Because biology is not very energy efficient. This 5% efficiency is actually quite close to the theoretical maximum efficiency. Breaking down the numbers from the paper I cited in response to the GP's post, about 1/2 the sun's energy is outside of the photosynthetically active spectrum. About 1/4 of that energy is lost due to inefficiencies of the photosynthetic machinery in gathering light energy. (At about 75% efficiency, this is by far the most efficient part of the process.) For C3 photosynthesis, about 2/3 of the energy that is captured is wasted in the inefficiency of carbohydrate synthesis in photosynthesis. About 2/3 of the energy produced goes into simply maintaining the photosynthesis machinery. Those losses add up in a hurry. The breakdown is a bit different for C4 photosynthesis, but the end result is in the same ballpark.
Interestingly, this estimate is right around the theoretical maximal efficiency of photosynthesis. As outlined in Current Opinion in Biotechnology2008, vol. 19, pp. 153-159 (sorry, subscription only), the maximum theoretical efficiency of C3 photosynthesis is a mere 4.6%. C4 photosynthesis has a bit higher potential at 6.0%.
We can't even reach these efficiencies in plants (best for crops in a growing season is 2.4% for C3 or 3.7% for C4; see above reference), so sarahbau is right in saying that the amount of energy we could hope to get from this is quite low.
Others have already pointed out that the objects you compared with are not nearly as massive as an asteroid of comparable size. Furthermore, energy scales with not just mass, but also velocity squared. Asteroids approach at much higher closing speeds than something in low earth orbit that is being nudged back toward the surface. And anything we put into orbit is going to have much more aerodynamic drag per unit mass than a small lump of metal alloy, so it will slow down much more on the way down. Thus the significantly higher damage from an asteroid as compared with something in low earth orbit of the same mass
If those numbers are correct (5% taking up 95% of bandwidth), then kicking out the top few percent of users (of the entire population, not necessarily of the current customer base) seems exceptionally good for one's bottom line. After that, there's no point removing the new "heavy users" since you've already removed most of your traffic, and your existing infrastructure can more than handle the remaining traffic, so you're better off getting the revenue.
Not sure about Boston, but in nearby Cambridge, Harvard and MIT have arranged agreements with the city to contribute hundreds of millions of dollars to the city over time in order to be good citizens and compensate for the lack of property taxes from them.
Numbers and stats are nice and all, but beyond the headline numbers, your job is to give an executive summary. Here is what I've been doing. These things are working well. These are improvements that I am targeting or hope to target. Here are the unique challenges (you described one) and risks that we face and how I plan to deal with them.
I'm not a system administrator, but I don't see how the above is any different no matter what your job description.
The thing is, how one draws something is a decisive factor in how one views something. The two go hand in hand, and must be practiced. How one draws a molecule has everything to do with how well one understands what it really looks like. I consider myself non-artistic, but can crank out 3D chemical structures quite readily. It's simply a matter of practicing the skill.
That's all nice and well when taking notes that somewhat resemble writing. But drawing complex figures simply is not fast on a computer. And ASCII art, while very pretty, certainly isn't the solution to that problem.
Why is this information not already available in digital form ahead of time?
I remember my freshman physics class with Prof. Georgi. Even now, as a PhD organic chemist, I consider it one of the most fascinating classes that I ever took. He gave us full copies of his lecture notes in advance of each class. That doesn't change the fact that I was scribling lots of notes during the lectures since I was doing my best to understand everything he covered.
Sure, I can type more quickly than I can write words, too. But how quickly can you sketch a complex 3D chemical structure on a keyboard, or even with a mouse? Or draw a force diagram for a physics problem? Short of having a large tablet in front of you and a stylus (i.e. the closest electronic equivalent of pencil and paper), there's many situations where pencil (or pen if you're willing) really is the way to go. One should use the right tool for the task at hand. I use a computer all the time. I am exceptionally fast and proficient with ChemDraw and can type well over 100 wpm sustained. But when I want to just quickly sketch out something important since my mind's having a streak of useful thoughts, pen or pencil is my tool of choice because of the flexibility and speed it gives me. This, coming from a 21st century postdoc headed toward an academic career.
Can't. I already have to write a different grant proposal next week. But if it can wait until the week afterwards, then maybe. You think we can get an NIH R01 grant for this?
As noted in the article, Wall Street is a major draw for the top students. While in grad school, even my professor mentioned to me on several occasions that I probably would make a lot more afterwards if I left research and did investment banking, private equity, patent law, management consulting, or any of a number of other jobs, though he hoped I would stick with academic chemistry. I am looking for an academic post now, but I certainly can see the draw of the more lucrative fields. For one example, when McKinsey was recruiting PhD's at our institute a few years ago, first year total compensation was estimated at $130-165k. That's quite a bit higher than what the total compensation would have been at the time for the coveted entry level PhD positions at the top pharmaceutical companies, and the compensation in the business world would rise much more quickly in subsequent years. Doing good science is hard, and during the tougher times in grad school, it was extremely tempting to jump ship.
