I see where you're coming from. There's no unique "killer" feature that can make any of the alternatives stand out as objectively superior to the current mobile platforms, but the same could have been said about the iPod or iPhone when they were released in their respective markets. It doesn't necessarily take a revolutionary product to change the landscape of a market, just a well executed one.
As far as how Nokia would have fared with MeeGo, it may have taken some skillful marketing, a few cross-licensing agreements that Nokia may not have been ready to commit to and a bit of luck, but the potential was there technically to make it a very competitive third player. I guess the argument could be made (IMHO a questionable one) that Windows Phone was in the same position at the time Elop made his decision, but even if that's the case why wouldn't having control over the full hardware/software stack be the better option for Nokia?
Have you ever used a N9? If any OS could be have been disruptive enough to overcome the duopoly of Android/iOS, MeeGo on the N9 was it. It still has simplest, most natural interface of any mobile device I've ever used and it accomplishes that without sacrificing any of the power or true multi-tasking capabilities of the N900. The only weakness in the platform at launch (besides very minor bugs) was the lack of apps. And that should have been only a temporary hurdle that would have resolved itself as other device manufacturers picked up MeeGo and the user base approached critical mass.
If Nokia hadn't intentionally sabotaged their own product by releasing the device in limited markets and declaring the platform dead before release, every indication is that the N9 would have been a huge success. That alone may not have been enough to become a player on par with Apple and Google, but it certainly would have been a better start than Windows Phone has been so far.
So why are these ultralight helicopters mainly controlled by a person? It seems to me they would be safer if fly-bi-wire with a computer doing most of the work of stability.
Weight. If you add the mass of the computer control and actuation systems necessary for fly by wire it would no longer qualify for the ultralight category. Oh, and it would cost a lot more than $30k, but possibly less than the $150k "jetpack" proposed here.
My "programming" experience is similar. The closest I've ever come to any formal training is in a numerical methods class in college where we coded some numerical integration and matrix inversion algorithms in Matlab.
Since then, I've taught myself to do some bash scripting by using Linux but nothing of significant complexity.
Your conception of perpetual motion is technically* correct, but there's an implication in general use that the motion is perpetual for a tangible physical system (one with friction or other non-isentropic processes)
Obviously you can't extract energy from a planetary orbit infinitely without degrading the orbit. However, if left alone, my understanding... limited though it is... is that it will keep orbiting forever assuming the orbit is stable and is left alone.
If space were a perfect vacuum and only two point masses existed, one orbiting the other, then the orbit may be perpetual. Although, we still don't understand gravity well enough to be sure that energy isn't radiated away from such a system in the form of gravitational waves (as mentioned by the GP).
I disagree, the IRS was (and still is) a bad idea. A better idea would be to fund the federal government from the states' treasuries. That way the job of your representatives and senators will be to decide whether your tax money is better spent on that new federal program or used on something in your state instead of trying to claw as much back from the general fund as they can.
Another along these lines is Asimov's The History of Physics. It may be difficult to get 11-14 year old kids to read a book with such a mundane (to them) title, but it does a great job of filling in the blanks of how new ideas in science grow from prior concepts and doesn't require the reader to have math proficiency above basic arithmetic.
The only craft I can see being able to cross that boundary zone would be a very small, very lightweight rotor that is able to make extremely fast accelerations, and thus cross the zone before it's able to affect the craft much. A full scale craft would simply have too much inertia/momentum to be able to make the transition fast enough, without tearing itself to pieces. Likewise for any craft trying to stop the rotor and use forward motion to generate the lift.
There is another solution. With coaxial rotors there's less of a stability problem because the lift can remain symmetric even if the retreating blades are completely unloaded. The Sikorsky X-2 (and S-97 Raider) use this configuration along with a pusher prop to achieve a 250 knot forward airspeed, but I don't think they drop the rotor speed all the way to zero.
Agree but I'd like to add that health and ammo pickups are scarce, weapons selection is extremely limited and loading times are horrendous. Still it's worthwhile occasionally. The sound quality is superb.
