These are concepts found in sci-fi or seem like they are just around the corner, but are painfully slow to come. Given are reasons for possible tardiness.
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'''Flying Cars''' - 3D commute

* Require too much energy
* Inherent design conflict: cars are safer when heavy, yet flying machines should be light (safety vs fuel economy).
** SkyCar has best mileage of 20 mpg, SUVs have worst mileage around that.
* Risk too high, look how careless people are in 2D.
** Though it's safer in 3D than 2D.
*** Please clarify.
** ''A 3D crash could be far worse than a 2D crash. Further, what about terrorist crackers or acts of war?''
** Complete computer-control via GPS may be possible (if in large population areas) so that terrorists and drunks cannot take control. However, cracks will be found.
* Already invested infrastructure in terms of roads, gas stations, and parking spaces.  
** If every house had a helipad, things might look different.
** Roads are congested (flying cars don't need them), and parking spaces can be reused.
* Balancing multiple turbofans requires powerful onboard computers which are only available ... gee, now.
* you can put a deposit for a SkyCar now, for delivery in 2009.
** Or you could have put a deposit in 2003, for delivery... last year. See the delivery date slide, here: http://web.archive.org/web/*/http://www.moller.com/purchase/purch_info.html
* May be more expensive in total than multi-layered car roads/highways.
* Traffic is often the factor limiting city crowdedness. If congestion is "solved", then cities may become even more crowded.
* See FlyingCar

03-14-2014

The Flying Car is hilariously impractical.

A friend once said, "I admire you because you can go up there and fly those things and not every idiot driving around on the freeway can do something like that." An excellent point.

On the other hand, after an unusual predicament in the air one day, a flight instructor said, "just remember, those same idiots driving down there are flying up here." And thus, it was all put into perspective very quickly. 

A society of flying cars, the ultimate myth.
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'''Cheap Nuclear Power''' - 50's predication: "will be too cheap to meter"

* Disposal is politically difficult (but compare to the environmental impact of burning fossil fuels).
* Expensive, as long as there is direct access to low-cost fossil fuels. (http://www.uic.com.au/nip08.htm) The marginal costs of nuclear power are lower, but the capital costs are much higher. (The marginal costs are higher if you demand extremely high levels of staff redundancy and security, as has been the case for most of nuclear's history.)
* High-profile accidents {3-mile Island, Chernobyl, Japan tsunami} involving actively cooled reactor designs have given it a possibly deserved reputation as unsafe, and thus made it politically unpopular.
''Note: converted to document mode. The subject is "reasons for possible tardiness" - not the actual merits and flaws of the technology.''
* Ummm...but surely actual flaws in a technology would contribute to tardiness! Surely you're not saying that perception is on topic here, but (claims of) actual reality are off-topic? How can a line be drawn there? I'm open to suggestion if you think there's a way.

'''TV Phones''' (actually, some cell-phones are starting to have this)

* Most people don't want to have to dress up to answer the phone
* Not something people actually want on an everyday basis, even if already dressed, let alone pay premium for
** webcams have different usage patterns
* Bandwidth hog
** ''really still?''
* Had to wait for cheap cameras (CCD tech)
* ''The old sci-fi presented it as the ''default'' option when one took a call. If two people at each end want visuals for their smart-phone calls, then they can activate or purchase apps that do that. However, it's not the default way our phones work and there does not seem to be enough demand to better coordinate that feature among vendors such that it's easy to switch on. Whether it will be one day is hard to say because the momentum seems stuck in a lack-luster state. It may take a catchy ad to make people want it enough to trigger vendor results.''

'''Safe, Effective Diet Pills'''

* There are probably several different "safety mechanisms" that have to be attacked at the same time. Evolution has appearently put in too many back-up mechanisms to make sure we store enough to survive dark days of injury, illness, and Katrina. Who knows, maybe only chubbites will survive armegeddon.
* See CreepingObesity.

'''Space Travel for the Masses'''

* Chemical fuel too weighty and too costly
** You'd be surprised how small a factor this is
** ''I dunno, a 15-to-1 fuel-to-payload ratio is quite smelly no matter how you dice it.''
** The cost of the fuel is next to nothing all things considered. It's the complexity that kills it.
** ''Perhaps if "for the masses" meant occasional vacation, I would agree. However, living and working in space would still be limited by the costs of chemical fuel even if the other costs were minimized.''
** Not really. You're using the AmericanCulturalAssumption that people would commute to space, which is absurd. If people only move back and forth every 3 months, paying a few thousand in fuel costs means nothing.
* Still too expensive to make it safe
* Economic "pushes" for space travel, such as asteroid mining, are not at a profitable level yet.
* Political bungling (showy moon shot over drab space station). Arms race.
* Technology is much too complex, hence $$$.

