Because "we don't understand gravity yet" contains no data and makes no predictions (ie, it may well be true but it is unscientific). I think of dark matter as a list detailing exactly where and how much we don't understand gravity or cosmological particle physics. When someone wants to test a new theory of gravity, they will know where to check for discrepancies with GR by looking at where dark matter is; alternately, when someone wants to test a new theory for cosmological particle physics, they can test whether it produces dark matter in the appropriate places.

Even if the system requires babysitting, it will probably improve the performance of impaired drivers. Think sleepy, drunk, or old people with poor attention, perception, and/or reaction time, narcoleptics, diabetics who got careless about blood sugar, "indestructible" teenage drivers, Mr I-Can't-Leave-My-Cellphone-For-Five-Minutes, parents with cranky kids, Mrs I-Can-Eat-Drink-And-Put-On-Makeup-Whlie-Driving, Mr I-Talk-With-My-Hands-And-Always-Make-Eye-Contact, folks who like to gawk at accidents/scenery/girls, folks having a sneezing fit/heart attack/seizure, and a few others.

The human at the wheel is there to take the blame in case something goes wrong. The requirement of having a human at the wheel will also soothe the fears of passengers of both autonomous* and manually driven automobiles, a measure that should help the adaptation of autonomous vehicles and thus save lives.

* Google, putting the "auto" into "automobile" since 2005.

All malware is data until you tell your computer to run it. If you get hacked by careless people, then I suppose having malware that reports them might work, but they'd have to run it or open it with a compromised program, and on a computer connected to the internet.

I guess someone didn't know the difference between POS software and POS software.

Doing that would eliminate almost all support for passing a bill to prevent domestic spying. What happens after he leaves office?

Yes, I'm sure that what you measured was productivity.

Maybe an even better measure of productivity would be a measure of how much energy your GPU uses?

Actually, that reminds me... earlier today I read that you can make some interesting stuff by microwaving some graphite. Apparently it's "just like popcorn".

As opposed to just randomly matching people so as to not have to learn things about people in general nor their users in particular?

edit: 1) Users of OKCupid trust OKCupid's rating system enough to try harder when it suggests a good match

No, it means that:
1) People trust OKCupid's rating system enough to try harder when it suggests a good match
2) OKCupid has to take into account their stated match rating, not just length of conversation, when trying to use conversation length as data to improve their algorithm.

Except for when it comes to actually building stuff with it.

The potential is there, obviously... but compare to how long it took to roll some up into simple tubes in an economically acceptable manner (ie, nanotubes are only just getting some actual use). I'm sure graphene as a computer component will be totally awesome -- but not until someone finds an *easy* way to build it, at most only 100X the cost of the equivalent in silicon.

I don't really think it's the government's business to tell merchants what they must accept in exchange for their goods. For example, they shouldn't be forced to accept the $10,000 US dollar bill, even if it is legal tender, nor whatever flavor of credit card. I'm sure the merchants can figure out for themselves what to accept in payment if they want to have customers.

They may think so, but it is people who decide what is money and what is not. People have burnt money as fuel in the past, when it was cheaper than coal or wood.

Well, because now we can cure even the most obscure diseases that afflict mice.

The NSA owns your computer, and the computer you want to trade bitcoins with*. They could enforce any regulations if they were willing to admit to this. Being a cryptocurrency rather than a physical one also means that they can vanish your money with the click of a button instead of having to personally visit you.

* Maybe I'm just paranoid, but there are so many hardware and software components, any of which could have backdoors or keyloggers installed. They could demand any domestic product secretly contain them from manufacture, and "inspect" any imports. Even easier with domestic software, or they could get a few of their agents helping to develop the software (I hear they have lots of talented folks).