Radiation dose comparison charts from XKCD

March 20, 2011

No, there’s no humor in this thing — just good, solid information.

XKCD put together a chart that shows in geometric terms how various radiation doses work. With a tip of the pen to Bob Parks, the chart notes that cell phones don’t count here because cell phones don’t put out ionizing radiation, the type that causes cancer, but just radio waves.

The chart won’t be easy to read here — click on the image and go to the XKCD site for a bigger, more readable image:

Radiation Dose Chart from XKCD

Radiation Dose Chart from XKCD

It’s a good, clear graphic in its full size.  Go see.


Quote of the Moment: Alan Kors, human history in 60 seconds

December 7, 2007

Someone should have said “every really good idea can be summarized in 30 seconds.” To whom shall we attribute that: Lincoln? Einstein? Twain? Jefferson? Jesus? Round up the usual suspects, indeed.

The School of Arts and Sciences at the University of Pennsylvania sponsors a series of lectures — some topic distilled down to 60 seconds.

These are geographies of human thought. A map of what to think, sans details. Here, we get the history of humans in 60 seconds (plus a few), from April 19, 2006:

Prof. Alan C. Kors, University of Pennsylvania

Human History

Alan Charles Kors

George H. Walker Endowed Term Professor of History

  • First, tribes: tough life.
  • The defaults beyond the intimate tribe were violence, aversion to difference, and slavery. Superstition: everywhere.
  • Culture overcomes them partially.
  • Rainfall agriculture, which allows loners.
  • Irrigation agriculture, which favors community.
  • Division of labor plus exchange in trade bring mutual cooperation, even outside the tribe.
  • The impulse is always there, though: “Kill or enslave the outsider.”
  • Gradual science from Athens’ compact with reason.
  • Division of labor, trade, the mastery of knowledge, plus time brought surplus, sometimes a peaceful extended order and, rules diversely evolved and, the cooperation of strangers – always warring against the fierce defaults of tribalism, violence, and ignorance.
  • No one who teaches you knows what will happen.

You can find video here : Kors, Human History, high bandwith; low bandwidth.

A couple dozen such lectures, from 2006 and 2007, here.

Tip of the old scrub brush to Dr. P. M. Bumsted.


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