I realize you're trying to be funny, but mitochondrial DNA is inherited from mothers only. Therefore, it is good for tracing lineage through females, but completely useless for tracing lineage through males.
It is true that if you are producing X BTUs of heat inside the room, then to maintain temperature, you have to pump that much heat out. However, the efficiency of this heat transfer depends on the temperature difference between the inside and the outside. To the extent you want to force air (or any other heat transfer medium) that is already colder than outside to dump energy into air (or other medium) that is warmer, that will cost you energy.
Also, too cold, and you will invite condensation. In your hypothetical scenario, you'd need to run some pretty powerful air conditioning to prevent condensation from forming everywhere.
If you have access to Angewandte Chemie, check out this review (free abstract) on hydrogen storage. In one of the first figures in the paper (not at work, forget offhand whether it was figure 1 or 2), it makes a comparison between diesel, hydrogen, and state of the art lithium batteries, considering both energy density and "fuel tank" requirements. Even though the authors are very much pro-hydrogen, the figure is very much pro-diesel. Sure, the weight of the hydrogen is miniscule. But the tanks even under calculated ideal circumstances are rather heavy.
I'm just very nervous about entrusting the company meat and potatoes to an external business.
Does your company maintain a bank account at an external institution? If so, you are already entrusting critical aspects to other businesses. It's a matter of who to trust, and with what. If a company is spending a lot of time and effort doing something--in this case, maintaining machines, but this is true of anything--then one of two things is true. Hopefully, it's because it's a core part of what the company does, i.e. its reason for being. The second possibility is that it's tying up lots of resources that might be better deployed. Put another way, outsourcing may be worthwhile even if it is the more expensive option if it allows a company to better focus on what brings home the bacon.
Slashdot Mirror
Because biology is not very energy efficient. This 5% efficiency is actually quite close to the theoretical maximum efficiency. Breaking down the numbers from the paper I cited in response to the GP's post, about 1/2 the sun's energy is outside of the photosynthetically active spectrum. About 1/4 of that energy is lost due to inefficiencies of the photosynthetic machinery in gathering light energy. (At about 75% efficiency, this is by far the most efficient part of the process.) For C3 photosynthesis, about 2/3 of the energy that is captured is wasted in the inefficiency of carbohydrate synthesis in photosynthesis. About 2/3 of the energy produced goes into simply maintaining the photosynthesis machinery. Those losses add up in a hurry. The breakdown is a bit different for C4 photosynthesis, but the end result is in the same ballpark.
and assuming 5% efficiency for photosynthesis
Interestingly, this estimate is right around the theoretical maximal efficiency of photosynthesis. As outlined in Current Opinion in Biotechnology 2008, vol. 19, pp. 153-159 (sorry, subscription only), the maximum theoretical efficiency of C3 photosynthesis is a mere 4.6%. C4 photosynthesis has a bit higher potential at 6.0%.
We can't even reach these efficiencies in plants (best for crops in a growing season is 2.4% for C3 or 3.7% for C4; see above reference), so sarahbau is right in saying that the amount of energy we could hope to get from this is quite low.
Others have already pointed out that the objects you compared with are not nearly as massive as an asteroid of comparable size. Furthermore, energy scales with not just mass, but also velocity squared. Asteroids approach at much higher closing speeds than something in low earth orbit that is being nudged back toward the surface. And anything we put into orbit is going to have much more aerodynamic drag per unit mass than a small lump of metal alloy, so it will slow down much more on the way down. Thus the significantly higher damage from an asteroid as compared with something in low earth orbit of the same mass
Which disqualifies your toaster since it's no longer on earth.
What would you do about the many friends who want a laptop? Nowadays, they're the majority.
Exactly. It's not that those guys got lucky. It's that they followed up on what exactly was interesting about what they observed.
17x16? That's easy. Any self-respecting member of /. should know that 16x16 = 256. Therefore, 17x16 = 256 + 16 = 272.
If those numbers are correct (5% taking up 95% of bandwidth), then kicking out the top few percent of users (of the entire population, not necessarily of the current customer base) seems exceptionally good for one's bottom line. After that, there's no point removing the new "heavy users" since you've already removed most of your traffic, and your existing infrastructure can more than handle the remaining traffic, so you're better off getting the revenue.
Okay. Color me stupid, but aren't there existing hardon colliders that function just fine, like the one in Brookhaven?
I'm not sure about any hardons colliding at Brookhaven. Hadrons, on the other hand...
Yes. Your bug fix should not break what is not already broken.
