On a small diesel engine I've worked on and used (marine yanmar 3 cylinder engine for a small sailboat), the way to kill it was to close a valve on the fuel line. This valve (installed on the engine itself) was connected to a wire which was connected to a T-handle in the cockpit. When you wanted to stop the engine, you put it to idle/neutral, pulled the handle, and when the engine stopped, switched off the power key on the engine control panel. If you where at sea and moving (under sail), you then pushed the throtle/transmission handle to reverse, in order to avoid "windmilling" of the propellor.
If you switched off the electronic key while it was running, nothing happened (except maybe blowing up some expensive charger electronics). The electronics where only for starter (with a handle supplied in case of emergencies... Never needed/dared to use it, as if the rusty disengagement mechanism failed you would have a 5kg handle spinning at ~1000 RPM, potentially making a huge hole in the bottom of the boat if it suddenly did disengage...), charging (cabin & running lights, "fridge", engine starter and nav/radio all ran on 12V), and sensors for basic warning systems (oil pressure+a few more). The machine itself was fully mechanical.
On a modern diesel car, I'm not shure exactly what happens when you switch off the "ignition" - but my best guess is (as someone here mentioned) that you stop the fuel pump. While I do drive a throtle-by-wire diesel car, it is equiped with a 3rd pedal which mechanically disengages the engine from the transmission, so it doesn't worry me too much...
They do sell stuff (incl. alcohol) on long distance trains in Norway. Personally I preffer to take the train if going Oslo-Bergen (and pay the 100 NOK (~12 USD) extra for 1st class - which gets you a better seat, access to free newspapers, coffe etc.) - it takes a bit longer than plane, but once you factor in transport to/from airports, the price and time difference is minuscle. And the scenery when crossing the mountains is just fantastic:)
For longer journeys, there are a ton of cheap airlines covering most of europe (expedia is your friend), and flying within the EU (except UK! they're worse than US, even just for transit...) is comparable to flying domestic in the US - few queues, polite security personell, and generally little hassle.
It's a fairly normal thing. My university (University of Oslo, 27'000 students and 7'000 staff, so fairly big) has (at least on the main campus) 3 student ran pubs (all fully legal) + 1 pubs and one restaurant serving beer ran by the university's food services + unknown number of student societies, of which many have a stash of alcohol and a box to put money in if you take a beer from this stash.
Other universities I've been to in Norway are have similar arrangements. The cafeterias at CERN serve beer and wine until ~midnight (and during lunch, which is very french...). Stanford uni has a pub on its grounds.
A lepton machine accelerates leptons, meaning electrons, muons, or taus (and technically speaking, I guess a neutrino-accelerator would also be a lepton machine...). A machine being a lepton machine doesn't say much about for what purpose someone built it.
Other than that, one doesn't accelerate "tons" of atoms in particle accelerators - try nanograms. Also, good luck trying to point such a high energy particle beam in any reasonable radius - they're pretty stiff. But they're probably not stiff enough not to be redirected by the earths magnetic field and miss the target.
The pointing problem may have a sort of (but very unrealistic I think) solution, have a look at http://arxiv.org/abs/hep-ph/03... appendix B "Possible accelerator scheme"
The FCC project is in a really early stage - it's basically a design study to see if it can be done. One reason to build a very large circular electron-positron collider is to properly study the Higgs (which cannot really be done at a proton machine like the LHC), and it *might* be cheaper to build it circular instead of linear (like CLIC and ILC).
Once you've done with the electron bit, it gets interesting to look at the next energy scale - and for that you need a huge proton machine. And if we anyway build the tunel, why not just rip out the (then) old electron ring and build a proton ring...
On the "more physics than the Higgs" side: As far as I understand, there has to be something more in order to "hold it together" - the Higgs is on the heavier side of what is expected without "something more", there is this pesky dark-matter problem, the issue of the observed matter/antimatter ratio being way larger than what is predicted by the current theory which is built on the data we have so far, and a few more theoretical arguments.
