JimsAstronomy

Tuesday, October 4, 2016

Studying the speed of light.

- 1904 - Studying the speed of light has lead to many new discoveries along the way. And, even to some new mysteries yet to be discovered, like Dark Energy and Dark Matter. It all started in the 1600’s with Ole Romer’s ingenious calculation.
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-----------------------------1904 - Studying the speed of light.
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- Ole Romer in 1676 used the moon, Io, of Jupiter whose orbit worked like a clock. One orbit took 1.769 days, or 42,456 hours, or 2,547,36 minutes.
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- Then, he used the orbit of the Earth about the Sun. The distance from the Earth to the Sun is 93,000,000 miles. Therefore, the diameter of a complete orbit is 186,000,000 miles.
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- Using the closest orbit to start the clock, then waiting six months to arrive at the most distant orbit, Ole found that Io crossed the crest of Jupiter 22 minutes later, every year. This meant it took light 22 minutes for light to cross the 186,000,000 mile additional distance.
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--------------------- distance = rate * time
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--------------------- rate = speed of light = distance / time
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-------------------- speed of light = 186 * 10^6 / 22 / 60
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--------------------- speed of light = 507,272,272 miles per hour.
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- Ole’s very first calculation in 1676 was 76% of the best answer we have today.
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--------------------- Speed of light = 676,616,692 mph
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- Christian Huygens and Isaac Newton got their own calculations to come up with:
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---------------------- speed of light = 492,126,000 miles per hour.
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- In the 1850’s scientists arrived at :
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--------------------- speed of light = 704,635,000 mph
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- It was about the time that physics was measuring electromagnetic charges and electrostatic charges , realized they traveled at the same speed, and that light must also be an electromagnetic wave.
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- In Einstein’s 1905 paper he proposed that the speed of light in a vacuum, measured by a non-accelerating observer, is the same, independent of the motion of the source or the observer. He delivered a lecture using 3 symbols for mass, energy and the speed of light and later proved that mass and energy were the same thing. Mass is simply concentrated energy according to :
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-------------------------- E = mc^2
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-------------------------- c = being the speed of light in a vacuum.
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- The speed of light travels at different speeds due to the medium in which it is traveling. It travels between atoms at its constant speed, but it is being absorbed and re-emitted by atoms as it moves through the medium making a “net” slower speed.
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- For example: a light beam traveling through a glass of water:
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------------------------ The speed in air is------------ 186,222 miles per second
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------------------------ The speed through glass --- 124,275 mps
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------------------------ The speed through water --- 140,430 mps
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----------------------- Through glass ----------------- 124.275 mps
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------------------------ Through air ------------------ 186,222 mps
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- Einstein’s claim that the speed of light from a moving source is counterintuitive. He maintained that the speed of light is always the same regardless of the initial reference frame. In other words light speed does not get added to its motion of a source in a medium. Further, a moving body approaching the speed of light would appear to slow down from the frame of the observer. The distance would shrink and the time would slow to keep the speed, the ratio, a constant.
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- It was not until the 20th century that measurements using laser interferometers and cavity resonators would more accurately measure the speed of light. In 1972 the value became:
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--------------------------- c = 299,792,458 meters per second.
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--------------------------- c = 670,616,692 miles per hour.
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- The other consequence of the speed of light being a “ constant” is the unification of “space-time”. In order for that to happen space and time become variables.
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- In the 1920’s the speed of light was used to determine that the Universe was expanding. And, the further away the galaxy was from us the faster it was receding.
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- This receding calculation was 68 kilometers per second per mega parsec distance away. Put in other units:
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------------------------ 47,000 miles per hour per million lightyears distance.
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- In the 1990’s this acceleration was measured to even be increasing over the past 5 billion years. That would mean the most distant galaxies are receding faster than the speed of light.
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- This does not mean that the galaxies are traveling that fast. It simply says the volume of space between us is expanding that fast. This realization has lead us to what is causing the accelerating expansion? We don’t know? We call it “ Dark Energy”. It remains a “Dark Mystery”. A driving force that we just can not explain.
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- In the meantime, we still think the speed of light is a constant:
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------------------------ c = 670,616,692 miles per hour
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------------------------ c = 186,282 miles per second, in the vacuum of space.
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- Other reviews available on this subject:
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- #1845 Why is the sky blue? It took 100 years to get the correct answer.
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- #1795 - Just seeing light uses half your brain. This review lists #940, #934, #726, #648, #550, #36 and a dozen other reviews about light.
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- Light does not know time.
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- The light that can be viewed through a telescope is 12,000,000, 000 years old and still ticking.
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---- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
- to: ------- jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
----- 707-536-3272 ---------------- Tuesday, October 4, 2016 -----
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Monday, October 3, 2016

