Power density in a Stirling is largely a function of working fluid density - a good chunk of NASA's research work regards how to change that on the fly (as you floored the gas pedal), something that isn't necessary in a series arrangement.
One other (currently untapped) benefit of a series hybrid is that you can use a more efficient engine design that isn't able to change power levels quickly - for example the Stirling or Kalina cycle external combustion engines. No, I would not expect a poorly-funded group to be able to pull this off.
BTW the Fisker Karma is 5300lb. A Corvette is 3200-3600lb, and a Volt is 3800lb. Certainly doesn't explain all of it, but that's one lead sled.
Resonance tricks work great with RF, where you're using a rather narrow frequency range (often less than +/- 2%), but they really don't work with AF where you're trying to faithfully reproduce a multi-octave range of frequencies. In fact, since you're trying to reproduce them all equally, resonance is something you specifically try to avoid.
When a company uses HTTPS proxies, it's just making it so all of the client browsers trust every HTTPS website.
Since the proxy is trusted by your browser, it doesn't complain.
You two are actually in agreement. An HTTPS proxy robs the end user of the choice as to whether to trust the certificate the remote web server presents. That decision instead has to be made automatically by the HTTPS proxy. It could be set to trust everything, it could be set to refuse to proxy any certificate it doesn't trust, but it's out of the end users' hands.
This really only needs a very very tiny adjustment even for very large telescopes. I'll use Hubbell as an example - it is 57600mm focal length and f/24. If its pixel density is the same as a typical 35mm sensor (it will likely not be anything near this), then you'll have sharp focus anywhere between 1400 miles and infinity (the hyperfocal distance is 2800 miles - http://www.outsight.com/hyperfocal.php). Hubble is fixed focus and routinely takes pictures of earth to calibrate its instruments (although it cannot track the earth's surface and has a minimum exposure time of 1/10s, so all you get are streaks - http://www.badastronomy.com/mad/2000/hubbleearth.html).
It also means that there's more data tracks on the same platter, requiring proportionally more revolutions to read or write the whole thing. I doubt rotational speed will increase any further than the 15krpm we have now, unless platter sizes shrink much further (and SSDs have already taken over that part of the market).
Internal combustion engines tend to become a lot less efficient at high elevation where the air is less dense.
Not necessarily. Lower air density reduces maximum available power, but the air is also much colder up there, and heat engines become more efficient as you increase the hot side vs. cold side temperatures, so it becomes a matter of whether this increased efficiency can make up for the friction losses of pumping a larger volume of lower pressure air around.
the wingspans going to be about the same probably with the same or at least very similar airfoil...
Doubtful. The B-52 uses the NACA 63A219.3 and 65A209.5 airfoils (root and tip, respectively). While the 6-series airfoils are designed to extend laminar flow towards the rear of the wing, they have been improved upon by the 7- and 8- series. The 8- series are known as "supercritical" airfoils, which specifically improve performance (and therefore efficiency) at high subsonic speeds.
If you decouple the power source (as opposed to power storage) from the wheels, you don't need torque/rpm flexibility and can switch to an efficient constant RPM engine.
Besides the turbines you linked to (which I'm not convinced scale down efficiently) there's the Stirling Cycle engine. It is more efficient than an Otto cycle engine and has fewer moving parts but like any external combustion engine, it cannot produce power until it is warmed up, and it also can't quickly change power levels.
A bigger sensor makes a *dramatic* difference - rent a full-size camera sometime and you'll see it for yourself.
A 50mm f/1.8 lens delivers within-an-order-of-magnitude sensitivity on a 3-year-old DSLR as it does on a 1/4" webcam sensor. The difference is that the 1/4" webcam sensor delivers a much smaller 540mm-equivalent field of view, while the APS-C DSLR sensor delivers a much wider 80mm-equivalent field of view. Try it. I have.
Sensor size doesn't have much to do with field of view unless you assume a fixed distance from the back of the lens.
Which I was ("for a given focal length").
A given lens with a given aperture will concentrate as much light on any given square millimeter of a large sensor as it will on a small sensor. The only exception to this is that the sensor must be small enough to be positioned within the light circle of the lens (for example if you match a DSLR-sized sensor to a webcam lens, you will get severe vignetting). A sensor with a higher pixel density may have more wasted space in-between pixels (and thus may absorb less light per square millimeter of surface area), but this has nothing to do with sensor size per se.
