Convergent Evolution of Boats with Sails

A Bejan,S Lorente,L Ferber

doi:10.1038/s41598-020-58940-5

A Bejan, S Lorente + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-58940-5

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Abstract

This article unveils the geometric characteristics of boats with sails of many sizes, covering the range 102–105 kg. Data from one hundred boat models are collected and tabulated. The data show distinct trends of convergent evolution across the entire range of sizes, namely: (i) the proportionality between beam and draft, (ii) the proportionality between overall boat length and beam, and (iii) the proportionality between mast height and overall boat length. The review shows that the geometric aspect ratios (i)–(iii) are predictable from the physics of evolution toward architectures that offer greater flow access through the medium.

Highlights

This article unveils the geometric characteristics of boats with sails of many sizes, covering the range 102–105 kg
Our predecessors have summarized each distinct phenomenon with its own law of physics, which serves as a ‘first principle’ in the edifice of science
A principle is a ‘first principle’ when it cannot be deduced from other first principles. This aspect of organization in science is illustrated by the evolution of thermodynamics to its current state[1,2]

Summary

OPEN Convergent Evolution of Boats with Sails

This article unveils the geometric characteristics of boats with sails of many sizes, covering the range 102–105 kg. The review shows that the geometric aspect ratios (i)–(iii) are predictable from the physics of evolution toward architectures that offer greater flow access through the medium. 150 years ago the transformation of potential energy into kinetic energy and the conservation of “caloric” were fused into one statement—the first law of thermodynamics—which serves as a first-principle in physics It was the same with another distinct tendency in nature: everything flows (by itself) from high to low. This tendency gave birth to artifacts (vehicles) in which people encapsulate themselves to acquire greater access From this idea, the convergent evolution of all boats with sails is deducible. What about the shape of the sail? When the aspect ratios of Eqs. (3, 4) apply, the drag force in the water [Eq (2)] becomes

2Cf CD

Fractional Sloop Fractional Sloop Fractional Sloop Cutter Masthead Sloop

Comparison with Current Designs

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