Weekly Head Voices #98: Lemons.

This, the ninety eighth edition of the WHV, looks back at the week of Monday August 10 to Sunday August 16, 2015.

Today we took a brief walk up into the mountain, as one does around these parts. This is what False Bay looks like from the Helderberg Nature Reserve:


When life hands you lemons, build a battery

Genetic Offspring Unit (GOU) #1 had to do a show and tell at school, so I helped her to construct a battery from 4 lemons. Besides that because of this I got to refresh my own knowledge (can you remember exactly why a battery such as this works?!) we got to chat about molecules, atoms, protons, neutrons, electrons, atomic numbers and the periodic table.

The next day she quite coolly took the whole kit to school, proceeded to connect up the disassembled kit before the class, and got the little LED to switch on, all the while explaining in high-level 9-year-old-ish how it worked.

In case you’re wondering, the experiment looked like this:


With zinc-covered screws and heavy duty stripped copper wire, we got about 0.9V per lemon. There was enough current to light up a small 3V LED.

(Will GOU#1 one day become an engineer? Stay tuned to this blog for the next 10 years to find out!)

Taking a break from Facebook

One of my more interesting Facebook friends announced that she was taking a break from Facebook, because “this stuff is toxic and no good”.

This made me evaluate what I thought of FB at the moment.

Toxic is a strong word, but after thinking about this for a while, I have to admit that a large part of the time I spend on the site is probably not that good for my karma. The problem is that there are a whole bunch of friends I really would like to stay in contact with, but for the most part they are quite silent. The people that do pipe up the most on FB are people with some or other silly and/or misguided agenda.

Although I have learnt to stop correcting the infinite number of people who are wrong on the internet, I’m still reading their contributions, getting slightly worked up, formulating a response, and then resisting posting it, all of this a number of times per day.

To the question whether seeing the one or two positive and life-affirming posts is justified by a seemingly much larger number of the opposite, my response has also become to take a break from Facebook and to see for myself.

I’m not going to cancel my account, so I will receive notifications for example when people message me, but I’m just going to stop checking the site completely. I am also giving myself permission to post new WHV editions there now and then: It’s sometimes the best way to reach some of those silent but desirable FB friends I mentioned, because not all of them are subscribed to this blog. THAT’S A SUBTLE HINT SILENT BUT DESIRABLE FRIENDS.

(BTW, I’m almost 3 days in now, so far no problems. I’ll report back in future WHVs.)

The mind is a terrible thing to taste

This week I learned about fascinating sleeping brain research (that summary is from the NIH, also see this one by Science Magazine) that was published in 2013.

In short, when mice sleep, the area between their brain cells is temporarily increased by 60% (!!), and the cerebro-spinal fluid between the cells flows much more rapidly than when they’re awake. This rapid flow literally flushes out of the brain the toxins that build up during the waking hours. HOW COOL IS THAT?!

Toxins flushed out via bright blue channels between brain cells. Image from Science Mag summary linked above.

Going down one detail level, the researchers showed that the glial cells (the non-neuronal cells in the brain) control the flow of cerebro-spinal fluid through channels in their cell membranes. By using different coloured dyes, they showed that there was significantly more flow during sleeping than when awake, clearing out toxins twice as quickly.

This research took place in mice, but the researchers hypothesise that this same mechanism operates in humans, and are working on verifying that this is the case.

Original article full text: Sleep Drives Metabolite Clearance from the Adult Brain, Xie et al., 2013, Science.

This is the end my friends

Have a great week kids, and do remember to get your sleep!

5 thoughts on “Weekly Head Voices #98: Lemons.”

  1. I deleted my Facebook account more than a year ago. Haven’t look back since. Don’t miss it. Good riddance. ;)

    1. BUT BUT BUT…

      What about your friends and family dotted all over the globe? How do you tap into the passive communication back-channel, or do just not do that?

  2. Yo Charl,

    Fabulous post! My daughter (8) is very interested in science experiments and I’m always on the lookout for stuff like the lemon experiment. Thanks a million for the reminder.

    Regarding FB, I came to the same conclusion, but my solution was to turn off all notifications from those life draining sources, and instead subscribing to various sites like Extreme Tech and Tom’s Hardware, BBC, National Geographic, or whatever floats my boat, cat videos not excluded… Essentially this turned boast-book, stalk-book, and look-what-I-ate-book into my news feed plus the occasional post from those people I am interested in hearing from. One platform to rule them all…

    Oh and I created a twitter account years ago but still don’t know what it’s for except to snap up the username @27182818.


    1. Good tip! When (if?) my FB break ends, I will put more effort into curating my stream. For now, I’m enjoying the extra bit of time.

      BTW, this is also what you should do with your twitter: Subscribe to the right set of people and craft your input stream. RT interesting stuff now and then. Currently, twitter and my RSS blog aggregator (inoreader tracking 42 blogs, websites and whatnot) are what I use to keep up to date.

      1. Great post! Love the lemon-experiments. Something much nicer than a lemonparty ;)

        My ‘fix’ for Facebook includes hiding about 80% of my friend’s posts. I guess I could unfriend them, but that is so aggressive ^^.

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