Chemistry to biology

Nanotechnology from Chemistry to Biology. The computer technology is advancing into smaller and smaller architectures. Where is the limit? What are new alternatives that can extend past the limit? Request Review 1846 if interested.

Monday, August 29, 2016

Juno’s mission arriving at Jupiter.

- 1903 - Juno’s mission arriving at Jupiter. The spacecraft has only 20 months to send data from 9 instruments before the intense radiation destroys the electronics. What will we learn about the biggest planet and the evolution of our Solar System?
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-----------------------------1903 - Juno’s mission arriving at Jupiter
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- The spacecraft “ Juno” made its closest approach August 29, 2016 in the first fly-by of the planet Jupiter. It was only 2,600 miles above the surface. It will be days before all the data being collected will begin to be analyzed and months before science can comprehend the new things to be learned.
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- The measurements are being made on the gravitational and magnetic fields, on the deep winds on the surface, and on the planet’s composition. The robotic probe is expected to continue its mission orbiting until February, 2018. Juno was launched August 5, 2011. Five years later it enters its orbit around this enormous gaseous planet after traveling 1.74 billion miles.
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- In order to get a boast of speed Juno had looped around Earth in a fly-by August 9, 2013. Stealing angular momentum from Earth’s gravity it gained another 8,800 miles per hour, reaching the Jupiter system traveling 165,000 miles per hour. ( See Review #1902 regarding the calculations using the Conservation of Angular Momentum ).
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- Juno becomes the fastest man-made object until it fires its engines for 30 minutes to put it into a 53.5 day orbit around Jupiter. The orbit is highly elliptical between 3,100 miles and 1,170,000 miles from the surface. A new orbit will eventually be reduced to 14 days allowing a total 37 orbits in its 20 month mission.
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- Juno carries nine instruments to explore the interior of the atmosphere. To map the gravity and magnetic fields. To track water in the atmosphere. To take pictures of the swirling clouds, the polar region, and the auroras at the poles.
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- The data collected takes 48 minutes, 19 seconds to return to Earth, if all goes well. Juno will be immersed in a strong and variable magnetic field and hazardous radiation. To shield the instruments they are surrounded by a 400 pound titanium vault. Titanium is radiation resistant. It will need it. The spacecraft must endure the equivalent of 100 million X-rays. The camera will have image resolution at 1.8 miles per pixel at its closest approach. ( Visit www.missionjuno.swri.edu/junocam ).
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- Juno is powered by a trio of 29 feet solar arrays that output 500 watts. These solar arrays will receive only 4% as much sunlight as they would orbiting Earth.
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- The instruments will map the deep winds that reach speeds of 384 miles per hour. The atmosphere consists of mostly hydrogen and helium, about the same ratios as our Sun. The instruments hope to measure the global water and ammonia that are in the atmosphere.
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- The magnetic field to be mapped is 1,000 times stronger that Earth’s. This map is created orbiting over the poles. It is designed to help science learn the origin of Jupiter’s magnetism and the nature of the planet’s core. Juno’s microwave radiometer will profile temperatures to a dept of 220 miles where pressures are 200 times Earth’s atmospheric pressure. This radiometer is only expected to survive for 11 orbits.
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- Measurements will be made of the ratio of oxygen to hydrogen and of the amount of water that exists in the atmosphere. Deep in the atmosphere the gravity is so intense that electrons are stripped form the hydrogen atoms and plasma becomes electrically conductive liquid metallic hydrogen. Science thinks this shell of metallic hydrogen might be the source of Jupiter’s magnetic field.
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- The magnetic field generates powerful auroras at the cloud tops that is 1,000 times stronger than Earth’s auroras.
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- Juno’s orbit crosses the paths of moons, Europa, Ganymede, and Callisto making it imperative that there is never an impact to cause pollution. Therefore in 2018 Juno will be sent into Jupiter’s atmosphere to disappear for good.
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- The end of Juno’s mission, February, 2018. But, the data will be analyzed for years to follow. Stay tuned, an announcement will be made shortly.
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- Other reviews available on this subject:
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- #1880 - More about the Juno mission
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- Lists 4 other reviews about Jupiter’s moons and rings.
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---- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
- to: ------- jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
----- 707-536-3272 ---------------- Monday, August 29, 2016 -----
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Friday, August 26, 2016

