JimsAstronomy

Thursday, December 25, 2014

Critical Thinking, best course I ever took.

-1710 - Critical Thinking - The best course I ever took? It takes practice to think critically. Some structure to your thinking by asking questions.
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--------------------- -1710 - Critical Thinking - The best course I ever took?
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- Problems are what you make them.
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- You have only 4 ways to analyze a problem:
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---------------------- Either things are what they appear to be;
---------------------- or, they neither are nor appear to be;
---------------------- or, they are and do not appear to be;
---------------------- or, they are not and yet appear to be.
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- The rules for “ Critical Thinking”:
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- Reporter's method of classifying questions:
----------------- who ?
-----------------what ?
----------------- where ?
-----------------when ?
----------------- why ?
----------------- how ?
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- Critical Thinking's method of classifying seven basic questions:
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----------------- Is it important?
---------------- Does the question need clarification?
---------------- What are the assumptions?
---------------- Is this true? What is the evidence?
---------------- Why?
---------------- What are the consequences?
---------------- What action should I take?
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1) Go/No Go Is this important?
--------------- Is this interesting?
--------------- Why think about this?
--------------- Why consume time or neurons on this?
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2) Questions of CLARIFICATION
--------------- What do you mean?
--------------- Do I understand fully the question or the problem?
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3) Questions of ASSUMPTION
--------------- What is being assumed?
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4) BASIC CRITICAL QUESTIONS
--------------- Is this true?
--------------- What's the EVIDENCE?
--------------- What's your source?
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5) BASIC SCIENTIFIC QUESTION
--------------- Why?
--------------- What caused this?
--------------- What's the EXPLANATION?
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6) IMPLICATIONS
--------------- What will be the effect?
--------------- What consequences?
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7) ACTIONS
--------------- What should be done?
--------------- What should I DO?
---------------------- Remember, doing nothing is a decision of no action.
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Learning starts when driven by the student's thoughts:
Follow the student's agenda, not yours.
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Questions are the tools for learning.
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Think critically about BOTH sides of an argument.
Begin with the hypothesis, the thesis.
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DEBATE is when the purpose is to persuade the other party.
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DIALOGUE is when the purpose is to help one another think more clearly,
more personally, more critically.
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The more education you have, the more you are able to overcome your fear
of asking embarrassing questions. Ask a stupid question and you may feel stupid, don’t ask it and you remain stupid.
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Questions of clarification:

Definitions, do we need to define any terms or hypotheses
Classifications, do we need to categorize things
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“Meaning building” questions: examples:
word etymology, what do the words mean?
Comparisons, what are similarities, or analogies?
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Academic motivation vs. intellectual motivation
(Do you really want to learn , if so a teacher will come?).
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Ambiguous vs. vague.
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Euphemisms and evasive words.
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Questions about ASSUMPTIONS: If the assumption is false would it make
the entire sentence be inaccurate?
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The basic critical question: Is this true?
Belief
Action
Value
Use of Language
Everything is Relative
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ARGUMENT = an idea that in support of another idea gives a direct
answer to the Basic Critical Question.
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The logical STRUCTURE of statements.
Separation of independent ideas.
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UNDERSTAND FIRST, THEN EVALUATE
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Sources - is it clean?
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does it have credibility?
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is it a rationalization?
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Being objective - if you're working hard to understand both sides

We use "stereotypes" all the time.
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Learn to live with questions. You don't always have to have answers.
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"I don't know",
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"I'm of two minds,"
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"I can see both sides of the issue, and haven't made up my mind", is
fine.
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RATIONALIZATION - does not express a true or a real reason.
Test: apply double negatives and see if the argument is still true.
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Real thinking, true dialogue is inarticulate honest, hesitation way of thinking.
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You must feel safe to open up.
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However, people find credibility in people who talk with confidence,
convincing, well dressed, good looking, good personality, earthy, the
most credible person in the US is...........Johnny Carson. Or, is it Barack Obama?
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People are sheep.
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People who are really trying to learn find credibility with knowledge,
experience, honesty, true dialogue, asking critical questions.
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Being objective - means weighing everything by the same standard.
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Humans have a problem using a tool and studying a tool at the same time.
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Doing a task and thinking how to do the task. Using a computer and
learning how a computer works.
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Collaborative learning = is dialogue, teamwork, working together to learn
together.
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These ideas about learning are in the cutting-edge of today's academic
and "the cutting-edge is the booting-edge."
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College graduates today will have four to ten "careers" not the one they
are thinking about. Critical thinking is a skill that will transcend all
ten of those careers. Other attributes for success will be flexibility,
ability to learn new things, teamwork with cultural diversity (global),
communications skills, enthusiasm for "change."

