The idea that marriage is for reproduction is ridiculous, as I tried to make clear above. Arguing that gay couples should not be allowed to marry because marriage is for having children should also mean arguing that older people should not be allowed to marry or that sterile people should not be allowed to marry. It's stupid and is basically a way to hide bigotry. Not only that, but it ignores the fact that adoption is and should be an option for many people, and that being "straight" or gay doesn't make you a good or bad parent, whether you adopt or have a child in some other way.
For now I'll accept the proposition that the "institution of marriage" is falling apart. In a little bit, I'll explain why I don't belive this is really true.
Are there any reasons that marriages don't last as long as they used to? Clearly there hasn't been a sudden rash of gay couples going out and causing marriages to collapse all across the country. Are husbands suddenly looking for lesbian couples to cheat on their wives with? are wives suddenly finding that gay men are more sensitive than their husbands? or are they realizing that their butch lesbian friends are more capable around the house?
I hope you can see that placing the blame for bad marriages on someone other than the couple directly involved in the marriage is (almost always) ridiculous.
Allowing people who love each other to legally declare their love for each other seems like a good way to "shore up" the statistics on marriage so that it doesn't look so bad. However, a better reason to "allow" "gay marriage" is because it's the right thing to do.
There is still the issue of what is wrong with the US now as opposed to 50 years ago when the divorce rate was much lower. I propose that the difference is that 50 years ago, women were not nearly as empowered and today they are able to make choices for themselves outside of their husbands' wishes. They are also better (though often not as well as they should be*) protected by the law.
Now, we have strong women who choose to work full time outside of the home, now we have women who won't put up with an abusive husband, now we have women who will fight back against the idea that the "man of the house" is in charge of every detail.
We also have the economic situation such that it's nearly impossible for a married couple to plan for retirement (or many times, even live from month to month) on a single salary (=> high stress on the marriage), so they both have to work full time jobs. This means there is (usually) no one at home to clean the house, cook dinner, go shopping, etc. This adds to the stress on the marriage because it's still, traditionally, the woman's "job" to do all of those things after she gets home from work. She doesn't have the time, the energy, or the inclination to do that after an 8 hour day at work. Neither does he.
The "institution" of marriage is broken because it relies on an outdated and unworkable ideal of one member working away from home and another working at home. While this works for some couples, there are many more for whom it doesn't work. Some people figure out a way to work as a couple under the new paradigm, but many people do not.
Another danger for the "institutioin" is that "older" people are panicked about it falling apart so they push their children to get married before they're ready, and that always leads to disaster.
Anyway, I think it's stupid and mean to lay the blame of straight couples not being able to stick together on gay couples who are able to stick together. I guess that's the American way, though: if you can't do it right the first time, find someone to blame it on.
Anyone and everyone should be allowed to marry who they want. It should simply be a contract between two (or whatever number of) people, and it should be enforced (and made difficult to get out of), just like any other contract. The concept of spiritual marriage should not even need government approval, and should certainly not infringe on the marriages of others.
(*) In Arizona, for example, spousal rape is usually only a misdemeanor. Until very recently, it wasn't even a crime.
So, according to your definition, women past the age of about 50 http://www.mayoclinic.com/invoke.cfm?objectid=94F4 C769-0E44-4BA5-AF20E9E264577527
should not be allowed to marry? A man or woman who is sterile due to age or accident or choice should not be allowed to marry? These situations preclude procreation, and thus, according to the extreme views you espouse above would preclude any reason to marry, other than for some sort of monetary benefit (I guess).
So this seems reasonable to me, and doesn't strike me as flip flopping.
Except, of course, for the fact that in previous statements, Bush has stated that in order to "protect" (from what, exactly?) marriage, it must be defined as only between a man and a woman, and that same sex couples do not deserve the same rights as others in this country. However, I agree: it's not flip-flopping, it's just that he doesn't actually know what he's said (or believed) in the past.
It's remarkable that two (at least) of the last three republican presidents can't (couldn't) remember what they say or do from day to day. It's also remarkable that those two presidents had essentially the same staff.
1) What is the "real image"? 2) With super resolution techniques, you only gain, at best, something like a factor of r~sqrt(n) in resolution, where n is the number of pictures you take. However, the computational time required goes as e^r, and you have a lot of issues with actually understanding the movement between images such that you could end up in a local minimum, far from the ideal solution. . .
The images you are seeing are JPEGs! They're not science data, they're press release data. The images are transmitted back with lossless or lossy compression, depending on the needs/resources. Lossless is obviously necessary when one wants to view the finest details, but is not always necessary, especially when you do a cost:benefit analysis. . .
The estimates given are for observing at Mars--these guys know what they're doing, and they know how to plan for Mars.
The only way to get better resolution is to pull tricks like MGS does or to get closer to the surface. Either one will be done sparingly because of wear and tear on the spacecraft:
Getting very much closer than the planned 300 km altitude will begin to put the spacecraft into the planet's exosphere, AND the plan is for a sun-synchronous orbit where the craft is between 320 (32cm/px) and 255(25.5cm/px) km above the surface;
Trim maneuvers like rolling the spacecraft to increase the time the camera observes a given spot--thereby increasing signal to noise and effective resolution will cost propellant, and thus can only be done a finite number of times.