'''Interstellar Space Travel'''

* For a trillion dollars, we may be able to build a multi-generation nuclear-powered ship that would take say 200 years get to the nearest stars. But that is still hardly Star Trek.
** There will be spacefaring cultures that live this way

'''Cure for Cancer'''

* Cancer seems to be just plain entropy and natural selection (of rogue cells). We would have to find a way to reverse entropy.
** The entropy argument makes no sense -- we reduce entropy all the time (within a limited region, by increasing entropy elsewhere).
** ''Yes, but how is this done at the micro-cellular level?''
* Hard to target problem cells since they are almost identical to legitimate cells.
* No single cause
* Still only have some broad ideas what causes cancer, new theories are still being developed in the 00s.

'''Cure for the Common Cold'''

* There is no "common" cold. Colds are really a variety of viruses.
* Viruses are too simple and thus far more difficult to break than bacteria without hurting the host.

'''Artificial Intelligence approaching at least Dog Levels'''

* A much harder problem than originally thought. 
** NeuralNetworking is fundamentally orthongonal to conventional computer architecture, and so is slow to simulate.  
** Hardware implementations are very expensive to build
** Hardware-power NN is only useful in a very limited problem-space, so there is a ChickeAndEgg problem for the technology.
* Computing power missing - A mammalian brain still has more computing power than what is affordable to most AI labs. Based on current growth rates, portable versions of that power point won't be reached until around 2025.
* Don't really need AI if bandwidth is strong because there are plenty of humans, see BrainsAsaCheapCommodity.
** What about dogs?

'''Appliances that Accept Voice Commands'''

* People confuse natural language processing with voice recognition; the former requires AI.
* People don't actually want to communicate to appliances that way.
** You need to use the commands often, dozens of times a day, in order to derive any benefit.
** People may feel silly talking to the drier but if it weren't more fundamental, they'd get over it.
* Computing power needed still too expensive for mass-market appliances
* Legal risks
** What legal risks??
** ''Scenario: You put a paper towel roll on top of the toaster. Some of it slides down partially into the toaster. You get into an argument with your spouse, and shout something like, "Go ahead, make me boast!" The toaster thinks you said "make me toast" and sets the paper towels on fire, burning down the house.''
* Privacy concerns and noise in crowded environments means it can only be used as a supplement
* But, limited forms of this exist now -- some cell phones can dial from voice commands.
* Interface designers are serving as a roadblock.
* It takes 10 years for any innovation to spread, voice recognition has to first get accepted by interface designers and then by consumers, hence 20 years. Yow!
** DragonNaturallySpeaking only came out in 1996 so voice recognition is perfectly on track. ''Please note that Naturally Speaking is a POS that can't capture vocal command input accurately, if at all. Even the phone "receptionist" voice nanny systems have a backup feature for callers to use their touch-tone keys to make selections when the nanny can't figure it out.''

*** ''Siri? seems like this is mostly on track and will happen within the next 5-10 years. Phones may be used as interface''

'''Independence from Oil'''

* Renewable hard to compete with something that has been storing solar energy up for hundreds of millions of years (oil).
* Nuclear power never quite panned out (see above)
* Petrol is actually a fantastic liquid fuel, the best ever conceived

[OffTopic material removed. This page is ''Technology''Disappointments, people, let's keep it on track.]

** ''something that is going to (have to) happen sooner than later''

'''3D User Interface'''

* VirtualReality is unfashionable, the eyestrain causes headaches in some people.
** See VirtualBoy debacle.
* Display Technology is not currently workable.
** Holograms are incredibly expensive and difficult to implement well - must encode massive amounts of information in a single point.
** Most systems require special glasses.
** Start-up ChickenAndEgg problem - little software/movies designed for 3d display to justify expensive applications.
** Very few screens have RefreshRate needed for decent shutter-glasses support.
** Hard to advertise 3d - it looks 2d on TV and in magazines.
* No decent tactile feedback.
** And 2D has any?!?
* Difficult to design spatial-controller - sonic-positioning or magnetic systems are difficult to implement and often have problematic secondary effects. Gyroscopes only record relative actions.
** But see Nintendo's Wii controllers: http://en.wikipedia.org/wiki/Wii_Remote
* No mainstream 3D guis for PC applications that take advantage of depth.
* Rotating or "shifting" around a virtual scene with 2D display provides almost the same depth info to the brain without 3D display hardware. See:
**Jim Gasperini's Stereo Time-for-space Images - http://www.well.com/user/jimg/stereo/stereo_list.html
**Burning Man wiggles - http://www.burningmanopera.org/2002/2002_stereo_wiggle1.html
**Kokogiak's Pathfinder wiggles - http://www.kokogiak.com/mars/mws.asp?n=1
**Brownpau's wiggles - http://what.was.the.question.brownpau.com/wiggle/