Not sure about Boston, but in nearby Cambridge, Harvard and MIT have arranged agreements with the city to contribute hundreds of millions of dollars to the city over time in order to be good citizens and compensate for the lack of property taxes from them.
I thought piracy was the key to stopping global warming. Why are they trying to speed up global warming?
Numbers and stats are nice and all, but beyond the headline numbers, your job is to give an executive summary. Here is what I've been doing. These things are working well. These are improvements that I am targeting or hope to target. Here are the unique challenges (you described one) and risks that we face and how I plan to deal with them.
I'm not a system administrator, but I don't see how the above is any different no matter what your job description.
Even the upgrade DVD will happily install on a clean drive, without verification of the operating system that might have previously been on the drive.
The thing is, how one draws something is a decisive factor in how one views something. The two go hand in hand, and must be practiced. How one draws a molecule has everything to do with how well one understands what it really looks like. I consider myself non-artistic, but can crank out 3D chemical structures quite readily. It's simply a matter of practicing the skill.
That's all nice and well when taking notes that somewhat resemble writing. But drawing complex figures simply is not fast on a computer. And ASCII art, while very pretty, certainly isn't the solution to that problem.
Why is this information not already available in digital form ahead of time?
I remember my freshman physics class with Prof. Georgi. Even now, as a PhD organic chemist, I consider it one of the most fascinating classes that I ever took. He gave us full copies of his lecture notes in advance of each class. That doesn't change the fact that I was scribling lots of notes during the lectures since I was doing my best to understand everything he covered.
Sure, I can type more quickly than I can write words, too. But how quickly can you sketch a complex 3D chemical structure on a keyboard, or even with a mouse? Or draw a force diagram for a physics problem? Short of having a large tablet in front of you and a stylus (i.e. the closest electronic equivalent of pencil and paper), there's many situations where pencil (or pen if you're willing) really is the way to go. One should use the right tool for the task at hand. I use a computer all the time. I am exceptionally fast and proficient with ChemDraw and can type well over 100 wpm sustained. But when I want to just quickly sketch out something important since my mind's having a streak of useful thoughts, pen or pencil is my tool of choice because of the flexibility and speed it gives me. This, coming from a 21st century postdoc headed toward an academic career.
Pencil/paper and digitizing later should be fine.
Who wants to write the grant proposal?
Can't. I already have to write a different grant proposal next week. But if it can wait until the week afterwards, then maybe. You think we can get an NIH R01 grant for this?
As noted in the article, Wall Street is a major draw for the top students. While in grad school, even my professor mentioned to me on several occasions that I probably would make a lot more afterwards if I left research and did investment banking, private equity, patent law, management consulting, or any of a number of other jobs, though he hoped I would stick with academic chemistry. I am looking for an academic post now, but I certainly can see the draw of the more lucrative fields. For one example, when McKinsey was recruiting PhD's at our institute a few years ago, first year total compensation was estimated at $130-165k. That's quite a bit higher than what the total compensation would have been at the time for the coveted entry level PhD positions at the top pharmaceutical companies, and the compensation in the business world would rise much more quickly in subsequent years. Doing good science is hard, and during the tougher times in grad school, it was extremely tempting to jump ship.
I realize you're trying to be funny, but mitochondrial DNA is inherited from mothers only. Therefore, it is good for tracing lineage through females, but completely useless for tracing lineage through males.
It is true that if you are producing X BTUs of heat inside the room, then to maintain temperature, you have to pump that much heat out. However, the efficiency of this heat transfer depends on the temperature difference between the inside and the outside. To the extent you want to force air (or any other heat transfer medium) that is already colder than outside to dump energy into air (or other medium) that is warmer, that will cost you energy.
Also, too cold, and you will invite condensation. In your hypothetical scenario, you'd need to run some pretty powerful air conditioning to prevent condensation from forming everywhere.
If you have access to Angewandte Chemie, check out this review (free abstract) on hydrogen storage. In one of the first figures in the paper (not at work, forget offhand whether it was figure 1 or 2), it makes a comparison between diesel, hydrogen, and state of the art lithium batteries, considering both energy density and "fuel tank" requirements. Even though the authors are very much pro-hydrogen, the figure is very much pro-diesel. Sure, the weight of the hydrogen is miniscule. But the tanks even under calculated ideal circumstances are rather heavy.
I'm just very nervous about entrusting the company meat and potatoes to an external business.
Does your company maintain a bank account at an external institution? If so, you are already entrusting critical aspects to other businesses. It's a matter of who to trust, and with what. If a company is spending a lot of time and effort doing something--in this case, maintaining machines, but this is true of anything--then one of two things is true. Hopefully, it's because it's a core part of what the company does, i.e. its reason for being. The second possibility is that it's tying up lots of resources that might be better deployed. Put another way, outsourcing may be worthwhile even if it is the more expensive option if it allows a company to better focus on what brings home the bacon.