amicus
Literotica Guru
- Joined
- Sep 28, 2003
- Posts
- 14,812
I have not kept count of the number of times I have heard the narrator of a science program state: “It has happened before…(pregnant pause…), it will happen again.”
The first couple dozen times I heard that said, I suppose I accepted it as a rational statement concerning recurring geological events on Earth.
But, from out of the blue, or perhaps an accumulation of data, my question began to percolate.
Is the statement, that if it happened once it WILL happen again, a true statement?
Let me propose that we consider Asteroids, Comets and Meteors to begin with as there have been a few films, “Deep Impact”, “Armageddon” and even an old Sean Connery/Natalie Wood, “Meteor”, that address the subject, I am certain there are many more, feel free to add if you wish.
Odd bits of left over solar system building material exist in the Asteroid Belt, between Mars and Jupiter, in the Kuiper Belt and in the Oort Cloud, both outside the boundaries of the Solar System proper.
The Asteroid Belt is said to be fairly stable, held in place by the gravitational fields of Mars and Jupiter.
Comets are said to originate beyond the solar system and some are on a periodic schedule in orbit around the sun. The most famous:
Impact craters on the Moon have been found to be between 3.5 and 4.5 billion years old. They remain visible today because there is no erosion or tectonic movement to erase them. It is said that Earth would display a similar pockmarked appearance were it not for weather and geological events that virtually erased them from the surface of the Earth.
Scientists still debate over the cause of the demise of the Dinosaurs, some stating an Asteroid impact some 65 million years ago was responsible, others say that climate change had already caused their extinction.
The Tungusta event in Siberia in 1908 is the most recent major asteroid event that science has recorded.
Long winded I know, but if I do not provide sufficient background, others will do so and fault my presentation.
The Sun, the Earth and the Solar system are about half way through their predicted lifetimes. The Sun is expected to continue for about another 5 billion years functioning essentially as it does today…give or take certain parameters.
Most of the left over material in the solar system was blown away by Solar winds when the Sun was young and vigorous. The rest has been swept up by the various planets and moons, as indicated by impact cratering.
Science does not know and cannot predict how many possible Earth crossing Comets exist outside the Solar System. One film portrayed a Comet impacting a large asteroid in the Asteroid Belt, dislodging it into an Earth impact orbit.
Other than long term Comets orbiting the Sun, science does not know what did or might cause objects in either the Kuiper Belt or the Oort Cloud to leave their orbits and enter the Solar System.
Add to all that, the Sun is zipping along in orbit around our Galaxy, the Milky Way, and takes about 240 million years to complete one circuit.
Science does not know what might occupy the Space ahead of Sol and its’ children and the whole Heliosphere as we plunge ahead into the future.
Taking note that the Sun, the Earth and the Solar system are in what one might call, Middle Age, one can conclude that the frivolities of youth are in the past and what happened once, may not, in fact, happen again.
In a nutshell; any further large asteroid events are unlikely?
Apply the same thought process to other such dooms-day predictions such as Super Volcano’s, namely Yellowstone, which has been predicted to erupt again since it has, repeatedly in the past, about every 640,000 years…and it is over-due.
The Earth is gradually cooling and Earth’s rotation is gradually slowing, both of which should indicate a lesser amount of volcanic activity of a major, extinction level size. (Just now Iceland erupted, go figure)
But wait! There’s more! (TV ads) Earth’s magnetic field reverses polarity! Has happened many times in the past, scientists say, and WILL happen again. The SAA (South American Anomaly) might even be a precursor to a field reversal.
Another Ice Age? When? Forget Global Warming; that is on the way regardless, as the Climate of Earth is in constant change, although science does not know precisely why.
Plate Tectonic movement, subduction earthquakes of monumental size and Tsunami’s as a result? Recent events remind us that such things are still happening.
But as Earth ages and cools and the magma beneath the surface is not so frisky, will not these things too, subside?
As I put in the Thread title, ‘Question’, make it plural, I guess, and before you yell at me, at least browse the links provided.
http://www.edinformatics.com/math_science/solar_system/kuiper_belt.htm
http://www.edinformatics.com/math_science/solar_system/oort_cloud.htm
http://www.reciprocalsystem.com/isus/rec/rec27/earthcore.html
http://nov55.com/heat.html
http://helios.gsfc.nasa.gov/qa_earth.html
http://www.solstation.com/stars/asteroid.htm
http://csep10.phys.utk.edu/astr161/lect/moon/moon_surface.html
http://www.astrosociety.org/education/publications/tnl/39/sun2.html
http://novan.com/earth.htm
Amicus the Curious…
The first couple dozen times I heard that said, I suppose I accepted it as a rational statement concerning recurring geological events on Earth.
