23 January 2014 by Alex Brown, posted in overseas science, speaking science

(I don't usually feel the need to do this, but just in case: this post discusses (the etymology of the word) cancer and contains a moderately graphic image of a tumour, so if that's the kind of thing that might upset you, it may be best to switch to reading in HTML only or something else altogether.)

Astrology page on Wikipedia

Wikipedia helps avoid confusion.

It's written in the stars

Astrology is a pretty weird set of ideas. The theory goes that the positions of far-off celestial bodies have significant influence on the day-to-day lives and personalities of we humans. I don't mean it's weird like quantum physics or reproductive biology are weird. To the extent that astrologers can ever be pinned down into making specific, measurable predictions (as opposed to Barnum statements in newspaper horoscopes), they always fail. So I mean "weird" in the sense that despite it not being supported by any evidence, lots of people seem to believe in it. It's weird like homeopathy, psychics and crystal healing are weird.

The Zodiac

The Zodiac

But that doesn't mean there is nothing to be learnt from astrology. Indeed, it was only relatively recently (ok, about 2 years ago) that I found out that the constellations in the Zodiac are not random, but are in fact aligned along the path that the Sun follows across the sky over the course of the year. The constellation Virgo really is between Leo and Libra, and so on. Admittedly, choosing which stars to include in constellations themselves is pretty ridiculous. But then again, so is seeing a face among two dots and a line, so I'm happy to let this one slide, if it means people are looking into space more than they might otherwise do : )

Wait, what?

A game I like to play when people I don't know spontaneously ask me "what's your sign?" (especially when it precedes "what's your name?") consists of pretending I have no idea what they are talking about. Now, it's important to be gentle when doing this. After all, deception is generally to be frowned upon, and it's not nice to "punch down" by mocking someone who believes in something silly because they aren't as clever as you. I'm looking at you, dihydrogen monoxide. For all you know, they're just one of that day's 10 000.

Credit: xkcd

Constellation Cancer

The constellation cancer. Definitely looks like a crab. Well played, Ancients. Credit: Wikipedia user Bedwyr. License: CC-BY-SA

Constellation Cancer with crab illustration

Astrologers are nothing if not creative.

I find that asking Socratic questions like "what do you mean, 'sign'?" and "does that mean there are only 12 kinds of people?" can help people challenge their own beliefs for themselves.

Also, it just so happens that my sign is Cancer. When the conversation gets this far, it can be quite fun to act surprised (again, sensitively). "You mean I'm a cancer?! That's not very nice..."

"No, the constellation is called cancer, because the stars look like a crab."

"Really? Does that mean I should walk through life sideways or something?"


A crab called Cancer.

(trigger warning: image of a tumour; click here to skip)

Krebs cycle

The Krebs cycle. Nothing to do with cancer. At least, not linguistically. Credit: Wikipedia user Narayanese. License: CC-BY-SA

This being Do You Speak Science?, no discussion of, well, anything would be complete without taking a look at its linguistic aspects. Each time I have the cancer/crab conversation, I'm reminded of German, which has only the word Krebs to mean both "cancer" and "crab". NB for the biochemists among you, this is not to be confused with the Krebs cycle, which just happens to be named after someone whose name was Mr Cancer/Crab. The etymology of the word crab is disputed, however it could plausibly be related to Krebs, too.

[Aside: I make it sound like this conversation is a common occurrence. It isn't really. Not many people I meet believe in astrology enough to ask after my sign. Maybe they're afraid of being mocked. Hmm...]

In French, "a crab" is un crabe, the disease is le cancer, as is the constellation. In Romanian, the disease is cancer (pronounced "kanchair"), whereas the constellation and animal are both called rac (pronounced "rak"). I was also intrigued to find out that rac can also mean "corkscrew", although a more common term is tirbuşon (compare French: tire-bouchon, literally "pull-plug/cap/cork/stopper"). Go figure.

Here's a table to summarise:

FrenchLe cancerCancerCrabe
GermanDer KrebsDer KrebsDer Krebs


According to Wikitionary, the Greek root of the word "cancer" (καρκίνος) does indeed mean "crab". The disease is supposedly named after the animal because veins around a tumour look a bit like it.

A tumour in breat cancer.

A tumour in breast cancer. Looks a bit like a crab. (I can sort of see it). Credit: Wikipedia user Emmanuelm. License: CC-BY

So there you have it. From some silly astrology to a bit of serious biology, via languages. So next time someone asks r tells you about a weird belief, run with it for a bit. You just might learn something.

Over to you:

  • Do people around you believe in astrology? Do they ask you about your star sign?
  • What are the signs of the zodiac called in your language?
  • What else can we learn from astrology or other "weird" ideas?
  • How do you say "cancer" (the disease, the animal or the zodiac sign) in your language?
  • Do crabs get cancer?
  • Any biochemists out there? Is a dysfuncitoning Krebs cycle associated with cancer?
  • Would you also be offended by being called a cancer? That's because cancer is a Very Bad Thing. Will you consider making a donation to help fight cancer? For instance, you could support Cancer Research UK, American Cancer Society, La ligue contre le cancer (France) or the Swiss Cancer League.

4 Responses to “Crabstrology”

  1. Nick Reply | Permalink

    Wasn't there a movement in the US a few years back to call Cancerians "Moon people" because it didn't sound like a nasty illness?

    Anyway: in Dutch, the star sign is "Kreeft" which means "Lobster" (a bit more up-market than "Krab", which I'll let you guess), and the disease is "kanker".

  2. Claire Reply | Permalink

    "Sorry, what? I'm not an angle!" is my usual response :)

  3. Alison Atkin Reply | Permalink

    I'm a goat-fish. I can both climb and swim. Maybe there's something to this astrology thing? ;)

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