And of course the shock-wave itself causes some major control issues as you pass through the barrier itself, at least as I understand it, as well as creating a huge amount of drag. That is a large reason they had so much trouble breaking the barrier in the first place: the planes would lose control as they passed through it and crash.
Yep. There were two big problems with control. The first was that as you move from subsonic to supersonic, the center of lift would move. The aircraft was balanced for controllability at subsonic flows, but when you passed from subsonic to supersonic, the aircraft became unstable and would either crash or break up. The second problem was that the control systems were easily manipulated by the pilot at subsonic speeds, but the shock wave created at the control surface hinge was too great for a human to overcome -- pilots literally weren't strong enough to push the control surfaces against the shock wave until engineers developed all-flying tail surfaces (stabilators rather than elevators). Overcoming drag was basically just a problem of developing a powerful enough engine.
With a zero degree angle of attack your aircraft with any amount of thrust will fall...
Are you sure about that? I think you confused "angle of attack" with "coefficient of lift."
There are airfoil designs (basically, any asymmetric airfoil) that will produce lift at an AoA of zero degrees. If lift is non-zero, then the only question is how fast does an aircraft need to be going to generate enough lift to overcome weight at a zero-degree angle of attack?
Also, just to be pedantic, the balancing act is between lift, weight, thrust and drag. Lift is related to AoA so I'll concede that you basically covered that force, but you completely neglected to mention drag above.
What's wrong with a swing-wing? The USAF has used them since at least the 1960s and still uses swing-wing aircraft today. The B-1 even is similar in size to an airliner: Rockwell B-1, Boeing 737 (smaller) and Boeing 747 (bigger). It would seem to me that if a similar sized aircraft, travelling faster, at comparable weights, is sufficiently strong for military use, it should be plenty strong for commercial air travel. I imagine that it would be quite a bit more expensive to maintain than a fixed-wing airliner, however.
Fly it high enough so that it doesn't matter, perhaps? In the U.S., the FAA defines the upper limit of controlled airspace as 60,000 feet above mean sea level. Weather balloons are capable of flying at nearly twice that altitude.
I think you -- and a lot of other people in this thread -- misunderstand the concept of "control." Here's a/. car analogy to help:
When I get in my car and turn on the key, the car has no choice in the matter. If the battery is sufficiently charged, there is gas in the tank, and all of the other systems are in working order, the car WILL start. As I turn the steering wheel, the car follows my directions. When I hit the gas, it speeds up; when I hit the brakes, it slows down. The car gets no say in whether or not it does the things I command.
On the other hand, when I go to work, my boss may give me instructions, and I may be highly motivated to follow those instructions, but I *ALWAYS* have a choice. I can do what my boss says or not -- and there have indeed been times when I have chosen "not" for various reasons (I knew it was a bad idea, I knew he would change his mind when he had additional information, I was busy with higher priorities, etc.).
The first example is "control" -- that which is controlled has no options in the matter. The second example is influence or incentive -- that which is influenced has a choice, and even though the likelihood of choosing something other than what the influencer wants may be minimal, there is a statistically significant chance of something else happening.
LOL. I've been a full time sys admin for ten years -- first with Solaris and FreeBSD servers, then in my current job with about 15 or so Gentoo (!) servers plus my laptop and a desktop. We migrated to Ubuntu about three years ago. In all honesty, we do a much better job of updating the Ubuntu servers than we did the Gentoo servers because it is so much easier to do, but I am starting to loathe my Ubuntu laptop. It's a lot easier to get wireless working in Ubuntu than Gentoo, but Unity, nVidia drivers*, and a few other problems are really starting to sour me on Ubuntu. I'm hoping 12.04 will bring back the stability I experienced up to 10.10; IMHO, the 11.xx series is Canonical's Vista.
*Yes, I know, those are proprietary drivers. I can't blame Canonical entirely for that, but IIRC, there are much newer drivers available that aren't available in the official "restricted" repositories.
I read old school paper books and I read using the Kindle or Nook apps. IMHO, there are advantages and disadvantages to both; therefore, choices are *GOOD*. People, like the author of TFA, saying that one format is inherently better than the other are sensationalist.
