" is inappropriate.
Dude, 6600 pounds is a really cheap payload. I'm surprised they can do anything with 3500 pounds now, that's like 10 bolts if you buy them from NASA. ;) ;)
A large chunk of the inefficiency at NASA itself is caused by, you guessed it, privatization of capabilities and variable cost contracts. It wouldn't matter that the work was being done by contractors instead of civil servants if the companies actually had an incentive to be efficient, but they don't. SpaceX, unlike all the other contractors NASA uses, is offered fixed-price launches, meaning they bear 100% of the financial risk and have every incentive to be efficient. I can only see this as an improvement.
Actually, I'm more interested in the motive force produced by the radiation of all that energy in one direction. I forget the equations for the impulse imparted by a photon though, and we'd have to compare it with the force from the solar wind as well. Maybe I should RTFA and see if they did already.
Yes exactly, you have to know position and time to know acceleration, this is why every Wiimote has a super duper GPS receiver that can resolve centimeter positions while indoors, which is why they all cost $10000000000 and are regulated by the military. What's that you say? They're only $20 and imported from China? Maybe that's because they use an ACCELEROMETER which senses the FORCE applied to a MASS whenever it gets ACCELERATED, without ever needing to know position OR time.
Tell that to your face when it's planted on the floor of a Jupiter colony. Alternatively, amaze your friends and relatives by standing on the wall while your spaceship accelerates. Gravitational acceleration is no different from any other acceleration, only the magnitude and direction different.
Actually Deceleration would mean a reduction in speed ( |v| ), while Acceleration would mean a change in velocity ( v ). Since you're only decelerating if the magnitude of your velocity is reducing relative to a specific inertial reference frame, then Deceleration is a pretty specific case of acceleration.
Furthermore, to specify this acceleration as a deceleration, you must assume that the velocity is directly *away* from the sun, which is likely not the case. So even if you did specify the reference frame (relative to the sun) and the initial velocity (away from the sun but not necessarily in a straight line), you cannot call it a deceleration and still convey the fact that the force is toward the sun.
And by the way, having just attended a lecture on spacecraft thermal design, I can say this is a perfectly reasonable theory. The thermal radiators used to dissipate excess heat into space necessarily need to be placed on the "dark" side of the spacecraft so they don't absorb energy from the sun. That means that the photons that radiate exert a force on the spacecraft pushing it back toward the sun, regardless of what direction it is moving. When the probe gets far enough from the sun, at some point the radiated heat will exceed the solar flux (which thins out as 1/r^2), and the net force will be toward the sun.
Well, the U.S. government is only a fraction of SpaceX's business, albeit a significant fraction. They are government contracting at its best: providing a service the government needs to do its job (launching research satellites and astronauts) for a fixed price regulated by a more-or-less competitive market, and for a fraction of the cost it would be if the government did it themselves. That's not socialism in my book any more than having a government in the first place is socialism.
SpaceX is not like a lot of other space contractors (e.g. United Space Alliance) that only exist by and for government contracts--those guys only exist to shave profits off the top of what should be government operations, and have every incentive to *raise* costs rather than lower them.
What is wrong with letting the private sector do what they are best at--taking existing technology and refining it to the point of profitability?
You may have untintentionally set up a straw man. My present argument was against privatisation of space flight research, not for restricting the privilege of lucky entrepreneurs to spend money on fun projects which might then make them more money.
The OP is arguing about diverting government money to "the free market", or something, as if SpaceX's profit-based implementation efforts are a substitute for NASA's research efforts (worse, he may be suggesting that one proper function of government is to channel money to private corporations). It's part of a wider philosophical obsession with applying capitalism everywhere that has resulted in the privatisation, stagnation and price-gouging of various industries and services since the early '80s.
Yes, I may have misinterpreted your comment a little. I detected some disdain in your comment about government projects being starved before privatization, etc., and then assumed that you were arguing against privatization in general because of that. I agree with everything you have said.
Yes, that's what I meant. Are you just supporting my argument, or was there more that you wanted to say?
So? What is wrong with letting the private sector do what they are best at--taking existing technology and refining it to the point of profitability? It's not trivial work, and we need it done just as much as we need the research in the first place. I think we've pretty well proven that the current system of government funding is incapable of actually producing an efficient production program.
Besides, the minute the space shuttle became a "production" vehicle, the progress stopped. It should never have been elevated to that status; the shuttle was an incomplete and half-baked idea from the start and should have been the first in a long list of modern spacecraft experiments by NASA. Instead, we were stuck with a boondoggle program in need of justification, hence Hubble and the space station. All worthy enterprises, but could have been so, so much cheaper if the shuttle had been refined for another 10 years--or changed completely--before production.
IMHO, the real test is to see if we can jump-start the real research in NASA while simultaneously promoting private-sector production development of existing technologies. And no, a Constellation-style (read: Apollo-style) heavy-lift rocket does not constitute real research. That too can be left to the private sector. I've said it a million times, Constellation was squarely on track to become just as expensive and unreliable as the shuttle--that "$9b wasted" was a drop in the bucket compared to what the program would have cost in the long run. The real research is in ion & plasma drives, space elevators, and planetary exploration vehicles, etc.
Sorry, we all know who you are, Mr. Anonymous Coward.
Yeah, we'll get patent reform all right...for the trolls, by the trolls. The America Invents act will make it easier than ever for a patent troll to actually steal an idea before it's patented, get the patent, and then win in court when they sue the original inventor.
Unfortunately, that is why we're all so depressed about patents (and many other things as well). It's because the status quo is one thing, but if Congress goes near it they can only make it worse.