The Moon and Angular Momentum.

- 1902 - How the Moon uses the Conservation of Angular Momentum. The math involved.
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-----------------------------1902 - The Moon and Angular Momentum.
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- If the moon’s orbit takes longer than a day the planet’s rotation slows down and the moon drifts further away to compensate due to the Conservation of Angular Momentum. Our Moon is drifting away at 1 ½ inches per year.
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- The orbital angular momentum of the Moon is 29 *10^33 kg^2 / second.
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- The rotational angular momentum of the Earth is 7.1 * 10^33 kg^2 / second .
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- The Moon’s orbit has 4 times the momentum as Earth’s rotation momentum decreasing the Earth’s rotation rate by 23 micro-seconds per year. This effect results in the Earth-Moon distance expanding by 1 ½ inches per year in order to restore the Conservation of Energy, the Conservation of Angular Momentum.
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----------------------- Momentum = mass * velocity = mass * distance / time
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--------------------- Angular Momentum = mass * radius ^2 * angular velocity.
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- This formula requires that we define the composition of the distance, or radius of the rotation. In this case we define it as a “uniform sphere”. Angular Velocity is in radians / second , or degrees of rotation per second.
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- To calculate the Angular Momentum of the spinning Earth:
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----------------------- Mass = 6 * 10^24 kilograms
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---------------------- Radius^2 = ( 6.4*10^6 meters )^2
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---------------------- Angular Velocity = 2*pi radians / 24 hours
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---------------- Angular Velocity = 2*pi radians / 86,400 seconds = 7.3 *10^-5 radians per second
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- The rotational inertia of a uniform sphere is:
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----------------------- Inertia - 2/5 mass * radius^2
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------------------------ I = 2/5 m*r^2
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- Of course, the Earth is not a uniform sphere so this calculation is only an approximation. Our calculated value will be 20% too high. But here it is:

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------------ Angular Momentum = 0.4 * (6 * 10^24) * ( 6.4*10^6)^2 * ( 7.3*10^-5)
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------------ Angular Momentum = 7.3 * 10^33 kilograms * meters^2 / second.
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- The more accurate calculation for the Earth’s rotational angular momentum is reduced by 20%:
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------------- Angular Momentum = 7.1 * 10^33 kilograms * meters^2 / second.
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- We now make the same calculation for the Moon’s rotational angular momentum;
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--------------------- Momentum = 2/5 * m * r^2 * w
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---------------------- Mass of the Moon = m = 7.35*10^22 kilograms
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--------------------- Radius = r = 1.74*10^6 meters
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--------------------- Angular Velocity = w = 2*pi / 27 days
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--------------------- Angular Velocity = w = 6.24 radians / 2,332,800 seconds
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-------------------- w = 2.7*10^-6 radians per second
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------------------- Momentum = 0.4 * ( 7.35*10^22 ) * (1.74*10^6 )^2 * ( 2.7*10^-6 )
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-------------------- Rotational Momentum = 2.4 *10^29 kg * m^2 /sec
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- Earth - Moon rotational momentum ratio = 7.1 *10^33 / 2.4 * 10^29 = 30,000. So, the Moon’s rotational momentum is not much of a factor for the Earth-Moon system, 1/30,000th is very small. Let’s try calculating the Moon’s orbital momentum.
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--------------------- Orbital Momentum = m * r^2 * w
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--------------------- m = 7.35 * 10^22 kilograms
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--------------------- r = 385,000 kilometers = 3.85 *10^8 meters
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---------------------- w = 2.7*10^-6 radians per second. It is the same because the Moon makes only one rotation with each orbit around the Earth.
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----------- Orbital Momentum = ( 7.35 * 10^22 ) * ( 3.85 *10^8 )^2 * ( 2.7*10^-6 )
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----------- Orbital Momentum = 29.4 *10^33 kg*m^2/sec
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- The Moon’s orbital angular momentum is 4 times greater than the Earth’s rotational momentum. The Earth’s rotation momentum is decreasing , loosing 23 micro-seconds (23*10^-6 sec) per year. The Moon’s orbital angular momentum is increasing to compensate and maintaining the Conservation of Angular Momentum a constant. The Earth-Moon distance is increasing 1 ½ inches per year.
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- The tidal friction increases the length of a day by only 1 second in 50,000 years. This effect is small compared to the effects of earthquakes and slight changes in the Earth’s internal mass distribution. These mass distribution changes can change Earth’s rotation by as much as one second per year. Thus the introduction of the “leap second” in our time standards.
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- Other reviews available on this subject:
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- #1899, #1900, #1901 about moons in our Solar System.
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---- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
- to: ------- jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
----- 707-536-3272 ---------------- Friday, August 26, 2016 -----
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Wednesday, August 24, 2016

The moons in our Solar System.

- 1901 - The moons in our Solar System. This Review is a summary of the moons around each of the eight planets and new Dwarf Planets. 182 moons discovered so far.
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-----------------------------1901 - Moons around the planets.
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- Review #1900 discussed the moons in our Solar System and the forces that keep them in orbit. This Review #1901 discusses each of the planets with their respective moons that are all outside the Roche Limit.