Of course, as a photographer I have to question using a tiny sensor [high signal noise/ low sensor speed] and a rather small objective lens [reduced light input] to take photographs from rifle distance. There's a reason why pro photographers carry big lenses.
Just to add to this - physical resolution (not in the number-of-pixels sense but in the optical resolving-power sense) for a given light wavelength and a given focal length is limited by aperture size. A tiny sensor combined with a large lens aperture and focal length will give you a very limited field of view, but it will still be just as sharp as if you had a much larger sensor covering more of that field of view.
FYI, GPS does not work this way at all. Signals are unidirectional - they are *only* sent from the satellites to the receivers. The data stream sent is primarily a very, very accurate timestamp as well as ephemeris data (indicating the orbit of the satellite). Based on that information, distance to each satellite is calculated by the receiver via speed of light delays and triangulation (this is why 3 satellites are required for position, and 4 are required for altitude as well). This is the reason that GPS beacons have to communicate their position by some other means (usually to a network of land-based receivers) - the satellites only know their own position information, not the position of any receiver.
IMHO concentrated solar power is absolutely the way forward for the Southwest and other desert regions of the US that have 250-300 sunny days per year. There's plenty of land available, no scary chemicals are needed anywhere in the process, and the power output will naturally match the air conditioning power demand.
However, it won't work so well in more moderate climates - you can't concentrate sunlight on cloudy days at all, and a few straight cloudy days are all it will take to use up all of that latent heat in a molten salt tower. It might still be worth installing but you'll have to have standby capacity (perhaps in the form of natural gas generators) to match it and that unfortunately drives up the price.
Also, apparently a number of these plants are being built to use fresh water to help reject turbine waste heat, and that's unsustainable in the sort of desert environments where these plants make sense.
Take the lens off the front and bolt the sensor to a used SLR camera lens. With the 10x or 15x crop factor, that old 50mm SLR lens will turn into a 500-750mm equivalent, and if you use a prime lens, it'll have even better low-light performance than the original wide angle lens. If you put it on a telescope, you can easily get into 5000mm+ territory, although it'll be very difficult to use without an expensive tripod and tracking system.
While I agree that all captains (whether you're on a teeny little sailboat or a SuezMax container ship) should know how to use their fallbacks, I think that disabling GPS during military exercises is going to increase the probability that innocent civilians are going to accidentally encroach on those military ships during those same exercises. Seems like a bad idea.
For the most part, the cell phone networks don't need GPS to operate. Just knowing the location wouldn't be good enough for signal beamforming anyway because of all the multipath in urban environments. It's often the other way around - GPS location information is often provided by the towers to the phones. The phones use that info (whether acquired via real GPS or cell phone network assisted GPS) for E911 and for whatever smartphone apps want it. However, CDMA *does* need *very* precise time synchronization to work - and this is usually implemented via GPS receivers on each tower.
Not quite that simple to get around. It has to be something about you that you find offensive.
It's possible something was lost in the Wikipedia translation, but their wording was "any content that the applicant deems detrimental to his/her image", not "about the applicant". The sky is the limit.
If someone who is offended can require a correction be made without comment, then surely anyone else can be offended by the correction and have it reverted - without comment.
People seem to want symbolic icons that represent the programs they want to run; they don't want to look through a long menu and read a bunch of text.
A lot of people want that - for themselves. However, most mere mortals eventually need some help with their computer and it's damn near impossible to walk someone through finding something just based on its icon over the phone.
It also makes it harder to unit test all code paths.
I'd wager that for every 1000 programmers out there that aren't validating external data and the results of their function calls, testing all code paths is the last thing on about 999 of their minds.
You can overbuild a house, it generally makes it stronger. You over code a piece of software it just adds to the number of possible points of failure.
In this context, "over coding" software refers to, for starters, defensive programming techniques (i.e. checking the return values of all the functions you call, fully validating external inputs, etc). It does not reduce the number of points of failure, but it does require the programmer to consider them and the gracefully handle them or transparently report the problems it can't handle. It does bloat the code somewhat, making it less concise, and it usually increases the amount of time required to make changes, but the transparent reporting of issues to the user significantly reduces the amount of time needed to debug flaws. Fewer bugs escape testing and the bugs that do escape can be accurately reported, are more likely to be reproducible, and are more easily fixed.
