Sunday, April 1, 2012

Screaming plants mean no more fairways?


Scientists have discovered that grass blades scream when cut with a lawnmower.

Well scream may be a bit of an exaggeration, at least by human standards. While human ears can only hear sounds up to about 16,000 Hz, scientists have now measured vocalizations of 85,326 Hz emanating from grass blades cut by a power lawn mower. Admittedly, these sounds are at very low levels, 3.1415 x 10-9 decibels, which is probably why they had not been detected earlier.

The first reports of plant communication began to surface close to 40 years ago (see New York Times editorial, "When Trees Talk"), but until now, phyto-communication was limited to volatile chemical and the sense of smell.

Cross-section through a grass leaf. The dermal cells are found
on the top and bottom, the phloem in the bottom part of the
vascular bundles, the xylem in the upper part of the vascular
bundles, and the paranchymal tissues fill in most of the space
between the upper and lower epidermis.  
Now, using a highly advanced nano-level sound detector, scientists at Whoville University recorded the screams coming from the grass immediately as the lawnmower's blades cut specifically through the phloem and dermal cells of the leaf, but not when the xylem or paranchymal cells were disrupted. Prof. Horton, who headed the research program, hypothesizes that these "screams" imply that humans have inflicted immeasurable suffering on grass, and likely also other plant species. This has led him to form a new NGO called Scientists for the Ethical Treatment of Grass, which is working for a ban of all lawn mowers. When asked how this would affect his golf game, Prof. Horton replied that in any event, he usually plays out of the rough.

Example of experimental setup. The nano-level sound detector
was embedded within the blades to allow simultaneous
detection of any noise emission as the blades were cut.  
Horton's current research is in developing a smaller version of his sound detector which can be embedded within a tooth cap so as to record any similar screams from fresh vegetables as they are macerated in the mouth.

In all fairness it should be noted that these results have been contested by Prof. Wickersham from Nool University. Wickersham and his colleague Kang Aroo claim that such faint vocalizations are theoretically impossible, and that the work from Who U. is just a figment of the researchers' imaginations. When asked for a comment, Prof. Horton said, "A sound is a sound no matter how small".

For more information on plant communication, be sure to get your copy of WHAT A PLANT KNOWS.


  1. Do you follow Wait Wait Don't Tell, from NPR? The "Bluff the Listener" segment from the most recent show is definitely for you.

    1. I never heard of it, but definitely will follow it now! Thanks!

    2. I Google'd "Whoville University". Really? I am not for animal cruelty or am not an environmentalist - just simply request some logical argument.

  2. Awesome! I had always suspected... :-)

    Thanks for the chuckle!

  3. 'I believe,' he said, speaking more slowly now,
    'that there is a whole world of sounds about us
    all the time that we cannot hear. It is possible
    that up there in those high-pitched inaudible
    regions there is a new exciting music being made,
    with subtle harmonies and fierce grinding discords,
    a music so powerful that it would drive us mad
    if only our ears were tuned to hear the sound
    of it."

    Roald Dahl, "The Sound Machine" 1949

  4. Is this a Joke or what?

    A sound or a noise is not the same as screams or vocalizations. A lot of things produce noises but that's different to vocalizations.

    This is definitely a sensationalist article. Is this a fake website? like a tabloid or something?

    Maybe the author of these conclutions thinks as a plant.

    1. Dear anonymous - please check the header of this post which emphasizes the date originally published: April 1! Sorry for the confusion.

  5. my teacher was telling me this in class today i had to cheack it out , and holly molly this is so darn interesting :D

  6. I heard about grass "screaming" when cut long before this so-called professor claims to have come to the conclusion, and though this was published on April Fools Day, doesn't mean to say there's no truth to it in some way. Just because we can't hear it, doesn't mean it doesn't make a sound. It has been revealed that Giraffe's are not completely mute, they do in fact make a rumbling sound. :-)

    1. Hi Anon, Definitely no science intended in this post. But that doesn't mean to say that sounds aren't emitted from plants. indeed trees in drought emit ultrasonic vibrations that come from the loss of water in their xylem tubes.

  7. it interest me, thanks for sharing, I'll look up some more information about this