This Stanford course by Professor Matthies was the best college course
I've taken - wish I had it 30 years ago.
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(1) "The Question Book"
Tools for Critical Thinking
Efficient Thinking
Collaborative Thinking
By Dennis Matthies (6-26-91)
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RSVP, with comments, suggestions, corrections. Index of reviews is available. -
-- Some reviews are at: -------------------- http://jdetrick.blogspot.com -------
---- email request for copies to: ------- jamesdetrick@comcast.net ---------
---- https://plus.google.com/u/0/ , “Jim Detrick” ----- www.facebook.com
------ www.twitter.com , --- 707-536-3272 ---- Thursday, December 25, 2014
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Tuesday, December 23, 2014

Where did Earth get its water?

- 1709 - Water from Comets, or , is there another explanation? New data is coming from the Rosetta mission to Comet 67P and the Curiosity Rover mission on Mars. What are the conclusions as to where Earth got its water?
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----------------- 1709 - Water from Comets, or , is there another explanation?
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- Our Solar System is 4,600,000,000 years old. Our planet is the 3rd rock from the Sun. Mercury, Venus, Earth were all too hot in the early evolution of the planets for them to retain liquid water. If the planets had surface H2O it would have all boiled off before the planets could have cooled down.
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- So, 75% of Earth’s surface is covered in water - ice. Where did this water come from?
One theory is that it came from all the asteroids and icy comets that were colliding with the Earth during its early evolution.
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- Evidence of all these collisions can be seen looking at the pock marked surface of our Moon. The Moon has no atmosphere so it would have lost all of its water if it did arrive this way. But, the Earth’s gravity was strong enough to retain an atmosphere. A dense atmosphere could hold the water, recycle it to the surface, and keep it from escaping into space.
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- So, did our water come from icy comets?
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- The Rosetta spacecraft has been visiting Comet 67P since August 6, 2014. One goal in its mission was to sample water if it were there and compare the H2O “fingerprint” with the H2O on Earth. The key is the amount of Deuterium in the water. Deuterium is a form of hydrogen with an additional neutron in the nucleus next to the proton. It is an isotope of normal hydrogen ,”H”, which is an atom with just one proton and one electron.
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- The ratio of Deuterium to Hydrogen is created unique to its time and place in the evolution of the Solar System. That is the “fingerprint”. Common ratios mean the water first formed in a common time and place.
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- The Comet 67P is now orbiting between Earth and Mars. At its furthest elongation of orbit it reaches just beyond Jupiter. The Comet 67P takes 6.5 years to complete one orbit around the Sun.
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- The Comet 67P has a Deuterium / Hydrogen ration that is 3 times greater than that in Earth’s oceans. Another Comet Hartley2 was measured on a different space mission and found to have an even greater D/H ratio. These result make it unlikely that these comets brought their water to Earth.
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- Astronomers have studied meteorites that hit the surface of Earth coming from Asteroids that normally orbit between Mars and Jupiter. These meteorites have mush lower water content, but, the D/H ratio is a close matching that that found in Earth’s oceans. Asteroids are dry, but if there were a large enough number of them striking Earth’s surface they still may be what brought water to Earth.
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- But, could there be another explanation?
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- Maybe the Earth had sequestered a large water supply deep in its interior. Plate tectonics could have slowly released the water to the surface after the surface had cooled down. The oceans may have been fed from below?
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- New rock and curst comes to the surface at the mid-ocean ridges. Could it be delivering water at the same time? We live on the only planet having liquid water on its surface. We also live on the only planet with active plate tectonics.
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- Rocks that appear dry can actually contain water. Hydrogen atoms can become trapped inside natural voids and crystal defects. Of course, oxygen is plentiful in the surrounding minerals. There are certain chemical reactions that free the hydrogen to bond with oxygen to become H2O, water. The subsurface mantle where this could happen is 80% of Earth’s total volume.
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- Science has tried to recreate these same chemical reactions. The elements are put under high pressure using a diamond anvil and high temperatures using a laser to simulate the conditions deep below the Earth’s surface.
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- The mineral bridgmanite which is a form of olivine. The mineral ringwoodite another form of olivine. The mineral garnet have all been tested to simulate conditions 500 miles deep.
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- The conclusions from the experiments were that Earth’s garnet may hold half as much water in its depths as is currently on the surface. This equates to about the volume of water that is in the Pacific Ocean.
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- Another avenue of study is the water on Mars. Is water still there and how did it get there? Ancient Mars maintained a climate that could have produced long-lasting lakes and rivers.
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- NASA’s Curiosity Rover has uncovered evenly layered rocks that are the typical pattern of lake-floor sedimentary deposits. This would suggest repeated filling and evaporation of Martian lakes. This cycle occurred over and over again.
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- The Rover also crossed over a boundary dominated by rivers to one dominated by lakes in its journey across the surface. The water is gone now. But, is it still deep underground?
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- Methane has been detected seeping out of the ground. Could this gas come form a deep underwater reservoir that is still chemically active?
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- How Earth and Mars got their water is a mystery yet to be solved. Without water there is not life as we know it. With water who knows what else we will find. Stay tuned, there is much more to learn.
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RSVP, with comments, suggestions, corrections. Index of reviews available ---
--- Some reviews are at: -------------------- http://jdetrick.blogspot.com -----
---- email request for copies to: ------- jamesdetrick@comcast.net ---------
---- https://plus.google.com/u/0/ , “Jim Detrick” ----- www.facebook.com ---
---- www.twitter.com , --- 707-536-3272 ---- Tuesday, December 23, 2014 ---
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Monday, December 22, 2014

