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Comment Re:Do away with them (Score 1) 78

Not sure what you actually mean when you say that SQL NULL means unknown but not absent? Is there a meaningful distinction you are making here?

It makes a difference when you start applying operations.

For example, if you compare a NULL to any value (even another NULL), the result is also NULL, rather than TRUE or FALSE. This doesn't make sense for absent values - two absent values should compare equal (and, indeed, two nulls in JS do). On the other hand, it makes perfect sense if NULL means unknown - if my last name is unknown, and your lastname is unknown, comparing them for equality can only produce "unknown" as a result, since it's not known whether they're the same or different.

Same thing with arithmetic operations. 1 + NULL equals NULL in SQL, again, because NULL is really "unknown", and so when you add an unknown value to 1, the result is also unknown. If NULL were an absent value, the expression should either produce an error, or give 1.

The most telling part, though, is the SQL truth table for Boolean operators that includes NULLs. Specifically:

TRUE AND NULL = NULL
FALSE AND NULL = FALSE
TRUE OR NULL = TRUE
FALSE OR NULL = NULL

Again, this makes perfect sense if and only if NULL means unknown. AND is always false if one of the operands is guaranteed to be false, so FALSE AND NULL is always false, regardless of what the actual unknown value is. On the other hand, FALSE AND NULL is NULL, because the result could be either false or true depending on the unknown value. With OR, it's the reverse - TRUE OR NULL is TRUE, because OR is always true if one of the operands is definitely true, regardless of what the other operand is. FALSE OR NULL is NULL because the result depends on the unknown value.

Philosophically, the difference also exists. Absent value means "I know what the value is, and there isn't one". For example, for a guy from Iceland, you know his last name - he doesn't have one. Unknown value means "I don't know what the value is, and there could be one". For example, you don't know if I'm from Iceland or not, so I may or may not have a last name, and you don't know which one if I do. These are two distinct states, and ought to be reflected as such in the database.

Comment Re:Anti-Hillary is not Pro-Trump (Score 1) 798

Part of that whole "land of the free" thing has been that you could live as a cash-only squatter and mind your own business without having the government sticking their nose into yours. Maybe not the most convenient way to live, but an option.

And, as a matter of fact, you can rent an apartment without an ID - provided that you find someone who agrees to rent one out to you on those terms. You probably won't find such a thing in an urban area, but out in the country, it's not all that hard. Either way, again, there's a big difference between having the government demand your ID, and having another party to a deal you're trying to make do the same. You can walk away from the deal and try to find a different one.

Comment Re:Anti-Hillary is not Pro-Trump (Score 1) 798

Popular myth and Hollywood. And yes, the social contract HAS generally demanded that you produce papers. You want a job? Papers please. You want a loan? Papers please. You want government benefits? Papers please!

The difference in all the cases that you describe, is that you have to actively do something to get into that situation. And you always have an option to turn around and walk away if you don't feel like it. Not at all the same as walking down the street minding your own business, and having a cop or a ICE agent harass you for papers.

Not that we already don't have that - those bullshit roaming immigration checkpoints within 100 miles of the border (which is where millions of American citizens live). But at least you can tell them to fuck off these days, and because they know they don't have the authority to actually detain you without a reasonable suspicion, and looking Hispanic does not constitute reasonable suspicion, they'll back off if you're persistent enough.

And the supporting documentation required to get one does require establishing said identity - or did until some of these states changed the laws so that illegal immigrants could get a driver's license (and those driver's licenses are different from 'normal' driver's licenses.)

Illegal immigrants don't necessarily lack the ability to establish their identity - they will usually have the passport of their originating country, for example. And getting a driver's license does not require a US-issued ID (given that it is the one and only ID that they have for most people, that wouldn't exactly work). So for a non-citizen, when you come to get a license, what you usually need is 1) a valid ID, possibly foreign (they usually ask for 2 different kinds for foreign ones), and some proof of residency - like, say, a utility bill with your name and a local address.

The same way we've already been doing it: you want a job? Papers please. You want a loan? Papers please. You want government benefits? Papers please! The problem is right now we're not enforcing it hard enough - _punish_ companies/people using illegal labor and they'll stop doing it once it's no longer cost-effective.

All of this is already the case. I don't know if you've heard, by the way, but deportations are at an all-time high under Obama.

