I thought Solar UV deionized the skip layer during the day, which is why AM band signals travel farther at night?
No, solar UV ionizes the skip layer during the day down to lower altitudes, leading to refraction of AM band signals from those lower altitudes back to the ground closer to the transmitter than they would at night. At night, the ionized layer is higher, the refraction takes place at higher altitudes, so the signal hits the ground farther away.
There is another effect, too: The higher ionization during the day also leads to increased absorption (attenuation) of the AM band signals at even lower levels of the ionosphere (the D layer) than those at which they are refracted. The D layer disappears at sunset, so absorption by this cause goes away, increasing the received signal strength at distant locations.
The above behavior is for the AM broadcast band (~1 MHz). Above around 10-13 MHz, the situation reverses; during the day, these higher frequencies refract from layers at higher altitudes and suffer less from absorption (the absorption goes as an inverse square of the frequency), so they travel great distances, while at night, there is insufficient ionization to refract the signals back to ground, so they continue out into space and are lost. And above around 20-50 MHz, depending on the state of the sunspot cycle, there is insufficient ionization even during the day to refract the signals back to ground, so one has to resort to secondary mechanisms (e.g., ionization trails of meteors) for long-distance propagation.
Typically, typically. The above is a gross generalization: The effects of the ionosphere on radio waves depends on their frequency, their polarization, their direction and location relative to the geomagnetic equator, the time of day, the month of the year, the status of the sunspot cycle (solar wind), the magnitude of the Earth's magnetic field, the magnitude and direction of the magnetic field in interplanetary space, and eleventeen other factors. Radio propagation prediction software (e.g., VOACAP) deals in probabilities, not certainties.
. ..at least by the definitions used by the FAA. See CFR 14, 101.22, viz.:
101.22 Definitions.
The following definitions apply to this subpart:
(a) Class 1—Model Rocket means an amateur rocket that:
(1) Uses no more than 125 grams (4.4 ounces) of propellant;
(2) Uses a slow-burning propellant;
(3) Is made of paper, wood, or breakable plastic;
(4) Contains no substantial metal parts; and
(5) Weighs no more than 1,500 grams (53 ounces), including the propellant.
(b) Class 2—High-Power Rocket means an amateur rocket other than a model rocket that is propelled by a motor or motors having a combined total impulse of 40,960 Newton-seconds (9,208 pound-seconds) or less.
(c) Class 3—Advanced High-Power Rocket means an amateur rocket other than a model rocket or high-power rocket.
Using these definitions, in the US the rocket is legally either a "High-Power Rocket" or an "Advanced High-Power Rocket", depending on the total impulse of the motor(s), but it is clearly not a "Model Rocket."
I have very clear memories of watching the funeral on TV
I was a little older, and I have vivid memories of that, too. In my area, "Superman" (the live-action TV show) came on at 3:30 weekday afternoons, and I remember how annoyed I was one Friday to discover that it was canceled, replaced by a lot of boring people in suits talking -- and it was the same on all three channels! However, I consoled myself that tomorrow would bring Saturday morning cartoons (a staple of life for children in the US for some decades, now swept into history). Boy, was I annoyed to discover on Saturday that all the cartoons had been pre-empted, too!
IIRC it was a week or more before programming returned to normal -- an eternity for a little kid.
If this latest revelation scares you, you'll go apoplectic to discover that this is SOP in IC design. Just about every IC more complicated than a 555 timer, from processors to Wi-Fi chips to you-name-it, has internal processors controlling substantially every part of their operation. It's a common technique to control every block one designs with an embedded core and a bit of code (in RAM, so that one could adjust the operation of the block after the design came back from fab by reloading RAM), making an easy-to-design programmable state machine. One ends up with a dozen or more cores in each chip design. Often there is one core programmed to run the top level of the design, controlling the warmup and warmdown procedures, reboot sequence, etc.
For those just tuning in, Rick Scott, Governor of the State of Florida, was previously the CEO of Columbia/HCA when it was found to have committed the largest Medicare fraud ever, up to that time ($1.7 Billion in 1997), leading to his resignation.
My idea has been to create an intellectual property tax that grows exponentially.
This already exists, in the form of patent maintenance fees. In addition to the fees one pays to get the patent to issue, to keep a patent in force one must pay fees at the 3.5, 7.5, and 11.5 year point. If any one of the fees is not paid, the patented material enters the public domain.
