This is by far the best point to getting a wireless router. It has 10/100 ports on it to hook up your wired computers, and it allows you to hook up your laptop or other computer you want mobile. It is very darn convenient.
By the way, if the poster's parents are not moving very large files around and they basically use the computer to surf the web and read email (i.e., they don't need 100 Mbps), then a wireless connection certainly is something to consider.
Besides, if you are connected via something like residential dsl which can't even do 10Mbps, why insist on 100Mbps everywhere in the house? Having that wire between the computer and the printer is great when you want to print very large files, but if that is the only real need for that kind of bandwidth then it may be worth the wireless instead of running wires (running them properly that is, such as through walls and not just strung in the open along the baseboard).
Though a bit gruff, this fellow is correct. Extending the cable is very easy; just cut the cord and add some extra cable in-between. If you're not one for soldering and/or crimping simple connectors onto the wire, just twist them together (perhaps with a wirenut) and tape them up.
It certainly is cheaper than purchasing new headphones, and if you're not going to use them anyway, then why not give it a try?
I believe that if your temperature and pressure are low enough, you'll get very slow (if any) sublimation. See the H2O phase diagram here. In that figure if you are down at point "D" you basically stay in the solid phase.
The example you mention with freezer ice is a bit contrived. You don't need low pressures there because the freezer, by design, is condensing out the water vapor which forces the ice/air interface to not be in equilibrium (the water vapor does not have the opportunity to refreeze because the freezer removes it).
Given that the solar wind sound speed is on the order of 30,000 km/s, one could argue that would be equivalent to flying at 150,000 km/s (ignoring relativistic effects).
What I'm arguing is that the stated danger levels of 4 mG are two orders of magnitude lower than the background field. You'll see miligauss variations just running or driving around within this background field due to local geological variations. But I also pointed out that for time scales that are comparable to 60 Hz powerlines that you still get stronger field variations form the solar wind/ionospheric interactions.
My second statement says nothing about arguing from theory. What I'm arguing is that for anyone to draw connections with cancer from data based on field levels that are orders of magnitude lower than terrestrial field variations is not based on science. That is pulling data out of the noise to prove something while at the same time selectively discarding the other noise terms. That is bad data analysis coupled with ignorance of the environment in which the data are collected. Again, if one holds a belief in EMF induced cancer for whatever reason, that is fine to a point; all I'm saying is don't say that this belief is grounded in any kind of believable scientific analysis.
Before you read too far into the Power Line "Facts" site, you might want to consider that the Earth's static magnetic field is on the order of.2-.6 G, depending on where you live. The field varies 0.1 G on the timescale of a day simply as the result of the Earth rotating under the magnetosphere. There are high frequency variations in the field on the order of tens of miligauss just from interactions with the solar wind on the magnetosphere, and much larger variations from solar flare events.
If you are going to run away fast from a 4 mG field, I'm afraid that you don't have too many places to run towards. Perhaps if you build an enclosure using mu-metal, or some other magnetic-shielding material, then you'd have a magnetic "bomb shelter" into which you can hide.
Miligauss fields are so far down in the noise that making connections between that and developing cancer is, from a scientific standpoint at least, wholly irresponsible and entirely bad science. There might be other reasons, personal or political, to make these claims, but they cannot be based on sound scientific principles.
Forgive my ignorance but I really haven't been following this story. If Eolas isn't willing to sell a license, then what is their angle? It would seem that they could make a pretty penny with even modest license terms considering the IE market share.
Keep in mind that a telescope really is an interferometer. It forms an image by combining light from all parts of the primary mirror in phase at the detector. A (two-beam) interferometer combines light from two beams in phase at the detector. You can easily convert a telescope from it's "normal" mode over to an interferometer by putting a mask with two holes on it. This is how Michelson made the first stellar diameter measurements, and the Kecks, operating in interferometer mode, are just using the same technique Michelson did, just on a much much larger scale.
For a long time, the Large Magellanic Cloud, an irregular type satellite galaxy of our own, was held to be the closest galaxy to the Milky Way. It is 179,000 light-years away.
But in 1994 the Sagittarius Dwarf Elliptical Galaxy was discovered at 80,000 light-years. It now holds the honor.
If you know the language and the language can do what you want to do, then why not?
Another good reason is if you are supporting existing software you might want to keep the code consistent.
