At 20g, it's too small to carry power + a radio emitter, and still have any consistency. Any signal it could put out at that weight would be completely drowned out by the atmosphere.
I can't find it now, but I remember stumbling across an amateur rocketry web site where the author (a licensed ham) had ground down a PIC chip (I think it was a 16C84 or 16F84) from 16 pins to the middle 8 pins, added a small clock crystal, watch battery, and a little antenna wire. The PIC repeatedly transmitted the author's callsign in CW on some HF frequency, performing the modulation in software.
9 orbits is only 7 hours. I'm pretty sure you could put that much battery in it and still be under 20 grams.
One idea I've been tossing around in the back of my head for a while is a backup-to-disk device which is kind of a cross between a tape library and a raid enclosure. It would emulate a tape robot and drives so that normal backup software could talk to it, and would just power up drives as they are needed and read/write to them. The advantages are that there is no expensive robot with moving parts, only a few drives need to be powered up at once, the drives will probably last longer if they stay off most of the time, "tape seeks" would stay nearly instant, and you don't need RAID controller ports for every drive you have (just a switching fabric for routing the ports you have to the drives you want to talk to.)
It'd probably only be practical with SATA or SAS (fewer wires and availability of multiplexing chips).
Maybe someone can do me a favor and steal my idea so I can buy some hardware like this fairly soon.:)
15% grade is insanely steep. 70mph up such a grade is VERY fast.
Yes, the Interstate standard is 6% (which would still require a lot more than 20HP with friction added in - an old 53hp Chevette won't climb some interstate passes at 70mph with the pedal floored), but there are lots of other state highways and such that are steeper. Some of them are also straight enough and far enough away from cliffs that 70mph is safe.
The only reason a smallish car has a 100HP engine is to get rapid acceleration. Any hybrid can replace that with a much lighter 15-20HP engine, which produces plenty for cruising at a fixed speed, plus some extra to charge up the storage unit for the desired rapid acceleration.
I'd size it a little bigger than that, unless you can really cut down on weight. 70mph up a 15% grade is 4.7m/s of vertical lift. If the car weighs 1000kg, that's 61hp , not counting air drag or rolling resistance.
Should it ever get to the point in the US where the 2nd Amendment is needed for the purpose that its proponents purport it's there for, I frankly would rather shoot myself. I have no interest to live through a major US revolution and then live in a nation of gun-wielding rednecks.
One (very macabre) way of looking at it is that it's an insurance policy. You pay the price of a moderate number of gun deaths per year to keep the government in check and therefore help avoid such a revolution.
Based on some numbers I looked up quick, the shuttle has a gross liftoff weight of around 4,500,000 pounds and a payload capacity of 50,000 pounds. That means cargo accounts for around 1.1% of the liftoff weight.
I don't have numbers for you, but I do know that to reach a certain orbit (delta-V) using fuel of a particular specific impulse (Isp), fuel weight and rocket weight have to be the same ratio. For a lighter payload, they would be able to bring less fuel (although they may just opt to not burn the last bit). The max rated liftoff weight would be for everything needed to lift the max rated payload.
Note that the bottom line of this graph is virtually dead flat.
It is pretty much flat, but it's worth noting that the graph uses inverted units for comparison: dollars per barrel for currency, and barrels per oz for gold. For consistency, they should have used something besides oz (milligrams, maybe) so that they could use barrels as the fraction denominator. As presented, it looks like gold has a response opposite to that of the dollar for short-term fluctuations.
From what I've read, the see-thru-chicks-clothes THz airport scanner is passive - receive only, which seems to imply that THz radiation is maybe also present in visible light sources (or maybe we generate it?).
Sorry, but there are (likely insurmountable) technical problems with using modern jetliner turbofan engines at supersonic speeds.
Those turbofans are sort of like a Concorde's turbojet but with a much larger ducted fan bolted onto the front. Some air from this fan is compressed, combusted, and exhausted, but most is simply blown backwards. The ratio of blow to burn is called the bypass ratio. The exhaust stream is big, slow, and cool instead of small, fast, and hot - that's why they are so much quieter.
High bypass-ratio turbofans can't go supersonic because the tip speed of the fan blades must stay subsonic for the fan to work. Also, the incoming air must be subsonic before it hits the fan blades - this requires long inlet ducts, not the short ring you see around a jetliner's fan.