NO! That's absolute nonsense! Government borrowing to make "investments" isn't magic. It's EXACTLY like borrowing and investing in the private sector. Your investment either generates positive returns or it's money wasted.... Congrats! You've just "invested" $1 and gotten back 40 cents. Where do you get the other 60 cents to pay back the loan Mr. Keynes?
There's one thing that's different between private and government debt. A government controls their currency and can inflate away that remaining 60 cents. Although I'm not necessarily suggesting that's a good move since it may have a negative impact on growth.
Just checked the plan prices. I compared "unlimited" everything since that's the closest match between features.
AT&T - unlimited voice $70 + 3GB data $30 + unlimited messaging $20 = $120 per month
T-Mobile - Unlimited voice, high speed data and messaging $70 + $20 Phone installment plan = $90 per month
Assuming the down payment on the phone is similar, the T-Mobile plan is ~$700 ($30*24) less over the 2 year AT&T contract. After the phone is paid in full the installment plan ends and saves $50/month over AT&T.
I agree, I just wish there more good sound engineers. It's inexcusable, but way too common, to see horribly clipped signals with no dynamic range on 44.1kHz / 16bit CDs. The only reason I prefer 24bit files is that they haven't been as badly affected by the loudness war.
True, if the temps. are low and there are no geometry constraints, aluminum would probably be the best choice regardless of cost. Although, I was thinking mostly about engine components. Cast Ti blocks would be stronger and reduce the need for cooling compared to aluminum and are still much lighter than steel/cast iron.
As far as other areas go, there are already quite a few bicycle parts that are already available in Ti which would likely become much more popular if the price dropped significantly.
I guess that really depends what you're comparing it to. Ti fatigue strength can be superior to almost all aluminums and even many standard stainless steels, but there are some nickel alloys that have an endurance limit at or above yield.
I'm an aerospace engineer, so I have had a bit of experience with various metal alloys, but I'm no metallurgist.
I know there are several other Ti alloys available, but there are only three that seem to be widely used. CP Ti (unalloyed, grades 1-4), Ti 6-4 and Ti 6-2-4-2
There are some significant differences between these in strength and temperature capability, but nothing like the range of steel and nickel alloys that are available. Steel can range from barely better than aluminum in tensile strength to over twice the capability of the best Ti alloys and nickel superalloys can maintain strength similar to the some of the best steels at over 1000F.
Titanium fills a niche for high strength at moderately high temperatures which lends itself well to many applications, but no material is perfect. There's always a balance of cost vs. weight/strength vs. environmental considerations and no one material will always prevail.
Titanium is a very good material, but it isn't perfect. The fatigue capability is relatively low for its strength, especially in cast form. Strength at temperature is good, but far short of nickel based superalloys that are similar in cost. Low ductility and elastic modulus means it isn't easily formable and makes machining more difficult. It has limited resistance to wear due to lower hardenability. Oh, and it can catch on fire under the right conditions.
Although, for many aerospace applications there's no substitute at almost any cost. It allows the weight of parts, that would otherwise need to be made of steel or nickel alloys, to be cut nearly in half (and that adds up quickly since it applies to a large portion of the main structural components in things like jet engines).
If the price does drop drastically, I'd expect to start seeing Ti show up a lot more in areas like the automotive industry, where weight is important but it's use had been limited by cost.
That's all true and makes for a good explanation of basic pressure vessel sizing. I was just trying to point out how much energy is being contained by structures like this. Most of the other posts seemed to dismiss the issue simply because the pressure isn't high.
At least I didn't go the inflammatory science "journalism" route and state that a fully inflated BA2100 is the equivalent of ~50kg of TNT!!!!!
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+1 grammarian silhouette
I see where you're coming from. There's no unique "killer" feature that can make any of the alternatives stand out as objectively superior to the current mobile platforms, but the same could have been said about the iPod or iPhone when they were released in their respective markets. It doesn't necessarily take a revolutionary product to change the landscape of a market, just a well executed one.