I'm not sure you can claim obsolescence for Fortran, especially at the time when punch cards went out (mid- to late-70's). The gold standard, F77, was used everywhere, and it remained the gold standard at least until F90 came out. While C was being used for taking care of OS issues (networking, etc.) Fortran ruled the roost for industrial machines and scientific/other computation. I think you'll find that many industrial settings still use machines running F77 on PDP-11's, and a good deal of numerical packages still use Fortran. I don't think anyone is going to write the next GUI app, Quake4, or networking protocol in Fortran, but there are still a lot of things you'd do well to use it.
Have you looked at ecos and RTLinux? I think there were one or two others but they don't come immediately to mind.
I can't say much about LabView and CE.NET, but I do work with VxWorks and it is easy to develop for and has a reliable performance. On the other hand, you pay alot for the licenses. We're doing R&D stuff and we just can't keep VxWorks in our budget (we just want to upgrade our processor board and it would run us something like $7k-$10k). We're considering other OS options and I would be interested in any other observations you have. If I am correct, one of the things that is appealing about QNX is that for our R&D work the license would essentially be very cheap or free (I think you don't pay until you want to use it commercially, if I recall correctly).
----->The Income Tax ammendment was never properly ratified by 2/3 of the states, and is not valid because of that. It's still enforced, but it's not valid.
I never understood this argument because it is just blatently false, and it is so easy to check. First off, 3/4 of the states need to ratify an ammendment, which is even more formidable, but that is beside the point for this argument. The 16th ammendment was proposed in July of 1909. At that time by my count there were 46 states (50 minus New Mexico (1/6/1912), Arizona (2/14/1912), Alaska (1/3/1959), and Hawaii (8/21/1959)). The first state to ratify was Alabama (8/10/1909) and the last was New Hampshire (3/7/1913). During that time even New Mexico and Arizona ratified, bringing the state pool to 48 states. Out of those 48 states, 38 ratified the ammendment. That is two more than what was needed for ratification (0.75*48 = 36), so the remaining 10 states didn't even need to vote on it.
Why do people keep saying the ammendment was never ratified?
Sorry my post is days old, but I only saw your comment via the Metamoderation page. If there is a valid argument regarding this ratification issue, please reply as I have been curious for some time as to why the non-ratification statement keeps coming up.
You are also assuming that your imaging aperture is smaller than the isoplanatic patch for your area; otherwise you'd need to add your own adaptive optics system to your telesope before you could rack and stack your images. The Keck adaptive optics aren't just for keeping the image from jumping around; they are for correcting the turbulence effects across the aperture (meaning that without the AO system it isn't that the whole image jumps around, but different parts of the image jump around in different directions---if your telescope aperture is small enough, then your whole image jumps around).
I don't know if I have the number correct, but I believe that for typical backyard viewing the Fried parameter is something like 6" to 8", so if you have a telescope aperture bigger than that then your pictures wouldn't differ in just tip and tilt.
NASA ADS is a great place for searching for articles in many journals (not just astronomy and astrophysics). There are also mirrors located around the world.
I don't think I can agree with you, unless my rough calculation is messed up.
The Cosmic Background Radiation at about 900MHz is about 10^(-21) W/(m^2 sr Hz). A 3 W cell phone radiating into a sphere puts out per square meter about 2.5x10^(-10) W/(sr Hz). This means that the strengths of the two signals are equal at about 500,000 meters, or only 500 km. Pluto's diameter is about 2,000 km, so you'd be lost in the noise without even leaving Pluto.
The glass spheres are just pressure housings for the photomultiplier tubes. You want glass because you want light to pass through, and you want a sphere because it is easy to make as well as being the best shape to stand up against pressure (they drill a kilometer into the ice, lower down a string of these detectors, then fill the hole back with water to refreeze).
Ice is used in this case because you want these detectors deep under the Earth's surface to shield from atmospheric muons and other background particles. This experiment exploits the fact that Antarctic ice is very clear and deep. Similar experiments have been done by dropping PMTs deep into the ocean (as well as the Sudbury and SuperK experiments that use water tanks in deep underground facilities).
You can differentiate between electrons and muons pretty easily in a Cherenkov detector because electrons produce much more light and in a much larger cone from both the initial electron as well as the electrons that get produced in the ensuing electromagnetic cascade. Muons won't produce the EM cascades. The cosine of the Cherenkov light cone angle goes as the inverse of the particle velocity, and the number of photons produced goes as 1 minus the inverse of the velocity.
