Bees Defying Aviation Laws: The Science Behind Their Flight

The idea that bees cannot fly according to the laws of aviation is a myth. This myth is often referenced in popular culture, including in the animated film Bee Movie. The myth dates back to the 1930s when French entomologist August Magnan noted that bees' flight should be impossible due to their small wings and large bodies. However, modern studies have shown that bees do not disobey the laws of physics and that their flight is consistent with our understanding of fluid dynamics. Bees create tiny hurricanes that lift them upwards, and their small size allows them to generate more lift than expected.

The myth that bees can't fly

The idea that bees cannot fly has persisted as a myth for almost a century. The myth is often referenced in popular culture, such as in the animated film Bee Movie, and has been propagated by various sources on the internet. However, the notion that bees cannot fly according to the laws of aviation is simply false.

The myth dates back to the 1930s when French entomologist August Magnan stated that bees' flight should be impossible due to their small wings and fat bodies. The story goes that an aerodynamicist, possibly Swiss professor Jakob Ackeret or physicist Ludwig Prandtl, was discussing bees with a biologist one night. The aerodynamicist did some quick calculations and concluded that bees should not be able to fly based on their weight and wing area. This myth was further perpetuated by journalists and has since been repeated by many people.

However, bees do not disobey any laws of physics. They simply fly in a completely different way from aeroplanes. Bees flap their wings back and forth, not up and down, creating vortices or spirals of air that provide lift. These vortices are like tiny hurricanes that lift the bees upwards. The high-speed flapping of bees' wings, at 230 times per second, also helps to counteract the low speeds and high drag associated with their small wings.

Modern slow-motion video and tracking equipment have helped scientists better understand bee flight in the last 20 years. These technologies have revealed the complex fluid dynamics and turbulence effects involved in insect flight, which were previously invisible to the naked eye.

So, while the myth that bees can't fly has persisted for many years, it has been proven false by modern science. Bees are remarkable creatures that can fly at altitudes greater than nine kilometres and create mini-hurricanes wherever they go.

How bees fly

The idea that bees cannot fly according to the laws of aviation is a myth. Bees do not fly like aeroplanes, and so the physics that explains how aeroplanes fly does not apply to bees.

Bees have two wings on each side of their body, which are held together with comb-like teeth called hamuli. These teeth allow the two wings to act as one large surface and help the bee create greater lift when flying. Bees have two sets of wings, one larger outer set and one smaller, inner set. In each set, the large and small wing is connected with hamuli.

Bees flap their wings back and forth, not up and down. This creates tiny hurricanes that lift them upwards. The wings move diagonally, starting up-and-back, then moving down-and-forward. They also flip their wings upside down as they flap, causing the air above the wing to swirl. This is known as leading edge vortices (LEVs). The wings of bees are flexible, allowing them to angle their wings at a sharper angle against the sky.

Honey bees can beat their wings over 230 times per second. This is made possible by muscles that cause the bee's thorax to squeeze in two directions: both up-and-down, and left-and-right.

The Reynolds number

> R = UL/v

Where:

• R is the Reynolds number
• U is the velocity of the flow
• L is the length of the object
• V is the viscosity of the fluid

In the context of bee flight, researchers have studied the airflow around the flapping wings of bees to understand the controversy surrounding the aerodynamics of bee flight. The Berkeley team, for instance, used a scaled-up model of an insect flapping in oil rather than air to study the fluid dynamics involved.

Measurements of drag forces and lift forces acting on honeybee trunks have been conducted at various velocities, corresponding to Reynolds numbers between 4.10^2 and 4.10^3. These experiments help to elucidate the flight dynamics of bees and the role of the Reynolds number in their ability to fly.

The laws of physics

The myth that bees shouldn't be able to fly according to the laws of physics has persisted for many years. This misconception possibly originated in the 1930s when, according to a story, an aerodynamicist or aeronautical engineer made calculations based on a bee's weight and wing area and concluded that bees should not be able to achieve flight. This notion was further popularized by the movie "Bee Movie," which referenced this idea in its opening lines.

However, the belief that bees cannot fly according to the laws of physics is incorrect. Bees do fly, and their ability to do so is a testament to the validity of our understanding of fluid mechanics and physics. Modern slow-motion video and tracking equipment have revealed the complex fluid dynamics involved in insect flight, which were previously invisible to the unaided eye.

The flight of bees differs significantly from that of airplanes. Airplane wings generate lift by forcing air downwards, which, in turn, pushes the wings and the plane upward. In contrast, the wings of bees and other insects create vortices in the air, similar to small hurricanes. These vortices have regions of lower pressure at their centres, and by keeping these eddies of air above their wings, bees can maintain lift and stay aloft.

Additionally, the wings of bees are not rigid but instead twist and rotate during flight. They make short, quick sweeping motions front and back, which generate enough force to keep the bee airborne. So, while bees may appear too large or heavy for their small wings, they are indeed capable of flight and do so without breaking the laws of physics.

The origin of the myth

The myth may also have been perpetuated by a story from the same decade, in which an aerodynamicist, named in some versions as physicist Ludwig Prandtl and in others as Swiss aeronautical engineer Jakob Ackeret, was asked about bee flight by a biologist. The aerodynamicist supposedly did some quick calculations and concluded, based on weight and wing area, that bees should not be able to fly.

The myth likely persisted due to the counterintuitive nature of bee flight, which does not conform to the same principles as airplane flight. Bees have small wings relative to their body size, and they achieve flight through a unique method: flapping their wings rapidly in a back-and-forth, figure-eight motion, creating vortices in the air like small hurricanes, which provide lift. This method of flight was not well understood until recently, with studies from 2005 helping to explain the mechanics behind it.

Frequently asked questions