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- There are only 3 natural moons orbiting the 4 inner planets. Earth has one and Mars has two. Our Moon was created by an enormous collision that the Earth had with a Mars-size object some 4.6 billion years ago. Mars on the other hand captured its two moons as orbiting asteroids, Phobos and Deimos.
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- Like our moon, Phobos and Deimos are tidally locked to Mars, always showing the same face as they orbit. These two captured asteroids were once part of the Asteroid Belt. Phobos is only 14 miles in diameter and Deimos only 7.8 miles in diameter. Phobos’ orbit is at 5,287 miles. Deimos farther out at 14,577 miles taking 30.35 hours to complete a single orbit.
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- These are the inner Rocky Planet moons. Beyond the Asteroid Belt things get much different for the four gaseous planets:
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- Jupiter has 67 known moons, but, if you count smaller “ moonlets” the count is over 200 satellites. The 4 largest moons can be seen with binoculars under good conditions. They were first discovered in 1610 by Galileo using his first telescope.
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----------------- Io is the most volcanically active.
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----------------- Europa likely has a massive subsurface ocean.
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----------------- Ganymede is the largest moon in our Solar System. Even larger than the planet Mercury.
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----------------- Callisto is also thought to have a subsurface ocean.
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- Jupiter’s inner smaller moons have diameters less than 124 miles. These orbit within 124,000 miles of the surface. The outer moons are irregular satellites with more eccentric orbits captured by Jupiter’s intense gravity.
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- Saturn has at least 150 moons and moonlets. 53 or Saturn’s moons have names. 34 of these are less than 6.2 miles in diameter. The inner large moons are Mimas, Enceladus, Tethys, and Dions. These moons have rocky cores but are composed of mostly water ice.
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- Titan is Saturn’s largest moon at 3,200 miles diameter. Titan is large enough to have its own atmosphere, which is primarily nitrogen. There are recordings of hydrocarbons and methane ice crystals in this nitrogen atmosphere. There are liquid methane-ethane lakes at the poles.
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- Uranus has 27 known moons. Titania is the largest at 981 miles diameter. Miranda at 293 miles. Miranda is primarily ammonia and carbon dioxide ice.
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- Neptune has 14 known moons, Triton is the larges at 1,678 miles diameter. It orbits 220,427 miles form Neptune, about the same distance our Moon orbits Earth.
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- Past Neptune are the Dwarf Planets, Pluto’s orbit and beyond. Pluto has the large moon Charon first discovered in 1978. The two smaller moons Nix and Hydra discovered in 2005. The 5th moon Styx discovered in 2012.
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- Charon is so large that Pluto and Charon orbit each other, and are tidally locked together. Ammonia hydrates and water crystals on the surface of Charon suggest active cryo-geysers. Pluto may have a subsurface ocean as well.
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- Other Dwarf Planets include Eris, Haumea, Makemake, and Sedna. Haumea has 2 known moons. Eris has one known moon.
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- More satellites will surely be found in the future. Ganymede is by far the largest, even larger than the planet Mercury. On the smaller size satellites have been found orbiting Jupiter that are only 0.6 miles diameter.
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- Other reviews available upon request on this subject:
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- Review # 1899 - Moon - far-side and rainbows. Also lists 8 more reviews about the moon
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---- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
- to: ------- jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
----- 707-536-3272 ---------------- Wednesday, August 24, 2016 -----
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Tuesday, August 23, 2016

