RE: boiling points versus altitude (air pressure actually, which is a function of altitude - but we can vary air pressure in a sealed container, regardless of altitude ):
I've experienced otherwise. Couldn't get those beans done in time in Denver!
Anybody who does serious baking has probably run across recipes where times were adjusted for altitude.
I wonder how many recognized that the boiling point changes, but got the direction wrong?
A more casual observer might recall the cooking directions, but unless they live at high altitude, might not recall if it was a longer or shorter cooking time (why bother noting this if it doesn't apply to you?). Further, even if I recall that cooking times are longer, I might use a somewhat reasonable line of thought that says
"Hmmm, it takes longer to cook, so maybe that means the boiling point is higher, so it takes longer to come to a boil, and therefore longer to cook?" That's wrong, it's the lower boiling point temperature that results in longer cooking, but the thought process has some merit.
Now I have enough science background, and general curiosity, and some 1st hand experience with all this to know the correct answer, but I still hesitated a bit, and thought it through so I didn't give a "DOH!" wrong answer when I knew what was right.
A couple real-life examples:
Pressure cookers - high pressure raises the boiling point, increasing the cooking temperature, lowering cooking time.
Car radiators - they are sealed, and allow higher temperatures w/o boiling over.
But unless you are the type to notice and think about these things, it might escape you, and just seem like some useless trivia you were taught in high school.
I may try this later today - looks like fun!
And this thread also led to some other reading, and I learned that freeze dried food works by freezing the food, then subjecting it to a vacuum which causes the ice to sublimate (turn directly to a gas w/o turning into water first - like 'dry ice'). This leaves the structure of the food mostly intact, and it re-absorbs water readily into all these little pockets left behind.
Not arresting them when they bring their inventions to school would be a good start.
I hate to 'try people in the media', but I'll go as far as to say a kid needs to think before bringing a case filled with a digital clock and wires into a school. Did you see that thing? It looks a lot like the Hollywood/TV depiction of a bomb a terrorist would use.
On the surface, it appears they over-reacted with the arrest and so forth (but we don't know everything behind this), but clearly they had to take the situation very seriously. Can you imagine if they shrugged it off and it did turn out to be a bomb?
Schools are on high alert about these kinds of things. Right or wrong, I don't find it surprising that there was a strong reaction to this little project.
Damned if you do, damned if you don't.
100% correct. I too didn't like the astrology answer since the correct answer on a science test shouldn't be psuedo-science.
But isolating pseudo-science from real science is a reasonable way to access someone's understanding of science, no? In-line with some of the other less-than-perfectly-worded questions, would any other answer fit? You know those have nothing to do with people's behavior.
-ERD50
I've forgotten my gas pressure laws so I already knew I was going to get the boiling point question wrong. Instead of getting lucky on a guess, I deliberately chose the wrong answer on that one.
I am so mad about the clock fiasco.