You are correct, the "resolution" of the cameras on spacecraft observing the planets they orbit depends very much on how close they are to a planet, and on how clear the atmosphere is in the observing wavelengths, but the plan for HiRISE is for a 30 cm/pixel (+- a few cm) resolution, which has already taken into account the orbit height and the atmosphere (for the most part) of Mars. In fact, if anything, the resolution is only likely to get worse, not better due to unplanned things like clouds in the way. . .
Re:Just wait for Mars Reconnaissance Orbiter.
on
Making Tracks on Mars
·
· Score: 4, Informative
HiRISE on MRO will be able to resolve about 30 cm/pixel, not 150 mm, with a swath width of > 6 km for the greyscale images. It is not a remake of the Ikonos, though it is similar. A slice through the CCD array (I don't remember the number of CCDs in the array off the top of my head--must be 20) of the camera is something like (lameness/HTML filter screws this up--ignore the dots):
........BBBB PPPPPPPPRRRRPPPPPPPP ........GGGG
Where the middle layer three CCDs deep are the "Blue", "Red", and "Green" (approx.) CCDs, while the others are the panchromatic (really the same as the "Red" in the color portion of the array). Each of the CCDs is something like
1024 pixels across, with a 6 pixel overlap on each side.
". . . is just one big rock with no layers at all"
That's not very likely. The gravitational potential energy that would be converted to heat as the planet accreted would be more than enough to melt the entire body, thus allowing the heavier materials to tend to sink to the center of the planet. A planet this size would almost certainly have differentiated.
Besides, it is mass and radius^2 that matter, not specifically density. For example, Jupiter has a bulk density around 1330 kg/m^3 (water is 1000 kg/m^3), but has a large equitorial surface gravity (23.12 m/s^2). Earth is 5.52x10^3 kg/m^3 with g=9.8 m/s^2
Dammit! Dammit!
I missed some important numbers in the density calculation.
volume of sphere = R^3*Pi*4/3, not R^3. Duh!
Ok, so the density is not 3.2x10^5 kg/m^3, but is instead, 3*3.2x10^5/(Pi*4) =~ 8000 kg/m^3. Like iron.
Earth, of course, is around 5.6x10^3 kg/m^3.
I'm an idiot!
g = gravitational acceleration (m/s^2) G = Universal gravitation = 6.67*10^-11 m^3/kg/s^2 M = mass (kg) R = radius (m)
So, we are told that the new planet has 14 times the mass of the earth. If we were also to assume that the person who submitted this article is correct and that the gravitational acceleration is 14 times that of the Earth ("14 Gs") [I assume he/she/it meant at the surface of the planet], then we have the following equation for the radius of the newly discovered planet:
R = sqrt (GM/g)
where, g = 14*9.8 m/s^2 M = 14*6x10^24 kg G = 6.67*10^-11 m^3/kg/s^2
=> R = 6.4x10^6 m. The same as the Earth (parent stated this correctly, others have not) [do the algebra before doing the arithmetic, the 14 drops out]
However: => Bulk the density of the planet is rho = M/R^3 = 14*6*10^24/(6.4*10^6)^3 = 3.2*10^5 kg/m^3
The density of Iron is about 8x10^3 kg/m^3. This would mean the planet is roughly four times more dense than iron, if its radius is as calculated (unlikely). However, Earth's bulk density is about 2.3x10^4 kg/m^3, so being 3-4 times the uncompressed density of iron is not problematic.
Besides, the star around which it orbits is one which produces more heavy materials than our star, so it's not unreasonable to assume that some greater proportion of its (the planet's) composition is more dense material. According to what we know (and as has already been stated), Iron is most likely to be produced. So, if the star puts out more dense materials in place of the less dense ones and emits roughly the same amount of iron, we may not really have too much of a problem. Especially considering that the radius of this planet is almost certainly somewhat larger than the radius of the Earth.
The dramatic tightening of export regulations is included in the National Defense Authorization Act, an annual military funding bill
that has already passed the U.S. House of Representatives. Though the proposed rules are only a tiny portion of the 630-page bill, they could have a devastating impact on the computer industry.
The courts may have moved to using Linux as their server (GREAT!), but they are still using MS products for their workstations/desktops. A friend of mine says that "all of their important data is stored on the Linux servers," but they still have to use Windows to do anything (like write opinions or whatever).
Also, they are currently still using WordPerfect, though apparently there is a push to move to Word, and there also seems to be a push to migrate the servers back to MS.
For my argument re: NASA, any Dan Birchall is the "right" Dan Birchall.;)
The "right" I actually referred to was in reference to the SpamCon Foundation. I found a reference to that separate from danbirchall.com, so I wasn't sure that you and the SpamCon Dan Birchall were one. Clearly you are.