For large entities, the fees are $1600, $3600, and $7400, respectively. For small entities, the fees are halved. For "micro" entities, the fees are halved again.
As a side note, one of IBM's corporate strategies has been to patent early and often, but vigorously and mercilessly prune their portfolio at these points, when they have a better idea of the value of the invention to the company. Many, if not most, of their patents do not make even the first cut and so are allowed to enter the public domain at year 3.5.
The only problem is that now when I am in a country that speaks a romance language my mind ends up defaulting to French, even if the language is Spanish, Portuguese, or Italian.
I have a related disability: At various times in my life I have been conversationally fluent in Spanish, Japanese, and German, but haven't used any of them to an appreciable extent in 20 years. However, when I do happen to visit a country speaking one of these languages, and need to say something (usually, "excuse me"), there's no telling which of the three languages will come out of my mouth. It's as if the brain has classified languages into "English" and "everything else", and merged all knowledge of foreign languages into one file.
I have to stop to think what the correct response would be and, nearly always, the social situation needing my response has passed by the time I complete the context-switch into the needed language. Maddening.
You'd think so, but with switching power supplies the best efficiency is attained when the switch spends as little time as possible in the transition region between "on" and "off" -- meaning that the switching waveform is as square as the designers can make it, and therefore rich in odd harmonics. Worse, some voltage regulation schemes vary the duty cycle of the waveform, and as soon as it gets away from a perfect 50%, the even harmonics appear. The circuits are relatively low Q, so the noise in each harmonic spreads out, effectively covering the first 200 MHz or so of spectrum.
The basic problem is that the market is very cost-sensitive, and eliminating anti-RFI components (filter inductors and capacitors) saves money, and produces a wall wart that is just as "functional" as far as the user can tell.
It's only when he turns on a radio that he notices a problem, and with 5-10 of the things in the house, the lay person will never come to associate the wall wart with his radio problem -- especially since his neighbors all have them, too. It's just RF smog.
I just wish there were a similar national effort towards reducing the amount of electrical noise these things generate. They're regulated on paper, but not in practice, and the noise they create, once it is radiated by the power cords and general house wiring, is a major source of shortwave radio interference.
a newspaper which makes no bones about it support for an independent Scotland
Maybe you should call "it support" to fix your apostrophe problem.
Sorry, no. The GP poster's statement is merely missing an "s" -- an apostrophe would be incorrect there. (It should read, "a newspaper which makes no bones about its support for an independent Scotland.")
Remember it this way: his, her, its. If you can replace "its" with "his" or "her", it does not need an apostrophe.
The confusion of place names in this region affects even how to address postal mail. See the excellent discussion on the various place names in Frank's Compulsive Guide to Postal Addresses.
(n.b.: Frank's agrees that "SCOTLAND is one of the countries of Britain.")
The engineers at my office wanted to watch the launch, so we invaded the accounting office that had the windows facing the Space Center. It was a beautiful launch, up to the time the exhaust trail forked, forming a "Y". The accountants all said, "Oh, look how beautiful!" The engineers all said, "Uh-oh. That's not supposed to happen. . .."
Congratulations! You hit my other favorite myth, that there is something special about water at 2.4 GHz. There isn't. Water vapor in the atmosphere has less than 0.001 dB/km (yes, kilometer) specific attenuation at 2.4 GHz. The first significant resonance for water isn't until 22.3 GHz, and even then it is less than 0.2 dB/km. It's a myth!
Water had nothing to do with the creation of the 2.4 GHz ISM band, or the placing of microwave ovens at that frequency. Amateurs do moonbounce communication in the 2.4 GHz band -- that should tell you all you need to know about propagation there.
Slashdot Mirror
And incorrect use of apostrophes.
Wasn't that in the arctic?
I'd be surprised if many consumers had ever stopped to wonder whether or not their router had a log file.
It's worse than that. I mentioned the existence of a log file to my neighbor once, and he thought it was a piece of equipment used by lumberjacks.
Wait, is this the Utah or Mars?
It could be the Mars, I suppose. . . .
Apparently you've not heard of the VIPR Program.
USLaunchReport has video of the accident. The first visible anomaly is at 1:11.
Anybody know if they are still using OTH Radar?