Colors in Astronomy?

- 1708 - My New Year’s Resolution. The colors in astronomy. This review explains how astronomers gets those beautiful color pictures of nebulae.
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----------------- 1708 - My New Year’s Resolution. The colors in astronomy.
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- I have a confession to make. All those beautiful astronomy pictures I have been attaching to my reviews, they are not real, they use “ false colors” to make the picture look beautiful. If you were looking out the window of your space ship those beautiful nebulae would be a mixed reddish color, or blurry gray.
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- Hydrogen atom emissions are red, 656.3 nanometers wavelength, and, there is so much hydrogen gas in the nebulae it would swamp out any other colors that were there . And, even then the light intensity must be high enough for you to see colors, otherwise your eyes only see gray.
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- So, what do astronomers do to fake these pictures?
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- They use filters to separate the wavelengths out of the gray - white light. Take a gray image. Reflect it off a diffraction grating to separate the wavelengths. The diffraction grating is simply etched glass, or plastic, with closely spaced lines. You can see diffraction grating by looking at the CD or DVD in the light. Witness the rainbow of colors coming from the reflection. That is a rainbow of different wavelengths of light.
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- One filter in the telescope would pick out the red hydrogen gas color - wavelength. A second filter would pick out the green oxygen gas color. A third filter would pick our the pink sulfur emissions color.
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- Now, you put these separate pictures on a CCD, digital camera. Upload it to a computer . Now assign any “ false color” you want to each of the separate images. Play around until you make the cover of Astronomy Magazine. Now you know the truth. I feel much better.
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- Where do colors come from? Colors are a special part of the light spectrum, the visible part of the full electromagnetic spectrum that occupies 400 nanometers to 700 nanometers wavelengths.. Each individual color depends on the individual wavelength. Cones in your eyeball match the size of these wavelengths. The light emissions come from the atoms of the elements. Atoms are different because they have a different number of protons in their nucleus matching the same number of electrons orbiting the nucleus.
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- The electrons occupy different energy levels as they orbit the nucleus. in order to jump from a higher to lower energy level the electron must emit that specific amount of energy. Each change requires that specific amount of energy. Energy comes in bundles called photons.
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----------------------- Photon Energy = h * c / w
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---------------------- Photon Energy = 6.626 *10^-34 Joules * Seconds * 3 * 10^8 meters / second // the wavelength.
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- Planck’s Constant, “h”, and the speed of light, “c”, are constants. So , energy is inversely proportional to the wavelength. The shorter the wavelength the greater the energy. Blue light contains more energy than red light. Ultraviolet contains more energy than infrared.
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- The hydrogen atom emits blue light at 486.1 nanometers wavelength when the electron jumps from energy level 4 to energy level 2. The electrons emits red light at 656.3 nanometers wavelength when the electron jumps from energy level 3 to energy level 2. Blue light carries more energy than red light because it had to jump further crossing more energy levels.
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- It is not really cheating. It is more use of artistic license in the name of science. Or, maybe astronomical use of educational license.
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- Sorry to break it to you, but, the Hubble Space Telescope can not even take color pictures. In fact, your eye, as wondrous of an instrument as it is, cannot distinguish any colors if the light intensity is at too low a level. The eye has a problem seeing colors especially at the edges of the visible spectrum, the blue edge, or the crimson edge. So, we just “enhance” the image for you, thanks to the power of filters and computers.
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- A single photon is a small bundle of energy. Here is the energy of blue light at 486.1 nanometers wavelength:
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----------------------- E = h * c / w
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---------------------- E = 6.626*10^-34 joule * sec * 3 *10^8 m/sec // 486.1*10^-9 m
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----------------------- E = 4.08 *10^-19 Joules
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- The energy of a photon of blue light is 0.000,000,000,000,000,000,408 Joules
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- A 100 watt light bulb puts out 100 Joules per second in photon energy. Sorry, for deceiving you about the beautiful images in astronomy. But, it is for our own good. It is not enough to have the best product, you have to have good marketing as well. Stay tuned for more revelations in astronomy.
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RSVP, with comments, suggestions, corrections. Index of reviews available ---
--- Some reviews are at: -------------------- http://jdetrick.blogspot.com -----
---- email request for copies to: ------- jamesdetrick@comcast.net ---------
---- https://plus.google.com/u/0/ , “Jim Detrick” ----- www.facebook.com ---
---- www.twitter.com , --- 707-536-3272 ---- Monday, December 22, 2014 ---
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Saturday, December 20, 2014