Dude, this Dan Birchall is not a NASA administrator of any kind (look at his home page). He's a freelance writer/web page designer/executive director of SpamCon, if I have the right Dan Birchall.
There is, in fact, no Birchall in administration at NASA, and as far as I can find, there is no Birchall associated with NASA.
My wife's comment before seeing pictures: "Are you going to build one for our car?" After seeing pictures: "Geez! We don't have room for that--we might as well get an 8-track player."
-- indicates an end to options, so touch creates a file named "-i".
"-i" will be at or near the top of the list when you do a listing (or any other alphabetically sorted operation, including rm). This will cause "rm -rf *" to be passed the file "-i" as its first (or nearly first) argument. This will cause rm to prompt for confirmation for each file (no -- in the rm argument list).
This "trick" will fail if you attempt to rm -rf a subdirectory that contains the "-i" file (it won't be passed as an argument to rm).
Actually, we usually hire undergrads to do this (@ $6/hr). It doesn't cost very much at all. We also only name the features that end up discussed in scientific papers (so we can refer to them as something other than "the crater north and slightly west of the previously discussed crater").
I use Linux to boot and do a data dump to/from another system via NFS. If the system won't even POST, then that's a problem--I haven't had that problem yet. [crosses fingers].
My solution to this has been to dump the hard drive as soon as I get the computer. If I need to send it back for repair, I re-image the hard disk with the initially installed system, thereby cleaning the hard drive of all of my information (to most people). I, of course, make a dump of MY stuff just before replacing it with the original crap.
This also helps with idiotic companies that don't support Linux as I can just dump the old OS back on the system before I send it back for repair.
I AM an environmentalist, and I KNOW that there was more danger with the rocket (bomb) that was sitting under Cassini hurting people than the RTG becoming a problem. IF the RTG did somehow become a problem, the "probability * consequences" was still so low that it's more dangerous for you (and the rest of the world) to drive your car to work. The issue is that there are some rather uninformed emotional reactions to the word "radiation".
Do you drive a car? Do you use a computer? Do you smoke? All of these have very real and very bad risks to yourself and others. Nothing you do is 100% safe. You're still doing it.
The problem is not that you oppose nuclear power, it's that you seem to be uninformed about nuclear power (and the rest of technology). The "risk" associated with your using electrical energy to power your computer is more than the risk NASA generates by using an RTG to power a spacecraft. The environmental consequences of burning coal, damming rivers, or however else you produce your electricity are much worse than the use (or even (VERY unlikely) destruction within Earth's atmosphere) of an RTG.
And you're still wrong. The Prius uses the gasoline engine to charge its batteries when it needs to, and this typically happens while the engine is moving the vehicle. There is enough excess energy produced by the gasoline engine that it can turn the electric motor (now a generator), thus charging the battery, without any affect on the power sent to the wheels. This isn't possible in a conventional vehicle and the energy is simply wasted.
The braking not only charges the batteries by utilizing the electric motor as a generator, but it also means the gasoline engine IS NOT RUNNING at all! There is no need to waste energy while breaking, so it's not just that there's a little bit of a conversion of kinetic energy to potential energy, there's ZERO potential energy converted to thermal energy via the gasoline engine.
The other reason the mileage goes up is because the gasoline engine is only used when it's needed, not when you're sitting at a light or decellerating or going down a hill, or any other time that you would normally be wasting energy on running a gasoline engine in a conventional car. It's about letting the computer do the smart driving for you.
The "transmission" on the Prius is another example of how to increase the efficiency. Since it's known that as you increase the number of gears in a transmission, you increase the efficiency of the vehicle, Toyota went to the extreme and effectively put an infinite number of gears in the Prius. The transmission is continuously changing the "gear ratio" as the power requirements (and availability) change, and in doing so greatly increases fuel effeciency.
I regularly get 50 mpg in the city and > 45 on the freeway. I didn't buy it for its mileage, though. I bought it because it qualifies for the California SULEV and sometimes for the ZEV ratings.
And a little less on the freeway. It took less than 11 gallons of gas to drive from Tucson to Los Angeles (500 miles), so we got better than 45 mpg on the freeway.
I get good gas mileage because I drive like an intelligent person. . . I don't need to accelerate all the way from one stop light to the next, in fact at the worst, I accelerate half way there and decellerate the other half. I drive at a constant speed when I don't need to be accelerating or decellerating--this allows the electric motor to take over because I don't need any extra power for acceleration.
However, I didn't buy it for the good gas mileage. I bought the Prius because 1) it's a SULEV (and sometimes ZEV) and 2) I wanted to support a technological change from the old, crusty, disgusting way of building individual transport that relies solely on fossil fuels. It's not the best technology imaginable, but it's currently the best mass produced technology.