It is much more than a conceptual idea. The US military did balloon-assisted launches in the 1950's, and recently amateur radio operators as well as amateur rocket folk have done it as well. For one link see here.
You aren't going to get big payloads into space this way as the heavy balloons can carry on the order of several tons. I'm not sure if, in the end, this would be any cheaper or easier than launching a Pegasus from an airplane.
One thing certainly would be neat is if they used hygrogen in the balloon, that would make quite an impressive fireball then the rocket is ignited.
In a wire it is certainly true that the electrons that are carrying the current, but in a plasma either species can be current carriers. In a lightning bolt the atmosphere is ionized so the electrons will want to move one way and the positive ions the other way.
Michelson pushed the limits of what could be accomplished at the time. He used apertures that were spaced 20 feet apart (I believe). After he died his collaborator Pease tried a 50 ft baseline but it wasn't stable enough. It took another 40-50 years until the technology caught up to stabilize longer baselines.
Michelson measured the diameters by resolving them. When you look at a point source with two apertures (which is the method he used), what you see are interference fringes. As you move your apertures apart, their resolving power increases. When you reach the point where you start resolving your source, your interference fringes go away.
The large interferometers use this same method where they make a whole bunch of fringe observations (for N apertures, you can measure N(N-1)/2 fringes), but the basic method is the same. If you make enough measurements, you can then do a transform on your data to turn it into an image.
You are correct, but the results are quite different. Though the technique used now is fundamentally the same as what Michelson used, Michelson would have been very hard pressed to measure oblatness because he (and Pease) were very limited in how they could change their baselines. In effect, Michelson and Pease could only measure the diameter across one direction of the star, so they could not have made an oblateness measurement.
The modern interferometers, besides having very long observing baselines, also make such a large number of baseline observations that they can actually do an inverse transform and get an image.
If you are interested, some nice info is found here, and the best collection of stellar interferometry links is found here.
Slashdot Mirror
By the way, if the poster's parents are not moving very large files around and they basically use the computer to surf the web and read email (i.e., they don't need 100 Mbps), then a wireless connection certainly is something to consider.
Besides, if you are connected via something like residential dsl which can't even do 10Mbps, why insist on 100Mbps everywhere in the house? Having that wire between the computer and the printer is great when you want to print very large files, but if that is the only real need for that kind of bandwidth then it may be worth the wireless instead of running wires (running them properly that is, such as through walls and not just strung in the open along the baseboard).
It certainly is cheaper than purchasing new headphones, and if you're not going to use them anyway, then why not give it a try?
A nice article on plasma engines can be found here.
The example you mention with freezer ice is a bit contrived. You don't need low pressures there because the freezer, by design, is condensing out the water vapor which forces the ice/air interface to not be in equilibrium (the water vapor does not have the opportunity to refreeze because the freezer removes it).
Given that the solar wind sound speed is on the order of 30,000 km/s, one could argue that would be equivalent to flying at 150,000 km/s (ignoring relativistic effects).
My second statement says nothing about arguing from theory. What I'm arguing is that for anyone to draw connections with cancer from data based on field levels that are orders of magnitude lower than terrestrial field variations is not based on science. That is pulling data out of the noise to prove something while at the same time selectively discarding the other noise terms. That is bad data analysis coupled with ignorance of the environment in which the data are collected. Again, if one holds a belief in EMF induced cancer for whatever reason, that is fine to a point; all I'm saying is don't say that this belief is grounded in any kind of believable scientific analysis.
If you are going to run away fast from a 4 mG field, I'm afraid that you don't have too many places to run towards. Perhaps if you build an enclosure using mu-metal, or some other magnetic-shielding material, then you'd have a magnetic "bomb shelter" into which you can hide.
Miligauss fields are so far down in the noise that making connections between that and developing cancer is, from a scientific standpoint at least, wholly irresponsible and entirely bad science. There might be other reasons, personal or political, to make these claims, but they cannot be based on sound scientific principles.
Forgive my ignorance but I really haven't been following this story. If Eolas isn't willing to sell a license, then what is their angle? It would seem that they could make a pretty penny with even modest license terms considering the IE market share.
Keep in mind that a telescope really is an interferometer. It forms an image by combining light from all parts of the primary mirror in phase at the detector. A (two-beam) interferometer combines light from two beams in phase at the detector. You can easily convert a telescope from it's "normal" mode over to an interferometer by putting a mask with two holes on it. This is how Michelson made the first stellar diameter measurements, and the Kecks, operating in interferometer mode, are just using the same technique Michelson did, just on a much much larger scale.