Moons in our Solar System.

- 1900 - How many moons are in our Solar System? What causes a moon to fall out of orbit? How can moons drift away or crash into their planet? What is the Roche Limit?
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-----------------------------1900 - Moons in our Solar System
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- The Earth has only one Moon. Mars has two, Phobos and Diemos. Mercury and Venus, our two inner planets, have none. So, there are only 3 moons orbiting the four rocky planets.
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- It is a whole different story for the 4 outer gaseous planets and beyond:
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---------------------------- Jupiter -- 67 known moons.

---------------------------- Saturn -- 53 known moons.

---------------------------- Uranus -- 27 known moons.

---------------------------- Neptune -- 14 known moons.
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---------------------------- TOTAL -- 161
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- Pluto has 5 moons.
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- So the definition of an orbiting moon needs more refinement. A definition adopted in 2006 has the count for the Solar System:
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----------------------------- TOTAL -- 173 know moons
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- If you include the Dwarf Planets, Pluto and beyond the count is:
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---------------------------- TOTAL -- 182 known moons.
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- It does not stop there:
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-------------------------- 76 known satellites around the asteroids in the Asteroid Belt.
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------------------------- 4 Trojan satellites sharing Jupiter’s orbit.
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-------------------------- 39 near -Earth objects with 2 satellites each.
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-------------------------- 14 Mars crossers
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------------------------- 84 Neptune crossers
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------------------------ 150 small moonlets in Saturn’s rings.
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- You count up all the known satellites orbiting other objects in the Solar System and the count becomes:
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--------------------------- 545 known satellites.
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- There are only 3 natural satellites in the Inner Solar System around the Rocky Planets. Theory has it that Mercury and Venus had moons in the past but they have long ago impacted on the surface.
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------------------------- Our Moon is 3,474 miles in diameter
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------------------------- 27.3% the size of the Earth. That is over one forth the size.
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------------------------ 1.23% the mass of the Earth. The Moon is monthly Earth’s crust.
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- What determines whether a moon will eventually crash into the planet or escape into free space? It is called the “ Roche Limit”.
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- If the moon’s orbit takes longer than a day the planet’s rotation slows down and the moon drifts further away to compensate due to the Conservation of Angular Momentum of the system.
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- If the moon’s orbit is faster than the planet’s rotation then the opposite occurs. The moon makes the planet rotate more quickly and the moon drifts closer to compensate. It will eventually impact the surface of the planet.
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- Our Moon has the first scenario. It is slowly drifting away from Earth at a rate of ½ inch per year.
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- Shortly after the Moon’s formation, 4.3 billion years ago, it was much closer and the Earth was spinning much faster. A day on the Earth was only 6 hours. And, the Moon’s orbit took only 17 days.
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- The Earth’s constant gravity pull eventually stopped the Moon’s rotation. Now, only one face always faces the Earth. And, the Moon’s constant gravity pull has been slowing the Earth’s rotation. To maintain the total angular momentum of the system the Moon has been slowly drifting away to compensate.
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- Today the Moon’s average distance is 238,855 miles. It is in a slightly elliptical orbit with its closest at 225,309 miles and its farthest at 251,904 miles. It takes a little over one second for reflected moonlight to reach the Earth. ( That is also the delay in radio communications).
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- If the Moon’s orbit actually gets close enough to reach the “ Roche Limit” the planet’s gravity will tear the body apart. It all depends on several factors: mass, size, density, composition. Our Earth - Moon limit is calculated to be 59,000 miles. So, we are safe from a Moon impact.
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- At 59,000 mile orbit the Earth’s gravity overwhelmingly over powers the gravity holding the Moon together near-side to far-side. At that point the Moon would turn into a ring of material orbiting the Earth. ( Like the rings of Saturn ). Eventually that orbiting material would crash into the Earth’s atmosphere and some to the surface. That would be one enormous meteor shower, and meteorites peppering the Earth’s surface.
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- For the average comet the Roche Limit is 11,185 miles orbiting Earth. That comet if orbiting the Sun would be torn apart at 808,000 miles.
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- Mars will experience the first moon landing with its moon Phobos. Phobos is orbiting more quickly that a Martian day. Phobos keeps drifting closer and closer to the planet. In a few million years it will be torn into a ring and all the pieces will begin crashing in to the surface.
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- Why don’t our own bonds of our body’s atoms get torn apart ? We are certainly inside the Roche Limit. What is holding us together? It is the electromagnetic forces of the atoms that are much, much stronger that the force of gravity.
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- Now, the same scenario would not work if out body approaches the gravity of a Blackhole. The intense gravity there below the Roche Limit would pull our body apart like a string of spaghetti.
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- All the moons in the Solar System are at least beyond the Roche Limit. Otherwise, they would have already broken up on the surface of their planet.
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- See Review #1901 to learn more about the many moons in our Solar System.
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---- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
- to: ------- jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
----- 707-536-3272 ---------------- Tuesday, August 23, 2016 -----
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Monday, August 15, 2016