But if you can go that fast, why bother with a compressor, aside from using it to accelerate for takeoff? Just use a ramjet, no moving parts, who cares how fast it goes (as long as you can still get the fuel mixed into the air before it's out the back.)
Jet turbines and ramjets share the same problem - they are only capable of subsonic combustion and must slow the supersonic airflow before they can burn fuel in it and reaccelerate it. Thus the recent experiments with scramjets (supersonic combustion ramjets). They aren't ready for use yet.
Or do you think Americans have double size wires in the streets/homes compared to Europeans? I think we'd all have 10,000V in our homes if that were so.
Yes, we do have wires that are larger in our houses (and more of them). Your average American house circuit is 15A (14AWG) or 20A (12AWG) at 120V. Much of post-war UK was wired with ring circuits to save copper and allow 14AWG wire to be used for 30A circuits, with breakers/fuses at each outlet instead of at the panel, requiring fewer total circuits.
There's obviously tradeoffs with higher voltages - thicker insulation is required, switch design becomes more critical (arcs become harder to extinguish), and electrocution becomes more of a concern. Go touch the flyback coil on a big CRT monitor and you'll understand.
And by avoiding the chemical reaction that drives traditional batteries, there's no real danger of a capacitor suddenly overloading--or exploding like a laptop's lithium-ion battery pack.
There is still a danger - Capacitors that store a lot of energy use very very thin insulators to separate large sheets of foil charged to large voltages. Insulators are only good for a certain number of volts per meter, and they won't make them much thicker than they need to be - it would reduce the capacity. Imperfections in this insulator will eventually result in short circuits and arcing. If there's enough energy stored in the capacitor to get the surrounding material hot enough, it could catch fire or vent explosively.
How long would it take? Probably bloomin ages, but that's not the issue.
Considering that the two inputs of the gravitational formula that are under your control (time and distance) are both squared, you want to accelerate as fast as you possibly can.
Once you're in orbit, then yes, you can use very small amounts of thrust over very long periods of time to circularize or raise an orbit (to the point of escape velocity if desired) but the whole throw-yourself-at-the-ground thing must be done very quickly if you are to fail at it.
There's actually not much in the way of a rule that says something going into orbit has to reach 'escape velocity'.
No, but you have to get almost there. Low Earth Orbit is 7.8km/s, escape velocity is 11.2km/s. In addition, any non-escape ballistic trajectory that starts from the earth will form an ellipse that will eventually intersect the earth, meaning your rocket must accelerate sideways a fair bit once it's up there.
You need much less speed to merely reach space and fall back down, but the article clearly said 'orbit'.
But does this mean they can cool the chip without the heat sink/fan combo
Heat engines, thermocouples, etc. don't harness "hot". They harness the flow of heat. If you do not provide any place for that heat to move to, they can't do anything.
Now, if you just want to get rid of that noisy fan, get a heat pipe and have it move the heat from your CPU to your chassis (if suitable) or to a radiator cooled by a much larger, slower, quieter fan.
That's exactly what I meant by ladder racking (or cable runways, or whatever the kids are calling it these days). Yes, the part that you can see looks better with a raised floor, but it sucks so much to run cable under a floor that that's all anyone ever does - no one ever organizes or cleans under there. Sure, they'll take a wet/dry vac to it after an A/C accident, but they won't go back under if they remember they forgot a can of soda pop down there. It'll sit there until the fruit flies eat it all up.
My favorite thing for patch panels/switches is to put them on separate horizontally adjacent racks. A cable goes up from the patch panel to the cable management bracket, over to a gap between the racks, forms a U where all of the slack is stored, then goes into cable management again and then down to its switch port. It looks good with all of the slack in one place, it's easy to make changes, and you don't have cables running directly across the front of equipment (making it impossible to remove, or in some cases, inspect).
And if you do wall-mount the switches and patch panels, use a hinged rack (example) so you can get to the back of it. And of course, tell your cabler which side should be hinged so they'll be forced to use two extra brain cells to run the cable so it can be hinged.
4 racks of computer equipment. Make it a proper little data centre with raised floors
And where are you going to put the ramp to wheel equipment up the extra 2 feet? Unless this is the basement and you can excavate and pour another slab, raised floors either need a lot of room to get into and out of, or they need their own floor (as in, "this entire first floor of this building is for the raised floor"). You won't have much luck convincing an architect to cut a 10x20' hole in a post-tensioned slab.
