you're reading...

Sea Turtles

The ocean + a blind turtle + some driftwood = lucky to be human

A friend of mine, Sandeep, loves to tell this story about how long a kalpa is. Kalpas are the unit of time by which things are measured in Buddhism, and it doesn’t particularly matter how long they are in years, per se, but that a kalpa is a very, very long period of time. This is to give the sense that Buddhism is concerned with the eternal, recurrent universe, that things like an individual’s life are fleeting and small – to place one in context.


Sandeep’s Story of the Blind Turtle

Sandeep’s story goes as follows. So there’s a blind turtle living at the bottom of the sea, who surfaces for air once every five billion years (the turtle is, well, pretty old). There’s a piece of driftwood, with a little hole in it, floating on the ocean surface, tossed about by wind and currents, waiting for the turtle. A kalpa is as long as it takes for the turtle to happen to pop its head through the hole in the driftwood one of the times it comes up for air.


Fig. 1 – Buddhism is like waiting for this blind turtle to find this wooden neck-hole in this great blue yonder. ‘And they think finding a needle in a haystack is tough’. Screen Shot 2016-01-17 at 12.12.07 PM




That’s a long time, and moreover a beautiful metaphor. Fascinated by this anecdote after I’d heard it, I looked it up. Sandeep has a graceful way with fudging the details, and it appears this particular anecdote is no exception: all the better if you ask me. We’ll be interested in the story as it actually goes, though, which requires some revision (cue: the noise of a record scratching as we start the whole thing from the top).


The Story of the Blind Turtle, As it Actually Goes

In Hinduism and certain writings of Buddhism, a kalpa is indeed a long unit of time, about 4.32 billion years – curiously close to the 4.54 billion years old the earth is thought to be, and probably where the 5 billion years in Sandeep’s story comes from. There is a story about a blind turtle, too, with the driftwood and all, but rather than illustrating how long a kalpa is, it illustrates something far more fundamental to the Buddhist ethos: how being human is special.


Fig. 2 – Revision: being human is like this blind turtle finding this wooden neck-hole in this great blue yonder. Maybe Barney was right… Screen Shot 2016-01-17 at 12.12.07 PM




The actual story, found in 129 Balapandita Sutta, is that there is a blind turtle, innumerable kalpas old, living at the bottom of the sea and surfacing for air every 100 years, and a wooden cattle-yoke waiting for it amongst the waves. The likelihood that the turtle pops its head through the hole in the cattle-yoke when surfacing is said to be greater than the likelihood of being reincarnated as a human. Being born human is luckier than a blind turtle popping its head through a cattle-yolk. The implication, then, is that you better get busy becoming enlightened while you’ve got the chance – only human beings are said to have the capacity to attain enlightenment.

Now, the fun part is that to a scientist, this looks like a comparison of two simple questions about oceanography and biology, respectively; how likely is it for the turtle to pop its head out in the wood, versus how likely it is for something to be reincarnated as human when it dies? We can estimate and compare these probabilities; we have ourselves a testable hypothesis! What is the probability of a turtle surfacing through a cattle-yoke’s hole, and what is the probability of being reincarnated as a human?


Two Simple Calculations, One Surprising Result

Let’s take the yoke first. A cattle-yoke hole typically measures 16” by 8”, so if we think of it as an ellipse, that’s about 400 square inches of hole to fit through. Then the total surface area of the oceans, added all up, is about 360 million square kilometers. If you assume that after 100 years the location of the turtle and the yoke are sufficiently randomized from their moving around, which seems reasonable, the probability that the turtle would poke its head out is just the ratio of these two areas, which after converting inches to kilometers is about P(turtle sticks head through yoke) = 7.2 x 10^-16.

How about reincarnation? This one seems possibly trickier, as that’s a lot of creatures to account for, but we’re in luck. It’s often thought by Buddhists that one can only be reincarnated as a multicellular organism, and by far the most abundant organisms are nematodes – rather gross tubular little roundworms. These reproduce about 1150 times faster than human beings; we live about 67 years, and they live about 3 weeks. Then there are about 7.4 billion humans on earth, and 10^22 nematodes. So if I die and I’m up for reincarnation, the probability I get reincarnated as human can be accurately estimated as the ratio between the number of humans and the number of nematodes, divided by that factor of 1150 to account for how much faster nematodes are born and die. That probability ends up being P(reincarnated as human) = 6.5 x 10^-16.


Fig. 3 – You might rather be the one holding the nematode than be the nematode, but I’d rather not hold a nematode at all, thank you very much.

Screen Shot 2016-01-17 at 12.13.17 PM










Those probabilities are remarkably similar – the metaphor is in fact precise! I wouldn’t mind a piece of whatever wisdom was available to the Majjhima Nikaya (who told the story in this Sutta). Another interesting consideration, though, is that this comparison wasn’t as close when the Majjhima Nikaya spoke it; there used to be far fewer humans on earth. Back then, though, there was no way to estimate the total area of the oceans, or the number of organisms on earth! Thus, the comparison only becomes precise once it is testable – a sort of inverse Uncertainty Principle. What will happen once there are 9 billion people on earth, and the comparison stops being true?


All in all

Thanks to a couple of neat modern estimates about the global extent of the oceans and the big picture numbers of life on earth, we can test the veracity of an ancient spiritual anecdote, which turns out to be strikingly accurate. Whether this demonstrates something miraculous about Buddhist sages, humanity, or science is up to you, but certainly it does feel a bit miraculous.


One Response to “The ocean + a blind turtle + some driftwood = lucky to be human”

  1. Thanks for the fun, interesting article!

    Posted by harold | January 19, 2016, 11:13 am

Post a Comment


  • by oceanbites 3 months ago
    Happy Earth Day! Take some time today to do something for the planet and appreciate the ocean, which covers 71% of the Earth’s surface.  #EarthDay   #OceanAppreciation   #Oceanbites   #CoastalVibes   #CoastalRI 
  • by oceanbites 4 months ago
    Not all outdoor science is fieldwork. Some of the best days in the lab can be setting up experiments, especially when you get to do it outdoors. It’s an exciting mix of problem solving, precision, preparation, and teamwork. Here is
  • by oceanbites 5 months ago
    Being on a research cruise is a unique experience with the open water, 12-hour working shifts, and close quarters, but there are some familiar practices too. Here Diana is filtering seawater to gather chlorophyll for analysis, the same process on
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 7 months ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 9 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 9 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 10 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 10 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 11 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 11 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 12 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 12 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 1 year ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
WP2Social Auto Publish Powered By : XYZScripts.com