QQC: Bryson Chapters 5 & 6

Quote: See left

Question: The question is, what sophisticated dating techniques do we have today (besides the leather jacket and sports car) that allow us to more accurately measure the dates beyond 200 million years? How much more of an idea do we have today of these ages when all of our modern conclusions are based on observational data (and, by the way, how do you observe 65 million years?)?

Comment: This is an interesting quote, considering that, for the most part, our dating techniques are based largely on radiometric dating, which is limited by our assumptions about the previous nature of the earth, and how it was formed. We assume certain factors and constants, based on what little observational data we have of 4.5 billion years ago. While after assuming the constants, the rest is pure and very certain math, there are assumptions made about the current status of the Earth, and whether of not it was necessary for these elements to be present at or during the construction phase of the solar system. To be more precise, we are assuming, based on our observational data, that not only does it take 4.5 billion years for U-238 (uranium) to decay into Pb-206 (lead), but that, based on what else we find in our samples (alpha particles, etc.), there had to be a specific amount of uranium present in the earth at formation time for the information to be correct. Most rocks on earth started out with (relatively) lots of uranium, and now rocks that have lead and helium and a little itty bit of uranium left in them must have had a certain amount of only uranium at the beginning of their decay cycle, which would have began with the formation of the solar system and earth. But what stops the uranium from beginning its decay before the formation of the solar system, since the solar system did not create the uranium? (Usually Stars, not planetary nebulae accretion disks, create new molecules via gravity and radiation) And who's to say that the lead and helium weren't already in the rock when the earth was formed, or that the rock didn't coalesce and include little bits of hydrogen and helium in its formation, considering that there was enough helium and hydrogen around to make a star that could burn for over 10 billion+ years (almost the accepted age of the universe, which is 13.7 bil.)? We might want to consider just what exactly the accurate as described in reference to these dating methods is based upon (and remember, the math itself is good).

QQC: Bryson; The Measure of Things

My QQCs seem to keep getting shorter and shorter...

Quote: See Right (for once)

Question: It is incredible to think of the discoveries that Cavendish made without feeling the need to tell anyone about them. I wonder if he made any other discoveries that no one still knows about... Also, how much are things on Earth affected by the Sun's gravity, considering that it holds everything in place up to over one light-year (5.87 trillion miles) away? Doesn't it have a slight affect on us on earth, or does the distance factor so exceed it's gravity that Earth is infinitely more attractive

Comment: I think that it's amazing that he made discoveries that, for the rest of the world, weren't made until the 19th century. I thought that it was interesting to note that when he measured the gravitational constant, that his value of 6 sextillion tonnes (that's a six followed by 21 zeros) for the weight (mass) of the earth has not really been improved upon, it was so accurate. That Mitchell, though, could have even thought of anything such as a machine to measure the gravitational constant is absolutely incredible, considering the actual values that he was considering measuring (the constant is something like 6x10^-6 or so, incredibly small).