Oh, yes, somebody's still using it. It corrupts many shortwave services from time to time. Heard it myself last month.
I thought Solar UV deionized the skip layer during the day, which is why AM band signals travel farther at night?
No, solar UV ionizes the skip layer during the day down to lower altitudes, leading to refraction of AM band signals from those lower altitudes back to the ground closer to the transmitter than they would at night. At night, the ionized layer is higher, the refraction takes place at higher altitudes, so the signal hits the ground farther away.
There is another effect, too: The higher ionization during the day also leads to increased absorption (attenuation) of the AM band signals at even lower levels of the ionosphere (the D layer) than those at which they are refracted. The D layer disappears at sunset, so absorption by this cause goes away, increasing the received signal strength at distant locations.
The above behavior is for the AM broadcast band (~1 MHz). Above around 10-13 MHz, the situation reverses; during the day, these higher frequencies refract from layers at higher altitudes and suffer less from absorption (the absorption goes as an inverse square of the frequency), so they travel great distances, while at night, there is insufficient ionization to refract the signals back to ground, so they continue out into space and are lost. And above around 20-50 MHz, depending on the state of the sunspot cycle, there is insufficient ionization even during the day to refract the signals back to ground, so one has to resort to secondary mechanisms (e.g., ionization trails of meteors) for long-distance propagation.
Typically, typically. The above is a gross generalization: The effects of the ionosphere on radio waves depends on their frequency, their polarization, their direction and location relative to the geomagnetic equator, the time of day, the month of the year, the status of the sunspot cycle (solar wind), the magnitude of the Earth's magnetic field, the magnitude and direction of the magnetic field in interplanetary space, and eleventeen other factors. Radio propagation prediction software (e.g., VOACAP) deals in probabilities, not certainties.
. . .at least by the definitions used by the FAA. See CFR 14, 101.22, viz.:
101.22 Definitions.
The following definitions apply to this subpart:
(a) Class 1—Model Rocket means an amateur rocket that:
(1) Uses no more than 125 grams (4.4 ounces) of propellant;
(2) Uses a slow-burning propellant;
(3) Is made of paper, wood, or breakable plastic;
(4) Contains no substantial metal parts; and
(5) Weighs no more than 1,500 grams (53 ounces), including the propellant.
(b) Class 2—High-Power Rocket means an amateur rocket other than a model rocket that is propelled by a motor or motors having a combined total impulse of 40,960 Newton-seconds (9,208 pound-seconds) or less.
(c) Class 3—Advanced High-Power Rocket means an amateur rocket other than a model rocket or high-power rocket.
Using these definitions, in the US the rocket is legally either a "High-Power Rocket" or an "Advanced High-Power Rocket", depending on the total impulse of the motor(s), but it is clearly not a "Model Rocket."
Yes, but it had to shoot first.
I have very clear memories of watching the funeral on TV
I was a little older, and I have vivid memories of that, too. In my area, "Superman" (the live-action TV show) came on at 3:30 weekday afternoons, and I remember how annoyed I was one Friday to discover that it was canceled, replaced by a lot of boring people in suits talking -- and it was the same on all three channels! However, I consoled myself that tomorrow would bring Saturday morning cartoons (a staple of life for children in the US for some decades, now swept into history). Boy, was I annoyed to discover on Saturday that all the cartoons had been pre-empted, too!
IIRC it was a week or more before programming returned to normal -- an eternity for a little kid.
. . . or even "copy-paste."
Well, at least this submission was not encumbered by the editorial process.
If this latest revelation scares you, you'll go apoplectic to discover that this is SOP in IC design. Just about every IC more complicated than a 555 timer, from processors to Wi-Fi chips to you-name-it, has internal processors controlling substantially every part of their operation. It's a common technique to control every block one designs with an embedded core and a bit of code (in RAM, so that one could adjust the operation of the block after the design came back from fab by reloading RAM), making an easy-to-design programmable state machine. One ends up with a dozen or more cores in each chip design. Often there is one core programmed to run the top level of the design, controlling the warmup and warmdown procedures, reboot sequence, etc.
Move along, nothing to see here.
When you make an allegation of corruption you need to back it up. Link to some source.
I'm not the OP (an AC), but for starters:
The Tampa Bay Times.
Forbes.