Just put the rack cabinets where you want them (3.5' of clearance in front, 2' to at least one side and the rear) and the plywood/OSB wall-o-punchdown-blocks where you want them, and install ladder racking between them so that all of the cables are organized and out of the way. Also, delivering each power circuit through conduit to receptacle boxes at the top of each rack cabinet is a really clean way of doing it - it prevents anyone from tripping over any power cords.
I suspect that a large percentage of raised-floor proponents haven't spent much time underneath one.
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I can't find it now, but I remember stumbling across an amateur rocketry web site where the author (a licensed ham) had ground down a PIC chip (I think it was a 16C84 or 16F84) from 16 pins to the middle 8 pins, added a small clock crystal, watch battery, and a little antenna wire. The PIC repeatedly transmitted the author's callsign in CW on some HF frequency, performing the modulation in software.
9 orbits is only 7 hours. I'm pretty sure you could put that much battery in it and still be under 20 grams.
I believe it implies the alien is from somewhere other than terra (Earth).
One idea I've been tossing around in the back of my head for a while is a backup-to-disk device which is kind of a cross between a tape library and a raid enclosure. It would emulate a tape robot and drives so that normal backup software could talk to it, and would just power up drives as they are needed and read/write to them. The advantages are that there is no expensive robot with moving parts, only a few drives need to be powered up at once, the drives will probably last longer if they stay off most of the time, "tape seeks" would stay nearly instant, and you don't need RAID controller ports for every drive you have (just a switching fabric for routing the ports you have to the drives you want to talk to.)
It'd probably only be practical with SATA or SAS (fewer wires and availability of multiplexing chips).
Maybe someone can do me a favor and steal my idea so I can buy some hardware like this fairly soon. :)
The United States is a Common Law country.
Yes, the Interstate standard is 6% (which would still require a lot more than 20HP with friction added in - an old 53hp Chevette won't climb some interstate passes at 70mph with the pedal floored), but there are lots of other state highways and such that are steeper. Some of them are also straight enough and far enough away from cliffs that 70mph is safe.
I'd size it a little bigger than that, unless you can really cut down on weight. 70mph up a 15% grade is 4.7m/s of vertical lift. If the car weighs 1000kg, that's 61hp , not counting air drag or rolling resistance.
One (very macabre) way of looking at it is that it's an insurance policy. You pay the price of a moderate number of gun deaths per year to keep the government in check and therefore help avoid such a revolution.
I don't have numbers for you, but I do know that to reach a certain orbit (delta-V) using fuel of a particular specific impulse (Isp), fuel weight and rocket weight have to be the same ratio. For a lighter payload, they would be able to bring less fuel (although they may just opt to not burn the last bit). The max rated liftoff weight would be for everything needed to lift the max rated payload.
Ok, let's call it stagflation.
It is pretty much flat, but it's worth noting that the graph uses inverted units for comparison: dollars per barrel for currency, and barrels per oz for gold. For consistency, they should have used something besides oz (milligrams, maybe) so that they could use barrels as the fraction denominator. As presented, it looks like gold has a response opposite to that of the dollar for short-term fluctuations.
We do generate it. Everything does, through black body radiation. According to Wien's displacement law, the peak frequency for something at 300 Kelvin is about 30 THz.
For many imaging applications, though, it's more useful to "light up" something and see the reflection. Kinda like using a camera flash.
Sorry, but there are (likely insurmountable) technical problems with using modern jetliner turbofan engines at supersonic speeds.
Those turbofans are sort of like a Concorde's turbojet but with a much larger ducted fan bolted onto the front. Some air from this fan is compressed, combusted, and exhausted, but most is simply blown backwards. The ratio of blow to burn is called the bypass ratio. The exhaust stream is big, slow, and cool instead of small, fast, and hot - that's why they are so much quieter.
High bypass-ratio turbofans can't go supersonic because the tip speed of the fan blades must stay subsonic for the fan to work. Also, the incoming air must be subsonic before it hits the fan blades - this requires long inlet ducts, not the short ring you see around a jetliner's fan.
Jet turbines and ramjets share the same problem - they are only capable of subsonic combustion and must slow the supersonic airflow before they can burn fuel in it and reaccelerate it. Thus the recent experiments with scramjets (supersonic combustion ramjets). They aren't ready for use yet.