Anyway, time to get back to thesis-writing @ CERN, hoping the power holds as they're testing "emergency stop tests" at the BOOSTER ring and power has been flickering a few times... So far the caps in my PSU have been able to eat the glitches...
It was apparently built to connect to the bridge, which wasn't built. Since the money was federal and they couldn't spend it anywhere else, they decided to go ahead and build it anyway.
When discussing a value measured in dollars, would you usually say "135 $" or "2x50 $ + 3x10$ + 5$"? Who cares what notes are currently circulating. And you forgot the 100$ bills and cents, and I've never seen 25$ bills...
In my experience, long filaments often break approximately in the middle, or close to a "mid-span post" if it is a very long filament. But that's just a few anecdotes from memory, not data...
It is sometimes feasible to "revive" a bulb by tapping it or turning it around untill you remake the electrical contact. However if you do this, be carefull if the glowing part of the filament becomes significantly shorter, as a shorter filament means smaller resistance means higher power and higher temperatures. Which may just mean that the filament will very soon break again, but it could also damage the lamp/wiring and be a fire hazard...
It's more fun when bulb "explodes" (without breaking the glass) and metalizes the inside of the glass:)
It's a comprehensible number IF you're used to pounds. To most people outside the US, pounds, miles, ounces (in all their weird varieties), galons, miles, yards, fathoms, inches, feet, fahrenheits and other weird US-specific not-base-10 units of measure are only usefull after converting them (mentally or via table and calculator) to the metric system. At least you probably have to learn the metric system at school - other places some of the units are only used as an excuse to practice multiplication (and the conversion constants quickly forgotten).
And Slashdot, while US-centric on political issues (probably because its the largest single country represented here), is read by many people outside the US. So at least providing both unit systems would be useful.
Sure? It's also the fact that the filament need to be thin in order to heat up as much as possible drawing as little current as possible, as the light output goes as temperature ^4, and higher temperature also means shifting up into bluer parts of the spectrum: https://en.wikipedia.org/wiki/Black-body_radiation
So, you want it to be thin, long (for high powers), and really hot. I think its strange they arent even more fragile...
Of course, if you want, you can make the filaments thicker and longer, giving you a lower temperature and the same total resistance (And thus the same total power). Problem is that you are now wasting a lot of power (well, even more power...) by emitting infrared. But the filament will be thicker, and the temperature lower, so it will last longer.
Also, by launching from an arial platform, you won't have to boost so much "down" to fight gravity drag, but can bost more "sideways" which is more efficient. If you could boost only tangentially to the earth, you'll avoid having to carry fuel for 1g of acceleration upwards.
Also, the air resistance is probably a bit lower at altitude as well.
For satelites aperture synthesis at optical wavelengths is purely theory, and will probably be for a long time. However, it is apparently doable for land-based telescopes: https://en.wikipedia.org/wiki/Astronomical_interferometer
The issue is (as explained in the article) that you need to know the relative position of the mirrors (and thus the length of the light-path) witin a small fraction of a wavelength, i.e. witin a few nm for light, and a few meters or cm for radar. Further, since you cannot measure both phase and amplitude of the collected light, you need to combine the beams optically as they are collected - which is somewhat doable for a set of big telescopes on a mountain top connected with light guides of some sort, not so much for satelites.
However, building a humongous optical interferometer telescope might be doable if we could put it on suitably large rock outside of the earths atmosphere...
Please upwote anon - s/he's completely right. Downlink is way easier when the satelite stays in one place relative to you, and you can just point a big dish at it. If all you get a few minutes per pass, a couple of times per day (if you have multiple ground stations), it gets way harder...
This version just as a few bands, true - but a future version could have many more. And I would assume that just clorophyll density with high resolution and short time between pictures would be quite valuable?
There are also other ways. The Lunar Orbiter probes launced by the US in the 60s used a film camera + automated film development. The images where then scanned and sent back to earth - the quality was pretty good. The main problem was that the computing power required to handle the scanned images (which I believe turned out as terrabytes of image data after digitizing of the old tapes by the LORIP project) just wasn't available at that time. If my memory serves me right, the camera system was probably based off contemporary spy satelites.