Extrapolating from a humidifier in an 30 cubic meter room to the entire Earth's atmosphere, which is about 4.6x10^18 cubic meters* (if you assume the majority of the atmosphere is contained within one scale height (9km) of the atmosphere**) is meaningless. Not only does the physics change because of confining walls and the shape of the room, there are other mechanisms at work in the atmosphere that simply do not happen in a small room with a humidifier. The time scale for warming and increasing the "atmospheric" water content in a small, enclosed room is effectively 0 when compared with that for the atmosphere.
There is no error in thinking that the time a certain molecule stays in the atmosphere matters. If that molecule doesn't stay in the atmosphere long enough to, relatively, affect the energy balance, then it is not as important as other molecules that live in the atmosphere longer***. If the type of molecule is not evenly distributed (spatially), then its global effect is NOT EASILY MODELED, especially if it's also a short-lived molecule.
The IPCC did not ignore surface water and its affect on global warming. They didn't use the models that made a poor job of accounting for the atmospheric water and its affect on global warming (positive and negative).
A bad and poorly understood model is sometimes worse than no model at all! This is especially true if you state, UP FRONT that you have not modeled something because of the poor constraints and incomplete understanding of its affect on the otherwise more simple model. If you CAN make approximations for how much said parameter will affect thing on an order of magnitude (or two or three) scale, then you can state, to "good" approximation what the affect will probably be. The IPCC understood this and said so in their write-up.
Yes, human activity with respect to the global water cycle does affect the atmospheric heat forcing. Consider, though, that the oceans make up more than 97% by volume of the water budget, the atmosphere makes up 1/1000 of a percent, streams and rivers (what humans modify) make up 1/10000 of a percent, lakes (also what humans modify) make up 1/10 of a percent, and ground water makes up 68/100 of a percent. So, yeah, if we were to completely vaporize the lakes and ground water, we'd completely destroy the Earth's climate.
*For the mathematically challanged w.r.t. volumes:
radius of Earth=6378 km radius of Earth+atmosphere = 6387 (km) volume of Earth = 4/3 * Pi * 6378^3 (km^3) volume of Earth+atm = 4/3 * Pi *6387^3 (km^3) volume of atm = V(earth+atm)-V(earth) volume of atm in m^3 = 10^9*volume of atm in km^3
** The scale height is the distance it takes for the atmospheric pressure to fall by a factor of e.
*** Assume, if you will, that the lifetime of water in the atmosphere is, say, a week (I found one reference to it:in this PDF). Now, assume 1 gram of water is "stuck" together through-out its atmospheric lifetime (clearly incorrect, but just for the sake of simple calculations). Now, let's start this gram of water at the tropopause, 9 or 10 km above the surface of the earth. It's about -80 C or so there. Let the gram fall through the atmosphere non-adiabatically (so that it can gain some heat) all the way to the surface at 25 C. This is a net change of 105 degrees C. So, the gram of water has absorbed 439 J to increase its temperature. Also assume, unrealisticly--but for kicks, that this gram of water went from the liquid phase to a gaseous phase (so that we can over estimate the amount of energy absorbed). It would absorb 2000 J. Assume all of that energy is absorbed sunlight that would otherwise have reflected off the surface of the earth and back in to space. Also assume all of that energy is later released as the gram of water reverses its path and returns back to the tropopause and that this energy directly heats the atmosphere. This me
The point isn't that water vapor is a green house gas. The point is that our conversion of water to hydrogen and oxygen and then releasing some of that hydrogen as gas (and converting some back to water) is NOT going to increase the amount of water vapor in the atmosphere. The easiest way to get hydrogen is to take it from water. The easiest way to get water is to take it out of the hydrologic cycle. Our use of the hydrogen gas derived from water will decrease the amount of water vapor in the atmosphere.
Since water vapour is a strong absorber in all wavelengths one would expect the lower atmosphere to warm slightly and the upper atmosphere to cool. There is data to support this.
Water is not a strong absorber at all wavelengths.
Take a look
Water is, for all intents, *transparent* in the visible wavelengths both as a gas and as a liquid. It's a good thing too, because the "visible" light (the light that goes through all that water vapor in the atmosphere and reaches the surface) happens to be the light that we humans evolved to see with. It also "just so happens" that the sun (as a near-black body emitter at about 5000 K) emits most of its energy at the visible wavelengths (coincidence?). . .
So, water vapor is not absorbing most of the energy that comes from the sun (even if it is a strong absorber at most infrared and UV wavelengths); it is, in fact, transparent to most of that energy until it condenses into clouds, which makes it reflect a lot of the visible wavelengths.
If you check the IPCC report in chapter 7 you will find that they simply decided to ignore the role of water vapour in their models. Given that the concentration of water vapour is at least 2 orders of magnitude more significant than CO2, this IMHO is a silly thing to do. You simply cannot ignore the most significant variable and expect your model to be meaningful.
First of all, they don't actually ignore water. The tend not to trust atmospheric models that have globally averaged water vapor. The surface water (oceans, lakes, rivers, etc.) are important energy transport mechanisms that are much better understood than the greenhouse gas, water vapor. Read chapter 8 of the IPCC. . .
