Increasing pressure compresses the air bubble in the octopus’ head, filling it further with water and making it sink (an illustration of Pascal’s principle that any change in pressure on an enclosed fluid is transmitted evenly to every part of the fluid)


Increasing pressure compresses the air bubble in the octopus’ head, filling it further with water and making it sink (an illustration of Pascal’s principle that any change in pressure on an enclosed fluid is transmitted evenly to every part of the fluid)


Recommended For You

About the Author: livescience

20 Comments

  1. It looks like you’re interested in everybody’s favourite cephalopod. Did you know that [octopuses have individual behaviours that are distinct and complex enough that researchers consider them to have individual personalities?](http://psycnet.apa.org/psycinfo/2001-10046-004)

    *This bot was created to share the remarkable complexity of the cognitive lives of octopuses. If you have any comments or suggestions, please reply to this comment*

  2. Doesn’t it just compress the air making it more dense than the water? I don’t think there’s any movement of the water into the octopus.

  3. I thought this was going to be a real octopus. I became very confused, but intrigued. Now I’m just sitting here disappointed.

  4. I know this isn’t /r/askscience but, if I were to take this toy into the ocean and submerge it, is there a depth that it would stop being bouyant and just sink?

  5. What you need

    A clear ONE liter plastic soda bottle and cap (not the big 2 liter bottle)

    A ball point pen cap that does not have holes in it

    Some modeling clay (“sculpey” works too)

    What to do

    1. Remove any labels from your bottle so that you can watch the action.

    2. Fill the bottle to the very top with water.

    3. Place a small pea-size piece of modeling clay at the end of the point on the pen cap. (see drawing)

    4. Slowly place the pen cap into the bottle, modeling clay end first. (some water will spill out – that’s okay) It should just barely float. If it sinks take some clay away. If it floats too much add more clay.

    5. Now screw on the bottle cap nice and tight.

    6. Now for the fun part. You can make the pen cap rise and fall at your command. Squeeze the bottle hard – the pen cap sinks…stop squeezing and the pen cap rises. With a little practice, you can even get it to stop right in the middle.

  6. I love this demonstration because it illustrates pascal’s principle, the compressibility of fluids, and archimedes’ principle all at once as well as being a fun and cheap DIY submarine toy!

  7. In the 1980’s Frosted Flakes came with a “Tony the Tiger” dive toy that would do this. You’d put the little Tony tiger in the bottle, squeeze, and he would go down. It was cool for that time.

    Edit: [i found the link](https://youtu.be/8FADnQ84MNw)

Leave a Reply

Your email address will not be published. Required fields are marked *