The problem isn't the resolution of the sensor chip (5 MPix), but the angular resolution of the optics, which is limited by diffraction (wave physics phenomenon) to some quantity which is dependent on the aperture of the lens. Bigger apperture (diameter of the light-opening) => higher angular resolution.
The other problem is that satelites are quite far up, so you get less spatial resolution (cm on the ground) per unit angular resolution than you would get by being closer (putting the camera on a plane).
The diffraction limit puts a hard limit on the achievable resolution no matter the quality of optics and sensor, and if you want to increase that limit, you need a bigger diameter telescope. This is why people are talking about "2 meter" and "5 meter" etc. mirrors on astronomical telescopes.
The father of this post mentions that it is possible to get around this problem by using more than one satelite (or the same satelite at two different points in its orbit), effectively creating a much larger aperture. This is called syntetic aperture, and for this to work you need to record both the amplitude and phase of the incoming wave. It works great for radar applications as the wave used here is slow enough to be followed by electronics, but visible light is just way to fast and we can only record incident power (amplitude^2) and thus cannot do an off-line computation of the interference patterns wanted.
People will have every reason to consume as much healthcare as they can get their hands on, and they will have no financial reason to moderate risky and unhealthy behaviors, such as smoking and overeating.
Sickness, pain, and death are also good moderators.
Slashdot Mirror
On a small diesel engine I've worked on and used (marine yanmar 3 cylinder engine for a small sailboat), the way to kill it was to close a valve on the fuel line. This valve (installed on the engine itself) was connected to a wire which was connected to a T-handle in the cockpit. When you wanted to stop the engine, you put it to idle/neutral, pulled the handle, and when the engine stopped, switched off the power key on the engine control panel. If you where at sea and moving (under sail), you then pushed the throtle/transmission handle to reverse, in order to avoid "windmilling" of the propellor.
If you switched off the electronic key while it was running, nothing happened (except maybe blowing up some expensive charger electronics). The electronics where only for starter (with a handle supplied in case of emergencies... Never needed/dared to use it, as if the rusty disengagement mechanism failed you would have a 5kg handle spinning at ~1000 RPM, potentially making a huge hole in the bottom of the boat if it suddenly did disengage...), charging (cabin & running lights, "fridge", engine starter and nav/radio all ran on 12V), and sensors for basic warning systems (oil pressure+a few more). The machine itself was fully mechanical.
On a modern diesel car, I'm not shure exactly what happens when you switch off the "ignition" - but my best guess is (as someone here mentioned) that you stop the fuel pump. While I do drive a throtle-by-wire diesel car, it is equiped with a 3rd pedal which mechanically disengages the engine from the transmission, so it doesn't worry me too much...
They do sell stuff (incl. alcohol) on long distance trains in Norway. Personally I preffer to take the train if going Oslo-Bergen (and pay the 100 NOK (~12 USD) extra for 1st class - which gets you a better seat, access to free newspapers, coffe etc.) - it takes a bit longer than plane, but once you factor in transport to/from airports, the price and time difference is minuscle. And the scenery when crossing the mountains is just fantastic :)
For longer journeys, there are a ton of cheap airlines covering most of europe (expedia is your friend), and flying within the EU (except UK! they're worse than US, even just for transit...) is comparable to flying domestic in the US - few queues, polite security personell, and generally little hassle.
It's a fairly normal thing. My university (University of Oslo, 27'000 students and 7'000 staff, so fairly big) has (at least on the main campus) 3 student ran pubs (all fully legal) + 1 pubs and one restaurant serving beer ran by the university's food services + unknown number of student societies, of which many have a stash of alcohol and a box to put money in if you take a beer from this stash.
Other universities I've been to in Norway are have similar arrangements. The cafeterias at CERN serve beer and wine until ~midnight (and during lunch, which is very french...). Stanford uni has a pub on its grounds.