I have found that most (but not all) of my reading for pleasure tends to be in real, paper books, since I typically read for fun at home. Consequently, having physical books in a bookshelf at home is adequate for those volumes. Furthermore, some of the books I read for pleasure don't lend themselves well to the eBook format. For example, my wife bought "Planet Earth's Greatest Motorcycle Adventure Tours" for me for Christmas. It's physically a rather large book, and filled with beautiful photographs from trips the author (Collette Coleman) had taken. I can't imagine trying to read that on my smartphone -- the text would be fine, but the photography would be completely wasted on that form factor.
On the other hand, most of my reading for information tends to be eBooks. It's handy to have a reference with you any time you have your phone/tablet/Ebook-reader-of-choice with you, and this type of writing lends itself well to the eBook format. In other words, for informative books, portability trumps form factor.
Ultimately, you pick the right tool for the job. I wouldn't buy a coffee table book in an electronic format, but there are some definite advantages to eBooks. IMHO, anyone writing off electronic media simply because it isn't bound in paper is simply limiting their options unnecessarily.
The short answer is, "You are working for the wrong employer." You say you work at a company that will install tracking software on your laptop and won't give you admin access. Therefore, you can't disable the tracking software. Furthermore, you say that you are addicted to the Internet. Working for a company that is likely to fire you for doing something that you don't have the self-discipline to avoid doing doesn't sound like a good plan to me.
The long, more realistic, answer is, "Read your corporate compliance policy. It should outline what is acceptable in your organization and what is not." A lot of companies consider laptop use, especially while traveling, to be more like telephone use. It is issued to you for business purposes, but let's face it: most (all?) of us will use it for some personal activities as well. So long as you aren't browsing NSFW sites on the clock, installing malware, etc., most IT departments really don't give a rip what you do. They have more important things to do -- and not nearly enough time in which to do them -- than to spy on your web surfing activity. More likely, the tracking software is to find out what you did that hosed your computer in the event that you were browsing sketchy web sites and infected it with something. However, different companies have different policies./. can't help you find out what your company's policy is -- you'll have to do that yourself.
Also being an old Datsun it was easy to find another alternator in the middle of nowhere.
I also suspect that "being an old Datsun" is why it worked: odds are, that car was carbureted rather than fuel injected. Had it been fuel injected, you would have been hosed, just like I was in my Talon. Fortunately, I had almost made it home, so my wife picked me up, I pulled the battery, took it home, put it on a charger, then drove back to my car a couple of hours later, reinstalled the battery and drove home.
If the alternator is dead, jumper cables won't do you any good (which was the case in the example I provided). If it's just a dead battery, then yeah, jump starting the car is fine -- I just left listing every possible case and selecting the appropriate option for solving the problem as an exercise for the reader;)
Have you ever looked at the plumbing coming out of a boiler? The maze of wires and copper pipes is truly breathtaking...and that's just inside my house. I can't imagine the boiler of a commercial building.
I've push-started petrol cars with batteries flatter than pancakes. I suspect the alternator provides a bit of oomph as well once you pop the clutch.
Your battery was only MOSTLY dead. If it was ALL dead there would be only one thing to do: call a tow truck (with apologies to Rob Reiner).
It worked for you because 1) the alternator was still working and 2) the battery may not have had enough current to turn the starter, but it did have enough to generate an electromagnetic field in the alternator -- perhaps weakly at first, but the longer it runs, the stronger it will get as the battery charges. If the battery is *completely* flat, however, the alternator isn't going to generate any current, and SuricouRaven is correct. Ask me how I know;)
Sometimes. Modern vehicles use electrical power for essential functions *besides* turning the starter motor, for example, fuel injection and generating spark.
I once toasted the alternator on my '97 Eagle Talon and didn't realize it, since the car had no volt/ammeter. I drove it for a day or two on battery power, but finally, the battery died, and the EFI stopped working reliably. I was able to limp into a parking lot before the car died completely, but it was surging pretty badly before I got it parked. If the battery is sufficiently dead or the alternator is not working, you can push the car all day, but it isn't ever going to start.
Think of it this way. When you have a sufficiently long wire, for example, inside the generator at your local power utility, the induced voltages and currents can be quite high -- high enough to kill you. On the other hand, if you have a sufficiently short wire, such as in the pickups of my electric guitar, the induced voltages and currents are much, much less potent -- in fact, you can't even feel the current from my Strat unless it has been amplified first.