Comet being studied by Rosetta spacecraft?

- 1707 - Comet being studied by Rosetta spacecraft. We are learning the composition of a comet that is 4,600,000,000 years old. It was born when the Solar System was first formed.
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--------------------------- - 1707 - Comet being studied by Rosetta spacecraft
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- This picture of the comet landscape is amazing. This “ dirty snowball” is 4,600,000,000 years old. We have 2 spacecraft, one lander and one in orbit, that are analyzing the composition of the comet. Its composition should be unchanged since the Solar System first formed.
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- The spacecraft took a journey of 10 years to reach this comet orbiting between Mars and Jupiter.
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- The size of the Comet 67P is measured in two lobes. One lobe is 2.5 by 2.0 By 0.8 miles and the smaller lobe is 1.6 by 1.6 by 1.2 miles. See Review # 1692 to learn how the first calculations put the volume at 9,400 million cubic meters. With that estimate the density came out to be 300 kilograms per cubic meter.
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- ------------------------------ Density = Mass / Volume
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--------------------------------- Density = (2.8 * 10^12 kilograms) / (9.4 *10^9 meter^3)
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-------------------------------- Density = 300 kg / m^3
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- This new calculation after more measurements were made put the density higher at 400 kg / m^3. The volume at 7,000 million cubic meters.
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------------------------------- Density = (2.8 * 10^12 kilograms) / (7.0 *10^9 meter^3)
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------------------------------- Density = 400 kg / m^3
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- This density for the comet is less than half that of pure water which is 1,000 kg / m^3. The comet would float in the Pacific Ocean, if it landed softly enough. But, so would the planet Saturn if the ocean was big enough. Saturn’s density is 687 kg/m^3.
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- Here is the density profile of the Solar System objects in kilograms per meter ^3:
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-------------------------------- Saturn ----------- 687 kg / m^3
-------------------------------- Ash -------------- 800 kg / m^3
-------------------------------- Water ----------- 1000 kg / m^3
-------------------------------- Uranus --------- 1271 kg / m^3
-------------------------------- Jupiter ---------- 1326 kg / m^3
-------------------------------- Sun -------------- 1408 kg / m^3
-------------------------------- Sugar ------------ 1600 kg / m^3
-------------------------------- Neptune -------- 1638 kg / m^3
-------------------------------- Pluto ----------- 1830 kg / m^3
-------------------------------- Titan ----------- 1880 kg / m^3
-------------------------------- Granit ----------- 2700 kg / m^3
-------------------------------- Moon ----------- 3344 kg / m^3
-------------------------------- Europa ---------- 3018 kg / m^3
-------------------------------- Diamond -------- 3510 kg / m^3
-------------------------------- Mars ------------- 3933 kg / m^3
-------------------------------- Titanium -------- 4500 kg / m^3
-------------------------------- Venus ------------ 5243 kg / m^3
-------------------------------- Mercury -------- 5427 kg / m^3
-------------------------------- Earth ------------ 5514 kg / m^3
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- Earth is one of the densest objects in the Solar System. As the comet approaches closer to the Sun it will start to outgas and create a comet tail. This will allow a detailed analysis of the comet’s composition. Already some of the elements have been identified:
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--------------------------------- Water ---------------------------- H2O
--------------------------------- Carbon monoxide --------------- CO
--------------------------------- Carbon dioxide ----------------- CO2
--------------------------------- Ammonia ----------------------- NH3
--------------------------------- Methane ------------------------ CH4
--------------------------------- Methanol ----------------------- CH4O
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- The spacecraft will stay with the comet for another year ( See Review #1696 ). Its closest approach to the Sun will occur in August 2015. Stay tuned, there is much more to learn.
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(1) Comets put simply are a planet that did not get formed from all the pieces in the early Solar System. Asteroids are pieces the same as comets but they are denser and rocky orbiting between Mars and Jupiter. Comets are icy pieces outside the orbit of Neptune. Of course, gravitational disturbances for all these pieces flying around often send a piece away from its home.
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(2) Other Reviews available on the subject:
#1623 - Comets are dirty snowballs.
#1612 - How many comets make a close flyby?
# 1600 - Comet ISON
# 1338 - Did comets bring water to Earth?
#1316 - The 5 comets we have visited.
#1292 - Using Calculus to measure the mass of a comet.
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RSVP, with comments, suggestions, corrections. Index of reviews available ---
--- Some reviews are at: -------------------- http://jdetrick.blogspot.com -----
---- email request for copies to: ------- jamesdetrick@comcast.net ---------
---- https://plus.google.com/u/0/ , “Jim Detrick” ----- www.facebook.com ---
---- www.twitter.com , --- 707-536-3272 ---- Saturday, December 20, 2014 ---
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Thursday, December 18, 2014

