I agree that there are much bigger risks in this mission than radiation, but, from what I remember from working in the nuclear industry:
- the annual limit of how much a nuclear plant is allowed to add to the exposure of a member of the general public is 100 mREM (1 mSv)
- the annual occupational dose limit for an Atomic Radiation Worker is 5 REM (50 mSv)
- acute effects start showing up at 50 REM (500 mSv) exposure "over a short period of time"
- the LD50/30 (the dose at which 50% of those exposed will die within 30 days, even with treatment) is 500 REM (5 Sv)

On that sort of scale, 100 REM *IS* a big deal.

Now, the fact that the exposure takes place over months may make all the difference, but it's still a large dose, isn't it?

Okay, could somebody check my math here?

From the NRC's web site, The LD50 is "The dose of radiation expected to cause death to 50 percent of an exposed population within 30 days (LD 50/30). Typically, the LD 50/30 is in the range from 400 to 450 rem (4 to 5 sieverts) received over a very short period." If I understand correctly, this shouldn't depend on TYPE of radiation, because the Sv or REM is a measure of BIOLOGICAL effect, i.e. it has built-in correction factors for how much biological effect a given amount of absorbed energy has.

So, somebody absorbing 662 millisieverts "over a very short period" would be worried about eventual cancer risk, but would also be dealing with acute radiation sickness, which would start to be a problem at any dose over about 500 millisieverts (50 REM).

So, my reaction was actually the opposite of cjameshuff's. Rather than dismissing this dose as not causing any effects, I was wondering why they are only concerned about long-term effects and not acute effects.

Or is it that spreading the dose over a period of months gives the body enough time to recover, so that there is no immediate radiation illness?

Citation needed.

Any ocean sailor knows that the world is round. If it were flat, a ship going off into the distance would just get smaller and smaller, rather than the hull disappearing first and the tops of the masts disappearing last.

It is a myth that people of Columbus's time thought he would fall off the edge of the earth. Rather, the opposition was due to people saying "the distance is much farther than you think, and your crew will starve to death before you reach the Far East". In fact, they were right, and Columbus was just lucky that there was an unexpected continent in the way.

Although most of you guys were still in diapers back when it was worth participating in. :-)

Now get off my lawn!

I haven't read any explanation of why they think this is happening, but is it actually true that "the sun is the suspected source of this cause"? I would have thought that it was some change in the environment (the local properties of space) that would cause both the change in decay rate and the solar flares.

Who is going to staff this "home"? Other 80 and 90 year olds? Or other people's kids and grandkids?

The grandparent post overstated the case, because of course there's no need for everyone to have their own kids to look after them when they're old. But we still need young people to follow us. So it's perfectly fine for lots of people to choose to be "evolutionary dead ends", as long as not everyon makes that choice. :-)

That's assuming that we know how the story will end. It won't necessarily end that way.

I agree.

I think I'm missing something here in this discussion. Signing a petition is a way of saying that *I* support this, it's a way of taking a public stand on the issue. That's why you sign your *name*, instead of ticking a box anonymously. That's also why petitions are, at least in theory, taken seriously -- it's not an anonymous mob who support the petition, it's a bunch of specific people who are willing to put their names on record.

Sometimes I think that if they did nothing, that might be a GOOD thing :-)

Just as a by-the-way, "apologist" does not mean what you seem to think it does.

Okay, I can understand measuring amount of data by comparing it to the data in a book or a DVD, but Lines Of Code?

The 1500's were the 16th century, not the 14th century.

Umm, the person I was replying to was saying that copyright should automatically expire as soon as the author dies, because then he or she doesn't need the money any more.

That's not a very good analogy.

Plumbers get paid for fixing the toilets at the time they fix them. And if the plumber dies before you pay your bill, you don't automatically get to forget the charges. Should the plumber have to buy insurance to cover that case? You might have life insurance to cover the fact that you won't be earning any more after you're dead, but do you buy insurance to cover your last paycheck because your employer won't have to pay it after you're dead?

So, yes, it is the "same difference".

Maybe a lot of slashdotters aren't old enough to have kids, but it seems to me that providing for one's widow and/or children is one of the things that an author would likely be concerned about, and probably even consider to be a "need".

Nobody is talking about locking up works "forever". This is about books that were written and published long after Mickey Mouse made his first appearance, and Mickey is still copyrighted (which seems to be stretching it a bit TOO far in my opinion).