5. Transit Fare Interoperability - Transit systems are typically city-wide or county-wide. Very few cross county jurisdictional boundaries. They are thus, in effect, silo'd. They have their own fare/rate structure (cost per boarding, discounts for multi-boarding passes), pass structure (monthly passes vs. 30-day passes), and absent a multi-jurisdictional agreement (Like Clipper in the Bay Area), many people need to purchase and maintain multiple bus passes for daily commutes. State SHOULD pass laws that require that each county get onboard with multi-jurisdictional pass/pricing schemes by 202X and then set another deadline to have groups of neighboring counties merge their pass/pricing schema until we have statewide transit passes. After all, it has taken over 20 years for the SF Bay area Clipper Card to get to where it is and it still only includes 22 of the local transit agencies. There are over 164 transit agencies in California alone.
Although for a number of urban areas even state-wide transit passes wouldn't necessarily be good enough because lots of people commute across state borders. (Darn those large cities built up against the edge of the state).
Although a number of those metro areas already have arrangements to handle some of that. Washington DC's metro system reaches out into nearby parts of both Maryland and Virginia, Philadelphia's mass transit extended across the river into New Jersey. Etc. The biggest outlier I'm aware of is New York. You have to switch from the MTA subway to PATH or Jersey Transit to take rail into New Jersey and those systems don't have a shared fare/rate structure with MTA.
Still, state-wide commonality would be a very good start.
The facts are Tesla no longer use the same sized batteries as other products, like laptops do, in their new models.
I don't see how draining stockpiles of 18650 cells would help them manufacture their cars that require 2170 cells. A more likely story is that Panasonic has halted production of 18650 cells to manufacture 2170 cells instead, while keeping enough capacity to honor existing customer contracts.
My understanding is that currently it is only the Tesla Model 3 that's using the larger 2170 cells. The Model S and X are sticking with the 18650 cell for the at least near term future. Having more (though smaller) cells per battery pack allows them a higher peak power output and hence better max acceleration.
Telsa wouldn't want a drop in performance numbers on their flagship vehicles from switching battery cells. (I suspect if, down the line they do switch to 2170s for S and X it'll come at the same time as a pack capacity boost so there are still enough cells to keep the peak power output at least as high as the current battery packs)
And since at the moment Tesla's selling more S and X models than 3s they might have caused a shortage is Panasonic's 18650s.
"But Tesla sells ELECTRIC cars!", someone says. Toyota sells more ELECTRIC cars than Tesla does.
As far as I can tell that's only true if you count even non-plugin hybrids. Telsa has delivered just over 200,000 vehicles world wide, all batter electric vehicles (BEVs).
Thought it's possible I've missed something Toyota BEVs:total 5,100 vehicles RAV 4 EV - total sales 5000 (over 2 generations) i Road - prototyple; none sold EQ EV / Scion EQ EV - 100
Toyota plug-in-hybrids ~106,000 PHEV Prius (gen 1) - 75,400 PHEV Prius Plus est 30,000
Doesn't exactly seem far to call a hybrid that gets 100% of it's initial energy from it's gas engine an "electric car"; but certainly Toyota has sold more hybrids that Tesla has sold cars.
But in BEVs Toyota is laughably behind, and even throwing in plug-in hybrids (with their vastly shorter electric-only ranges) they're look to have moved barely more than half the electric cars that Tesla has...
So let me get this straight: If a component on the network starts sending out uncontrolled messaging that looks like a denial of service, or an out of control / perpetually errored state, the network corrects for this problem by disconnecting the component causing chaos. That sounds like the CAN network is doing exactly what it should be doing: maintaining the integrity of the shared network at the expense of disconnecting an infected or malfunctioning node. What am I missing?
My reading of the article is that the missing bit from your post is that the the purportedly malfunctioning component doesn't judge for itself whether it appears to be "sending out uncontrolled messaging" it believes any other device on the bus that it it's sending garbage.
That means a malicious component on the CAN bus can just spam every other component with bogus error messages about their output until they disconnect themselves.
Still that's only a problem when attackers can place or control a device on the CAN bus. (And some cars already mitigate the risk of remote access to those devices by splitting the CAN bus two, putting all the infotainment connected components on one bus and the engine and safety ones on the another (with just a one-way output only bridge from the safety CAN to the infotainment CAN.
Most people do not have an effectively unlimited number of fingers, and hence it's possible for the police to try all of them
At least on my phone 4 failed fingerprint authentication attempts and the phone requires the passphrase to unlock.