January 2015 Watch Venus and Mercury and compare?

- 1706 - January 2015 watch for Mercury and Venus, low in the western sky. These two planets could not be more different. Try this review for comparisons.
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--------------------------- - 1706 - January 2015 watch for Mercury and Venus.
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- There are two planets between us and the Sun. Venus, then Mercury. Neither have a moon. We have one moon, Mars has two and Jupiter + Saturn have 129 moons.
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- January, 2015, Mercury can be viewed with binoculars low in the western sky. Venus will shine beside it at -3.9 Magnitude. Mercury will be 3 degrees lower right to Venus and 4 degrees above the horizon. ( One degree is your thumb at arms length. A Full Moon is ½ degree.)
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- On January 21 Mercury will b 5.5 degrees below the crescent Moon.
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- Neither Mercury nor Venus have a “ daily” spin. A single rotation takes “months“. A day on Venus takes 243 days with the rotation being opposite to the rest of the planets. A year takes 225 days. The rotation is so slow you could walk faster around the planet than the speed with which it is turning. To be on Earth’s equator you would have to walk 1,000 miles per hour to keep up.
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- The density of Mercury and Venus are similar to Earth’s: mass / volume = kilograms / meter^3 , diameter is in miles:
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------------------------- Mars -------------------- 3,933 kg/m^3 ----- 4,225 miles
------------------------- Venus ------------------- 5,243 ---------------- 7,518
------------------------- Mercury ---------------- 5,427 ---------------- 3,000
------------------------- Moon ------------------- 3,340 ----------------- 2,159
------------------------- Earth -------------------- 5,514 ----------------- 7,927
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- Venus has tremendous atmosphere. Its barometric pressure is equivalent to being 3,000 feet under the ocean. That would crush any submarine, let alone any spaceship.
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- Mercury has virtually no atmosphere. Its surface is as dark as an asphalt parking lot. In contrast Venus is the brightest “star” in the sky. Venus Reflectivity is 75% compared to Earth’s Reflectivity of 29%.
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- Venus orbit’s the Sun in a near perfect circle at 79,200 miles per hour. Mercury has an elongated orbit that expends out 43,000,000 miles to as close to the Sun as 25,500,000 miles. Earth’s orbit is 93,000,000 miles and circular.
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- Venus is almost upside down compared to the disk of the Solar System. It is tilted at 177 degrees. Mercury on the other hand has almost no tilt at all, nearly perpendicular to within 1/30th of a degree. Mercury spins 3 times with 2 rotations around the Sun. Three days is exactly 2 Mercury years. (Year = 88 days. Day = 58.6 days Resonance 3:2 = 3*58.6 = 88*2 = 176 days.)
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- Because the Mercury orbit is so elongated the size of the Sun grows 150% larger and 200% in radiation intensity during its short year.
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- Venus does not have any day to night temperature change. It averages 860 F. It’s a pressure cooker with a dense atmosphere that keeps everything at 860 F. But, the pressure is so great water would not boil until it was 500 F.
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- Mercury’s temperature ranges over 1,100 F. Cold enough to liquefy oxygen at -325 F to hot enough to melt lead at 860 F. The core of Mercury is 81% of its mass. The crust is 289 miles thick and contains 19% of the planet’s mass.
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- Other Reviews about Mercury request: #1479, #1478, #1369, #1165, #815, # 44.
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- Other Reviews about Venus request: #1480, #945, #587.
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RSVP, with comments, suggestions, corrections. Index of reviews available ---
--- Some reviews are at: -------------------- http://jdetrick.blogspot.com -----
---- email request for copies to: ------- jamesdetrick@comcast.net ---------
---- https://plus.google.com/u/0/ , “Jim Detrick” ----- www.facebook.com ---
---- www.twitter.com , --- 707-536-3272 ---- Thursday, December 18, 2014 ---
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Tuesday, December 16, 2014

Radiation, how much is harmful?

