WHAT IF... The Moon Didn't Exist?
Page 1 of 1 [ 1 post ]
Today, 6:45 pm
I've been reading some textbooks I found at the city market, and this is an excerpt from one of them. I thought someone else might find its science-based speculations interesting. Enjoy!
Quote:
WHAT IF... The Moon Didn't Exist?
From "Discovering the Universe", 11th ed., by Neil F. Comins, page 223.
(C) 2019, 2014, 2012, 2008 by W. H. Freeman and Company.
• • •
Throughout history, people have woven myths about the moon and its effects on everything from childbirth to stock market activity. Countless romances have begun under a full moon, and entire nations have dedicated themselves to reaching it.
What if the moon never existed? Would life have even developed on Earth? If so, how would it be different? Would a self-aware species like ourselves have evolved?
Delayed Origins
It would have been much more difficult for life to start evolving on a moonless Earth. In the first place, the minerals from which life developed in our Earth's young oceans were swept down there, in large part, by gigantic tides, a thousand times higher than the tides of today, created by the moon when it was some 10 times closer to Earth than at present. The newly formed Earth, spinning more than 4 times faster than at present, caused these tides to move miles inland and back out to sea every 1-1/2 hours or so.
A moonless Earth would still have tides, caused by the sun. However, these tides would never be more than one-third as high as Earth's present tides. Minerals would wash into the oceans incredibly slowly from the flow of rivers. as a result, it would likely take much longer, hundreds of millions or even billions of years longer, for enough minerals to be dissolved for life to firmly establish itself.
Harsh Conditions
Animal life's transition from oceans to land would also be much harder because of continuous winds, between 50 and 150 mi/h, created by the planet's rapid rotation. The resulting waves (wind causes waves) would be enormous and perpetual. Fish with legs near shores would almost certainly be pounded to a pulp rather than being able to sedately move onto land and then back into the water, as apparently happened on Earth.
But we see on Earth how life develops in the most incredible forms and places. It seems plausible, then, that sea life would find a way to make the transfer to dry land and continue to evolve there.
Allowing then for diverse terrestrial life on the moonless Earth, what would be different about that life compared to life on our Earth? For one thing, creatures evolving there would have to withstand the perpetual pummeling from winds and the debris they carry. Turtlelike shells are one solution.
Obviously, there would be no eclipses or moonlight—all clear nights would be equally dark and star-filled. therefore, nocturnal animals would be less successful at hunting, foraging, and traveling. Instead, these animals might evolve more enhanced senses to compensate for their inability to see visible light at night.
Rush Hour
Clearly, naked apes do not seem a likely bet on a moonless Earth, or birds battling the ever-present winds. But given enough time, complex, even self-aware life likely would evolve. After all, we evolved because of the challenges faced by our ancestors, and Earth without a moon would clearly provide challenges of its own.
The physiology of life on Earth evolved based on a 24-hour day. This is most evident in our biological clocks, or circadian rhythms, which are the internal mechanisms that regulate sleeping, waking, eating, and other cyclic activities. (Interestingly, some creatures have biological clocks that are set by the tides and by moonlight, rather than just by the day-night cycle.) Faced with a 7-hour day, these circadian rhythms would be hopelessly out of sync with the natural world. To function in such a world, all of its creatures would have to evolve biological clocks based on 7-hour cycles, which certainly could have occurred. Considering all that we have to do now, imagine what life would be like with only 6 hours in each day!
Wobbling Earth
Finally, rapidly rotating terrestrial planets without large moons are unstable, and calculations show that they dramatically change the direction of their rotation axes. If Earth had no moon, we would have seasons that vary dramatically over the millennia, from those like we have today to times of no seasons to times when the sun passes over every place on Earth, including the poles! Our moon stabilizes Earth's rotation, preventing such phenomena. It would be incomparably harder for complex life to persist on a moonless Earth than it is on our world.
Ω
From "Discovering the Universe", 11th ed., by Neil F. Comins, page 223.
(C) 2019, 2014, 2012, 2008 by W. H. Freeman and Company.
• • •
Throughout history, people have woven myths about the moon and its effects on everything from childbirth to stock market activity. Countless romances have begun under a full moon, and entire nations have dedicated themselves to reaching it.
What if the moon never existed? Would life have even developed on Earth? If so, how would it be different? Would a self-aware species like ourselves have evolved?
Delayed Origins
It would have been much more difficult for life to start evolving on a moonless Earth. In the first place, the minerals from which life developed in our Earth's young oceans were swept down there, in large part, by gigantic tides, a thousand times higher than the tides of today, created by the moon when it was some 10 times closer to Earth than at present. The newly formed Earth, spinning more than 4 times faster than at present, caused these tides to move miles inland and back out to sea every 1-1/2 hours or so.
A moonless Earth would still have tides, caused by the sun. However, these tides would never be more than one-third as high as Earth's present tides. Minerals would wash into the oceans incredibly slowly from the flow of rivers. as a result, it would likely take much longer, hundreds of millions or even billions of years longer, for enough minerals to be dissolved for life to firmly establish itself.
Harsh Conditions
Animal life's transition from oceans to land would also be much harder because of continuous winds, between 50 and 150 mi/h, created by the planet's rapid rotation. The resulting waves (wind causes waves) would be enormous and perpetual. Fish with legs near shores would almost certainly be pounded to a pulp rather than being able to sedately move onto land and then back into the water, as apparently happened on Earth.
But we see on Earth how life develops in the most incredible forms and places. It seems plausible, then, that sea life would find a way to make the transfer to dry land and continue to evolve there.
Allowing then for diverse terrestrial life on the moonless Earth, what would be different about that life compared to life on our Earth? For one thing, creatures evolving there would have to withstand the perpetual pummeling from winds and the debris they carry. Turtlelike shells are one solution.
Obviously, there would be no eclipses or moonlight—all clear nights would be equally dark and star-filled. therefore, nocturnal animals would be less successful at hunting, foraging, and traveling. Instead, these animals might evolve more enhanced senses to compensate for their inability to see visible light at night.
Rush Hour
Clearly, naked apes do not seem a likely bet on a moonless Earth, or birds battling the ever-present winds. But given enough time, complex, even self-aware life likely would evolve. After all, we evolved because of the challenges faced by our ancestors, and Earth without a moon would clearly provide challenges of its own.
The physiology of life on Earth evolved based on a 24-hour day. This is most evident in our biological clocks, or circadian rhythms, which are the internal mechanisms that regulate sleeping, waking, eating, and other cyclic activities. (Interestingly, some creatures have biological clocks that are set by the tides and by moonlight, rather than just by the day-night cycle.) Faced with a 7-hour day, these circadian rhythms would be hopelessly out of sync with the natural world. To function in such a world, all of its creatures would have to evolve biological clocks based on 7-hour cycles, which certainly could have occurred. Considering all that we have to do now, imagine what life would be like with only 6 hours in each day!
Wobbling Earth
Finally, rapidly rotating terrestrial planets without large moons are unstable, and calculations show that they dramatically change the direction of their rotation axes. If Earth had no moon, we would have seasons that vary dramatically over the millennia, from those like we have today to times of no seasons to times when the sun passes over every place on Earth, including the poles! Our moon stabilizes Earth's rotation, preventing such phenomena. It would be incomparably harder for complex life to persist on a moonless Earth than it is on our world.
_________________
Page 1 of 1 [ 1 post ]
| Similar Topics | |
|---|---|
| The Moon May Be 100 Million Years Older Than First Thought |
18 Dec 2024, 6:38 pm |