For those just tuning in, Rick Scott, Governor of the State of Florida, was previously the CEO of Columbia/HCA when it was found to have committed the largest Medicare fraud ever, up to that time ($1.7 Billion in 1997), leading to his resignation.
My idea has been to create an intellectual property tax that grows exponentially.
This already exists, in the form of patent maintenance fees. In addition to the fees one pays to get the patent to issue, to keep a patent in force one must pay fees at the 3.5, 7.5, and 11.5 year point. If any one of the fees is not paid, the patented material enters the public domain.
For large entities, the fees are $1600, $3600, and $7400, respectively.
For small entities, the fees are halved.
For "micro" entities, the fees are halved again.
As a side note, one of IBM's corporate strategies has been to patent early and often, but vigorously and mercilessly prune their portfolio at these points, when they have a better idea of the value of the invention to the company. Many, if not most, of their patents do not make even the first cut and so are allowed to enter the public domain at year 3.5.
That's called a "direct" flight. A "non-stop" flight is just that, a flight with no stops.
*sigh* There's never a mod point around when you need one.
Go is arguably the hardest game to play (and master) there is.
No. Try human copulation.
The only problem is that now when I am in a country that speaks a romance language my mind ends up defaulting to French, even if the language is Spanish, Portuguese, or Italian.
I have a related disability: At various times in my life I have been conversationally fluent in Spanish, Japanese, and German, but haven't used any of them to an appreciable extent in 20 years. However, when I do happen to visit a country speaking one of these languages, and need to say something (usually, "excuse me"), there's no telling which of the three languages will come out of my mouth. It's as if the brain has classified languages into "English" and "everything else", and merged all knowledge of foreign languages into one file.
I have to stop to think what the correct response would be and, nearly always, the social situation needing my response has passed by the time I complete the context-switch into the needed language. Maddening.
You'd think so, but with switching power supplies the best efficiency is attained when the switch spends as little time as possible in the transition region between "on" and "off" -- meaning that the switching waveform is as square as the designers can make it, and therefore rich in odd harmonics. Worse, some voltage regulation schemes vary the duty cycle of the waveform, and as soon as it gets away from a perfect 50%, the even harmonics appear. The circuits are relatively low Q, so the noise in each harmonic spreads out, effectively covering the first 200 MHz or so of spectrum.
The basic problem is that the market is very cost-sensitive, and eliminating anti-RFI components (filter inductors and capacitors) saves money, and produces a wall wart that is just as "functional" as far as the user can tell.
It's only when he turns on a radio that he notices a problem, and with 5-10 of the things in the house, the lay person will never come to associate the wall wart with his radio problem -- especially since his neighbors all have them, too. It's just RF smog.
I just wish there were a similar national effort towards reducing the amount of electrical noise these things generate. They're regulated on paper, but not in practice, and the noise they create, once it is radiated by the power cords and general house wiring, is a major source of shortwave radio interference.
a newspaper which makes no bones about it support for an independent Scotland
Maybe you should call "it support" to fix your apostrophe problem.
Sorry, no. The GP poster's statement is merely missing an "s" -- an apostrophe would be incorrect there. (It should read, "a newspaper which makes no bones about its support for an independent Scotland.")
Remember it this way: his, her, its. If you can replace "its" with "his" or "her", it does not need an apostrophe.
The confusion of place names in this region affects even how to address postal mail. See the excellent discussion on the various place names in Frank's Compulsive Guide to Postal Addresses.
(n.b.: Frank's agrees that "SCOTLAND is one of the countries of Britain.")
The engineers at my office wanted to watch the launch, so we invaded the accounting office that had the windows facing the Space Center. It was a beautiful launch, up to the time the exhaust trail forked, forming a "Y". The accountants all said, "Oh, look how beautiful!" The engineers all said, "Uh-oh. That's not supposed to happen. . . ."
Congratulations! You hit my other favorite myth, that there is something special about water at 2.4 GHz. There isn't. Water vapor in the atmosphere has less than 0.001 dB/km (yes, kilometer) specific attenuation at 2.4 GHz. The first significant resonance for water isn't until 22.3 GHz, and even then it is less than 0.2 dB/km. It's a myth!
Water had nothing to do with the creation of the 2.4 GHz ISM band, or the placing of microwave ovens at that frequency. Amateurs do moonbounce communication in the 2.4 GHz band -- that should tell you all you need to know about propagation there.