Without the moon, there would be no life on Earth.
When that huge impact happened, what was blown off was most of the lighter, surface material of the early Earth. All of those light silicates eventually clumped up to form the moon, leaving a body with a much thinner crust and a higher overall proportion of heavy metals. This made it much easier for convection currents to run inside the Earth's core, allowing the creation of a magnetic field. This deflected the solar wind, protecting the Earth from most of the hard radiation from the Sun. Venus doesn't have much in the way of protection:
Theories of the dynamos operating in the liquid cores of the newly accreted terrestrial planets suggest that there was a magnetic moment of Venus of the same order as Earth's for about the first billion years of Venus' life. During that time, thermal convection from the heat left over from accretion drove the dynamo. However, after that energy source diminished, there was apparently no source to replace it. While solid core formation in Earth's interior maintains its dynamo to this day by virtue of the related 'stirring' of the molten core around it, Venus appears to either lack the necessary internal ingredients (chemical or physical) for solid core formation, or to have ceased such processes at an earlier time if they resulted in complete core solidification or arrested core solidification.
It's the moon pulling on the Earth that keeps this "stirring" going, by tugging on the surface and slowing it at a faster rate than the core.
The relatively thin crust made it much easier for the surface to crack and float around in pieces. If it were really thick, like on Venus, it would be too rigid for easy cracking, bumping, and grinding. Plate tectonics causes a lot of carbon on the surface to be sucked under the surface and recycled.
Tidal forces caused by the moon also pulled on the early Earth atmosphere, causing it to expand upward beyond the protection of the magnetic field. Once up there, the gases were swept away.
... the features of email. BCC and CC, searchability...... everyone's being familiar with Email helps it...
Everyone's familiar with it, but no one can agree on what to call it.
Is it "email", "Email", "e.mail", "E.mail", "e-mail" or "E-mail"?
A few years ago, we had a big, mandatory, all-hands training session on the rollout of Groupwise, with hours and hours spent introducing us to all the nifty collaborative tools that come with it... calenders and meeting schedulers and priority alerts and all kinds of crap. I can still hear the repeated refrain from the trainbots: "Groupwise is a lot more than just e.mail!"
As far as I'm aware, nobody uses any of it, except for the e.mail.
No kidding. In the Real World, you will constantly be told to work with somebody on this or that project. The boss knows damn well this is a terrible mismatch. Since you are a hard working, knowledgeable, productive employee and Bob is either lazy, stupid, incompetent or all three, the boss' idea is that, through some miracle of "setting a good example" or "crosstraining" or "peer-peer development", your good qualities will rub off on him, making him a better worker.
In fact, what will happen is that Bob will blather for a while during the planning meetings, offering obvious and/or stupid suggestions that you have already thought of and/or dismissed, and making grandiose claims of how much great work you'll do together. When the time comes to actually do something, though, he will either be nowhere to be found, or he will be so "busy" with other things that he will be of no use.
You will be left to do the work of two people by yourself.
When it comes time to turn the work in, though, he will not only request, but will *demand* an equal share in the credit, since everything that was accomplished "was his idea".
These people are leeches, fleas, ticks, surviving from day to day by being carried along, sucking the lifeblood of the actual workers.
You can either accept that ticks are a part of the ecology, and everybody has to put up with them, or undertake a huge effort to rid yourself of the tick. Either way, don't expect anything useful to come from the tick - all it wants is a free ride.
I'm guessing that the mathematicians and the physicists will issue a joint statement announcing that they have, in fact, established this connection, and that the number which lies at the heart of both the physical world and the abstract world of mathematics is, in fact, 42.
The announcement will be made at a press conference this Saturday, April 1.
Having seen the Google video, I predict this will be a bust. The player goes from cellular life to primitive vertebrates to sentience to resource management to diplomacy to space exploration. Each phase is described as "a simple version of Populous" or "a simple version of SimCity" or "a simple version of Civilization", etc.
People who like to play SimCity are not necessarily going to be interested in playing SimAnt, Populous or Civilization, especially if they have to play games they don't like for 12 hours before they get to advance to be allowed to play the part of the game that they *do* like.
Besides, why would anyone spend a bunch of time playing a series of watered down versions of SimAnt/Populous/SimCity/Civilization when they can play the real thing?
So how did they get such a big energy increase? From their press release:
The new achievement -- temperatures of billions of degrees -- was obtained in part by substituting steel wires in cylindrical arrays 55 mm to 80 mm in diameter for the more typical tungsten wire arrays, approximately only 20 mm in diameter. The higher velocities achieved over these longer distances were part of the reason for the higher temperatures.
(The use of steel allowed for detailed spectroscopic measurements of these temperatures impossible to obtain with tungsten.)