So if you have only 1 finger enrolled and it's not a common one the police only have a 40% change of brute forcing the fingerprint authentication. (Less if you can deliberately choose some wrong fingers)
Still that's more just a hope they might not get in. (And most people probably have at least 2 fingers enrolled)
Part of the reason it wasn't commercially viable was that it had limited route availablility -- it could not go supersonic over CONUS, so was limited to JFK-LHR and JFK-CDG. If the sonic boom is reduced to non-invasive levels, then suddenly more routes become feasible... LAX-, ORD-, SFO- etc...
The other restriction was Concorde's limited range. If it had been designed for transpacific routes the over-ocean limitation wouldn't have been so bad. Cutting by more than half the 11 hour West Coast to Tokyo, or 15 hour to Sydney flights might have gotten more sustained interest than the 7 hour transatlantic flight -- certainly it would have spread the fixed R&D costs over more planes on more routes.
But the combination of transatlatic range and only supersonic over the ocean sharply limits your possible routes (Though West Coast to Hawaii is within its range. Chartered and exhibition flights did island hop across the Pacific through Hawaii, but there was never commercial supersonic service there)
The issues with electric planes have been beat to death here
Where? Slashdot? I can't recall ever reading about electric flight beyond drones, though I'm sure there has to have been some in the past.
What issues?
The main problems are batteries, not electric propulsion itself. That batteries are far heavier that fuel on a lbs/kw basis, plus you don't get the bonus of the plane getting lighter the longer it flies. And high bypass turbines on planes aren't as inefficient in use as the ICE in cars (and planes are much more weight sensitive than cars) so you can't trade weight and drivetrain efficiency for useful range like you can in electric cars.
Also, for commercial planes they spend very little time on the ground between flights; so you don't have time to recharge batteries. So you're looking at a battery swap technology as well to keep the turnaround time comparable to refueling.
That said, if the distributed electric propulsion is as efficient as NASA thinks it might still be a net win even if you have to pair up the electric motor and prop placement of this X-57 with an onboard electric generator. In which case all the downsides of batteries are irrelevant. (Then you could look into whether a hybrid design with a some batteries and a smaller generator made sense)
I'm not a petroleum engineer, but I'm familiar with the industry and I can find no process known for manufacturing petroleum products from raw materials. You can find processes for converting one form of fossil fuel from another (ie petrol from coal) or for extracting petroleum from tar sands. None of these processes actually create petroleum from raw materials.
I guess it depends on how you define "raw materials" but my understanding is that the old Fischer Tropsch process can produce petroleum products from carbon monoxide and hydrogen. This was invented in the '20s and was used by the Germans in WWII to produce something like 1/4 of their automobile fuels.
Now admittedly for economic reasons the raw materials tend to be derived from coal and/or natural gas; the later often in places where it's not economical to distributed that gas directly into the marketplace. But there's nothing, AFAIK, in the chemistry to prevent you from using other raw sources - they'd just take more energy to process and generate the petroleum. Of course there is a net energy loss in this process, but it would let you use fixed power generated by other sources, plus raw feedstocks, to generate synthetic petroleum for mobile applications. However there's little economic point at this time given that it costs more than even shale oil.
Locking Torque converters have been the rule for a LONG time, like since the 70's... With all due respect for the guys from Car Talk, this *helps* with the efficiency, but there still is some energy losses due to the necessity of running the automatic part of the transmission. You have to keep the shift clutches engaged, that takes hydraulic pressure which implies a pump is running someplace. You also must circulate the transmission fluid to keep the various things lubricated and cool, which takes some power too. Power consumption in the transmission means less power for driving getting to the wheels.
I'm not saying the differential between the automatic and the manual is all that much these days, it's not, but if you are on the highway the manual is going to be better. Now if you want to argue that it's unlikely that your average skilled driver would be able to achieve better gas mileage in a mixed environment of city and highway driving on their manual, that for 99.9% of drivers would do better on an automatic, I can only agree with you. However, just straight out driving down the road at highway speed, not shifting, that manual is going to be hard to beat, all things being equal.
Of course things are rarely equal. For example (outside of big rig trucks) manual transmissions seem to top out at 6 gears, while most automatics are now at least 7 with some having 8, or even 9 gears. (A far cry from the old 3 speed automatics).
That gives a better chance that the automatic can select a more ideal gear ratio for your speed than the manual. Potentially having the engine at a better RPM could more than offset the parasitic losses of the automatic transmission.
A typical gas-powered sedan's fuel tank may hold around 15 U.S. gallons of gasoline, which weighs about 40 kg. The tank itself may add another 10 or 20 kg, for a total of ~55 kg. In contrast, the battery pack of the Tesla model S weighs 540 kg! - even though its range is still a bit less.