Ditto for the wires in the power grid compared to the wires in your car or your PC.
If you think only the right-leaners have done that, then I humbly submit that you haven't been paying attention. Bush and his cronies may have kicked off the recent trend in sacrificing freedom for security*, but Obama and his cronies haven't done anything to reverse the process -- or even to slow it down -- and since we are about 8 months away from the next presidential election, it's not like he hasn't had time. I have no idea how the situation in the U.S. compares to overseas, so my apologies if you are talking about the U.K., Canada or Australia, etc.
*Yes, I know there were examples of our leadership trying to do likewise long before Bush. The pace just seems to have accelerated beyond what I ever imagined since 9/11.
"Nightwatch" at least sounded cool, in a subtly malicious sort of way. "Department of Homeland Security" just sounds...Stalin-esque. But yeah, I cringe, too.
As it turns out many terms including seemingly benign words such as flu, agent, response, cops drill, etc are on the list of words that set off warning bells for the government spooks.
Anyone think that maybe there's going to be a flurry of activity as those who like to tweak DHS post comments containing words like "flu," "agent," "response," "cops" and "drill" on Twitter, Facebook, G+, etc.? I'm sure it would be annoying for DHS to have to wade through all of those false positives containing words like "flu," "agent," "response," "cops" and "drill." Not that *I* would ever post anything like "flu," "agent," "response," "cops" and "drill." just to be obnoxious or anything;)
I rather suspect a tight, low cut tank top -- with or without pizzas and coke -- would get me thrown OUT of most places (at least those that I'd have any interest in going to, anyway)
Slashdot Mirror
Only if by "near the speed of sound", you really mean "a little over 100 mph."
And of course the shock-wave itself causes some major control issues as you pass through the barrier itself, at least as I understand it, as well as creating a huge amount of drag. That is a large reason they had so much trouble breaking the barrier in the first place: the planes would lose control as they passed through it and crash.
Yep. There were two big problems with control. The first was that as you move from subsonic to supersonic, the center of lift would move. The aircraft was balanced for controllability at subsonic flows, but when you passed from subsonic to supersonic, the aircraft became unstable and would either crash or break up. The second problem was that the control systems were easily manipulated by the pilot at subsonic speeds, but the shock wave created at the control surface hinge was too great for a human to overcome -- pilots literally weren't strong enough to push the control surfaces against the shock wave until engineers developed all-flying tail surfaces (stabilators rather than elevators). Overcoming drag was basically just a problem of developing a powerful enough engine.
With a zero degree angle of attack your aircraft with any amount of thrust will fall...
Are you sure about that? I think you confused "angle of attack" with "coefficient of lift."
There are airfoil designs (basically, any asymmetric airfoil) that will produce lift at an AoA of zero degrees. If lift is non-zero, then the only question is how fast does an aircraft need to be going to generate enough lift to overcome weight at a zero-degree angle of attack?
Also, just to be pedantic, the balancing act is between lift, weight, thrust and drag. Lift is related to AoA so I'll concede that you basically covered that force, but you completely neglected to mention drag above.
What's wrong with a swing-wing? The USAF has used them since at least the 1960s and still uses swing-wing aircraft today. The B-1 even is similar in size to an airliner: Rockwell B-1, Boeing 737 (smaller) and Boeing 747 (bigger). It would seem to me that if a similar sized aircraft, travelling faster, at comparable weights, is sufficiently strong for military use, it should be plenty strong for commercial air travel. I imagine that it would be quite a bit more expensive to maintain than a fixed-wing airliner, however.
Off-topic? Seriously? I found it relevant and kind of funny, actually.
Fly it high enough so that it doesn't matter, perhaps? In the U.S., the FAA defines the upper limit of controlled airspace as 60,000 feet above mean sea level. Weather balloons are capable of flying at nearly twice that altitude.
I think you -- and a lot of other people in this thread -- misunderstand the concept of "control." Here's a /. car analogy to help:
When I get in my car and turn on the key, the car has no choice in the matter. If the battery is sufficiently charged, there is gas in the tank, and all of the other systems are in working order, the car WILL start. As I turn the steering wheel, the car follows my directions. When I hit the gas, it speeds up; when I hit the brakes, it slows down. The car gets no say in whether or not it does the things I command.