Healthcare is first case of being forced to buy a product just for being alive.
Except that's not true. You're forced to pay income tax if you make income, which Congress was given carte blanche to do via the 16th amendment. You pay *less* income tax if you buy health insurance. But if you didn't make enough to get taxed that much, then you're not paying for this anyway (you are, however, still getting it).
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NASA pursued this in the 70s and 80s for the DOE: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880002196_1988002196.pdf. The numbers they list for both ICE and Stirling are pretty laughable today but they serve as a reminder of just how much we've improved on engine tech in the past 30 years.
Power density in a Stirling is largely a function of working fluid density - a good chunk of NASA's research work regards how to change that on the fly (as you floored the gas pedal), something that isn't necessary in a series arrangement.
One other (currently untapped) benefit of a series hybrid is that you can use a more efficient engine design that isn't able to change power levels quickly - for example the Stirling or Kalina cycle external combustion engines. No, I would not expect a poorly-funded group to be able to pull this off.
BTW the Fisker Karma is 5300lb. A Corvette is 3200-3600lb, and a Volt is 3800lb. Certainly doesn't explain all of it, but that's one lead sled.
Resonance tricks work great with RF, where you're using a rather narrow frequency range (often less than +/- 2%), but they really don't work with AF where you're trying to faithfully reproduce a multi-octave range of frequencies. In fact, since you're trying to reproduce them all equally, resonance is something you specifically try to avoid.
You two are actually in agreement. An HTTPS proxy robs the end user of the choice as to whether to trust the certificate the remote web server presents. That decision instead has to be made automatically by the HTTPS proxy. It could be set to trust everything, it could be set to refuse to proxy any certificate it doesn't trust, but it's out of the end users' hands.
This really only needs a very very tiny adjustment even for very large telescopes. I'll use Hubbell as an example - it is 57600mm focal length and f/24. If its pixel density is the same as a typical 35mm sensor (it will likely not be anything near this), then you'll have sharp focus anywhere between 1400 miles and infinity (the hyperfocal distance is 2800 miles - http://www.outsight.com/hyperfocal.php). Hubble is fixed focus and routinely takes pictures of earth to calibrate its instruments (although it cannot track the earth's surface and has a minimum exposure time of 1/10s, so all you get are streaks - http://www.badastronomy.com/mad/2000/hubbleearth.html).
It also means that there's more data tracks on the same platter, requiring proportionally more revolutions to read or write the whole thing. I doubt rotational speed will increase any further than the 15krpm we have now, unless platter sizes shrink much further (and SSDs have already taken over that part of the market).
Not necessarily. Lower air density reduces maximum available power, but the air is also much colder up there, and heat engines become more efficient as you increase the hot side vs. cold side temperatures, so it becomes a matter of whether this increased efficiency can make up for the friction losses of pumping a larger volume of lower pressure air around.
Doubtful. The B-52 uses the NACA 63A219.3 and 65A209.5 airfoils (root and tip, respectively). While the 6-series airfoils are designed to extend laminar flow towards the rear of the wing, they have been improved upon by the 7- and 8- series. The 8- series are known as "supercritical" airfoils, which specifically improve performance (and therefore efficiency) at high subsonic speeds.
Besides the turbines you linked to (which I'm not convinced scale down efficiently) there's the Stirling Cycle engine. It is more efficient than an Otto cycle engine and has fewer moving parts but like any external combustion engine, it cannot produce power until it is warmed up, and it also can't quickly change power levels.
I can also recommend Wings & Things. I usually make the "Blackboard Bomber" design from there.
A 50mm f/1.8 lens delivers within-an-order-of-magnitude sensitivity on a 3-year-old DSLR as it does on a 1/4" webcam sensor. The difference is that the 1/4" webcam sensor delivers a much smaller 540mm-equivalent field of view, while the APS-C DSLR sensor delivers a much wider 80mm-equivalent field of view. Try it. I have.
Which I was ("for a given focal length").
A given lens with a given aperture will concentrate as much light on any given square millimeter of a large sensor as it will on a small sensor. The only exception to this is that the sensor must be small enough to be positioned within the light circle of the lens (for example if you match a DSLR-sized sensor to a webcam lens, you will get severe vignetting). A sensor with a higher pixel density may have more wasted space in-between pixels (and thus may absorb less light per square millimeter of surface area), but this has nothing to do with sensor size per se.