But, from out of the blue, or perhaps an accumulation of data, my question began to percolate.
Is the statement, that if it happened once it WILL happen again, a true statement?
Let me propose that we consider Asteroids, Comets and Meteors to begin with as there have been a few films, “Deep Impact”, “Armageddon” and even an old Sean Connery/Natalie Wood, “Meteor”, that address the subject, I am certain there are many more, feel free to add if you wish.
Odd bits of left over solar system building material exist in the Asteroid Belt, between Mars and Jupiter, in the Kuiper Belt and in the Oort Cloud, both outside the boundaries of the Solar System proper.
The Asteroid Belt is said to be fairly stable, held in place by the gravitational fields of Mars and Jupiter.
Comets are said to originate beyond the solar system and some are on a periodic schedule in orbit around the sun. The most famous:
“…Halley's Comet's last appearance was in 1986, and its average period of revolution around the Sun is 76 years. But it turns out that the gravitational pull of the giant planets creates variations in that period of up to a few years (so the time between successive appearances isn't always exactly 76 years). Its next appearance should be in 2061…”
Impact craters on the Moon have been found to be between 3.5 and 4.5 billion years old. They remain visible today because there is no erosion or tectonic movement to erase them. It is said that Earth would display a similar pockmarked appearance were it not for weather and geological events that virtually erased them from the surface of the Earth.
Scientists still debate over the cause of the demise of the Dinosaurs, some stating an Asteroid impact some 65 million years ago was responsible, others say that climate change had already caused their extinction.
The Tungusta event in Siberia in 1908 is the most recent major asteroid event that science has recorded.
Long winded I know, but if I do not provide sufficient background, others will do so and fault my presentation.
The Sun, the Earth and the Solar system are about half way through their predicted lifetimes. The Sun is expected to continue for about another 5 billion years functioning essentially as it does today…give or take certain parameters.
Most of the left over material in the solar system was blown away by Solar winds when the Sun was young and vigorous. The rest has been swept up by the various planets and moons, as indicated by impact cratering.
Science does not know and cannot predict how many possible Earth crossing Comets exist outside the Solar System. One film portrayed a Comet impacting a large asteroid in the Asteroid Belt, dislodging it into an Earth impact orbit.
Other than long term Comets orbiting the Sun, science does not know what did or might cause objects in either the Kuiper Belt or the Oort Cloud to leave their orbits and enter the Solar System.
Add to all that, the Sun is zipping along in orbit around our Galaxy, the Milky Way, and takes about 240 million years to complete one circuit.
Science does not know what might occupy the Space ahead of Sol and its’ children and the whole Heliosphere as we plunge ahead into the future.
Taking note that the Sun, the Earth and the Solar system are in what one might call, Middle Age, one can conclude that the frivolities of youth are in the past and what happened once, may not, in fact, happen again.
In a nutshell; any further large asteroid events are unlikely?
Apply the same thought process to other such dooms-day predictions such as Super Volcano’s, namely Yellowstone, which has been predicted to erupt again since it has, repeatedly in the past, about every 640,000 years…and it is over-due.
The Earth is gradually cooling and Earth’s rotation is gradually slowing, both of which should indicate a lesser amount of volcanic activity of a major, extinction level size. (Just now Iceland erupted, go figure)
But wait! There’s more! (TV ads) Earth’s magnetic field reverses polarity! Has happened many times in the past, scientists say, and WILL happen again. The SAA (South American Anomaly) might even be a precursor to a field reversal.
Another Ice Age? When? Forget Global Warming; that is on the way regardless, as the Climate of Earth is in constant change, although science does not know precisely why.
Plate Tectonic movement, subduction earthquakes of monumental size and Tsunami’s as a result? Recent events remind us that such things are still happening.
But as Earth ages and cools and the magma beneath the surface is not so frisky, will not these things too, subside?
As I put in the Thread title, ‘Question’, make it plural, I guess, and before you yell at me, at least browse the links provided.
http://www.edinformatics.com/math_science/solar_system/kuiper_belt.htm
http://www.edinformatics.com/math_science/solar_system/oort_cloud.htm
http://www.reciprocalsystem.com/isus/rec/rec27/earthcore.html
http://nov55.com/heat.html
http://helios.gsfc.nasa.gov/qa_earth.html
http://www.solstation.com/stars/asteroid.htm
http://csep10.phys.utk.edu/astr161/lect/moon/moon_surface.html
http://www.astrosociety.org/education/publications/tnl/39/sun2.html
http://novan.com/earth.htm
Amicus the Curious…