On the other hand, when I go to work, my boss may give me instructions, and I may be highly motivated to follow those instructions, but I *ALWAYS* have a choice. I can do what my boss says or not -- and there have indeed been times when I have chosen "not" for various reasons (I knew it was a bad idea, I knew he would change his mind when he had additional information, I was busy with higher priorities, etc.).
The first example is "control" -- that which is controlled has no options in the matter. The second example is influence or incentive -- that which is influenced has a choice, and even though the likelihood of choosing something other than what the influencer wants may be minimal, there is a statistically significant chance of something else happening.
LOL. I've been a full time sys admin for ten years -- first with Solaris and FreeBSD servers, then in my current job with about 15 or so Gentoo (!) servers plus my laptop and a desktop. We migrated to Ubuntu about three years ago. In all honesty, we do a much better job of updating the Ubuntu servers than we did the Gentoo servers because it is so much easier to do, but I am starting to loathe my Ubuntu laptop. It's a lot easier to get wireless working in Ubuntu than Gentoo, but Unity, nVidia drivers*, and a few other problems are really starting to sour me on Ubuntu. I'm hoping 12.04 will bring back the stability I experienced up to 10.10; IMHO, the 11.xx series is Canonical's Vista.
*Yes, I know, those are proprietary drivers. I can't blame Canonical entirely for that, but IIRC, there are much newer drivers available that aren't available in the official "restricted" repositories.
Seriously? It's a hassle to have to log into each server and click a link?
You must never have run Gentoo*...
*Which is still my favorite distro, despite occasionally being a real PITA to update.
I know. It was bad. I just couldn't believe no one else had said it yet ;)
Ok, yeah, that's cool, but what you really need is an airship covered with light emitting diodes across one side because then you could have...
...wait for it...
...a LED Zeppelin!
I read old school paper books and I read using the Kindle or Nook apps. IMHO, there are advantages and disadvantages to both; therefore, choices are *GOOD*. People, like the author of TFA, saying that one format is inherently better than the other are sensationalist.
I have found that most (but not all) of my reading for pleasure tends to be in real, paper books, since I typically read for fun at home. Consequently, having physical books in a bookshelf at home is adequate for those volumes. Furthermore, some of the books I read for pleasure don't lend themselves well to the eBook format. For example, my wife bought "Planet Earth's Greatest Motorcycle Adventure Tours" for me for Christmas. It's physically a rather large book, and filled with beautiful photographs from trips the author (Collette Coleman) had taken. I can't imagine trying to read that on my smartphone -- the text would be fine, but the photography would be completely wasted on that form factor.
On the other hand, most of my reading for information tends to be eBooks. It's handy to have a reference with you any time you have your phone/tablet/Ebook-reader-of-choice with you, and this type of writing lends itself well to the eBook format. In other words, for informative books, portability trumps form factor.
Ultimately, you pick the right tool for the job. I wouldn't buy a coffee table book in an electronic format, but there are some definite advantages to eBooks. IMHO, anyone writing off electronic media simply because it isn't bound in paper is simply limiting their options unnecessarily.
The short answer is, "You are working for the wrong employer." You say you work at a company that will install tracking software on your laptop and won't give you admin access. Therefore, you can't disable the tracking software. Furthermore, you say that you are addicted to the Internet. Working for a company that is likely to fire you for doing something that you don't have the self-discipline to avoid doing doesn't sound like a good plan to me.
/. can't help you find out what your company's policy is -- you'll have to do that yourself.
The long, more realistic, answer is, "Read your corporate compliance policy. It should outline what is acceptable in your organization and what is not." A lot of companies consider laptop use, especially while traveling, to be more like telephone use. It is issued to you for business purposes, but let's face it: most (all?) of us will use it for some personal activities as well. So long as you aren't browsing NSFW sites on the clock, installing malware, etc., most IT departments really don't give a rip what you do. They have more important things to do -- and not nearly enough time in which to do them -- than to spy on your web surfing activity. More likely, the tracking software is to find out what you did that hosed your computer in the event that you were browsing sketchy web sites and infected it with something. However, different companies have different policies.