This 10x weight increase is acceptable in a sedan, because the gas-powered sedan already weighed about 1400 kg; adding another ~500 kg is significant, but not overwhelming.
Also the electric motors and associated fixed gearboxes probably weight significantly less than the ICE engine, transmission, and associated hardware. So the net weight increase for switching to electric propulsion is probably noticably less than the 10x increase you ballparked.
If criminals didn't frequently obtain their firearms by stealing them from legitimate users I might buy your argument a little more.
A smartgun should be able to prevent a criminal from immediately using a stolen gun; in other words they can grab it away from you and then shoot you with it.
But bullets and guns are ultimately too simple of devices to keep people from being able to strip off the "smarts" and render a stolen smart gun usable again. Ultimately all the smarts are doing is deciding whether or not the firing pin get to strike the primer in the base of the bullet. It seems there's only a couple ways the smarts can control that; one is to disrupt the mechanical linkage between the trigger, the firing pin, and the bullet and the other is to replace that with an electronic path where you use a servo or something activate the firing pin. The first type you remove the ability to disrupt the mechanical path and the second type you replace the smart electronics with a simple connection from the trigger switch to the electronic firing pin activator.
Smart guns, if they have sufficiently lower failure rates solve a number of problems; but criminal stealing a gun and making it usable for a later crime really isn't one of them.
This is not true. Assisted GPS doesn't rely on cell networks, it makes use of cell networks for faster fixes. They still work fine without service, but they do take much longer to get a fix. This is evidenced by the fact that you can put your phone in airplane mode and hold it near the window of an airliner and still get a 10-satellite fix.
Now, that said, you may be able to have maps downloaded for offline use, but in Google Maps searching and route-finding still require a data connection, limiting its usefulness.
Some people may have been confused on this point because Apple, up until iOS 8.3 (released less than 5 months ago), would also turn off iPhone GPS receivers when you put them into airplane mode.
always thought the most unlikely technological development in my lifetime was the handheld GPS device. It would be "most unlikely" because it required tremendous, simultaneous, and largely unforeseen advances in several different technologies, each of which was hard to predict in 1981. The list is at least:
1. Low power, low voltage, low noise L-band receivers, sensitive enough to be compatible with the weak signal coming from the internal antenna of a handheld device; 2. Stupendous amounts of digital signal processing, also at low power and low voltage; 3. Digital map databases of (substantially) every road in the world, accurate to a few meters; 4. A substantially world-wide, wideband wireless data link to get the digital map into the handheld device in the first place; 5. Low power, low voltage, high resolution, multicolor flat panel displays; 6. Gigabytes of low power, low voltage data storage memory; and 7. High energy density, high power density batteries capable of supplying the whole thing.
And, perhaps most impressive of all, the manufacturing technology to make all of the above small enough to fit in a handheld device, at a price low enough to sell by the zillions.
Of the list above, probably only #2 could have been predicted, and then only if one were willing to extrapolate the then-relatively-new Moore's Law by a very large amount. (Recall that Mead and Conway had only written their Introduction to VLSI systems the previous year; until then it was not clear that such complex chips could even be designed on human time scales, let alone built for a profit.)
The fact that a handheld GPS device is now an anachronism, since the technology is now small enough and low-power enough to be integrated into other handheld devices, like smart phones, pleases me no end.
Add to that list an item 0: That a satellite cluster deigned, paid for, and deployed for military use would be freely available for civilian use. (President Regan's decision to allow that, in the wake of the Korean Air flight 007 wasn't made until 1983 and the satellites weren't launched until 1989).
Without the military necessity and funding behind it there's basically no chance that the GPS satellites would have been deployed, and without Regan's decision there's no reason they would necessarily have supported unencrypted civilian use.
But yeah, I like your unlikely technology prediction. Although certainly much less capable handheld GPS units existed long before the map based raod navigation one's you were primarily referring to.
The Germans lost the battle for many reasons. They were losing aircraft fast, not just in combat but due to maintenance needed. Planes have to be pulled out of the line and refurbished every so often. They can't fight forever. Unknown to the Germans, the British were far out producing them in fighter aircraft. Almost double the production. The problem the British faced was a lack of pilots to man those aircraft, and a degradation of the support infrastructure. Same as pilots, the ground crew, maintenance and airfield engineers were wearing out. But, so were the German ones. It turned into a battle of attrition. The Germans were deeper to begin with, but the British were losing less over time. The Germans eventually broke first. Their change in tactics was to cover the wearing out of their air force.