Yes, we do have wires that are larger in our houses (and more of them). Your average American house circuit is 15A (14AWG) or 20A (12AWG) at 120V. Much of post-war UK was wired with ring circuits to save copper and allow 14AWG wire to be used for 30A circuits, with breakers/fuses at each outlet instead of at the panel, requiring fewer total circuits.
There's obviously tradeoffs with higher voltages - thicker insulation is required, switch design becomes more critical (arcs become harder to extinguish), and electrocution becomes more of a concern. Go touch the flyback coil on a big CRT monitor and you'll understand.
But you do have a 14th Amendment right (Jus Soli) to enter the country, if you were born there. They can't keep you out.
Kind of like how the larger the area you intend to cover for wind power, the larger your wind turbine needs to be? :)
Take a look at one (of several) of the 100MW plants going in in California.
There is still a danger - Capacitors that store a lot of energy use very very thin insulators to separate large sheets of foil charged to large voltages. Insulators are only good for a certain number of volts per meter, and they won't make them much thicker than they need to be - it would reduce the capacity. Imperfections in this insulator will eventually result in short circuits and arcing. If there's enough energy stored in the capacitor to get the surrounding material hot enough, it could catch fire or vent explosively.
The final rule - if this is your first day at BGP, you HAVE to flood.
Considering that the two inputs of the gravitational formula that are under your control (time and distance) are both squared, you want to accelerate as fast as you possibly can.
Once you're in orbit, then yes, you can use very small amounts of thrust over very long periods of time to circularize or raise an orbit (to the point of escape velocity if desired) but the whole throw-yourself-at-the-ground thing must be done very quickly if you are to fail at it.
No, but you have to get almost there. Low Earth Orbit is 7.8km/s, escape velocity is 11.2km/s. In addition, any non-escape ballistic trajectory that starts from the earth will form an ellipse that will eventually intersect the earth, meaning your rocket must accelerate sideways a fair bit once it's up there.
You need much less speed to merely reach space and fall back down, but the article clearly said 'orbit'.
Google only has satellite data for remote areas. For populated areas, it has much higher resolution aerial photography data.
Heat engines, thermocouples, etc. don't harness "hot". They harness the flow of heat. If you do not provide any place for that heat to move to, they can't do anything.
Now, if you just want to get rid of that noisy fan, get a heat pipe and have it move the heat from your CPU to your chassis (if suitable) or to a radiator cooled by a much larger, slower, quieter fan.
Action Item, is that you?
That's exactly what I meant by ladder racking (or cable runways, or whatever the kids are calling it these days). Yes, the part that you can see looks better with a raised floor, but it sucks so much to run cable under a floor that that's all anyone ever does - no one ever organizes or cleans under there. Sure, they'll take a wet/dry vac to it after an A/C accident, but they won't go back under if they remember they forgot a can of soda pop down there. It'll sit there until the fruit flies eat it all up.
My favorite thing for patch panels/switches is to put them on separate horizontally adjacent racks. A cable goes up from the patch panel to the cable management bracket, over to a gap between the racks, forms a U where all of the slack is stored, then goes into cable management again and then down to its switch port. It looks good with all of the slack in one place, it's easy to make changes, and you don't have cables running directly across the front of equipment (making it impossible to remove, or in some cases, inspect).
And if you do wall-mount the switches and patch panels, use a hinged rack (example) so you can get to the back of it. And of course, tell your cabler which side should be hinged so they'll be forced to use two extra brain cells to run the cable so it can be hinged.
And where are you going to put the ramp to wheel equipment up the extra 2 feet? Unless this is the basement and you can excavate and pour another slab, raised floors either need a lot of room to get into and out of, or they need their own floor (as in, "this entire first floor of this building is for the raised floor"). You won't have much luck convincing an architect to cut a 10x20' hole in a post-tensioned slab.
Just put the rack cabinets where you want them (3.5' of clearance in front, 2' to at least one side and the rear) and the plywood/OSB wall-o-punchdown-blocks where you want them, and install ladder racking between them so that all of the cables are organized and out of the way. Also, delivering each power circuit through conduit to receptacle boxes at the top of each rack cabinet is a really clean way of doing it - it prevents anyone from tripping over any power cords.
I suspect that a large percentage of raised-floor proponents haven't spent much time underneath one.