Monthly Archives: March 2010

From Eternity to Book Club: Chapter Twelve

Here is a link to this week’s instalment of the book club for From Eternity to Here by Sean Carroll:

From Eternity to Book Club: Chapter Twelve “Black Holes: The Ends of Time.”

In the blog, Sean Carroll writes black holes are important for two reasons:

… we care about the entropy of the universe and gravity plays a crucial role in how the universe evolves … when the system is a black hole; Bekenstein and Hawking gave us a formula that allows us to calculate the entropy with confidence.

… the answer that Bekenstein and Hawking derive is somewhat surprising, and ultimately game-changing. The entropy is not proportional to the volume inside the black hole (whatever that might have meant, anyway) — it’s proportional to the area of the event horizon. That’s the origin of the holographic principle …

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From Eternity to Book Club: Chapter Eleven

Here is a link to last week’s blog posting of the book club for From Eternity to Here by Sean Carroll:

From Eternity to Book Club: Chapter Eleven

Sean Carroll makes the following couple points in the blog posting:

Some people labor under the impression that the transition from classical mechanics to quantum mechanics ends up “quantizing” everything, and turning continuous parameters into discrete ones, perhaps even including time. It doesn’t work that way; the conventional formalism of quantum mechanics (such as the Schrödinger equation) implies that time should be a continuous parameter. Things could conceivably change when we eventually understand quantum gravity, but they just as conceivably might not.

I personally come down on the side that believes that there’s no fundamental irreversibility, only apparent irreversibility, in quantum mechanics.

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Biology may not be so complex after all, physicist finds

Secondary Source Summary

ScienceDaily (2010-03-19) — Centuries ago, scientists began reducing the physics of the universe into key laws described by a handful of parameters. Such simple descriptions have remained elusive for complex biological systems — until now. A biophysicist has identified parameters for several biochemical networks that distill the entire behavior of these systems into simple equivalent dynamics. The discovery may hold the potential to streamline the development of drugs and diagnostic tools, by simplifying the research models.


References:

Emory University (2010, March 19). Biology may not be so complex after all, physicist finds. ScienceDaily. Retrieved March 19, 2010, from http://www.sciencedaily.com /releases/2010/03/100301102757.htm

Primary Source Abstract

Biochemical processes typically involve huge numbers of individual reversible steps, each with its own dynamical rate constants. For example, kinetic proofreading processes rely upon numerous sequential reactions in order to guarantee the precise construction of specific macromolecules. In this work, we study the transient properties of such systems and fully characterize their first passage (completion) time distributions. In particular, we provide explicit expressions for the mean and the variance of the completion time for a kinetic proofreading process and computational analyses for more complicated biochemical systems. We find that, for a wide range of parameters, as the system size grows, the completion time behavior simplifies: it becomes either deterministic or exponentially distributed, with a very narrow transition between the two regimes. In both regimes, the dynamical complexity of the full system is trivial compared to its apparent structural complexity. Similar simplicity is likely to arise in the dynamics of many complex multistep biochemical processes. In particular, these findings suggest not only that one may not be able to understand individual elementary reactions from macroscopic observations, but also that such an understanding may be unnecessary.


References:

Golan Bel, Brian Munsky, Ilya Nemenman. The simplicity of completion time distributions for common complex biochemical processes. Physical Biology, 2009; 7 (1): 016003 DOI: 10.1088/1478-3975/7/1/016003

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NASA: Grades 5 – 12 Engineering Design Process


References:

NASA – Engineering Design Process. Retrieved March 18, 2010 from http://www.nasa.gov/audience/foreducators/plantgrowth/reference/Eng_Design_5-12.html

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NASA: Elementary School Standard-Based Engineering Design Process


References:

NASA – Elementary School Standard-Based Engineering Design Process. Retrieved March 17, 2010 from http://www.nasa.gov/audience/foreducators/plantgrowth/reference/Eng_Design_K4.html

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Mann (2005, p.124): Structured Problem Solving Steps

Step 1 Identify and define the problem
Step 2 Quarantine the problem and take other immediate remedial actions
Step 3 Involve the appropriate, knowledgeable people
Step 4 Conduct root cause analysis
Step 5 Identify root cause solutions, assess them, and test the preferred alternative
Step 6 Implement the root cause solution
Step 7 Monitor and revise the solution as indicated by performance data

References:

Mann, David William (2005). Creating a lean culture: tools to sustain lean conversions. New York, NY, USA: Productivity Press

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From Eternity to Book Club: Chapter Ten

Here is a link to this week’s blog posting of the book club for From Eternity to Here by Sean Carroll:

From Eternity to Book Club: Chapter Ten

Sean Carroll writes in the blog posting:

One of the fun things about this chapter is the extent to which it is driven by direct quotations from great thinkers — Boltzmann, of course, but also Poincare, Nietzsche, Lucretius, Eddington, Feynman … It’s very educational to learn that ideas like “the multiverse” and “the anthropic principle” aren’t recent inventions of a new generation of postmodern physicists, but in fact have been part of respectable scientific discourse for over a century.

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