The paper that proposes a model to explain the results says that the final plasma was pinched down to 3.6mm. If a glass tube containing fusable material (D+T ?) were at the center of the hohlraum, it would also get crushed from the inrushing plasma.
I had to Google NEN to determine that it stands for New England Nuclear. Sorry, no can do. The only isotopes I use are permanent fixtures of my irradiator, just over 50,000 Curies of cesium-137, behind three feet of steel and lead. *Warm* steel and lead.
I didn't see 28 Days, but I can certainly understand the sentiment. Irradiated food is not only safe, wholesome and nutritious, it is ofter safer, healthier and more nutritious than non-irradiated food, since the spoilage organisms and any human pathogens have been eliminated. This is especially important for commodities that have a history of foodborne illness outbreaks, or in an environment where multiple foods may pose an increased risk of harboring pathogens.
This isn't just me spouting the party line because I drank the Kool-Aid. There's more than 60 years of research by industry, academia and government on the safety and nutritional adequacy of irradiated food, and it's culminated in as solid an endorsement as anything could receive.
Plasma treatment of food is also deeply, deeply cool. There are some exceptionally fascinating aspects to this technology, not just for food, but for lots and *lots* of applications. You'll be hearing more about it in two or three years. As it happens, I'm writing a book chapter on non-thermal plasma treatment of food. It's open in another window, and I should be working on it instead of procrastinating on Slashdot.
In my experience, this is hardly an accurate generalization. Californians can be just as resistant to challenges to their worldview, especially to the notion that California is not the best place on earth. I was once visiting family in San Francisco, in July. I woke up one morning to see that it was raining. I commented on this over breakfast.
"It's raining", I said. [not the wittiest thing I've ever said, but it was early in the day.]
"Oh, no, it never rains this time of year.", said my Mom.
"Look outside. It's raining."
"No, it never rains this time of year. That's just fog."
"How do you define 'fog'? Water is falling from the sky in drops. If you stand outside for three minutes, you will get wet from the water falling from the sky. Water falling from the sky is not 'fog', it is 'rain'. Water is falling from the sky, therefore it is raining."
"No, it's just a heavy fog. It never actually rains this time of year."
I gave it up at that point. Later in the day, I mentioned to my brother and sister-in-law that it had been raining in the morning, and got the exact same reaction. It never rains this time of year, therefore, despite the drops of water falling from the sky and splashing on your hair, glasses and the pavement at your feet, it cannot possibly be raining.
A year later I mentioned this interchange to someone from San Francisco. He agreed with them, that I must have been mistaking an unusually heavy fog for rain, since it doesn't rain in San Francisco in July. Even outside the rose-colored glow of California, he did not accept the definition of "water falling from the sky" as equivalent to "rain".
I've come to the conclusion that Easterners are hide-bound reactionaries, Californians are loopy lotus-eaters.
No kidding. I grew up in St. Louis (poor boys and soda), moved to Chicago (heroes and soda pop), then to East Lansing, Michigan (grinders and pop), then to Philadelphia (hoagies and soda).
Salary, housing costs, public transportation issues... all of these things are big picture that you can address ahead of time. It's the little stuff that gets under your skin and will determine wether you are comfortable in your new surroundings or not. Culture shock will be a far greater adjustment than anything else.
I've lived here six and a half years, and this stuff still gets me. Even worse, my kids are growing up speaking with a Philly accent, which continues to sound strange and ill-pronounced to my midwestern ear.
I moved to the Philadelphia suburbs from Michigan several years ago. At a volunteer function, somebody was going to make run over to a sandwich shop to get lunch for everybody. I ordered an Italian hoagie.
"With oil or mayo?", asked the person who was making the run. "Neither. I'd like mustard on my sandwich. Brown if they have it, otherwise yellow is OK."
I swear to God, all conversation stopped and everyone stared at me. These were all people who had grown up in the Philadelphia area, locals for at least 5 genereations.
"Mustard? On a hoagie? You want me to ask them to put mustard on a hoagie?" She sounded like I'd asked for a crunchy frog with a side of anthrax ripple.
Asking for mustard on a sandwich was apparently such an outrageously bizzare concept that, it took me a minute or two to convince them that I was serious about it, and did not want oil or mayo, but mustard. This was such heresey, that one year later, at this same function, this woman's son referred to me as the guy who wanted mustard on his hoagie.
This, in a place where they put mustard on pretzels, and eat it with a straight face.
Your biggest problem won't be computer, work or salary related... it will be cultural.
I think that at some point every sport imposes artificial limitations, in order to make sure that the competition is between the players, and not between their wallets. Technological innovation is allowed up to a point, but then the organizers look at how the innovation changes the character of the game and decide to deliberately restrict this, in order to preserve the original character.