'''Cybernetic Implants'''
* Despite neatness, there's no real reason to implant things in the human body recreationally.
** Information can be displayed just as well on a wrist-watch display.
** Robotics are clumsy compared to human limbs.
* Translating information to neurochemical signals is very hard. 
* Equipment maintenance is hard enough without difficult removal and bodily fluids.
* Technology is improving too quickly to bother implanting obsolete tech. ''True, dat!''
* Cyberpunk pop-culture never happened.
** It never was a ''pop'' culture; it was originally portrayed as an elite subculture.
''However''
* But, cochlear implants. And now vision!
* There are many styles of video enhanced eyeglasses on the market. It isn't pop-culture, but it exists.
* Permanently implantable hearts are on the way.
* Lots of people already have implanted defibrillators (such as DickCheney) and pacemakers.
** More than 100,000 pacemakers are implanted worldwide every year. (Google for "pacemakers every year")
** Also, some modern pacemakers support wireless communication for diagnostics. Only a small step to personal internetworking.
* 800 000 artificial knee joints are installed every year http://www.microswiss.ch/tld/2004/papers/Kauert.pdf
* Consider how many people ''do'' implant things into their body recreationally or culturally. Adding piezoelectronics to a piercing shouldn't be too hard.

'''Energy-beam Weapons''' - phaser, lazer, sonic screwdriver, etc.
* That's a "disappointment"? I'm actually kind of relieved that these haven't been developed on-schedule.
*Actually the Active Denial System has been in development for 30 years, and the military announced last year they would begin using it on US citizens. ''[citation needed] :)''
* Also NASA is working on Project Orion, a lower powered "laser broom" designed to sweep space junk out of orbit.
* Is this entry a joke? How about MIRACL (http://en.wikipedia.org/wiki/MIRACL), just one of the directed energy weapons about which one can actually get published data. Google can find you all kinds of real, actual beam weapon projects about which little data is published other than the seriousness with which national defense agencies treat these weapons.

'''Easy-to-Maintain Personal Computers''' - Dealing with them is as much of a headache for consumers as owning an automobile.
* Changes too frequent to commoditize the technology service and QA.
** ''Old page. What is an iPad? I've spent close to zero time maintaining any of my personal (non-server) computers in the past 5 years.''
** This differs from my observation. It's still a heated cat-and-mouse game between hackers and system vendors. The tighter the security, the more intentional applications and add-ons have problems also. Apple is perhaps the closest to the ideal by controlling almost the entire product, but at the cost of freedom and flexibility. I doubt there is a free lunch here, only trade-offs. Consumers often choose dazzle over safety and reliability because that's human nature and partly because they don't know any better.

'''Car Key Alternative''' - I hate looking for lost keys.
* Many cars now have an RFID-based lock (but until they have RFID implants, you could still lose the RFID dongle.)
** worse, you could lose the dongle in the car structure, leaving you unable to lock the car until the dongle battery fails.
* If you're cheap enough, you can get a car that uses a coathanger for the door lock and a screwdriver for the ignition.  But you then you'd probably want one that needs keys.
** ''Old page. Many cars have USB keys now''

'''Non-Lethal Ranged Weaponry''' - Law enforcement and security details would go a lot smoother and be less contentious if there were safe ways to render somebody incapacitated without killing them in the process.
*Difficult to match the range, accuracy, speed, predictability, etc. of a fired bullet.
*Bean bags, tazers, and mace are all employed by law enforcement with limited success.
*Effectiveness versus lethality varies too much for most Less Lethal systems to be truly effective across the board, and the need for effective stopping power reaches the breakover point of applying lethality in cases where it really matters. For those cases where lethality is not justifiable at all there are other means of applying stopping power, such as brute force or club-type weapons.

'''Reliable Tires''' - Tires are still based on air-filled balloon technology, making them problematic.
* ...but do a web search for "Tweel".

'''Reliable Car Battery''' - Car batteries are still a constant headache. The solution seems to either be better problem detection/warning, and/or redundancy of some kind.

'''Cheat Death via ScannedBrainSimulation'''

'''Screen Doors that Open, Close, and Lock Smoothly''' - Why can't they get these right?
*''They are available, but they cost money, and most people opt for cheap.''
* Maybe they can't tell the difference in the store.

'''Dog breeds that use litter boxes instead of your lawn'''

[EditHint: Reorg to put car-related items together]
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repeated interest in JulyZeroFive and JanuaryZeroSix

See: FailedScienceFictionProphecies

CategoryScienceFiction, CategoryFuture