Adventures in Ethics and Science

Since folks in the U.S. have a long weekend, and because the last entry was younger-offspring-centric, you get a bonus Sprog Blog.

Elder offspring: (following up a request at breakfast for a slice of bagel with avocado spread on it) It’s not brown avocado, is it?

Dr. Free-Ride: No, it’s just ripe and freshly spooned out of its skin. So it will be nice and green.

Elder offspring: Good.

Dr. Free-Ride: Hey, do you know why avocado turns brownish if it’s out of the skin awhile?

Elder offspring: No.

Dr. Free-Ride: “Oxidation”. It reacts with the oxygen in the air, and the reaction converts the green stuff to brownish stuff.

Elder offspring: Weird.

Dr. Free-Ride: Can you think of anything else where reacting with oxygen in the air might change the color of something?

Elder offspring: If I hold my breath, I’ll turn blue.

Dr. Free-Ride: Hmm. That’s a change in color that has to do with a lack of oxygen. What about blood?

Elder offspring: It’s red.

Dr. Free-Ride: But did you know that it’s red because there’s oxygen bound to its hemoglobin? When the oxygen it’s carrying is used up, it isn’t red until it picks up more oxygen.

Elder offspring: No way!

Dr. Free-Ride: It’s true. Have a look at your arms for a minute. See those veins by your wrists?

Elder offspring: They look blue.

Dr. Free-Ride: That’s blood that’s delivered its oxygen and needs to get more.

Elder offspring: Cool.

Elder offspring’s blood-related artwork after the jump.


Please notice that this artwork was presented to me on Mother’s Day. When my children say I have their hearts, they’re kind of literal minded. Happily, Elder offspring was willing to let me wait to post this on a Friday rather than stealing Super Sally’s thunder.

Other blood-related discussions:

*Friday Sprog Blogging: bloody minded.
*Friday Sprog Blogging: how the dinosaurs really went extinct.


  1. #1 Larry Ayers
    May 27, 2007

    Janet, I am very fond of your sprog posts. Wait a few years until your sprogs become uncommunicative adolescents, then perhaps you might consider compiling the sprog-posts into a book. My kids are grown, but your posts remind me of many conversations with them when they were young!

  2. #2 Dave
    May 29, 2007

    Janet, I look forward to your sprog posts every week. I only hope that my kids (when I have them) are as cool as yours.

    But a nitpick! Venous blood isn’t blue. Perhaps an opportunity for another science lesson?

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