And don't forget the limited range of the German fighters.
The Battle of Britain was more the battle for southeast Britain. Unless RAF Fighter Command cooperated, by staying in a losing fight, there was basically no way for the Luftwaffe to seize and maintain air superiority in support of a seaborne invasion.
The RAF had plenty of bases north or west of the Luftwaffe fighter's effective range; so if the attrition started going too badly against the RAF they had the option of temporarily pulling back to train up additional units, but could still surge forward if / when the invasion began. And Luftwaffe bombers would get shredded trying daylight unescorted raids against those more distant airbases.
Ultimately, as painful as it might have been to people on the ground in that southwest portion of Britain, the Luftwaffe could only inflict a level of attrition that the RAF was willing to accept. It would be quite different if the Luftwaffe had the range to put fighters over any part of the UK, because then the RAF has to come up and fight, or its units get destroyed on the ground by fighter sweeps or escorted tactical bombing missions; though at least it would still have the option of training new pilots in Canada - so it wouldn't be quite as bad off as the Luftwaffe was by the end of the war where there was a good chance a trainee pilot would be shot down by Allied fighters before finishing flight training.
I like the idea of towable range extenders, but if you're renting one, what are the advantages over automated battery swapping instead?
I can see a couple advantages to towable range extenders.
Probably the biggest one is that once you've rented it you can continue to extend the range indefinitely by utilizing existing widely deployed infrastructure (stopping at a gas station to top up the generator's tank). So you can use to for trips into areas where the charging or battery swap stations haven't reached yet.
It also sidesteps the issue or concern about people swapping out, or receiving, an old reduced effective capacity battery pack at a swap station.
And the rental place needs less infrastructure than a battery swap place. To do battery swap you need the tools (or automated machines) and access to pull the existing pack and install a new one. For a towable rental you barely need more than an empty lot to park them until they've been rented.
And when a battery swap place gets a battery back they need a pretty hefty electrical connection to charge it back up for the next use. The towable rental place needs a gas can (or to take the returned genset by a gas station to top it up); plus they could use the rental car style gas fees to encourage people to return the range extender with a full tank - no practical way to do the same for battery swap.
You could just wander into the stars, get lost, run out of gas, or fall afoul of an enemy you weren't prepared to defeat, lose the game and have to find a 20-gameplay-hour-old savegame to usefully recover.
You could certainly get taken out by an enemy you couldn't defeat; wander into Ur-Quan space with too slow a main ship, or those damned slylandro probes. (Doesn't do much good to emergency escape if you can't run clear in hyper)
But short of providing a fight with the traders, or in the very near end game (after they fled), it was virtually impossible to permanently run out of gas. The traders always come alone eventually and give you more. I once got bored and pushed it and I think I ran out my ship out of fuel five or six times in a row and they kept showing up like AAA (even if you have no resources or info to trade them you still get gas to get back to Earth)
The new USS America [wikipedia.org] has a flight deck of the same size. France's (only) aircraft carrier is about ten meters longer. The gigantic Nimitz-class supercarriers are the exception to the rule.
Just using flight deck length is misleading. While the French Charles de Gaulle carrier is only 13 meters longer, it's almost 70% wider and and overall it's twice as big (displacement).
Here's a bit more detailed listing, name (year launched) tonnage (standard), length x beam (flight deck)
Izumo (2013) 19,500 tons, 248 x 38 m
HMS Invincible (1980) 22,000 tons, 209 x 36 m
HMS Ark Royal (1955) 36,800 tons, 245 x 52 m
Charles de Gaulle (2001) 37,085 tons, 245 x 52 m
USS America (2012) 45,000 tons, 257 x 32 m
USS Midway (1945) 45,000 tons, 295 x 34 m
HMS Queen Elizabeth (2016, planned) 70,6000 tons, 284 x 70 m
USS Nimitz (1975) 100,000 tons, 332 x 77 m
The Izumo is less than half the displacement of a late-war WWII design, and lacks the flight deck area of more modern carriers (which due to their angled flight deck are substantially wider at the flight deck than at the waterline). Unsurprisingly it's closest to the displacement to the Royal Navy's old through-deck cruisers (aka 'Harrier carriers') which had the similar mission of supporting helicopters for anti-submarine patrol.
Does the valet key somehow negate the manual trunk release? Honest question, as I own a hatchback.
Not automatically, but (most?) cars have a disable switch you can throw to disconnect the trunk release button/lever. It's always behind a lockable area that the valet key can't open - I've seen them in the trunk itself (often a lever on the side of the lock mechanism) or in the glove compartment.
