Did anyone else think this was going to be about the Higgs boson?
Where does a tree get its mass?
11–20 of 61 posts
Re: Where does a tree get its mass?
#12Feynman knows:
Re: Where does a tree get its mass?
#13Excellent. After the first line I deliberately closed my eyes and tried to re-reason it (and got it right, thankfully). It was quite refreshing to have a blog post make you actually stop and really think for a second. The point was good as well. ;)
It's the whole blog, not just the post :) Really worth bookmarking.
Re: Where does a tree get its mass?
#14An interesting topic, but I couldn't get more than a few paragraphs in. It's really poorly written.
EDIT "couldn't" (I suppose if I'm going to gripe about grammar, I should at least proof read...)
Re: Where does a tree get its mass?
#15The concept of uncertainty is hard to grasp. In my high school (1979) we were required to use slide rules for the first year of science class, despite the availability of inexpensive calculators. The reason was to impress upon us the importance of significant figures, and also to develop our intuition for orders of magnitude. Unless your slide rule is really expensive, you just can't get more than 3 significant figures from it, which is a good match to the accuracy of just about every measurement in high school. It also tells you the figures without the magnitude--you have to determine in your head whether you just calculated microns or kilometers.
Re: Where does a tree get its mass?
#16The analogy at the end (section IV) made the whole article easier to "get". ...an answer cannot be more precise than its data. Or its question.
Except the example he gave was also wrong. 3 + 4.2 is 7.2, using exact arithmetic, which should be the default assumption.
If you're measuring values under uncertainty, then his explanation makes some sense. But that's a property of measurement and uncertainty, not of numbers or arithmetic.
Re: Where does a tree get its mass?
#17Feynman knows: http://www.youtube.com/watch?v=N1pIYI5JQLE
Can't upvote you enough for this. By the way, Feynman also knows the difference "between knowing the name of something and knowing something": http://www.youtube.com/watch?v=05WS0WN7zMQ
Re: Where does a tree get its mass?
#18As far as I know, most of the CO2 in plants goes to respiration for energy production. Not saying it doesn't go to mass, as well, but it's the energy side of things that people learn in elementary school.
We're not stupid, and this man needs to think about his accusations before he blogs about them...
Re: Where does a tree get its mass?
#19As far as I know, most of the CO2 in plants goes to respiration for energy production. Not saying it doesn't go to mass, as well, but it's the energy side of things that people learn in elementary school. We're not stupid, and this man needs to think about his accusations before he blogs about them...
In defence I don't read his points as being "you're stupid" but more about the fact that we don't think about what we are talking about.
The Ask question... wrong! thing strikes me as simply a device to make this point.
Re: Where does a tree get its mass?
#20Earlier quoted context omitted.
Yes, and the question was where does the tree get it's mass from. I suppose you could look at it in the twisted sense of 'what in the tree contributes so much to it's mass', but that's a rather tortured use of English.
If the meant "50% of the mass of some trees is from water" that then he should have said so. Some trees are more than 50% water by mass is a true statement, but it means something else. The author saying something related to the truth, but I think he has a poor understanding of what is going on. Reading that I felt like a teacher who wants to give some created for a student using the correct words while realizing the…
> As to precision it's more accurate to say 3 +/- 0.5 times 101 +/- 0.5 = 256.25 to 355.25 or 305.75 +/- 49.5 than to just say 300.
Ah, problem is you've changed the question now. Which is a reasonable thing to do when face with 3 + 101.5 = ?, but not the point the author was making (or, actually, it is the exact point the author is making) :)