- 1705 - Radiation. Energy in the sub-atomic world can come in waves or particles. How much radiation is needed before it is harmful to your health? How will radiation affect spaceflight? Can the risk be measured?
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--------------------------- 1705 - Radiation
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- Radiation can hurt you. Yes, or it can help you if you need an X-ray, or some medical treatment. Radiation in the form of electromagnetic waves covers the spectrum of 24 orders of magnitude. That is 10 times 24 times magnitudes of energy. In electron volts it ranges from:
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---------- 3 hertz electric power ---------- 0.00000000000000 249 electron volts
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------------------- Gamma Rays ---------------- 2,490,000,000 electron volts
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- In between these extremes of long wavelengths to short wavelengths we have a spectrum of wavelengths:
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------------------------ Radio
------------------------ Microwaves
------------------------ Infrared
------------------------ Visible red -- 700 nanometers ---- 0.356 electron volts
------------------------ Visible blue --400 nanometers ----- 0.624 electron volts
------------------------ Ultraviolet
------------------------ X-Rays
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- The shorter the wavelength , the higher the energy.
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- Radiation can also be particles. Cosmic Rays are not rays, ( a misnomer ) they are subatomic particles, mostly protons.
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- These high energy waves and high velocity particles can break atoms apart. Atoms that hold your body together. Radiation can damage genes, and can cause cancer, the mutations of cells.
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- Most of the radiation we experience comes from our Sun. But, it can come from radioactive dirt, elements like Uranium. Or, the potassium in bananas. Or, it can come from outside our Solar System, from supernovae, exploding stars, or, from Blackholes.
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- We are very fortunate that Earth’s atmosphere blocks most of the harmful radiation before it reaches the surface.
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- To quantify radiation we will introduce a unit of radiation called “ millirems” One “rem” carries a 0.055% chance of eventually developing cancer. A “millirems” is 1/1000th of a rem. ( See footnote ( ))
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- The average person receives 360 mrem per year. In the U.S. the average is 610 mrem. The additional radiation in the U.S. comes form X-rays, CAT Scans, and radon gas oozing out of the ground.
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- Hard to believe but you get 0.010 mrem for eating one banana. The potassium is good for you, but, it comes at a price.
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- If you lived 50 miles from a nuclear power plant you could receive 0.009mrem per year. More if you eat a lot of bananas.
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- If you frequent high elevations like airplane pilots and flight attendant you have a 1% greater occurrence of cancer compared to surface dwellers.
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- A whole body CT scan can give you the same amount of radiation as a survivor of the atomic bomb blast at Hiroshima, one mile from ground zero.
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- Astronauts on excursions on the Moon received radiation without an atmosphere for protection. They reported seeing flashes and streaks crossing their field of vision. Actually these were Cosmic Rays, mostly protons, ripping through their brains.
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- We were a week on the Moon. What is going to happen to astronauts on a one year trip to Mars?
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- We have some data from the spacecraft that delivered the Curiosity Rover to Mars. The results of radiation measured was equivalent to getting a whole body CT scan every 5 days for a year. This is the same as being a Hiroshima survivor , one mile from ground zero, 24 times over a year. The same bomb goes of twice a month.
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- A round trip mission to Mars would have the radiation exposure of 66,240 mrems.
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- This is equivalent of an average persons exposure over a 184 year lifetime. In the U.S. it would be a 107 year lifetime. ( 66,240 / 620 = 107 years ). A trip to Mars would increase the risk of dying form cancer by 4%. And, this exposure that was measured did not include any major solar flares occurring. And, it did not include any time on the Martian surface. It was only the trip there and back. It assumes astronauts could find caves or shelter of some sort to protect themselves from radiation once on the surface.
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- Mars has magnetosphere, or appreciable atmosphere to protect the surface from radiation from space. But, astronauts could become cave dwellers like we started out on this planet.
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- Radiation is a problem that needs to be solved if we are going to have safe space exploration. It is not enough to restrict bananas from astronauts diets. We need technology to again come to the rescue. We have a few years to work on it. A trip to Mars is a few decade in our future, if we don’t blow ourselves up with atomic bomb radiation in the meantime.
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- Stay tuned, there is still more to learn.