Hit that disconnect, lock the trunk and glove compartment with the normal key and then the valet key won't be able to access the trunk. (My old car you also had to lock the folding rear seats with the normal key; those weren't linked to the trunk release button, so it was more of a pain)
een done. S-72 and X-50 prototypes. Its very unstable. The bring a rotor to a controlled stop thing is easy, existing rotor brakes can be geared to align it fairly precisely when it comes to a stop. The lift transition is the issue. It's not just that lift is basically 0. It's that one half of the rotor disc (the theoretical abstract describing the lift forces) has to completely reverse the airflow of the lifting surface.
Its essentially an expanded case of the Retreating Blade Stall problem.
But the retreating half of the rotor disc has to, as some point, go from generating lift from a retreating motion through the air (moving backwards relative to airframe, due to rotation) to generating lift from an advancing motion through the air (moving forwards, relative to airframem though no longer rotating). The easiest way to think about it isnt to think of it as going from rotating to fixed, but rather think about a rotor that is simply being reversed in direction (simplfies a lot of math).
So at some point in the middle there, half the rotor disc will fall below stall speed, and experience a stall similar to the effect of a Retreating Blade Stall. Worse, won't regain sufficient lift until its now going ~100 KIAS in the opposite direction. Think of it as stalling between -100 and +100 KIAS (example number) as it crosses the transition.
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.
Theoretically couldn't it work if the craft had enough sufficient fixed wings to provide most of the lift necessary for level flight at transition speed?
Then you should be able to trim the rotor disk to near zero lift (beginning a relatively mild decent) before braking it to a stop. Once stopped, retrim it for forward lift and level off.
Mind you those big wings would likely do ugly thing to the airflow in vertical lift mode...
"Track performance and give bonuses to the people who manage to stop the intruders."
Ensure the bonus even goes to the average schmo hot-dog vendor who challenges somebody who doesn't have their ID showing. It's not a new strategy, but turning it into a game like this shifts cultures. Suddenly all the con-man defenses of "seriously, don't you know me?", "man, you're uptight, chill." or "Bob says it's okay" fall out the window to your "hey, I get $50 if you don't have a badge".
Not to pick on hot-dog vendors. They're probably more people savvy than most of your security team.
But like implementing bonuses for lines of code written, or number of bugs eliminated, be careful to put in safeguards against people gaming the system.
If all you do to "intruders" is ask them to leave it probably won't be long before someone gets the bright idea to ask a few friends to drop by and try to slip in. Or even for a coworker or two to "forget" their badge in order to split the reward.
This is ridiculous. Just pressurize the server room or whole building and be done with it. That layer of air would automagically reappear for the heads to glide over the platters.
Of course that means that the room pressurization would be a single point of failure for every hard drive you had. Lose pressure and every drive suffers a head crash simultaneously... Oops.
If I didn't need the storage volume I'd certainly prefer drives like SSDs that didn't require pressurization to work at that altitude. One less thing to go wrong. (Although the ability to pressurize the building when necessary to make maintenance / upgrades easier on the IT guys would be cool and useful)
I don't agree, and largely because you don't have a 'right' to drive within the United States, which is likely where they'll draw any legal help for challenges within the US. You also have limited rights in public places. What's the difference between a black box in the car and investigators measuring your travel speed using a camera from a gas station across the street? Or even in the same parking lot?
I'd say about the same difference between unmarked cars following your car around 24/7 and a GPS tracking device.
Yet the Supreme Court unanimously found that there was a significant difference in that scenario; that the later required a warrant (while the former didn't)
Sometime technology makes something so easy or so covert to widely accomplish that it, in practice, makes it effectively a change in kind not just degree. When that happens laws are written, or courts can find, that because something has become far easier to do that additional protections are required to maintain an acceptable level of practical freedom.
Requiring an expiration date on the ID also limits how long the person the ID is legitimately issued to could illegally vote in their old district/state after moving away.
The address on the ID was presumably accurate when issued; but who knows how long it'll remain accurate. Getting a new ID issued with the new address doesn't alter the old ID, and it's not like voting stations are checking any kind of ID revocation list.
Slashdot Mirror
Although for a number of urban areas even state-wide transit passes wouldn't necessarily be good enough because lots of people commute across state borders. (Darn those large cities built up against the edge of the state).
Although a number of those metro areas already have arrangements to handle some of that. Washington DC's metro system reaches out into nearby parts of both Maryland and Virginia, Philadelphia's mass transit extended across the river into New Jersey. Etc.