You also simply cannot ignore the fact that concentration is not the only variable when it comes to global warming. How efficeint is water vapor at absorbing in the visible and UV and re-emitting in the infrared? how does its non-even spatial distribution affect its efficeincy as a greenhouse gas? Compare that with CO2 and, say SF6, whose lifetimes in the atmosphere are much, much greater than water.
Go back and read the IPCC again. . . The atmospheric lifetime of CO2 is on the order of 50-200 years. The atmospheric lifetime of H2O is much shorter than that of CO2 (nobody is really sure by how much shorter). However, the biggest thing about water vapor is that as the concentration in the atmosphere increases, it does trap more energy from the sun, but it also increases the likelyhood that the vapor will condense to form clouds, thus increasing the "albedo" of the atmosphere, lowering the amount of energy that stays on the earth. It's difficult to model and thus is usually ignored when other gases like CO2 (which only *increase* the amount of heat retained) are increasing in concentration.
Another problem with water vapor is that it isn't evenly distributed throughout the atmosphere, either "horizontally", vertically, or temporally, mostly because its atmospheric lifetime is so short. CO2 and other strong, long lived gases are much more evenly distributed, so it's relatively simple to create a mathematical model of the effects CO2 et al. have on the energy budget of the Earth. It's not so simple with a patchy gas like water vapor.
The jury is NOT out on the matter of the increase of the average temperature of the earth. It IS increasing. The jury is ou
Slashdot Mirror
The idea that marriage is for reproduction is ridiculous, as I tried to make clear above. Arguing that gay couples should not be allowed to marry because marriage is for having children should also mean arguing that older people should not be allowed to marry or that sterile people should not be allowed to marry. It's stupid and is basically a way to hide bigotry.
Not only that, but it ignores the fact that adoption is and should be an option for many people, and that being "straight" or gay doesn't make you a good or bad parent, whether you adopt or have a child in some other way.
For now I'll accept the proposition that the "institution of marriage" is falling apart. In a little bit, I'll explain why I don't belive this is really true.
Are there any reasons that marriages don't last as long as they used to? Clearly there hasn't been a sudden rash of gay couples going out and causing marriages to collapse all across the country. Are husbands suddenly looking for lesbian couples to cheat on their wives with? are wives suddenly finding that gay men are more sensitive than their husbands? or are they realizing that their butch lesbian friends are more capable around the house?
I hope you can see that placing the blame for bad marriages on someone other than the couple directly involved in the marriage is (almost always) ridiculous.
Allowing people who love each other to legally declare their love for each other seems like a good way to "shore up" the statistics on marriage so that it doesn't look so bad. However, a better reason to "allow" "gay marriage" is because it's the right thing to do.
There is still the issue of what is wrong with the US now as opposed to 50 years ago when the divorce rate was much lower. I propose that the difference is that 50 years ago, women were not nearly as empowered and today they are able to make choices for themselves outside of their husbands' wishes. They are also better (though often not as well as they should be*) protected by the law.
Now, we have strong women who choose to work full time outside of the home, now we have women who won't put up with an abusive husband, now we have women who will fight back against the idea that the "man of the house" is in charge of every detail.
We also have the economic situation such that it's nearly impossible for a married couple to plan for retirement (or many times, even live from month to month) on a single salary (=> high stress on the marriage), so they both have to work full time jobs. This means there is (usually) no one at home to clean the house, cook dinner, go shopping, etc. This adds to the stress on the marriage because it's still, traditionally, the woman's "job" to do all of those things after she gets home from work. She doesn't have the time, the energy, or the inclination to do that after an 8 hour day at work. Neither does he.
The "institution" of marriage is broken because it relies on an outdated and unworkable ideal of one member working away from home and another working at home. While this works for some couples, there are many more for whom it doesn't work. Some people figure out a way to work as a couple under the new paradigm, but many people do not.
Another danger for the "institutioin" is that "older" people are panicked about it falling apart so they push their children to get married before they're ready, and that always leads to disaster.
Anyway, I think it's stupid and mean to lay the blame of straight couples not being able to stick together on gay couples who are able to stick together. I guess that's the American way, though: if you can't do it right the first time, find someone to blame it on.
Anyone and everyone should be allowed to marry who they want. It should simply be a contract between two (or whatever number of) people, and it should be enforced (and made difficult to get out of), just like any other contract. The concept of spiritual marriage should not even need government approval, and should certainly not infringe on the marriages of others.
(*) In Arizona, for example, spousal rape is usually only a misdemeanor. Until very recently, it wasn't even a crime.
Except, of course, for the fact that in previous statements, Bush has stated that in order to "protect" (from what, exactly?) marriage, it must be defined as only between a man and a woman, and that same sex couples do not deserve the same rights as others in this country. However, I agree: it's not flip-flopping, it's just that he doesn't actually know what he's said (or believed) in the past.
It's remarkable that two (at least) of the last three republican presidents can't (couldn't) remember what they say or do from day to day. It's also remarkable that those two presidents had essentially the same staff.
1) What is the "real image"?