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- (1) See Cosmic Rays:
- #1659 - Cosmic Rays are ionized atomic nuclei traveling at near light speeds. the energy of Cosmic Rays spread over 12 order of magnitude from 10^8 to 10^20 electron volts.
- #1624 - Cosmic Rays coming from supernovae explosion and their accelerating shockwaves.
- #1568, #1496, #1377 - Cosmic Rays and Gamma Rays
- #810 - Sunspots and Cosmic Rays
- #709 - The risks of space travel.
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- (2) Here is how radiation causes damage to your body. Energy is absorbed when ionization occurs. Ionization is when a neutral charge separates into a positive charge and a negative charge, a free proton and free electron.
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- Chemical bonds are broken when this energy is absorbed destroying needed substances in a living cell. The ions may induce abnormal chemical reactions in the cell. The cell could just die. The cell could become a cancer. The gene may be mutilated causing an abnormal offspring. Cells in the body that reproduce rapidly are the most susceptible to this radiation damage.
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- (3) Radiation effects is an inexact science. When the body absorbs an ionized radiation particle or wave it is “ one dose of radiation”. How many doses are harmful? It is nearly impossible to quantify the effect of a “ dose “ of radiation on the human body. There are too many variables . A single alpha particle could cause more damage that 1,000 X-rays. It just depends.
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- How do you measure it? Science has come up with several measurement units: Roentgens, Grays, Sieverty, Rads, Rems. 1 Gray = 1 Joule / kilogram. The rem, or millirems is the one selected in this review.
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- (4) When you get down to the subatomic level particles and waves are the same thing. Their behavior is quantified in quantum mechanics math.
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------------------------ E = h*f , Energy = Planck’s Constant * frequency
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- But, the answer is not a single number. The math conclusions from quantum mechanics requires predictions about the probabilities of different outcomes from an event. It can not predict an outcome of a single event with certainty. Probabilities quantify the amount of uncertainty in the answer.
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- (5) How much radiation do you get from ordinary sunlight? How does that compare to the radiation from a 50,000 watt TV broadcasting station?
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- Solar energy arriving on the surface of the Earth is 1000 watts / meter^2.
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- This energy arrives as an electromagnetic wave. A magnetic wave traveling perpendicular to an electric wave. The amplitude of the electric field, “Eo”, can be calculated by:
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--------------------- Eo^2 = 2 * I / c * eo
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--------------------- “c” is the speed of light = 3 * 10^8 meters / second
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------------------- “eo” is permittivity of free space = 8.854*10^-12 Coulombs^2 / Newton* meters^2.
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- ------------------ “I” = power / surface area = 1000 watts / meter^2
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--------------------- “P” = power = watts = volt * Coulomb / sec = volts*amperes = Joules / sec.
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-------------------- “ V” = volt = Joule / Coulomb = Joule / ampere*sec.
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-------------------- “E” = Energy = Joules = mass * velocity^2 = m*v^2
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-------------------- “ F” = Force = Newton = Joule * meter = mass * acceleration = energy over distance.
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---------------------- Eo^2 = 2 * 1000 / 3*10^8 * 8.854*10^-12 volts^2 / meter^2
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--------------------- Eo^2 = 75*10^4 volts^2 / meter^2
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----------------------- Eo = 868 volts per meter , radiation arriving from sunlight.
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----------------------- Amplitude of the magnetic field, Bo = Eo /c
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----------------------- Bo = 0.3*10^-5 Tesla
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----------------------- Tesla = kg / Ampere * sec^2
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- That does not tell us much until you compare the power of sunlight to the power of a 50,000 watt TV broadcast.
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---------------------- I = Power / 4 *pi*r^2
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--------------------- Eo = 0.02 volts per meter, radiation from the TV broadcast.
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- Sunlight provides 43,000 more radiation that a 50,000 watt TV broadcast station. ( 868 v/m / 0,02 v/m)
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(6) The average exposure is 360 millirems per year. If one is classified as an “occupational radiation worker“, as astronauts are, then the maximum radiation dose is limited to 5,000 millirems per year. Radiation can come in a single dose or a long exposure. If a single dose 75,000 brings on radiation sickness, nausea. If you receive 300,000 millirems over 30 days you have a 50 / 50 chance of death. Here are examples of the average radiation the average person might receive:

----------------------------- Single dose

------------ CT Scan --------------------------- 1,100 millirems
------------ X-ray ------------------------------ 80 millirems
------------ Mammogram ------------------------ 13 millirems
------------ Panoramic Dental X-ray ------------ 1 millirems

------------------------------Long Exposure

------------ Average person --------------------------- 300 millirems /year
------------ Average medical exposure ---------------- 53 millirems /year
------------ Potassium in the body --------------------- 39 millirems /year
------------ Natural gas in the home -------------------- 9 millirems /year
------------ Eyeglasses containing thorium ----------- 10 millirems /year
------------ Drinking water ------------------------------- 5 millirems /year
------------ Building materials --------------------------- 3 millirems /year
------------ Airplane trip at 39,000 feet ---------------- 0.5 millirems /year

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RSVP, with comments, suggestions, corrections. Index of reviews available ---
--- Some reviews are at: -------------------- http://jdetrick.blogspot.com -----
---- email request for copies to: ------- jamesdetrick@comcast.net ---------
---- https://plus.google.com/u/0/ , “Jim Detrick” ----- www.facebook.com ---
---- www.twitter.com , --- 707-536-3272 ---- Tuesday, December 16, 2014
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Sunday, December 14, 2014

The two sides to the Moon?

- 1704 - There are 2 sides to a Full Moon? Why are they so different. Here are the current theories.
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--------------------------- 1704 - There are 2 sides to a Full Moon?
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- Our Moon is tidally locked with mother Earth. The same side of the Moon always faces us. We call it a Full Moon , but, we only see a “Half Moon“. The Moon rotates one revolution ( one moon day) with the same period as it revolves once around the Earth.
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- It was 1959 before we got the first blurry images of the far-side of the Moon. The far side is much different than the “ Full Moon” side that we see. The crust on the far side is much thicker and more densely cratered. The flat plains of “lunar maria” we see is missing on the far side.
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- On the near-side “maria” cover 30% of the surface. These “seas” on the Moon look darker because they are made of iron basalts. The lighter parts of the moon’s landscape are mineral feldspar magma.
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- The largest “mare” on the near-side is 1,600 miles across. It is rich in potassium and phosphorus minerals.
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- The far-side is absent of mare and is covered almost entirely by craters.
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- Why are the two side of the Moon so different?
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- The far-side crust is twice as thick as the near-side crust ( 37 miles versus 12 to 19 miles).
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- The Moon was formed in the early evolution of the Earth when a Mars-size protoplanet impacted Earth and splashed a cloud of molten debris, crust, into orbit. The material first settled into a ring in orbit around the Earth, then, over time coalesced into our satellite.
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- As the surface of the Moon cooled heavy elements sank toward the center and the lighter elements floated to the surface. Cooling further the mantle crystallized.
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- Large impacts from asteroids and meteors struck the Moon creating the great basins. Many smaller ones created the craters.
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- So far there is not an explanation for the difference between the two sides. The next hypothesis is that the Mars-size protoplanet splashed material in to orbit that created two moons, not a single moon. After tens of millions of years the smaller moon impacted the larger moon and the two merged.
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- The calculations to support this theory have the smaller moon impacting at 6,000 miles per hour, having a total mass of 1/30th the mass of the larger Moon.
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- The shockwave traveling through the Moon would explain how radioactive elements are found on the near-side and not the far-side. This would also explain why the near-side has a thinner crust. With a thinner crust this would explain the different effect of the meteor and asteroid impacts. Larger craters would naturally be gouged out of the crust. The seas (mare) would be created by the heated mantle uplifting to the surface.
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- To be definitive on this hypothesis for the Moon’s evolution we need more data and more computer models. The picture seems plausible, but, stay tuned there is still more to learn.
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- When I tell someone the Moon is 1/4th the size of the Earth they don’t believe me. Actually it is more than that it is 27% the size of the Earth.
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-------------------- Diameters: 2,160 miles / 7,926 miles = 27%
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- However, size is not the same as mass. The Moon is made of the lighter Earth-crust. All the heavy metals have sunk to the center of the Earth. The Moon is light density. The Earth has a heavy, dense core. The Moon is only 1.2% the mass of the Earth.
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------------- Masses: 7.348 * 10^22 kilograms / 598.42 * 10^22 kilograms = 1.2%
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- To get off the Earth the rocket needs to be going 25,000 miles per hour. To get of the Moon the rocket only needs to be going 5,400 miles per hour.
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- The escape velocity is the speed the rocket needs to reach to escape the force of gravity, or, to climb out of the well of warped space-time, depending on how you see gravity working.
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- The square of the velocity is directly proportional to the larger mass, “M”, and indirectly proportional to the distance from its center, the radius ,”R“..
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-------------------- V^2 = 2*G*M / R
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- “G” is the Gravitational Constant which is the acceleration of gravity the same everywhere in the Universe ( we think ). It is a very small number, gravity is a weak force.
----------------- G = 6.67*10^-11 meters^3 / kilogram*seconds^2
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---------------- V^2 = 2* (6.67*10^-11) * ( 7.348*10^22) / 1.7*10^ meters
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---------------- V^2 = 5.76*10^6
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---------------- V = 2,400 meters / second = 5,400 miles per hour.
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RSVP, with comments, suggestions, corrections. Index of reviews available ---
--- Some reviews are at: -------------------- http://jdetrick.blogspot.com -----
---- email request for copies to: ------- jamesdetrick@comcast.net ---------
---- https://plus.google.com/u/0/ , “Jim Detrick” ----- www.facebook.com ---
---- www.twitter.com , --- 707-536-3272 ---- Sunday, December 14, 2014 ---
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