The far-side of the Moon and Rainbows

- 1899 - The cow jumped over the far-side of the Moon. The first sight of a new face for the world to see. What did we learn? That rainbows are only in your head.
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---------------------1899 - The Far - Side of the Moon.
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- The Moon orbit’s the Earth showing us only one face. No one saw the far-side until 1959, but, the photo-quality was so poor. The most that could be concluded is that it was very different than the near-side. The large dark maria were not as numerous. Maria is Latin for “ seas”. Instead its surface was mostly bright, rugged highlands, crisscrossed with rays from large, fresh craters.
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- The Moon was two distinct hemispheres of individual character. The maria are ancient lava flows which erupted from the surface 3 billion years ago. The eruptions were caused by the heat from decaying radioactive elements deep under the surface. The heat melted the magnesium and iron-rich mantle producing liquid rock that covered the surface.
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- The flowing magma formed giant impact features called “basins”. Some are more than 620 miles in diameter. The basins were caused by asteroids impacting the Moon some 4 billion years ago. The basins created fractures that allowed magma to break through to the surface.
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- Impact craters and basins cover the entire surface. Not all basins are filled with lava. Something must have caused the volcanic flooding of almost all the near- side basins but only a few of the far-side basins.
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- The Moon’s crust consists of aluminum and calcium rich rocks. The Moon must have been nearly totally molten covered by an ocean of magma in which these low density minerals floated to the surface. The denser iron-rich minerals became the “ mantle”. It was the mantle that slowly re-melted due to the heat from radioactive elements. This magma erupted as maria basalts.
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- The Moon’s crust is some 20 miles thick similar to parts of Earth’s crust. The crust on the far-side is thicker than on the near-side. Also, the Moon’s center of mass is offset a couple miles in the direction of Earth. This is what likely caused the Moon’s rotation to synchronize with its orbit of Earth.
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- The half-life of the radioactive elements is 4.5 billion years where by it decays to lead. The internal heat generated explains much of the surface, but, the rest is the result of a complex history of impacts, mare flooding, and other random geological events. We only partly understand why the near-side and far-side of the Moon are so different. Maybe the cow knows.
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- Another strangness is the “giant in the room”. Compared with other rocky planets our Moon is so huge. It’s crust is also similar the Earth’s rock having the same oxygen isotopes. Minerals composed of sodium and calcium aluminum silicates are the same as Earth’s curst.
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- The Moon’s formation occurred 4.6 billion years ago when two planets occupied the same orbit around the Sun collided in a grazing angle. The ejected material formed Saturn-like rings around Earth. Over thousands of years these rings accreted into a huge mass of orbiting particle eventually forming the Moon we have today.
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- The Full Moonlight is 400,000 times dimmer than Sunlight. This is not intuitive because our eyes protect us from huge brightness changes. The 6th magnitude stars mark the lower limits of human visual experience. The upper limits is 9 trillion times brighter.
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- We only see dimness in black and white. With more light intensity we can see colors. But, these colors only occur in our brains. The photons are only electromagnetic pulses. They have neither luminosity or color. Just as magnetism and electricity is not visible, neither are photons. Instead photos deliver an electromagnetic force that excite the cells in the back of the eye. The impulses for these cells produce the subjective perception of light and color. That is why the rainbow of colors occurs strictly inside your head.
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- Your brain’s 100 billion neurons are what creates the brightness and colors in our visual Universe. It will be hard to convince you that the visual scene external to your eyes is only an illusion.
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- The photons originated in the Sun. The brightness of the Sun is 400 trillion, trillion watts. What reaches us is only 1,000 watts per square meter. The photons do not come from the Sun’s disk that we see. Instead the inner most core , 1/200th of the volume , produces photons in the center compact fusion generator. The outer edge is the photosphere where these photons are released. This edge is only a few hundred miles thick.
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- Eight minutes later the photons show up on Earth. But, none turn in to colored light until your brain does its trick. The energy of the photons depends on the frequency of the photon oscillations. Higher frequencies carry more energy. The frequency also controls the color the eyes detect and the brain registers. The frequencies increase from red light to blue light. The rainbows are only in you head.
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- Other reviews available on this subject:
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- #1704 - There are two sides to get a Full Moon. The size of the Moon is 27% the size of the Earth. However, the Moon is only 1.2% the mass of the Earth. To get a rocket to leave the Moon it needs to accelerate to only 5,400 miles per hour.
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- #1681 - Enceladus and Europa might support life? We have 173 moons orbiting our 8 planets. Over 150 asteroids also have orbiting satellites.
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- #1678 - Moon history from the beginning. The Moon has almost no atmosphere. You can count cratering yourself on website “NASA Lunar Reconnaissance Orbiter” www.moonzoo.org The Moon is 250,000 miles away but these images are from only 400 miles away.
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- #1450 - Full Moon on Doug’s birthday.
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- #1291 - Two Moons over Miami. The early Universe was a chaotic place.
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- #1243 - What is behind the Man in the Moon? As the Moon cooled it preserved some water in the form of hydroxyl. The Moon is spiraling away in its orbit 1.5 inches each year.
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- #1651 - Moon may be the best habitats for life.
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- #64 - written November 11, 2004. What you did not know about our Moon.
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