2) With super resolution techniques, you only gain, at best, something like a factor of r~sqrt(n) in resolution, where n is the number of pictures you take. However, the computational time required goes as e^r, and you have a lot of issues with actually understanding the movement between images such that you could end up in a local minimum, far from the ideal solution. . .
The images you are seeing are JPEGs! They're not science data, they're press release data. The images are transmitted back with lossless or lossy compression, depending on the needs/resources. Lossless is obviously necessary when one wants to view the finest details, but is not always necessary, especially when you do a cost:benefit analysis. . .
The estimates given are for observing at Mars--these guys know what they're doing, and they know how to plan for Mars.
The only way to get better resolution is to pull tricks like MGS does or to get closer to the surface. Either one will be done sparingly because of wear and tear on the spacecraft:
Getting very much closer than the planned 300 km altitude will begin to put the spacecraft into the planet's exosphere, AND the plan is for a sun-synchronous orbit where the craft is between 320 (32cm/px) and 255(25.5cm/px) km above the surface;
Trim maneuvers like rolling the spacecraft to increase the time the camera observes a given spot--thereby increasing signal to noise and effective resolution will cost propellant, and thus can only be done a finite number of times.
You are correct, the "resolution" of the cameras on spacecraft observing the planets they orbit depends very much on how close they are to a planet, and on how clear the atmosphere is in the observing wavelengths, but the plan for HiRISE is for a 30 cm/pixel (+- a few cm) resolution, which has already taken into account the orbit height and the atmosphere (for the most part) of Mars. In fact, if anything, the resolution is only likely to get worse, not better due to unplanned things like clouds in the way. . .
Where the middle layer three CCDs deep are the "Blue", "Red", and "Green" (approx.) CCDs, while the others are the panchromatic (really the same as the "Red" in the color portion of the array). Each of the CCDs is something like 1024 pixels across, with a 6 pixel overlap on each side.
Check out:
http://hirise.lpl.arizona.edu http://marsoweb.nas.nasa.gov/hirise
". . . is just one big rock with no layers at all"
That's not very likely. The gravitational potential energy that would be converted to heat as the planet accreted would be more than enough to melt the entire body, thus allowing the heavier materials to tend to sink to the center of the planet. A planet this size would almost certainly have differentiated.
Besides, it is mass and radius^2 that matter, not specifically density. For example, Jupiter has a bulk density around 1330 kg/m^3 (water is 1000 kg/m^3), but has a large equitorial surface gravity (23.12 m/s^2). Earth is 5.52x10^3 kg/m^3 with g=9.8 m/s^2
Dammit! Dammit! I missed some important numbers in the density calculation. volume of sphere = R^3*Pi*4/3, not R^3. Duh! Ok, so the density is not 3.2x10^5 kg/m^3, but is instead, 3*3.2x10^5/(Pi*4) =~ 8000 kg/m^3. Like iron. Earth, of course, is around 5.6x10^3 kg/m^3. I'm an idiot!
Ok, here's the math:
g = GM/R^2
g = gravitational acceleration (m/s^2)
G = Universal gravitation = 6.67*10^-11 m^3/kg/s^2
M = mass (kg)
R = radius (m)
So, we are told that the new planet has 14 times the mass of the earth. If we were also to assume that the person who submitted this article is correct and that the gravitational acceleration is 14 times that of the Earth ("14 Gs") [I assume he/she/it meant at the surface of the planet], then we have the following equation for the radius of the newly discovered planet:
R = sqrt (GM/g)
where,
g = 14*9.8 m/s^2
M = 14*6x10^24 kg
G = 6.67*10^-11 m^3/kg/s^2
=> R = 6.4x10^6 m. The same as the Earth (parent stated this correctly, others have not)
[do the algebra before doing the arithmetic, the 14 drops out]
However:
=> Bulk the density of the planet is rho = M/R^3 = 14*6*10^24/(6.4*10^6)^3 = 3.2*10^5 kg/m^3
The density of Iron is about 8x10^3 kg/m^3. This would mean the planet is roughly four times more dense than iron, if its radius is as calculated (unlikely). However, Earth's bulk density is about 2.3x10^4 kg/m^3, so being 3-4 times the uncompressed density of iron is not problematic.
Besides, the star around which it orbits is one which produces more heavy materials than our star, so it's not unreasonable to assume that some greater proportion of its (the planet's) composition is more dense material. According to what we know (and as has already been stated), Iron is most likely to be produced. So, if the star puts out more dense materials in place of the less dense ones and emits roughly the same amount of iron, we may not really have too much of a problem. Especially considering that the radius of this planet is almost certainly somewhat larger than the radius of the Earth.
Just use postmaster@{the site name that wants to abuse your email address}
No worries about screwing up someone's address, the spammer gets what they deserve, and that's that.
Emphasis mine. It's already left the house.
Just repeating rumours that my friends at the courts have passed on. . .
The courts may have moved to using Linux as their server (GREAT!), but they are still using MS products for their workstations/desktops. A friend of mine says that "all of their important data is stored on the Linux servers," but they still have to use Windows to do anything (like write opinions or whatever).