Comment Re:Am I reading this right? (Score 1) 70

The weird thing, if it is the COPVs, is... there was so much attention focused on them after CRS-7. It'd be weird if this was the cause. And extremely frustrating, too, as they're not manufactured in-house. SpaceX surely tests the tanks, so they too would bear some responsibility for it getting past their test procedures, if this is the cause. Personally (as I mentioned elsewhere in the comments), having a composite vessel sitting in liquid oxygen always strikes me as a dangerous situation to begin with.... if we were good at maintaining LOX-composite compatibility, we'd be making the stages themselves out of composites rather than aluminum.

Of course, the COPVs aren't the only part of the "helium pressurization system". Still concerning that whatever it was slipped past them.

Comment Re:Huh. (Score 3, Interesting) 70

The helium isn't used for cooling; it's a pressurant. It's lower mass to make a small COPV and have that store your pressurant in it than to have the whole LOX tank be strong enough to withstand the pressure.

It's always bothered me, the concept of having a COPV sitting around in LOX, though. Ignoring the thermal cycling, LOX and epoxy aren't exactly fast friends. We don't make LOX tanks out of composites because composites tend to become impact sensitive in LOX (there've been some attempts, but it's still an active reseach field, not a "solved problem"). Not sure there's that much difference between making your whole tank out of composites vs. having a composite tank inside of one. I don't know what SpaceX does, if anything, to try to protect them, but the general concept has always concerned me.

Comment Re:Anti-Hillary is not Pro-Trump (Score 1) 798

It's amusing how "papers, please!" was one of the most chilling American stereotypes of the Soviet "evil empire", encapsulating everything that's wrong with it in a few words... and less than three decades later, so many Americans not only see why it's problematic, they actually think it's a solution to some of their problems.

Comment Re:Anti-Hillary is not Pro-Trump (Score 1) 798

If you're driving, the driver license (and only the driver license - not any other form of ID) is a prerequisite to demonstrate that you have the right to drive.

But you don't have to drive to get around. You can walk, bike, get a bus etc. And none of those require a driver license, or any other form of ID. If you get pulled over on a bike, the officer doesn't have any right to ask you for ID, and you have no obligation to show them one.

Comment Re:Anti-Hillary is not Pro-Trump (Score 1) 798

Historically, in this country, the social contract has not amounted to "papers, please!". That was supposed to be the kind of thing reserved for commies and fascists, not for the land of the free and the home of the brave. This is also the reason why many people don't actually have a birth certificate etc on hand - because they don't need it, and because the law doesn't require them to.

Also, driver's license does not actually signify either citizenship or legal status. The amount of supporting documentation that is required to issue one varies from state to state, and not all of them ask for an SSN. Of course, even if it did, not everyone has a driver's license - as the name makes evident, it's a document that is issued for a specific reason, and not all people even need it.

In any case, the main question was not about identification, but how exactly you imagine checking for it. So, again: are you proposing to stop random people on the street, going on about their business and not engaging in any criminal activity, and demand to see their papers? If yes, are you going to do this for everyone, or just for those who look Hispanic?

Comment Re:Anti-Hillary is not Pro-Trump (Score 1) 798

It's not a dodge at all. I'm merely pointing out that Trump's proposals require massive civil rights violations of all ethnic minorities who are collectively suspected of being illegals, in order to determine who of them is actually here illegally. There's no way to decouple these.

Comment Re:Bottom line... (Score 2) 178

In order for encrypted data to be used the decryption key must be somewhere, failure to protect the keys can occur just as easily as any other form of security failure.
Also as users we have no idea how companies are storing our data anyway, so the only option available is for us to not hand it over in the first place.

Comment Re:Smarter Aliens (Score 1) 275

To put it another way: the total mass of the universe is about 180000000000000000000000000000000000000000000000000000 kilograms, which is the mass equivalent of 16200000000000000000000000000000000000000000000000000000000000000000000 joules. There is no shortage of "resources" in the universe. Even the rarest of "resources" is available in unthinkable abundance to any entity that has a range broader than a single planet. Not like it's particularly easy to actually exhaust resources on a given planet; you just move from the easiest ones to the much more abundant, but harder to access ones (while simultaneously your technology advances with time, making resources in general more accessible; prices are based on the competition between these two factors, but in the long term generally follow a downward trend)

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