The biggest outlier I'm aware of is New York. You have to switch from the MTA subway to PATH or Jersey Transit to take rail into New Jersey and those systems don't have a shared fare/rate structure with MTA.
Still, state-wide commonality would be a very good start.
My understanding is that currently it is only the Tesla Model 3 that's using the larger 2170 cells. The Model S and X are sticking with the 18650 cell for the at least near term future. Having more (though smaller) cells per battery pack allows them a higher peak power output and hence better max acceleration.
Telsa wouldn't want a drop in performance numbers on their flagship vehicles from switching battery cells. (I suspect if, down the line they do switch to 2170s for S and X it'll come at the same time as a pack capacity boost so there are still enough cells to keep the peak power output at least as high as the current battery packs)
And since at the moment Tesla's selling more S and X models than 3s they might have caused a shortage is Panasonic's 18650s.
As far as I can tell that's only true if you count even non-plugin hybrids. Telsa has delivered just over 200,000 vehicles world wide, all batter electric vehicles (BEVs).
Thought it's possible I've missed something
Toyota BEVs:total 5,100 vehicles
RAV 4 EV - total sales 5000 (over 2 generations)
i Road - prototyple; none sold
EQ EV / Scion EQ EV - 100
Toyota plug-in-hybrids ~106,000
PHEV Prius (gen 1) - 75,400
PHEV Prius Plus est 30,000
Doesn't exactly seem far to call a hybrid that gets 100% of it's initial energy from it's gas engine an "electric car"; but certainly Toyota has sold more hybrids that Tesla has sold cars.
But in BEVs Toyota is laughably behind, and even throwing in plug-in hybrids (with their vastly shorter electric-only ranges) they're look to have moved barely more than half the electric cars that Tesla has...
My reading of the article is that the missing bit from your post is that the the purportedly malfunctioning component doesn't judge for itself whether it appears to be "sending out uncontrolled messaging" it believes any other device on the bus that it it's sending garbage.
That means a malicious component on the CAN bus can just spam every other component with bogus error messages about their output until they disconnect themselves.
Still that's only a problem when attackers can place or control a device on the CAN bus. (And some cars already mitigate the risk of remote access to those devices by splitting the CAN bus two, putting all the infotainment connected components on one bus and the engine and safety ones on the another (with just a one-way output only bridge from the safety CAN to the infotainment CAN.
At least on my phone 4 failed fingerprint authentication attempts and the phone requires the passphrase to unlock.
So if you have only 1 finger enrolled and it's not a common one the police only have a 40% change of brute forcing the fingerprint authentication. (Less if you can deliberately choose some wrong fingers)
Still that's more just a hope they might not get in. (And most people probably have at least 2 fingers enrolled)
The other restriction was Concorde's limited range. If it had been designed for transpacific routes the over-ocean limitation wouldn't have been so bad. Cutting by more than half the 11 hour West Coast to Tokyo, or 15 hour to Sydney flights might have gotten more sustained interest than the 7 hour transatlantic flight -- certainly it would have spread the fixed R&D costs over more planes on more routes.
But the combination of transatlatic range and only supersonic over the ocean sharply limits your possible routes (Though West Coast to Hawaii is within its range. Chartered and exhibition flights did island hop across the Pacific through Hawaii, but there was never commercial supersonic service there)
The main problems are batteries, not electric propulsion itself. That batteries are far heavier that fuel on a lbs/kw basis, plus you don't get the bonus of the plane getting lighter the longer it flies. And high bypass turbines on planes aren't as inefficient in use as the ICE in cars (and planes are much more weight sensitive than cars) so you can't trade weight and drivetrain efficiency for useful range like you can in electric cars.
Also, for commercial planes they spend very little time on the ground between flights; so you don't have time to recharge batteries. So you're looking at a battery swap technology as well to keep the turnaround time comparable to refueling.
That said, if the distributed electric propulsion is as efficient as NASA thinks it might still be a net win even if you have to pair up the electric motor and prop placement of this X-57 with an onboard electric generator. In which case all the downsides of batteries are irrelevant. (Then you could look into whether a hybrid design with a some batteries and a smaller generator made sense)
I guess it depends on how you define "raw materials" but my understanding is that the old Fischer Tropsch process can produce petroleum products from carbon monoxide and hydrogen. This was invented in the '20s and was used by the Germans in WWII to produce something like 1/4 of their automobile fuels.
Now admittedly for economic reasons the raw materials tend to be derived from coal and/or natural gas; the later often in places where it's not economical to distributed that gas directly into the marketplace. But there's nothing, AFAIK, in the chemistry to prevent you from using other raw sources - they'd just take more energy to process and generate the petroleum.