Just to add to this - physical resolution (not in the number-of-pixels sense but in the optical resolving-power sense) for a given light wavelength and a given focal length is limited by aperture size. A tiny sensor combined with a large lens aperture and focal length will give you a very limited field of view, but it will still be just as sharp as if you had a much larger sensor covering more of that field of view.
Ahh. I read "box" as "the entirety of the tracking device".
FYI, GPS does not work this way at all. Signals are unidirectional - they are *only* sent from the satellites to the receivers. The data stream sent is primarily a very, very accurate timestamp as well as ephemeris data (indicating the orbit of the satellite). Based on that information, distance to each satellite is calculated by the receiver via speed of light delays and triangulation (this is why 3 satellites are required for position, and 4 are required for altitude as well). This is the reason that GPS beacons have to communicate their position by some other means (usually to a network of land-based receivers) - the satellites only know their own position information, not the position of any receiver.
IMHO concentrated solar power is absolutely the way forward for the Southwest and other desert regions of the US that have 250-300 sunny days per year. There's plenty of land available, no scary chemicals are needed anywhere in the process, and the power output will naturally match the air conditioning power demand.
However, it won't work so well in more moderate climates - you can't concentrate sunlight on cloudy days at all, and a few straight cloudy days are all it will take to use up all of that latent heat in a molten salt tower. It might still be worth installing but you'll have to have standby capacity (perhaps in the form of natural gas generators) to match it and that unfortunately drives up the price.
Also, apparently a number of these plants are being built to use fresh water to help reject turbine waste heat, and that's unsustainable in the sort of desert environments where these plants make sense.
Take the lens off the front and bolt the sensor to a used SLR camera lens. With the 10x or 15x crop factor, that old 50mm SLR lens will turn into a 500-750mm equivalent, and if you use a prime lens, it'll have even better low-light performance than the original wide angle lens. If you put it on a telescope, you can easily get into 5000mm+ territory, although it'll be very difficult to use without an expensive tripod and tracking system.
Is it possible that you meant to reply to a child of this comment instead of to my comment?
While I agree that all captains (whether you're on a teeny little sailboat or a SuezMax container ship) should know how to use their fallbacks, I think that disabling GPS during military exercises is going to increase the probability that innocent civilians are going to accidentally encroach on those military ships during those same exercises. Seems like a bad idea.
For the most part, the cell phone networks don't need GPS to operate. Just knowing the location wouldn't be good enough for signal beamforming anyway because of all the multipath in urban environments. It's often the other way around - GPS location information is often provided by the towers to the phones. The phones use that info (whether acquired via real GPS or cell phone network assisted GPS) for E911 and for whatever smartphone apps want it. However, CDMA *does* need *very* precise time synchronization to work - and this is usually implemented via GPS receivers on each tower.
It's possible something was lost in the Wikipedia translation, but their wording was "any content that the applicant deems detrimental to his/her image", not "about the applicant". The sky is the limit.
If someone who is offended can require a correction be made without comment, then surely anyone else can be offended by the correction and have it reverted - without comment.
A lot of people want that - for themselves. However, most mere mortals eventually need some help with their computer and it's damn near impossible to walk someone through finding something just based on its icon over the phone.
I'd wager that for every 1000 programmers out there that aren't validating external data and the results of their function calls, testing all code paths is the last thing on about 999 of their minds.
In this context, "over coding" software refers to, for starters, defensive programming techniques (i.e. checking the return values of all the functions you call, fully validating external inputs, etc). It does not reduce the number of points of failure, but it does require the programmer to consider them and the gracefully handle them or transparently report the problems it can't handle. It does bloat the code somewhat, making it less concise, and it usually increases the amount of time required to make changes, but the transparent reporting of issues to the user significantly reduces the amount of time needed to debug flaws. Fewer bugs escape testing and the bugs that do escape can be accurately reported, are more likely to be reproducible, and are more easily fixed.
Except that's not true. You're forced to pay income tax if you make income, which Congress was given carte blanche to do via the 16th amendment. You pay *less* income tax if you buy health insurance. But if you didn't make enough to get taxed that much, then you're not paying for this anyway (you are, however, still getting it).