Also being an old Datsun it was easy to find another alternator in the middle of nowhere.
I also suspect that "being an old Datsun" is why it worked: odds are, that car was carbureted rather than fuel injected. Had it been fuel injected, you would have been hosed, just like I was in my Talon. Fortunately, I had almost made it home, so my wife picked me up, I pulled the battery, took it home, put it on a charger, then drove back to my car a couple of hours later, reinstalled the battery and drove home.
If the alternator is dead, jumper cables won't do you any good (which was the case in the example I provided). If it's just a dead battery, then yeah, jump starting the car is fine -- I just left listing every possible case and selecting the appropriate option for solving the problem as an exercise for the reader ;)
Have you ever looked at the plumbing coming out of a boiler? The maze of wires and copper pipes is truly breathtaking...and that's just inside my house. I can't imagine the boiler of a commercial building.
Short answer: Google "zone valve powerhead"
I've push-started petrol cars with batteries flatter than pancakes. I suspect the alternator provides a bit of oomph as well once you pop the clutch.
Your battery was only MOSTLY dead. If it was ALL dead there would be only one thing to do: call a tow truck (with apologies to Rob Reiner).
;)
It worked for you because 1) the alternator was still working and 2) the battery may not have had enough current to turn the starter, but it did have enough to generate an electromagnetic field in the alternator -- perhaps weakly at first, but the longer it runs, the stronger it will get as the battery charges. If the battery is *completely* flat, however, the alternator isn't going to generate any current, and SuricouRaven is correct. Ask me how I know
You can pushstart a car to start it.
Sometimes. Modern vehicles use electrical power for essential functions *besides* turning the starter motor, for example, fuel injection and generating spark.
I once toasted the alternator on my '97 Eagle Talon and didn't realize it, since the car had no volt/ammeter. I drove it for a day or two on battery power, but finally, the battery died, and the EFI stopped working reliably. I was able to limp into a parking lot before the car died completely, but it was surging pretty badly before I got it parked. If the battery is sufficiently dead or the alternator is not working, you can push the car all day, but it isn't ever going to start.
Think of it this way. When you have a sufficiently long wire, for example, inside the generator at your local power utility, the induced voltages and currents can be quite high -- high enough to kill you. On the other hand, if you have a sufficiently short wire, such as in the pickups of my electric guitar, the induced voltages and currents are much, much less potent -- in fact, you can't even feel the current from my Strat unless it has been amplified first.
Ditto for the wires in the power grid compared to the wires in your car or your PC.
Wasn't it an Apple that messed everything up in the first place? ;)
If you think only the right-leaners have done that, then I humbly submit that you haven't been paying attention. Bush and his cronies may have kicked off the recent trend in sacrificing freedom for security*, but Obama and his cronies haven't done anything to reverse the process -- or even to slow it down -- and since we are about 8 months away from the next presidential election, it's not like he hasn't had time. I have no idea how the situation in the U.S. compares to overseas, so my apologies if you are talking about the U.K., Canada or Australia, etc.
*Yes, I know there were examples of our leadership trying to do likewise long before Bush. The pace just seems to have accelerated beyond what I ever imagined since 9/11.
"Nightwatch" at least sounded cool, in a subtly malicious sort of way. "Department of Homeland Security" just sounds...Stalin-esque. But yeah, I cringe, too.
As it turns out many terms including seemingly benign words such as flu, agent, response, cops drill, etc are on the list of words that set off warning bells for the government spooks.
Anyone think that maybe there's going to be a flurry of activity as those who like to tweak DHS post comments containing words like "flu," "agent," "response," "cops" and "drill" on Twitter, Facebook, G+, etc.? I'm sure it would be annoying for DHS to have to wade through all of those false positives containing words like "flu," "agent," "response," "cops" and "drill." Not that *I* would ever post anything like "flu," "agent," "response," "cops" and "drill." just to be obnoxious or anything ;)
I rather suspect a tight, low cut tank top -- with or without pizzas and coke -- would get me thrown OUT of most places (at least those that I'd have any interest in going to, anyway)
:)
Then again, I'm a dude
I kind of wondered :)
Not the first time I've been "whooshed" and probably won't be the last either, lol.