The PGA doesn't allow those new super-dimpled balls that add 50 yards to every drive. Rotary engines are banned in Le Mans. The NFL outlawed stickum on receiver's gloves.
It can be behavioral, not just technological. The National League doesn't allow designated hitters. The NBS put in a shot clock.
If you think that these innovations should be allowed, then you can start a new league where they are, and have a version of the game that's different in character and tone that the one that restricts them. The game dynamics in the American League are very different than in the National League. Is one better than another?(*) No, just different.
Artificial limitations are rules, and every game uses rules to create the kind of competition the players want.
(*) Actually, yes, the National League is better, because the designated hitter rule is the stupidest, more asinine mistake ever in the history of baseball. I was just being ecumenical and even handed up there, but what I really think is pure flamebait.
I'm reminded of a conversation I had way back in the day, when I played D&D a lot. (This was back before PCs, so it was all books and dice, paper and pencil.) A friend was telling me all about this cool item he'd read about in one of his books, a quiver of ice arrows or something.
I thought up a cool item (a lightning sword or something) and said, "Cool! I'll write it up and use it in our next session!" He got really mad, and said you can't just make stuff up and start to use it. You have to go on a quest, win it through serious effort and struggle.
I reminded him that it's all make-believe anyway, and why couldn't I just magically get this? He insisted it wasn't the same, that it wasn't right. If I had obtained it through a big quest worthy of such an item, that would be OK, but just suddenly having it wasn't. I suggested that I make up some long story about a tremendous quest that I had gamed with another group, which culminated in me having the item. "Not the same!", he insisted.
I was irritated at the time, because I really wanted the cool item, but now, I see that he was right. If you don't play by the rules, then the game is no challenge, and if you aren't playing for the challenge, to test your skill and creativity and endurance, then you are just there for the scenery, a tourist watching a movie.
Ignoring the rules makes any game go faster, and let's you score better, but so what? Your drive off the tee goes into the rough? Pick up the ball and carry it to the hole... hole in one! It's fourth and 16 on your own 9 yard line? Give yourself twelve extra downs in the possession... touchdown! You're only 18 miles into the marathon, and your legs are giving out? Take a shortcut through central park... first place!
If you don't want to actually play the game, why pretend to be a player?
the waste problem, the uranium mining, transport and processing needed to produce the fuel, transport and trade with radioctive fuel and waste materials, the "dirty" building which will sooner or later need to be decommissioned, the finite uranium resources available, the potential misuse for weapons, etc. etc.
As opposed to the much greater environmental impact and economic costs associated with mining, processing, transportation, harmful waste products and finite resource base associated with coal, our current favorite source of electricity?
And don't get me started on the "potential for weaponization". I once got hit with a lump of coal, and it hurt like hell.
I don't think that they are proposing that you re-use the heat. Power generators like to have steam go from ~900F to ~500F, to imporve efficiency. Everything after that is waste, which they dump out of the cooling tower. If the power plant is nearby some homes & offices, you could capture that heat and pipe it to where it's needed, but that would require more heat exchangers, etc. I'm not sure the economics would work.
For the desalination or hydrogen cracking, I believe they are talking about that being the *primary application* of the reactor. In a place where you need power, you use the heat to make electricity. In a place where you need water, you use it to desalinate. In a place where you need hydrogen, you use it to crack water.
Electricity is great for running stationary objects like buildings, but not so good at vehicles. A storable fuel is better for that.
Consider some seaside urban area that is outgrowing its supply of fresh water. Since these reactors are modular, you could install one reactor to make electricity, one to make water and one to make hydrogen for the cars. The power, water and hydrogen distribution grids are all in place and benefit from economies of scael, and you can share the administrative/training/regulatory overhead of running the reactors.
Need even more power/water/H2? Install another module.
Escape velocity is defined as @sqrt(2GM/r). G is 6.67e-11 m^3 s^-2 kg^-1. M and r (hald the diameter) for this asteroid are 2.7e11 kg and 290 m, respectively.
So, Ve for this asteroid is = @sqrt(2*6.67e-11*2.7e11/290) = 0.35 m/s
This number is a *lot* lower that I would have guessed without having done the calculations.
I stand corrected... if you can land any kind of functioning acceleration system, achieving escape velocity for material pitched off the asteroid will be no big deal, even if you want to use really big rocks.
The Navy's rail gun gives a muzzle velocity of 2500m/s for a 20kg round. A system operating at even a fraction of this power level would be able to fling even very, very large rocks off at escape velocity.