It seems that the Texas location is fair game again.
There are not too many places where a 100Km circle can be scribed
and not slice through hills, mountains, and towns.
That's why you build it ~100 m underground.
A lepton machine accelerates leptons, meaning electrons, muons, or taus (and technically speaking, I guess a neutrino-accelerator would also be a lepton machine...). A machine being a lepton machine doesn't say much about for what purpose someone built it.
Other than that, one doesn't accelerate "tons" of atoms in particle accelerators - try nanograms. Also, good luck trying to point such a high energy particle beam in any reasonable radius - they're pretty stiff. But they're probably not stiff enough not to be redirected by the earths magnetic field and miss the target.
The pointing problem may have a sort of (but very unrealistic I think) solution, have a look at
http://arxiv.org/abs/hep-ph/03...
appendix B "Possible accelerator scheme"
The FCC project is in a really early stage - it's basically a design study to see if it can be done. One reason to build a very large circular electron-positron collider is to properly study the Higgs (which cannot really be done at a proton machine like the LHC), and it *might* be cheaper to build it circular instead of linear (like CLIC and ILC).
Once you've done with the electron bit, it gets interesting to look at the next energy scale - and for that you need a huge proton machine. And if we anyway build the tunel, why not just rip out the (then) old electron ring and build a proton ring...
On the "more physics than the Higgs" side: As far as I understand, there has to be something more in order to "hold it together" - the Higgs is on the heavier side of what is expected without "something more", there is this pesky dark-matter problem, the issue of the observed matter/antimatter ratio being way larger than what is predicted by the current theory which is built on the data we have so far, and a few more theoretical arguments.
Anyway, time to get back to thesis-writing @ CERN, hoping the power holds as they're testing "emergency stop tests" at the BOOSTER ring and power has been flickering a few times... So far the caps in my PSU have been able to eat the glitches...
Except this would be the "Road to Nowhere":
https://en.wikipedia.org/wiki/...
It was apparently built to connect to the bridge, which wasn't built. Since the money was federal and they couldn't spend it anywhere else, they decided to go ahead and build it anyway.
Totally agree. Lack of "ribbon" UI (or at least not forcing it on the user) is a feature, not something I would miss.
That would maybe clear out the most of the electrons (as done in laser plasma wakefield acceleration), but leave the ions behind.
When discussing a value measured in dollars, would you usually say "135 $" or "2x50 $ + 3x10$ + 5$"? Who cares what notes are currently circulating. And you forgot the 100$ bills and cents, and I've never seen 25$ bills...
Baaah, didn't se the not. Strange way of writing, this Anonymous Coward has..
The D-mark isn't legal tender in Germany either, not since 1999 when they switched to the Euro..
In my experience, long filaments often break approximately in the middle, or close to a "mid-span post" if it is a very long filament. But that's just a few anecdotes from memory, not data...
It is sometimes feasible to "revive" a bulb by tapping it or turning it around untill you remake the electrical contact. However if you do this, be carefull if the glowing part of the filament becomes significantly shorter, as a shorter filament means smaller resistance means higher power and higher temperatures. Which may just mean that the filament will very soon break again, but it could also damage the lamp/wiring and be a fire hazard...
It's more fun when bulb "explodes" (without breaking the glass) and metalizes the inside of the glass :)
It's a comprehensible number IF you're used to pounds. To most people outside the US, pounds, miles, ounces (in all their weird varieties), galons, miles, yards, fathoms, inches, feet, fahrenheits and other weird US-specific not-base-10 units of measure are only usefull after converting them (mentally or via table and calculator) to the metric system. At least you probably have to learn the metric system at school - other places some of the units are only used as an excuse to practice multiplication (and the conversion constants quickly forgotten).
And Slashdot, while US-centric on political issues (probably because its the largest single country represented here), is read by many people outside the US. So at least providing both unit systems would be useful.