As far as how Nokia would have fared with MeeGo, it may have taken some skillful marketing, a few cross-licensing agreements that Nokia may not have been ready to commit to and a bit of luck, but the potential was there technically to make it a very competitive third player. I guess the argument could be made (IMHO a questionable one) that Windows Phone was in the same position at the time Elop made his decision, but even if that's the case why wouldn't having control over the full hardware/software stack be the better option for Nokia?
Have you ever used a N9? If any OS could be have been disruptive enough to overcome the duopoly of Android/iOS, MeeGo on the N9 was it. It still has simplest, most natural interface of any mobile device I've ever used and it accomplishes that without sacrificing any of the power or true multi-tasking capabilities of the N900. The only weakness in the platform at launch (besides very minor bugs) was the lack of apps. And that should have been only a temporary hurdle that would have resolved itself as other device manufacturers picked up MeeGo and the user base approached critical mass.
If Nokia hadn't intentionally sabotaged their own product by releasing the device in limited markets and declaring the platform dead before release, every indication is that the N9 would have been a huge success. That alone may not have been enough to become a player on par with Apple and Google, but it certainly would have been a better start than Windows Phone has been so far.
So why are these ultralight helicopters mainly controlled by a person? It seems to me they would be safer if fly-bi-wire with a computer doing most of the work of stability.
Weight. If you add the mass of the computer control and actuation systems necessary for fly by wire it would no longer qualify for the ultralight category. Oh, and it would cost a lot more than $30k, but possibly less than the $150k "jetpack" proposed here.
Why don't these places ever use revolving doors?
Hospitals? Umm ... probably because the gurneys wouldn't fit through.
Although, I think the standard entry for most secure-ish facilities is full height turnstiles activated using some sort of personal entry token.
My "programming" experience is similar. The closest I've ever come to any formal training is in a numerical methods class in college where we coded some numerical integration and matrix inversion algorithms in Matlab.
Since then, I've taught myself to do some bash scripting by using Linux but nothing of significant complexity.
Red matter raises tons of questions! Too bad most of them are inquiries about the sexual proclivities of the writer's mothers.
Your conception of perpetual motion is technically* correct, but there's an implication in general use that the motion is perpetual for a tangible physical system (one with friction or other non-isentropic processes)
Obviously you can't extract energy from a planetary orbit infinitely without degrading the orbit. However, if left alone, my understanding... limited though it is... is that it will keep orbiting forever assuming the orbit is stable and is left alone.
If space were a perfect vacuum and only two point masses existed, one orbiting the other, then the orbit may be perpetual. Although, we still don't understand gravity well enough to be sure that energy isn't radiated away from such a system in the form of gravitational waves (as mentioned by the GP).
* The best kind of correct
I disagree, the IRS was (and still is) a bad idea. A better idea would be to fund the federal government from the states' treasuries. That way the job of your representatives and senators will be to decide whether your tax money is better spent on that new federal program or used on something in your state instead of trying to claw as much back from the general fund as they can.
Another along these lines is Asimov's The History of Physics. It may be difficult to get 11-14 year old kids to read a book with such a mundane (to them) title, but it does a great job of filling in the blanks of how new ideas in science grow from prior concepts and doesn't require the reader to have math proficiency above basic arithmetic.
The only craft I can see being able to cross that boundary zone would be a very small, very lightweight rotor that is able to make extremely fast accelerations, and thus cross the zone before it's able to affect the craft much. A full scale craft would simply have too much inertia/momentum to be able to make the transition fast enough, without tearing itself to pieces. Likewise for any craft trying to stop the rotor and use forward motion to generate the lift.
There is another solution. With coaxial rotors there's less of a stability problem because the lift can remain symmetric even if the retreating blades are completely unloaded. The Sikorsky X-2 (and S-97 Raider) use this configuration along with a pusher prop to achieve a 250 knot forward airspeed, but I don't think they drop the rotor speed all the way to zero.
Agree but I'd like to add that health and ammo pickups are scarce, weapons selection is extremely limited and loading times are horrendous. Still it's worthwhile occasionally. The sound quality is superb.