I guess I didn't express myself clearly. People are accumstomed to thinking of escape velocity as just that, the velocity at which you can leave an earth orbit. No one ever thinks about the effect of the gravitational pull that the spacecraft is exerting on the earth, because they don't need to, it's trivial.
However, when you fling those rocks off the surface of the asteroid, the pull that they exert on the asteroid is non-trivial, especially since you're going to be chucking a significant % of the asteroids mass. Fling the rock to the left, the asteroid moves slightly to the right... until the mutual gravitational pull of the rock & asteroid pulls them back together, when the rock comes flying back to the left and the asteroid moves slightly back to the right.
//high school physics analogy mode:ON//Imagine an ice skater who throws a baseball. She moves to the right slightly, it moves to the left a lot. But if the ball is on the end of a bungie cord, and they continue to intereact, it will eventually come back fast, she will move back slightly, and they will meet in the middle, right where they started.//high school physics analogy mode:OFF//
It's not really an escape velocity problem where you're trying to get the rock out of an orbit around the asteroid... if the rock comes back, then that negates the effect of its having been flung. If you don't fling the rock away really, really fast, it's essentially a two-body system; you need to keep them apart long enough to give some third body a chance to interact with the system. Put a lot of space between then by giving the rock a lot of energy, and it's more likely to encounter some other gravity well to keep it away for good. Decay of its solar orbit, contact with earth, or some other third body.
The problem is that you have to throw the rocks really, really hard. If you just lob them off the surface, you'll give the asteroid a minute nudge as the rock flies away, but there will still be a gravitational attraction between the asteroid and the piece of rock you threw. If they remain close together (and I'm speaking of close in astronomical terms), then they will just make up a two-body system with the center of mass precisely where it was before. Eventually, the asteroid and the cloud of rocks you threw will just attract each other back together right at the pre-existing center of mass, with no net change in orbit.
You need to fling the rocks far enough away so that some other body becomes more important to them, gravitationally speaking. Once the cloud of rocks get dragged away by the Earth, the Sun, Venus or some other convenient gravity well, they are far enough away from the asteroid to be really out of the picture in terms of influencing the asteroid's orbit.
If you start soon enough, you don't have to throw them so far, since the small rocks' orbits around the sun will decay sooner than the asteroid. However, you'll need a couple of dozen solar orbits to really make them fall inward much, taking them out of the asteroid's influence. Since each asteroid's orbit is almost two years, if you want to land a cannon and start flinging rocks, you need to be at T-60 years (30 orbits) for it to be effective. That means a working gas cannon/rail gun/etc., on the asteroid, flinging rocks, in 2040.
The Navy is thinking about a ship-mounted rail gun. This can fling a 15kg round at 2.5km/s, with a rate of fire of 6-12 rounds per minute. It would need a dedicated nuclear reactor, and a machined 5kg sabot for each round, and machined rounds, but nevermind. Assuming that this rail gun could fling 22kg rounds at 10 per minute at 1km/s, that's one metric ton every 10 minutes, or 6 metric tons an hour. If you can sustain that rate of fire for 12 hours out of every 24, day in, day out, that means you'd have flung your 1,000,000th metric ton 13,888 days after you start. That's 38 years of continuous operation. Land 10 rail guns, it's 3.8 years.
Keeping the gun(s) fed would be a challenge. Add in the operation and mainenance for the guns, the reactor, and the munitions manufacturing facility (where you turn rocks into rounds), the mining facility (where you dig up the rocks in the first place), not to mention the living quarters, and you've got all of the problems of a major space colony. Oh, and the cosmic rays would probably kill any astronaut who is on-site operating or repairing it.
A 15 month delay in notification for an extremely unlikely event which might happen (if at all) 1176 months from now is not a big deal.
This is roughly equivalent to your wife finding out yesterday (March 1, 2006) that there is a 1 in 3000 chance that she might blow $900 on a spa trip with her mother for Mother's Day (May 14, 2006) and waiting one day to tell you about it.
Potentially catastrophic? Sure. Something to be worried about? No, because the overwhelming likelihood is that as the date approaches, the probability of the event actually taking place will drop to zero, just like all the other "near misses" that never happened, like the proposed mother/daughter cruise to Turkey, or that "girl's night out" to Las Vegas they keep talking about.
Actually, that should be "Escherichia coli", not the informal term "Escheria", since the enterohemorrhagic and verotoxigenic strains are of most significance.
Acinetobacter baumannii This drug is perhaps most well known for its presence in troops returning from Iraq, where it has infected dozens of patients and spread to others inside hospitals.
Obviously, a drug can't infect anyone. A. baumanii is not a drug, it's a bug.
And don't get me started on the inclusion of Aspergillus in a list of dangerous bacteria.
