In addition to studying questions like what causes diseases and what is the origin or life and the universe, science also on occasion investigates important questions like why is it that the cord of your earphones get tangled up if you lay them down for even a second? It is easy to dismiss this as just one’s imagination but physicists find that this is a real effect and that the spontaneous formation of knots has an explanation.

It turns out that depending on the stiffness of the string, they tend to form coils and then the loose ends weave through the strands of the coils, like braiding, and voila!, you have a knot.

We performed experiments in which a string was tumbled inside a box and found that complex knots often form within seconds. We used mathematical knot theory to analyze the knots. Above a critical string length, the probability P of knotting at first increased sharply with length but then saturated below 100%.

Based on the observation that long, stiff strings tend to form a coiled structure when confined, we propose a simple model to describe the knot formation based on random “braid moves” of the string end. Our model can qualitatively account for the observed distribution of knots and dependence on agitation time and string length.

A good follow up to this would be to find ways to avoid the knots forming in the first place.

It is incredible that some people dismiss science as not being useful.

1. Doug Little says

Well we all know that the whole field of physics was created to determine exactly why a piece of buttered toast lands butter side down when it falls off the table.

2. JPS says

When I was in the events technical support business I often asked “What were those cables doing alone in the dark?!?!”.

3. says

It is incredible that some people dismiss science as not being useful.

Especially when they use computers connected to the internet to do it.

4. Rob Grigjanis says

find ways to avoid the knots forming in the first place

Possible? I’m a frayed knot.

5. hyphenman says

@ Doug Little

There’s a demon for that. : )

6. Mano Singham says

Rob, @#4,

Ha! Ha! Good one.

7. Lassi Hippeläinen says

#3: They are the kind of people who connect to the Internet wirelessly. With tubes.

8. says

Well we all know that the whole field of physics was created to determine exactly why a piece of buttered toast lands butter side down when it falls off the table.

That’s built into the fabric of the universe. Landing with a bias of butter side down is primarily related to
‣ the number of rotations expected by by a piece of buttered toast falling from
‣ the average height of a table, which is related to
‣ the average height of a human, which is detrmined by
‣ the tension between the r^2 growth of surface area vs. the r^3 growth of mass, and ultimately by
‣ the gravitational constant, which may be related to,
‣ the original baryon density of the big bang.

So a “butter-side-down” bias was more or less inevitible.

9. astrosmash says

Reminds me of a post you did a few years back on the weird physics of crumpled paper and it’s counterintuitive strength under compression

10. Crimson Clupeidae says

I eagerly await the cdesign proponentists to come along and tell us how these complex structures absolutely cannot form from simple designs and first principles.

All hail the intelligent knot tie-er!!

11. dean says

Well we all know that the whole field of physics was created to determine exactly why a piece of buttered toast lands butter side down when it falls off the table.

So if you could butter one side of toast, and then fasten the unbuttered side to the back of a cat, and drop it – would the bias of landing butter side down couple with cats always landing on their feet and cause the toast to spin endlessly in mid-air? Free energy!!!

12. hyphenman says

@dean

I haven’t heard that one in a very long time. I think I first came across it in a ’70s issue of either Analog or IASFM.

Cheers,

Jeff

13. dean says

I think I first came across it in a ’70s issue of either Analog or IASFM

I think I read it in the early 70s, and then when I was a junior in college the professor I had for thermodynamics tossed it out in jest during one day’s discussion.

14. thebookofdave says

Yeah, but why doesn’t science tackle the really important questions? Like how a sheet of toilet paper is strongest at the perforations. Answer me that, science!

15. Mano Singham says

@thebookofdave,

I’ll send the word out to get cracking on it.