Of course there is a net energy loss in this process, but it would let you use fixed power generated by other sources, plus raw feedstocks, to generate synthetic petroleum for mobile applications. However there's little economic point at this time given that it costs more than even shale oil.
Of course things are rarely equal. For example (outside of big rig trucks) manual transmissions seem to top out at 6 gears, while most automatics are now at least 7 with some having 8, or even 9 gears. (A far cry from the old 3 speed automatics).
That gives a better chance that the automatic can select a more ideal gear ratio for your speed than the manual. Potentially having the engine at a better RPM could more than offset the parasitic losses of the automatic transmission.
Also the electric motors and associated fixed gearboxes probably weight significantly less than the ICE engine, transmission, and associated hardware. So the net weight increase for switching to electric propulsion is probably noticably less than the 10x increase you ballparked.
A smartgun should be able to prevent a criminal from immediately using a stolen gun; in other words they can grab it away from you and then shoot you with it.
But bullets and guns are ultimately too simple of devices to keep people from being able to strip off the "smarts" and render a stolen smart gun usable again. Ultimately all the smarts are doing is deciding whether or not the firing pin get to strike the primer in the base of the bullet. It seems there's only a couple ways the smarts can control that; one is to disrupt the mechanical linkage between the trigger, the firing pin, and the bullet and the other is to replace that with an electronic path where you use a servo or something activate the firing pin.
The first type you remove the ability to disrupt the mechanical path and the second type you replace the smart electronics with a simple connection from the trigger switch to the electronic firing pin activator.
Smart guns, if they have sufficiently lower failure rates solve a number of problems; but criminal stealing a gun and making it usable for a later crime really isn't one of them.
Except he didn't say " IQ greater than the its number of gears" he said " IQ greater than the largest number on the gear lever".
Presumably your CVT has 13 as the largest number on its gear lever.. (What, you didn't know we were talking hexadecimal?)
Some people may have been confused on this point because Apple, up until iOS 8.3 (released less than 5 months ago), would also turn off iPhone GPS receivers when you put them into airplane mode.
Add to that list an item 0:
That a satellite cluster deigned, paid for, and deployed for military use would be freely available for civilian use. (President Regan's decision to allow that, in the wake of the Korean Air flight 007 wasn't made until 1983 and the satellites weren't launched until 1989).
Without the military necessity and funding behind it there's basically no chance that the GPS satellites would have been deployed, and without Regan's decision there's no reason they would necessarily have supported unencrypted civilian use.
But yeah, I like your unlikely technology prediction. Although certainly much less capable handheld GPS units existed long before the map based raod navigation one's you were primarily referring to.
Yes. I should have used "ability to train", or "ability to continue to train", instead of "option of training".
I did know they did flight training in Canada, and didn't mean to imply otherwise.
And don't forget the limited range of the German fighters.
The Battle of Britain was more the battle for southeast Britain. Unless RAF Fighter Command cooperated, by staying in a losing fight, there was basically no way for the Luftwaffe to seize and maintain air superiority in support of a seaborne invasion.
The RAF had plenty of bases north or west of the Luftwaffe fighter's effective range; so if the attrition started going too badly against the RAF they had the option of temporarily pulling back to train up additional units, but could still surge forward if / when the invasion began. And Luftwaffe bombers would get shredded trying daylight unescorted raids against those more distant airbases.
Ultimately, as painful as it might have been to people on the ground in that southwest portion of Britain, the Luftwaffe could only inflict a level of attrition that the RAF was willing to accept. It would be quite different if the Luftwaffe had the range to put fighters over any part of the UK, because then the RAF has to come up and fight, or its units get destroyed on the ground by fighter sweeps or escorted tactical bombing missions; though at least it would still have the option of training new pilots in Canada - so it wouldn't be quite as bad off as the Luftwaffe was by the end of the war where there was a good chance a trainee pilot would be shot down by Allied fighters before finishing flight training.
I can see a couple advantages to towable range extenders.
Probably the biggest one is that once you've rented it you can continue to extend the range indefinitely by utilizing existing widely deployed infrastructure (stopping at a gas station to top up the generator's tank). So you can use to for trips into areas where the charging or battery swap stations haven't reached yet.
It also sidesteps the issue or concern about people swapping out, or receiving, an old reduced effective capacity battery pack at a swap station.
And the rental place needs less infrastructure than a battery swap place. To do battery swap you need the tools (or automated machines) and access to pull the existing pack and install a new one. For a towable rental you barely need more than an empty lot to park them until they've been rented.