Geez, it's no wonder people are concerned about the state of science education in America. If this were an article about the six most popular cars and had this many errors (e.g. a discussion of the Honda Accordes, a reference to the Rav4 as a sedan and the inclusion of the Harley-Davidson Softail), it would be treated as a joke.
Slashdot Mirror
When that huge impact happened, what was blown off was most of the lighter, surface material of the early Earth. All of those light silicates eventually clumped up to form the moon, leaving a body with a much thinner crust and a higher overall proportion of heavy metals. This made it much easier for convection currents to run inside the Earth's core, allowing the creation of a magnetic field. This deflected the solar wind, protecting the Earth from most of the hard radiation from the Sun. Venus doesn't have much in the way of protection: It's the moon pulling on the Earth that keeps this "stirring" going, by tugging on the surface and slowing it at a faster rate than the core.
The relatively thin crust made it much easier for the surface to crack and float around in pieces. If it were really thick, like on Venus, it would be too rigid for easy cracking, bumping, and grinding. Plate tectonics causes a lot of carbon on the surface to be sucked under the surface and recycled.
Tidal forces caused by the moon also pulled on the early Earth atmosphere, causing it to expand upward beyond the protection of the magnetic field. Once up there, the gases were swept away.
... the features of email. BCC and CC, searchability ... ... everyone's being familiar with Email helps it...
Everyone's familiar with it, but no one can agree on what to call it.
Is it "email", "Email", "e.mail", "E.mail", "e-mail" or "E-mail"?
A few years ago, we had a big, mandatory, all-hands training session on the rollout of Groupwise, with hours and hours spent introducing us to all the nifty collaborative tools that come with it... calenders and meeting schedulers and priority alerts and all kinds of crap. I can still hear the repeated refrain from the trainbots: "Groupwise is a lot more than just e.mail!"
As far as I'm aware, nobody uses any of it, except for the e.mail.
No kidding. In the Real World, you will constantly be told to work with somebody on this or that project. The boss knows damn well this is a terrible mismatch. Since you are a hard working, knowledgeable, productive employee and Bob is either lazy, stupid, incompetent or all three, the boss' idea is that, through some miracle of "setting a good example" or "crosstraining" or "peer-peer development", your good qualities will rub off on him, making him a better worker.
In fact, what will happen is that Bob will blather for a while during the planning meetings, offering obvious and/or stupid suggestions that you have already thought of and/or dismissed, and making grandiose claims of how much great work you'll do together. When the time comes to actually do something, though, he will either be nowhere to be found, or he will be so "busy" with other things that he will be of no use.
You will be left to do the work of two people by yourself.
When it comes time to turn the work in, though, he will not only request, but will *demand* an equal share in the credit, since everything that was accomplished "was his idea".
These people are leeches, fleas, ticks, surviving from day to day by being carried along, sucking the lifeblood of the actual workers.
You can either accept that ticks are a part of the ecology, and everybody has to put up with them, or undertake a huge effort to rid yourself of the tick. Either way, don't expect anything useful to come from the tick - all it wants is a free ride.
I'm guessing that the mathematicians and the physicists will issue a joint statement announcing that they have, in fact, established this connection, and that the number which lies at the heart of both the physical world and the abstract world of mathematics is, in fact, 42.
The announcement will be made at a press conference this Saturday, April 1.
it's like I bought a very fast Mac, then just over two weeks later I received a very fast PC of equivalent specs for free.
Not quite free, since you have to buy a copy of XP.
Um...
You *did* pay for that copy of XP, right?
If you feel something hurting, stop. right away. Then look at what you're doing and what could cause it, and try something different.
The same advice could be given to undergraduates taking CompSci courses.
Having seen the Google video, I predict this will be a bust. The player goes from cellular life to primitive vertebrates to sentience to resource management to diplomacy to space exploration. Each phase is described as "a simple version of Populous" or "a simple version of SimCity" or "a simple version of Civilization", etc.
People who like to play SimCity are not necessarily going to be interested in playing SimAnt, Populous or Civilization, especially if they have to play games they don't like for 12 hours before they get to advance to be allowed to play the part of the game that they *do* like.
Besides, why would anyone spend a bunch of time playing a series of watered down versions of SimAnt/Populous/SimCity/Civilization when they can play the real thing?
One where the mortgage has a stamp on it that reads, "Paid in Full".
(28 years and 3 months from now, I'm gonna tell the bank to KMA!)
The paper that proposes a model to explain the results says that the final plasma was pinched down to 3.6mm. If a glass tube containing fusable material (D+T ?) were at the center of the hohlraum, it would also get crushed from the inrushing plasma.
I had to Google NEN to determine that it stands for New England Nuclear. Sorry, no can do. The only isotopes I use are permanent fixtures of my irradiator, just over 50,000 Curies of cesium-137, behind three feet of steel and lead. *Warm* steel and lead.