Sure? It's also the fact that the filament need to be thin in order to heat up as much as possible drawing as little current as possible, as the light output goes as temperature ^4, and higher temperature also means shifting up into bluer parts of the spectrum:
https://en.wikipedia.org/wiki/Black-body_radiation
So, you want it to be thin, long (for high powers), and really hot. I think its strange they arent even more fragile...
Of course, if you want, you can make the filaments thicker and longer, giving you a lower temperature and the same total resistance (And thus the same total power). Problem is that you are now wasting a lot of power (well, even more power...) by emitting infrared. But the filament will be thicker, and the temperature lower, so it will last longer.
I think they are filled with an intert gas, like Argon.
This.
Also, by launching from an arial platform, you won't have to boost so much "down" to fight gravity drag, but can bost more "sideways" which is more efficient. If you could boost only tangentially to the earth, you'll avoid having to carry fuel for 1g of acceleration upwards.
Also, the air resistance is probably a bit lower at altitude as well.
For satelites aperture synthesis at optical wavelengths is purely theory, and will probably be for a long time. However, it is apparently doable for land-based telescopes:
https://en.wikipedia.org/wiki/Astronomical_interferometer
The issue is (as explained in the article) that you need to know the relative position of the mirrors (and thus the length of the light-path) witin a small fraction of a wavelength, i.e. witin a few nm for light, and a few meters or cm for radar. Further, since you cannot measure both phase and amplitude of the collected light, you need to combine the beams optically as they are collected - which is somewhat doable for a set of big telescopes on a mountain top connected with light guides of some sort, not so much for satelites.
However, building a humongous optical interferometer telescope might be doable if we could put it on suitably large rock outside of the earths atmosphere...
Please upwote anon - s/he's completely right. Downlink is way easier when the satelite stays in one place relative to you, and you can just point a big dish at it. If all you get a few minutes per pass, a couple of times per day (if you have multiple ground stations), it gets way harder...
This version just as a few bands, true - but a future version could have many more. And I would assume that just clorophyll density with high resolution and short time between pictures would be quite valuable?
There are also other ways. The Lunar Orbiter probes launced by the US in the 60s used a film camera + automated film development. The images where then scanned and sent back to earth - the quality was pretty good. The main problem was that the computing power required to handle the scanned images (which I believe turned out as terrabytes of image data after digitizing of the old tapes by the LORIP project) just wasn't available at that time. If my memory serves me right, the camera system was probably based off contemporary spy satelites.
https://en.wikipedia.org/wiki/Lunar_Orbiter_program
The problem isn't the resolution of the sensor chip (5 MPix), but the angular resolution of the optics, which is limited by diffraction (wave physics phenomenon) to some quantity which is dependent on the aperture of the lens. Bigger apperture (diameter of the light-opening) => higher angular resolution.
The other problem is that satelites are quite far up, so you get less spatial resolution (cm on the ground) per unit angular resolution than you would get by being closer (putting the camera on a plane).
The diffraction limit puts a hard limit on the achievable resolution no matter the quality of optics and sensor, and if you want to increase that limit, you need a bigger diameter telescope. This is why people are talking about "2 meter" and "5 meter" etc. mirrors on astronomical telescopes.
The father of this post mentions that it is possible to get around this problem by using more than one satelite (or the same satelite at two different points in its orbit), effectively creating a much larger aperture. This is called syntetic aperture, and for this to work you need to record both the amplitude and phase of the incoming wave. It works great for radar applications as the wave used here is slow enough to be followed by electronics, but visible light is just way to fast and we can only record incident power (amplitude^2) and thus cannot do an off-line computation of the interference patterns wanted.
People will have every reason to consume as much healthcare as they can get their hands on, and they will have no financial reason to moderate risky and unhealthy behaviors, such as smoking and overeating.
Sickness, pain, and death are also good moderators.
Not all TV news companies are for-profit corporations - take for example the BBC and their countless clones.
In norway we say that "it's not the fart that kills you, its the smell" (where fart = speed and smell = crash)