Interesting, that may be the inspiration for this: xkcd.com/955
NO! That's absolute nonsense! Government borrowing to make "investments" isn't magic. It's EXACTLY like borrowing and investing in the private sector. Your investment either generates positive returns or it's money wasted. ...
Congrats! You've just "invested" $1 and gotten back 40 cents. Where do you get the other 60 cents to pay back the loan Mr. Keynes?
There's one thing that's different between private and government debt. A government controls their currency and can inflate away that remaining 60 cents. Although I'm not necessarily suggesting that's a good move since it may have a negative impact on growth.
Just checked the plan prices. I compared "unlimited" everything since that's the closest match between features.
AT&T - unlimited voice $70 + 3GB data $30 + unlimited messaging $20 = $120 per month
T-Mobile - Unlimited voice, high speed data and messaging $70 + $20 Phone installment plan = $90 per month
Assuming the down payment on the phone is similar, the T-Mobile plan is ~$700 ($30*24) less over the 2 year AT&T contract. After the phone is paid in full the installment plan ends and saves $50/month over AT&T.
I agree, I just wish there more good sound engineers. It's inexcusable, but way too common, to see horribly clipped signals with no dynamic range on 44.1kHz / 16bit CDs. The only reason I prefer 24bit files is that they haven't been as badly affected by the loudness war.
Or you can watch Pi, which actually has some math in it. (okay, so it's more numerology than actual math, but at least there's numbers in there).
Oh, so that's what was creating the smoke that so many people were interested in earlier this week. White smoke means cold fusion rather than hot?
It looks really weird. Why didn't they use a thinner cable?
Because this is a picture of the scientist
There's a picture here.
True, if the temps. are low and there are no geometry constraints, aluminum would probably be the best choice regardless of cost. Although, I was thinking mostly about engine components. Cast Ti blocks would be stronger and reduce the need for cooling compared to aluminum and are still much lighter than steel/cast iron.
As far as other areas go, there are already quite a few bicycle parts that are already available in Ti which would likely become much more popular if the price dropped significantly.
I guess that really depends what you're comparing it to. Ti fatigue strength can be superior to almost all aluminums and even many standard stainless steels, but there are some nickel alloys that have an endurance limit at or above yield.
I'm an aerospace engineer, so I have had a bit of experience with various metal alloys, but I'm no metallurgist.
I know there are several other Ti alloys available, but there are only three that seem to be widely used. CP Ti (unalloyed, grades 1-4), Ti 6-4 and Ti 6-2-4-2
There are some significant differences between these in strength and temperature capability, but nothing like the range of steel and nickel alloys that are available. Steel can range from barely better than aluminum in tensile strength to over twice the capability of the best Ti alloys and nickel superalloys can maintain strength similar to the some of the best steels at over 1000F.
Titanium fills a niche for high strength at moderately high temperatures which lends itself well to many applications, but no material is perfect. There's always a balance of cost vs. weight/strength vs. environmental considerations and no one material will always prevail.
Titanium is a very good material, but it isn't perfect. The fatigue capability is relatively low for its strength, especially in cast form. Strength at temperature is good, but far short of nickel based superalloys that are similar in cost. Low ductility and elastic modulus means it isn't easily formable and makes machining more difficult. It has limited resistance to wear due to lower hardenability. Oh, and it can catch on fire under the right conditions.
Although, for many aerospace applications there's no substitute at almost any cost. It allows the weight of parts, that would otherwise need to be made of steel or nickel alloys, to be cut nearly in half (and that adds up quickly since it applies to a large portion of the main structural components in things like jet engines).
If the price does drop drastically, I'd expect to start seeing Ti show up a lot more in areas like the automotive industry, where weight is important but it's use had been limited by cost.
That's all true and makes for a good explanation of basic pressure vessel sizing. I was just trying to point out how much energy is being contained by structures like this. Most of the other posts seemed to dismiss the issue simply because the pressure isn't high.
At least I didn't go the inflammatory science "journalism" route and state that a fully inflated BA2100 is the equivalent of ~50kg of TNT!!!!!