I didn't see 28 Days, but I can certainly understand the sentiment. Irradiated food is not only safe, wholesome and nutritious, it is ofter safer, healthier and more nutritious than non-irradiated food, since the spoilage organisms and any human pathogens have been eliminated. This is especially important for commodities that have a history of foodborne illness outbreaks, or in an environment where multiple foods may pose an increased risk of harboring pathogens.
This isn't just me spouting the party line because I drank the Kool-Aid. There's more than 60 years of research by industry, academia and government on the safety and nutritional adequacy of irradiated food, and it's culminated in as solid an endorsement as anything could receive.
I'm presenting a talk on the subject at the Institute of Food Technologists's annual meeting in Orlando this July. Any Slashdotters who are registered for the meeting may want to swing by.
Plasma treatment of food is also deeply, deeply cool. There are some exceptionally fascinating aspects to this technology, not just for food, but for lots and *lots* of applications. You'll be hearing more about it in two or three years. As it happens, I'm writing a book chapter on non-thermal plasma treatment of food. It's open in another window, and I should be working on it instead of procrastinating on Slashdot.
I like my job. It's fun being a scientist.
In my experience, this is hardly an accurate generalization. Californians can be just as resistant to challenges to their worldview, especially to the notion that California is not the best place on earth. I was once visiting family in San Francisco, in July. I woke up one morning to see that it was raining. I commented on this over breakfast.
"It's raining", I said. [not the wittiest thing I've ever said, but it was early in the day.]
"Oh, no, it never rains this time of year.", said my Mom.
"Look outside. It's raining."
"No, it never rains this time of year. That's just fog."
"How do you define 'fog'? Water is falling from the sky in drops. If you stand outside for three minutes, you will get wet from the water falling from the sky. Water falling from the sky is not 'fog', it is 'rain'. Water is falling from the sky, therefore it is raining."
"No, it's just a heavy fog. It never actually rains this time of year."
I gave it up at that point. Later in the day, I mentioned to my brother and sister-in-law that it had been raining in the morning, and got the exact same reaction. It never rains this time of year, therefore, despite the drops of water falling from the sky and splashing on your hair, glasses and the pavement at your feet, it cannot possibly be raining.
A year later I mentioned this interchange to someone from San Francisco. He agreed with them, that I must have been mistaking an unusually heavy fog for rain, since it doesn't rain in San Francisco in July. Even outside the rose-colored glow of California, he did not accept the definition of "water falling from the sky" as equivalent to "rain".
I've come to the conclusion that Easterners are hide-bound reactionaries, Californians are loopy lotus-eaters.
No kidding. I grew up in St. Louis (poor boys and soda), moved to Chicago (heroes and soda pop), then to East Lansing, Michigan (grinders and pop), then to Philadelphia (hoagies and soda).
Salary, housing costs, public transportation issues... all of these things are big picture that you can address ahead of time. It's the little stuff that gets under your skin and will determine wether you are comfortable in your new surroundings or not. Culture shock will be a far greater adjustment than anything else.
I've lived here six and a half years, and this stuff still gets me. Even worse, my kids are growing up speaking with a Philly accent, which continues to sound strange and ill-pronounced to my midwestern ear.
I moved to the Philadelphia suburbs from Michigan several years ago. At a volunteer function, somebody was going to make run over to a sandwich shop to get lunch for everybody. I ordered an Italian hoagie.
"With oil or mayo?", asked the person who was making the run.
"Neither. I'd like mustard on my sandwich. Brown if they have it, otherwise yellow is OK."
I swear to God, all conversation stopped and everyone stared at me. These were all people who had grown up in the Philadelphia area, locals for at least 5 genereations.
"Mustard? On a hoagie? You want me to ask them to put mustard on a hoagie?" She sounded like I'd asked for a crunchy frog with a side of anthrax ripple.
Asking for mustard on a sandwich was apparently such an outrageously bizzare concept that, it took me a minute or two to convince them that I was serious about it, and did not want oil or mayo, but mustard. This was such heresey, that one year later, at this same function, this woman's son referred to me as the guy who wanted mustard on his hoagie.
This, in a place where they put mustard on pretzels, and eat it with a straight face.
Your biggest problem won't be computer, work or salary related... it will be cultural.
I think that at some point every sport imposes artificial limitations, in order to make sure that the competition is between the players, and not between their wallets. Technological innovation is allowed up to a point, but then the organizers look at how the innovation changes the character of the game and decide to deliberately restrict this, in order to preserve the original character.