It is probably a reference to the Pathfinder Mission, which is a demo or proof-of-concept mission.
Oops. If I had paid attention I would have noticed that I was scooped by 12 hours here.
The closest galaxy is (quote taken from here):
If you know the language and the language can do what you want to do, then why not?
Another good reason is if you are supporting existing software you might want to keep the code consistent.
I'm not sure you can claim obsolescence for Fortran, especially at the time when punch cards went out (mid- to late-70's). The gold standard, F77, was used everywhere, and it remained the gold standard at least until F90 came out. While C was being used for taking care of OS issues (networking, etc.) Fortran ruled the roost for industrial machines and scientific/other computation. I think you'll find that many industrial settings still use machines running F77 on PDP-11's, and a good deal of numerical packages still use Fortran. I don't think anyone is going to write the next GUI app, Quake4, or networking protocol in Fortran, but there are still a lot of things you'd do well to use it.
You can see here.
I can't say much about LabView and CE.NET, but I do work with VxWorks and it is easy to develop for and has a reliable performance. On the other hand, you pay alot for the licenses. We're doing R&D stuff and we just can't keep VxWorks in our budget (we just want to upgrade our processor board and it would run us something like $7k-$10k). We're considering other OS options and I would be interested in any other observations you have. If I am correct, one of the things that is appealing about QNX is that for our R&D work the license would essentially be very cheap or free (I think you don't pay until you want to use it commercially, if I recall correctly).
One link for ratification times is found here.
Why do people keep saying the ammendment was never ratified?
Sorry my post is days old, but I only saw your comment via the Metamoderation page. If there is a valid argument regarding this ratification issue, please reply as I have been curious for some time as to why the non-ratification statement keeps coming up.
I don't know if I have the number correct, but I believe that for typical backyard viewing the Fried parameter is something like 6" to 8", so if you have a telescope aperture bigger than that then your pictures wouldn't differ in just tip and tilt.
NASA ADS is a great place for searching for articles in many journals (not just astronomy and astrophysics). There are also mirrors located around the world.
The Cosmic Background Radiation at about 900MHz is about 10^(-21) W/(m^2 sr Hz). A 3 W cell phone radiating into a sphere puts out per square meter about 2.5x10^(-10) W/(sr Hz). This means that the strengths of the two signals are equal at about 500,000 meters, or only 500 km. Pluto's diameter is about 2,000 km, so you'd be lost in the noise without even leaving Pluto.
Ice is used in this case because you want these detectors deep under the Earth's surface to shield from atmospheric muons and other background particles. This experiment exploits the fact that Antarctic ice is very clear and deep. Similar experiments have been done by dropping PMTs deep into the ocean (as well as the Sudbury and SuperK experiments that use water tanks in deep underground facilities).
You can differentiate between electrons and muons pretty easily in a Cherenkov detector because electrons produce much more light and in a much larger cone from both the initial electron as well as the electrons that get produced in the ensuing electromagnetic cascade. Muons won't produce the EM cascades. The cosine of the Cherenkov light cone angle goes as the inverse of the particle velocity, and the number of photons produced goes as 1 minus the inverse of the velocity.
You aren't going to get big payloads into space this way as the heavy balloons can carry on the order of several tons. I'm not sure if, in the end, this would be any cheaper or easier than launching a Pegasus from an airplane.
One thing certainly would be neat is if they used hygrogen in the balloon, that would make quite an impressive fireball then the rocket is ignited.
In a wire it is certainly true that the electrons that are carrying the current, but in a plasma either species can be current carriers. In a lightning bolt the atmosphere is ionized so the electrons will want to move one way and the positive ions the other way.
Michelson pushed the limits of what could be accomplished at the time. He used apertures that were spaced 20 feet apart (I believe). After he died his collaborator Pease tried a 50 ft baseline but it wasn't stable enough. It took another 40-50 years until the technology caught up to stabilize longer baselines.
The large interferometers use this same method where they make a whole bunch of fringe observations (for N apertures, you can measure N(N-1)/2 fringes), but the basic method is the same. If you make enough measurements, you can then do a transform on your data to turn it into an image.
The modern interferometers, besides having very long observing baselines, also make such a large number of baseline observations that they can actually do an inverse transform and get an image.
If you are interested, some nice info is found here, and the best collection of stellar interferometry links is found here.