And when a battery swap place gets a battery back they need a pretty hefty electrical connection to charge it back up for the next use. The towable rental place needs a gas can (or to take the returned genset by a gas station to top it up); plus they could use the rental car style gas fees to encourage people to return the range extender with a full tank - no practical way to do the same for battery swap.
You could certainly get taken out by an enemy you couldn't defeat; wander into Ur-Quan space with too slow a main ship, or those damned slylandro probes. (Doesn't do much good to emergency escape if you can't run clear in hyper)
But short of providing a fight with the traders, or in the very near end game (after they fled), it was virtually impossible to permanently run out of gas. The traders always come alone eventually and give you more. I once got bored and pushed it and I think I ran out my ship out of fuel five or six times in a row and they kept showing up like AAA (even if you have no resources or info to trade them you still get gas to get back to Earth)
Just using flight deck length is misleading.
While the French Charles de Gaulle carrier is only 13 meters longer, it's almost 70% wider and and overall it's twice as big (displacement).
Here's a bit more detailed listing,
name (year launched)
tonnage (standard), length x beam (flight deck)
Izumo (2013)
19,500 tons, 248 x 38 m
HMS Invincible (1980)
22,000 tons, 209 x 36 m
HMS Ark Royal (1955)
36,800 tons, 245 x 52 m
Charles de Gaulle (2001)
37,085 tons, 245 x 52 m
USS America (2012)
45,000 tons, 257 x 32 m
USS Midway (1945)
45,000 tons, 295 x 34 m
HMS Queen Elizabeth (2016, planned)
70,6000 tons, 284 x 70 m
USS Nimitz (1975)
100,000 tons, 332 x 77 m
The Izumo is less than half the displacement of a late-war WWII design, and lacks the flight deck area of more modern carriers (which due to their angled flight deck are substantially wider at the flight deck than at the waterline). Unsurprisingly it's closest to the displacement to the Royal Navy's old through-deck cruisers (aka 'Harrier carriers') which had the similar mission of supporting helicopters for anti-submarine patrol.
Not automatically, but (most?) cars have a disable switch you can throw to disconnect the trunk release button/lever. It's always behind a lockable area that the valet key can't open - I've seen them in the trunk itself (often a lever on the side of the lock mechanism) or in the glove compartment.
Hit that disconnect, lock the trunk and glove compartment with the normal key and then the valet key won't be able to access the trunk. (My old car you also had to lock the folding rear seats with the normal key; those weren't linked to the trunk release button, so it was more of a pain)
Theoretically couldn't it work if the craft had enough sufficient fixed wings to provide most of the lift necessary for level flight at transition speed?
Then you should be able to trim the rotor disk to near zero lift (beginning a relatively mild decent) before braking it to a stop. Once stopped, retrim it for forward lift and level off.
Mind you those big wings would likely do ugly thing to the airflow in vertical lift mode...
But like implementing bonuses for lines of code written, or number of bugs eliminated, be careful to put in safeguards against people gaming the system.
If all you do to "intruders" is ask them to leave it probably won't be long before someone gets the bright idea to ask a few friends to drop by and try to slip in. Or even for a coworker or two to "forget" their badge in order to split the reward.
Of course that means that the room pressurization would be a single point of failure for every hard drive you had. Lose pressure and every drive suffers a head crash simultaneously... Oops.
If I didn't need the storage volume I'd certainly prefer drives like SSDs that didn't require pressurization to work at that altitude. One less thing to go wrong. (Although the ability to pressurize the building when necessary to make maintenance / upgrades easier on the IT guys would be cool and useful)
I don't agree, and largely because you don't have a 'right' to drive within the United States, which is likely where they'll draw any legal help for challenges within the US. You also have limited rights in public places. What's the difference between a black box in the car and investigators measuring your travel speed using a camera from a gas station across the street? Or even in the same parking lot?
I'd say about the same difference between unmarked cars following your car around 24/7 and a GPS tracking device.
Yet the Supreme Court unanimously found that there was a significant difference in that scenario; that the later required a warrant (while the former didn't)
Sometime technology makes something so easy or so covert to widely accomplish that it, in practice, makes it effectively a change in kind not just degree. When that happens laws are written, or courts can find, that because something has become far easier to do that additional protections are required to maintain an acceptable level of practical freedom.
Requiring an expiration date on the ID also limits how long the person the ID is legitimately issued to could illegally vote in their old district/state after moving away.
The address on the ID was presumably accurate when issued; but who knows how long it'll remain accurate. Getting a new ID issued with the new address doesn't alter the old ID, and it's not like voting stations are checking any kind of ID revocation list.