The PGA doesn't allow those new super-dimpled balls that add 50 yards to every drive. Rotary engines are banned in Le Mans. The NFL outlawed stickum on receiver's gloves.
It can be behavioral, not just technological. The National League doesn't allow designated hitters. The NBS put in a shot clock.
If you think that these innovations should be allowed, then you can start a new league where they are, and have a version of the game that's different in character and tone that the one that restricts them. The game dynamics in the American League are very different than in the National League. Is one better than another?(*) No, just different.
Artificial limitations are rules, and every game uses rules to create the kind of competition the players want.
(*) Actually, yes, the National League is better, because the designated hitter rule is the stupidest, more asinine mistake ever in the history of baseball. I was just being ecumenical and even handed up there, but what I really think is pure flamebait.
I'm reminded of a conversation I had way back in the day, when I played D&D a lot. (This was back before PCs, so it was all books and dice, paper and pencil.) A friend was telling me all about this cool item he'd read about in one of his books, a quiver of ice arrows or something.
I thought up a cool item (a lightning sword or something) and said, "Cool! I'll write it up and use it in our next session!" He got really mad, and said you can't just make stuff up and start to use it. You have to go on a quest, win it through serious effort and struggle.
I reminded him that it's all make-believe anyway, and why couldn't I just magically get this? He insisted it wasn't the same, that it wasn't right. If I had obtained it through a big quest worthy of such an item, that would be OK, but just suddenly having it wasn't. I suggested that I make up some long story about a tremendous quest that I had gamed with another group, which culminated in me having the item. "Not the same!", he insisted.
I was irritated at the time, because I really wanted the cool item, but now, I see that he was right. If you don't play by the rules, then the game is no challenge, and if you aren't playing for the challenge, to test your skill and creativity and endurance, then you are just there for the scenery, a tourist watching a movie.
Ignoring the rules makes any game go faster, and let's you score better, but so what? Your drive off the tee goes into the rough? Pick up the ball and carry it to the hole... hole in one! It's fourth and 16 on your own 9 yard line? Give yourself twelve extra downs in the possession... touchdown! You're only 18 miles into the marathon, and your legs are giving out? Take a shortcut through central park... first place!
If you don't want to actually play the game, why pretend to be a player?
the waste problem, the uranium mining, transport and processing needed to produce the fuel, transport and trade with radioctive fuel and waste materials, the "dirty" building which will sooner or later need to be decommissioned, the finite uranium resources available, the potential misuse for weapons, etc. etc.
As opposed to the much greater environmental impact and economic costs associated with mining, processing, transportation, harmful waste products and finite resource base associated with coal, our current favorite source of electricity?
And don't get me started on the "potential for weaponization". I once got hit with a lump of coal, and it hurt like hell.
I don't think that they are proposing that you re-use the heat. Power generators like to have steam go from ~900F to ~500F, to imporve efficiency. Everything after that is waste, which they dump out of the cooling tower. If the power plant is nearby some homes & offices, you could capture that heat and pipe it to where it's needed, but that would require more heat exchangers, etc. I'm not sure the economics would work.
For the desalination or hydrogen cracking, I believe they are talking about that being the *primary application* of the reactor. In a place where you need power, you use the heat to make electricity. In a place where you need water, you use it to desalinate. In a place where you need hydrogen, you use it to crack water.
Electricity is great for running stationary objects like buildings, but not so good at vehicles. A storable fuel is better for that.
Consider some seaside urban area that is outgrowing its supply of fresh water. Since these reactors are modular, you could install one reactor to make electricity, one to make water and one to make hydrogen for the cars. The power, water and hydrogen distribution grids are all in place and benefit from economies of scael, and you can share the administrative/training/regulatory overhead of running the reactors.
Need even more power/water/H2? Install another module.
Escape velocity is defined as @sqrt(2GM/r). G is 6.67e-11 m^3 s^-2 kg^-1. M and r (hald the diameter) for this asteroid are 2.7e11 kg and 290 m, respectively.
So, Ve for this asteroid is = @sqrt(2*6.67e-11*2.7e11/290) = 0.35 m/s
This number is a *lot* lower that I would have guessed without having done the calculations.
I stand corrected... if you can land any kind of functioning acceleration system, achieving escape velocity for material pitched off the asteroid will be no big deal, even if you want to use really big rocks.
The Navy's rail gun gives a muzzle velocity of 2500m/s for a 20kg round. A system operating at even a fraction of this power level would be able to fling even very, very large rocks off at escape velocity.
I guess I didn't express myself clearly. People are accumstomed to thinking of escape velocity as just that, the velocity at which you can leave an earth orbit. No one ever thinks about the effect of the gravitational pull that the spacecraft is exerting on the earth, because they don't need to, it's trivial.