At least they air any truths at all, which is more than can be said for most news outlets. And no, they don't air what you call "inconvenient truths"--if they are actually falsehoods. For example, on the Dianne Rehm show about vaccines and autism, she deliberately did not bring anyone from the "other side" because they have been so thoroughly proven false. To give falsehoods like that airtime would be irresponsible journalism, yet it is perpetrated every day by mainstream media "covering the controversy".
Well I'm assuming that the guy who makes a living telling investors whether their prospects' patents are unique (and thus valuable) knows more on the subject than I do. The point, I thought, was that even if they are legally distinguishable, the amount of "value added" is so little from one to the next that it's hard to consider them new inventions. All it does is make any one application infringe on even more patents.
Another amusing quote was of a software engineer who said he has four patents in his name, and he doesn't have a clue what they mean. By the time the lawyers were done with them, it was all gobbledegook to the person who invented them. That just seems wrong to me.
Yeah, the guy from Intellectual Ventures said there were two cases, TWO CASES out of their 35,000 patents, that had actually been licensed to manufacturers. And he couldn't even remember what industry they were involved in, much less which patents. When their entire spiel is that they "take languishing ideas and put them to good use", that is a pretty piss poor record.
I listened to the whole thing live streaming from my NPR station. I was interested to hear that almost everything considered "common knowledge" here on Slashdot held up under their scrutiny. They visited a company that makes software to find duplicate patents, and they said that about 30% of patents granted are duplicates of the same idea. They also said that the one case Intellectual Ventures gives as their "poster child" of an "inventor whose idea was being used illegally until IV came along" actually had over 5500 duplicates granted in the same time frame (nevermind all the prior art that existed). That one patent, by the way, was traced to a patent troll company that is obligated to give Intellectual Ventures a cut of their revenue from it...and the creator of the patent is trying to sue them, IIRC. So much for "encouraging innovation by helping poor inventors".
Another interesting statistic is that they cited polls claiming that 80% of software engineers say patents hurt their business and creativity. I know we've been repeating this to each other for years, but it's nice to see it backed up every now and then.
I'm curious how much of that research that companies do actually makes it to the light of day. Granted, university research is frequently stuck behind journal paywalls as well, but is there any comparison to be made? How much research that doesn't result in a patent actually gets published for others to use?
The difference is even greater because in the winter, there is less sunlight to do the heating. The savings during the summer win hands down. If the power goes out, the color of the roof is not going to make an appreciable difference--unless maybe you sleep in the attic. Never heard of anybody doing that.
All other comments aside, I'm curious what makes you think a Harvard architecture (separate program and data memory) would be transparent to users. I've used Harvard architecture microcontrollers extensively, so I know how secure that can make it. I also know that the minute you want to transmit a program using another program, i.e. downloading a program from the internet or even a software update, you have to make a bridge between data and program memory. If that bridge is transparent, there may as well be no distinction to begin with. The best you could do is have a popup that says "program y wants to make this code executable. Allow?" And then it's no different from the Unix "execute" permission, a tried and true technology that Windows only somewhat emulates.
The Republicans have gone so far right that they are dragging the rest of us with them. Almost daily, President Obama is championing proposals first brought by Republicans less than two years ago, only to be jeered off the stage by today's ultra-conservatives. It's like following in the wake of a glacier, lots of good bits to pick up, but no way to stop it from moving down the mountain (before it hits the sea and disintegrates).
I have heard it naked expressed that the real purpose of NASA is to make sure certain DOD contractors make a profit.
And I've heard that the NASA divisions of certain DOD contractors never turn a profit. They only do it for shits and giggles, somewhere to stick people without a contract, and can charge enough in contract overage to cover their costs.
In other words, and to be blunt, building things shovels money into the pockets of politically well connected contractors. Running things, not so much.
No argument there.
However, the flip side of this is that it is much easier to shut down a not-yet-built program, than to shut down an existing one. So, the Hubble Space Telescope (which is still functioning well, and could probably be kept going for decades), is viewed as obsolete, and is shut down by NASA managers. The Webb (which is not intended for on-orbit servicing, and so will only last 5 years or so), is beloved by NASA managers, but is an obvious target for cost-cutters in the Congress. What's worse to me is that, if it is funded and launched, it will probably be late, and will die well before any replacement, thus causing huge gaps in our ability to observe from above the atmosphere.
The only reason Hubble kept going was because of the shuttle servicing missions. It cost about $2b to make. For the price of the five servicing missions (>$4b) we could have built and launched several new telescopes with the same or better upgraded technology and much less risk. The only reason it was designed to be serviced was as a manned spaceflight experiment and to give the ill-conceived space shuttle something to do.
I think that end-of-lifing of the Hubble ST is a major strategic blunder by NASA - just try getting that money re-established now. As far as what is to be done, I am not sure. I wish that we would stop electing so many bought and paid for politicians, though. That would be a start.
The reason Hubble is being decommissioned is because the shuttle is being decommissioned (because it is too costly and dangerous) and can no longer service it, not because it is obsolete. And they aren't going to throw a working telescope out, they're going to wait until it breaks again and then not fix it.
So...you're saying we should eliminate most of the government *except* NASA? Is that the one thing out of everything the private sector can't do? Just curious because I totally wasn't expecting that from a Ron Paul supporter. Most libertarians say things like "sell it off" or "starve it to make it more efficient". And yes, I did just skim through several pages on the subject.
Because that's when they started PLANNING to shut down the shuttle and Hubble, more or less. You can't just go *click* over with things like that.
How is this profiling? It's not like they are predicting who will commit a crime, they're only predicting where crime will be highest. That makes perfect sense, because you want to station your officers where they will do the most good.