Also, they are currently still using WordPerfect, though apparently there is a push to move to Word, and there also seems to be a push to migrate the servers back to MS.
For my argument re: NASA, any Dan Birchall is the "right" Dan Birchall. ;)
The "right" I actually referred to was in reference to the SpamCon Foundation. I found a reference to that separate from danbirchall.com, so I wasn't sure that you and the SpamCon Dan Birchall were one. Clearly you are.
There is, in fact, no Birchall in administration at NASA, and as far as I can find, there is no Birchall associated with NASA.
The program director of NASA's Mars program is Scott Hubbard. http://mars.jpl.nasa.gov/newsroom/pressreleases/00 -10-26.html
(search for mars program director)
My wife's comment before seeing pictures:
"Are you going to build one for our car?"
After seeing pictures:
"Geez! We don't have room for that--we might as well get an 8-track player."
touch -- -i:
-- indicates an end to options, so touch creates a file named "-i".
"-i" will be at or near the top of the list when you do a listing (or any other alphabetically sorted operation, including rm). This will cause "rm -rf *" to be passed the file "-i" as its first (or nearly first) argument. This will cause rm to prompt for confirmation for each file (no -- in the rm argument list).
This "trick" will fail if you attempt to rm -rf a subdirectory that contains the "-i" file (it won't be passed as an argument to rm).
Actually, we usually hire undergrads to do this (@ $6/hr). It doesn't cost very much at all. We also only name the features that end up discussed in scientific papers (so we can refer to them as something other than "the crater north and slightly west of the previously discussed crater").
I use Linux to boot and do a data dump to/from another system via NFS. If the system won't even POST, then that's a problem--I haven't had that problem yet. [crosses fingers].
My solution to this has been to dump the hard drive as soon as I get the computer. If I need to send it back for repair, I re-image the hard disk with the initially installed system, thereby cleaning the hard drive of all of my information (to most people). I, of course, make a dump of MY stuff just before replacing it with the original crap.
This also helps with idiotic companies that don't support Linux as I can just dump the old OS back on the system before I send it back for repair.
I AM an environmentalist, and I KNOW that there was more danger with the rocket (bomb) that was sitting under Cassini hurting people than the RTG becoming a problem. IF the RTG did somehow become a problem, the "probability * consequences" was still so low that it's more dangerous for you (and the rest of the world) to drive your car to work. The issue is that there are some rather uninformed emotional reactions to the word "radiation".
Do you drive a car? Do you use a computer? Do you smoke? All of these have very real and very bad risks to yourself and others. Nothing you do is 100% safe. You're still doing it.
The problem is not that you oppose nuclear power, it's that you seem to be uninformed about nuclear power (and the rest of technology). The "risk" associated with your using electrical energy to power your computer is more than the risk NASA generates by using an RTG to power a spacecraft. The environmental consequences of burning coal, damming rivers, or however else you produce your electricity are much worse than the use (or even (VERY unlikely) destruction within Earth's atmosphere) of an RTG.
And you're still wrong. The Prius uses the gasoline engine to charge its batteries when it needs to, and this typically happens while the engine is moving the vehicle. There is enough excess energy produced by the gasoline engine that it can turn the electric motor (now a generator), thus charging the battery, without any affect on the power sent to the wheels. This isn't possible in a conventional vehicle and the energy is simply wasted.
The braking not only charges the batteries by utilizing the electric motor as a generator, but it also means the gasoline engine IS NOT RUNNING at all! There is no need to waste energy while breaking, so it's not just that there's a little bit of a conversion of kinetic energy to potential energy, there's ZERO potential energy converted to thermal energy via the gasoline engine.
The other reason the mileage goes up is because the gasoline engine is only used when it's needed, not when you're sitting at a light or decellerating or going down a hill, or any other time that you would normally be wasting energy on running a gasoline engine in a conventional car. It's about letting the computer do the smart driving for you.
The "transmission" on the Prius is another example of how to increase the efficiency. Since it's known that as you increase the number of gears in a transmission, you increase the efficiency of the vehicle, Toyota went to the extreme and effectively put an infinite number of gears in the Prius. The transmission is continuously changing the "gear ratio" as the power requirements (and availability) change, and in doing so greatly increases fuel effeciency.
I regularly get 50 mpg in the city and > 45 on the freeway. I didn't buy it for its mileage, though. I bought it because it qualifies for the California SULEV and sometimes for the ZEV ratings.
I get good gas mileage because I drive like an intelligent person. . . I don't need to accelerate all the way from one stop light to the next, in fact at the worst, I accelerate half way there and decellerate the other half. I drive at a constant speed when I don't need to be accelerating or decellerating--this allows the electric motor to take over because I don't need any extra power for acceleration.
However, I didn't buy it for the good gas mileage. I bought the Prius because 1) it's a SULEV (and sometimes ZEV) and 2) I wanted to support a technological change from the old, crusty, disgusting way of building individual transport that relies solely on fossil fuels. It's not the best technology imaginable, but it's currently the best mass produced technology.