//high school physics analogy mode:ON//Imagine an ice skater who throws a baseball. She moves to the right slightly, it moves to the left a lot. But if the ball is on the end of a bungie cord, and they continue to intereact, it will eventually come back fast, she will move back slightly, and they will meet in the middle, right where they started.//high school physics analogy mode:OFF//
However, when you fling those rocks off the surface of the asteroid, the pull that they exert on the asteroid is non-trivial, especially since you're going to be chucking a significant % of the asteroids mass. Fling the rock to the left, the asteroid moves slightly to the right... until the mutual gravitational pull of the rock & asteroid pulls them back together, when the rock comes flying back to the left and the asteroid moves slightly back to the right.
It's not really an escape velocity problem where you're trying to get the rock out of an orbit around the asteroid... if the rock comes back, then that negates the effect of its having been flung. If you don't fling the rock away really, really fast, it's essentially a two-body system; you need to keep them apart long enough to give some third body a chance to interact with the system. Put a lot of space between then by giving the rock a lot of energy, and it's more likely to encounter some other gravity well to keep it away for good. Decay of its solar orbit, contact with earth, or some other third body.
The problem is that you have to throw the rocks really, really hard. If you just lob them off the surface, you'll give the asteroid a minute nudge as the rock flies away, but there will still be a gravitational attraction between the asteroid and the piece of rock you threw. If they remain close together (and I'm speaking of close in astronomical terms), then they will just make up a two-body system with the center of mass precisely where it was before. Eventually, the asteroid and the cloud of rocks you threw will just attract each other back together right at the pre-existing center of mass, with no net change in orbit.
You need to fling the rocks far enough away so that some other body becomes more important to them, gravitationally speaking. Once the cloud of rocks get dragged away by the Earth, the Sun, Venus or some other convenient gravity well, they are far enough away from the asteroid to be really out of the picture in terms of influencing the asteroid's orbit.
If you start soon enough, you don't have to throw them so far, since the small rocks' orbits around the sun will decay sooner than the asteroid. However, you'll need a couple of dozen solar orbits to really make them fall inward much, taking them out of the asteroid's influence. Since each asteroid's orbit is almost two years, if you want to land a cannon and start flinging rocks, you need to be at T-60 years (30 orbits) for it to be effective. That means a working gas cannon/rail gun/etc., on the asteroid, flinging rocks, in 2040.
The Navy is thinking about a ship-mounted rail gun. This can fling a 15kg round at 2.5km/s, with a rate of fire of 6-12 rounds per minute. It would need a dedicated nuclear reactor, and a machined 5kg sabot for each round, and machined rounds, but nevermind. Assuming that this rail gun could fling 22kg rounds at 10 per minute at 1km/s, that's one metric ton every 10 minutes, or 6 metric tons an hour. If you can sustain that rate of fire for 12 hours out of every 24, day in, day out, that means you'd have flung your 1,000,000th metric ton 13,888 days after you start. That's 38 years of continuous operation. Land 10 rail guns, it's 3.8 years.
Keeping the gun(s) fed would be a challenge. Add in the operation and mainenance for the guns, the reactor, and the munitions manufacturing facility (where you turn rocks into rounds), the mining facility (where you dig up the rocks in the first place), not to mention the living quarters, and you've got all of the problems of a major space colony. Oh, and the cosmic rays would probably kill any astronaut who is on-site operating or repairing it.
A 15 month delay in notification for an extremely unlikely event which might happen (if at all) 1176 months from now is not a big deal.
This is roughly equivalent to your wife finding out yesterday (March 1, 2006) that there is a 1 in 3000 chance that she might blow $900 on a spa trip with her mother for Mother's Day (May 14, 2006) and waiting one day to tell you about it.
Potentially catastrophic? Sure. Something to be worried about? No, because the overwhelming likelihood is that as the date approaches, the probability of the event actually taking place will drop to zero, just like all the other "near misses" that never happened, like the proposed mother/daughter cruise to Turkey, or that "girl's night out" to Las Vegas they keep talking about.
That's... disturbing. Orbits way, way far apart, and then too damn close together.
Obviously, a drug can't infect anyone. A. baumanii is not a drug, it's a bug.
And don't get me started on the inclusion of Aspergillus in a list of dangerous bacteria.
Geez, it's no wonder people are concerned about the state of science education in America. If this were an article about the six most popular cars and had this many errors (e.g. a discussion of the Honda Accordes, a reference to the Rav4 as a sedan and the inclusion of the Harley-Davidson Softail), it would be treated as a joke.
In that case, I'm going to sue NBC because their skyscraper screws up my cell phone signal when I go to my favorite park bench.
4. Profit!
University of Missouri - Rolla, a fine engineering school.