Color-changing fiber and theory reveal fundamental mystery of knots

January 02, 2020

Color-changing fibers and mathematical theory combine to disclose the simple rules that govern the strength and stability of commonly used knots, researchers report. The new study addresses a centuries-old mystery - what makes knots work? Fibers tied into knots and tangles remain one of humanity's most ancient and enduring technologies and play a ubiquitous, fundamental role in our daily lives. From ships' sails and shoes to micro-sutures and turbulent quantum liquids, it's well known that some knots are better suited than others for specific purposes - a fact that's given rise to a great variety of knotted structures. It's known that the subtle interaction between topology (how a knot is tied), elasticity and friction give knots their inherent mechanical properties and strength. However, there remains no comprehensive mathematical theory capable of fully explaining how knots "work." Thus, the ability to understand why some knots hold fast while others easily slip currently evades explanation. To address these long-enduring questions, Vishal Patil and colleagues developed an experimental and theoretical analysis that reveals the key rules underlying the mechanical stability of "bend knots," which are commonly used in both sailing and climbing activities. Combining optomechanical experiments using recently developed color-changing photonic fibers, which show stress differences in different parts of a knot and theoretical knot modeling, Patil et al. were able to quantifiably predict the strain distribution in a knotted structure and reveal several key topological factors that determine a knot's stability. According to the authors, the framework could be used to design and explore new classes of knots with specific behaviors.
-end-


American Association for the Advancement of Science

Related Stability Articles from Brightsurf:

Solar hydrogen: let's consider the stability of photoelectrodes
As part of an international collaboration, a team at the HZB has examined the corrosion processes of high-quality BiVO4 photoelectrodes using different state-of-the-art characterisation methods.

Extra stability for magnetic knots
Tiny magnetic whirls that can occur in materials - so-called skyrmions - hold high promises for novel electronic devices or magnetic memory in which they are used as bits to store information.

Scientists boost stability and efficiency of next-gen solar tech
Researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) have created next-generation solar modules with high efficiency and good stability.

Highest peak power and excellent stability
Optical amplifiers based on chirped pulse amplification (CPA) are used to generate high intensity pulses.

More ecosystem engineers create stability, preventing extinctions
Biological builders like beavers, elephants, and shipworms re-engineer their environments.

Environmental conditions found to affect stability of virus that causes COVID-19
A new study led by Marshall University researcher M. Jeremiah Matson found that environmental conditions affect the stability of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human nasal mucus and sputum.

The mystery of visual stability
We move our eyes several times per second. These fast eye movements, called saccades, create large image shifts on the retina -- making our visual system work hard to maintain a stable perceptual world.

Functional polymers to improve thermal stability of bioplastics
One of the key objectives for contemporary chemistry is to improve thermomechanical properties of polymers, in particular, thermostability of bioplastics.

New role assigned to a human protein in transcription and genome stability
DNA-RNA hybrids, or R loops, are structures that generate genomic instability, a common feature of tumor cells.

NIST researchers boost microwave signal stability a hundredfold
Researchers at the National Institute of Standards and Technology (NIST) have used state-of-the-art atomic clocks, advanced light detectors, and a measurement tool called a frequency comb to boost the stability of microwave signals 100-fold.

Read More: Stability News and Stability Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.