There is no error in thinking that the time a certain molecule stays in the atmosphere matters. If that molecule doesn't stay in the atmosphere long enough to, relatively, affect the energy balance, then it is not as important as other molecules that live in the atmosphere longer***. If the type of molecule is not evenly distributed (spatially), then its global effect is NOT EASILY MODELED, especially if it's also a short-lived molecule.
The IPCC did not ignore surface water and its affect on global warming. They didn't use the models that made a poor job of accounting for the atmospheric water and its affect on global warming (positive and negative).
A bad and poorly understood model is sometimes worse than no model at all! This is especially true if you state, UP FRONT that you have not modeled something because of the poor constraints and incomplete understanding of its affect on the otherwise more simple model. If you CAN make approximations for how much said parameter will affect thing on an order of magnitude (or two or three) scale, then you can state, to "good" approximation what the affect will probably be. The IPCC understood this and said so in their write-up.
Yes, human activity with respect to the global water cycle does affect the atmospheric heat forcing. Consider, though, that the oceans make up more than 97% by volume of the water budget, the atmosphere makes up 1/1000 of a percent, streams and rivers (what humans modify) make up 1/10000 of a percent, lakes (also what humans modify) make up 1/10 of a percent, and ground water makes up 68/100 of a percent. So, yeah, if we were to completely vaporize the lakes and ground water, we'd completely destroy the Earth's climate.
*For the mathematically challanged w.r.t. volumes:
** The scale height is the distance it takes for the atmospheric pressure to fall by a factor of e.
*** Assume, if you will, that the lifetime of water in the atmosphere is, say, a week (I found one reference to it:in this PDF). Now, assume 1 gram of water is "stuck" together through-out its atmospheric lifetime (clearly incorrect, but just for the sake of simple calculations). Now, let's start this gram of water at the tropopause, 9 or 10 km above the surface of the earth. It's about -80 C or so there. Let the gram fall through the atmosphere non-adiabatically (so that it can gain some heat) all the way to the surface at 25 C. This is a net change of 105 degrees C. So, the gram of water has absorbed 439 J to increase its temperature. Also assume, unrealisticly--but for kicks, that this gram of water went from the liquid phase to a gaseous phase (so that we can over estimate the amount of energy absorbed). It would absorb 2000 J. Assume all of that energy is absorbed sunlight that would otherwise have reflected off the surface of the earth and back in to space. Also assume all of that energy is later released as the gram of water reverses its path and returns back to the tropopause and that this energy directly heats the atmosphere. This me
Water is not a strong absorber at all wavelengths. Take a look
Water is, for all intents, *transparent* in the visible wavelengths both as a gas and as a liquid. It's a good thing too, because the "visible" light (the light that goes through all that water vapor in the atmosphere and reaches the surface) happens to be the light that we humans evolved to see with. It also "just so happens" that the sun (as a near-black body emitter at about 5000 K) emits most of its energy at the visible wavelengths (coincidence?). . .
So, water vapor is not absorbing most of the energy that comes from the sun (even if it is a strong absorber at most infrared and UV wavelengths); it is, in fact, transparent to most of that energy until it condenses into clouds, which makes it reflect a lot of the visible wavelengths.
First of all, they don't actually ignore water. The tend not to trust atmospheric models that have globally averaged water vapor. The surface water (oceans, lakes, rivers, etc.) are important energy transport mechanisms that are much better understood than the greenhouse gas, water vapor. Read chapter 8 of the IPCC. . .
You also simply cannot ignore the fact that concentration is not the only variable when it comes to global warming. How efficeint is water vapor at absorbing in the visible and UV and re-emitting in the infrared? how does its non-even spatial distribution affect its efficeincy as a greenhouse gas? Compare that with CO2 and, say SF6, whose lifetimes in the atmosphere are much, much greater than water.
Go back and read the IPCC again. . . The atmospheric lifetime of CO2 is on the order of 50-200 years. The atmospheric lifetime of H2O is much shorter than that of CO2 (nobody is really sure by how much shorter). However, the biggest thing about water vapor is that as the concentration in the atmosphere increases, it does trap more energy from the sun, but it also increases the likelyhood that the vapor will condense to form clouds, thus increasing the "albedo" of the atmosphere, lowering the amount of energy that stays on the earth. It's difficult to model and thus is usually ignored when other gases like CO2 (which only *increase* the amount of heat retained) are increasing in concentration.
Another problem with water vapor is that it isn't evenly distributed throughout the atmosphere, either "horizontally", vertically, or temporally, mostly because its atmospheric lifetime is so short. CO2 and other strong, long lived gases are much more evenly distributed, so it's relatively simple to create a mathematical model of the effects CO2 et al. have on the energy budget of the Earth. It's not so simple with a patchy gas like water vapor.
The jury is NOT out on the matter of the increase of the average temperature of the earth. It IS increasing. The jury is ou