flight Archives - DOES GOD EXIST? TODAY

August 9, 2024August 8, 2024

The Bernoulli Effect and Flying Slowly

We have marveled at the ability of birds to reach incredible speeds and make quick turns. However, the greatest challenge is flying slowly. The wing shape allows flight, as air traveling along the top surface moves faster than air on the wing bottom. This is an application of a principle of physics known as the Bernoulli effect.

The Bernoulli effect says that when air moves rapidly, it exerts minimum pressure at right angles to the direction of the motion. You can demonstrate that with a simple experiment. Place two identical books on a table with a small space between them. Lay a piece of paper over the top of the two books and blow through the channel between them. The paper will collapse because the pressure of the moving air is lower than the air pressure above the paper. Blow hard, and the paper will collapse rapidly. Blow slowly, and the paper will bend down a little.

Airplane wings use this principle to get lift. As the plane moves faster, the lift increases, and the plane can rise. When the plane slows down, there is less lift, and the plane decreases its altitude. Birds do the same thing but have a unique design feature that allows slow flight. This special structure called a bastard wing or alula enables them to stay aloft even when flying slowly.

The alula consists of several feathers attached to the first digit of the wing bones. By moving that digit, the bird can separate the feathers of the alula from the rest of the wing, creating a slot that helps channel air over the wing. This enhances lift and allows the bird to stay aloft when flying slowly, such as when landing. When a bird seems to hover, the Bernoulli effect created by the alula design gives them that ability. Humans have not found a way to duplicate all the designs of the bird wing, so hovering is still a challenge for modern aircraft.

Much of what engineers know has come from studying the design God built into His creatures. Birds continue to teach us a lot about flying in various applications, including slowly flying. (See Romans 1:20.)

May 2, 2018January 13, 2022

Advanced Civilization Support

We have often mentioned before the evidence that our planet was designed to support life. More than that, it was designed to support advanced life. It was even designed for advanced civilization support.

You can see evidence for advanced civilization support in the minerals of Earth’s crust—minerals that are essential for machinery and electronics that enable technology. One thing which perhaps you have not considered is how the size of our planet also supports advanced civilization. Among the achievements of science is space flight. The ability to use rockets to leave Earth’s surface makes it possible for us to place satellites in orbit. Those satellites include:

*Communication satellites which make possible nationwide and international television, news, sports, telephone, and video conversations.
*Global positioning satellites giving us GPS which we use for many purposes including airplane, ship, and personal navigation plus farming and safety uses.
*Weather satellites giving us advance warning of storms and helping to keep us safe.
*Observational satellites that allow us to study and learn more about our planet.
*Telescopic satellites which enable us to study our solar system and the universe.

We often fail to realize how important those satellites are for our advanced civilization. Also, the ability to use rockets to leave Earth’s surface allows us to send out space probes to explore our solar system and universe.

What does the design of our planet have to do with our ability to leave the surface? The answer relates to gravity. Astronomers have been looking for habitable planets orbiting other stars. They believe that they have found many of those exoplanets. However, the planets that are more likely to be located in habitable zones (where liquid water can exist) are much larger than Earth. A much-larger rocky planet would have much more mass and therefore much more gravity. Launching a rocket into space from such a planet would be much more difficult, if not impossible. Even airplane flight and the flight of birds could be affected by increased gravity.

A planet with a diameter 70 percent greater than Earth’s diameter would have ten times the mass. The advantage of having much more gravity would be that a planet like that could hold a thicker atmosphere which could give more protection from harmful cosmic rays and incoming asteroids. The disadvantage of a thicker atmosphere would be that it might also block useful solar rays. However, getting a rocket off the ground and into space could be prohibitive. It would require a much larger rocket which would require more fuel. That would require an even larger rocket to carry the extra fuel. The weight of the larger rocket and fuel would require an even larger rocket requiring even more fuel. This quickly spirals out of control.

So what is the conclusion? We live on a planet that is large enough to hold an atmosphere that protects us but small enough that we can to break the bond of gravity to go into space. A smaller planet would not have the atmosphere we need. A larger planet would not allow us to explore beyond our planet or even to send up satellites that help to make advanced civilization possible. As Goldilocks might say, “God made it just right.”
–Roland Earnst © 2018

July 25, 2017November 27, 2018

Majesty in Miniature

Majesty In Miniature

“Majesty in Miniature” is the title of an interesting article in the July 2017 issue of National Geographic (pages 99-118). The article is about the amazing hummingbirds.

Scientists have had a hard time getting data as they try to understand how hummingbirds do what they do. The birds fly at speeds up to 35 mph (56 kph) and they have a “reverse gear.” Their metabolic rate is the highest of any vertebrate on the planet. For every minute they are in flight, they drink more than 12 ounces (355 ml) of water. They consume more than their body weight of nectar every day. Their tongues lap up to 15 times a second. Proportionally their brain is one of the largest in the animal kingdom making up 4.2% of their body weight. It is only with the advent of high-speed cameras and advanced wind tunnels that some of the mysteries of the majesty in miniature have been answered.

Hummingbird brains have a large hippocampus which allows them to remember locations. Their brain has a large lentiformis mesencephali motion sensor which gives the bird stabilization when flying. It has a small arm wing which allows wrist motion to control a larger area of the wing leading to a more powerful upstroke. When a hummingbird hovers, it rotates its wings between the upstrokes and the downstrokes making a figure eight motion. This motion creates vortexes that allow both the downstroke and the upstroke to provide lift. Birds such as pigeons push down to propel forward, but there is no lift in the upstroke. The design of the hummingbird wing gives it the unique ability to get lift out of both strokes.

The design of all of these features defies any chance explanation. Nearly everything the hummingbird does is unique to that species. We don’t see birds with some of these characteristics, and yet all of them are essential to the hummingbird’s survival. Indeed this bird is majesty in miniature, and a testimony to God’s wisdom and design. He has equipped all creatures to live in their particular, unique environment.
–John N. Clayton © 2017