--------- #1491 - Globular Nebulae are dark silhouettes surrounded by star light.
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- Astronomers are looking at stars and galaxies in the night sky. The stars are the sources of light in the Universe. It seems unusual that astronomers can also be studying dark objects in the night sky.
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- The Globules are dark clouds in space that are often silhouetted by light emissions in the background. The dark clouds are called Bok Globules after the Dutch-American astronomer Bart Bok.
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- Astronomers have located about 100 of these globules in the Milky Way Galaxy. However, they expect there are 10,000’s more whose silhouettes we just can not see.
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- Most globules are about 30,000 AU in diameter. An AU is an astronomical unit of distance that is the distance between the Earth and the Sun, 93 million miles. So, these globules are 30,000 times larger then the orbit of the Earth. Our entire Solar System is 60 AU across.
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- Globules appear as dark clouds , however, these are very, very light clouds. The air we breath is 100,000,000,000 times denser then these clouds. But, if you were inside one of these globules it would be totally dark. No star light would penetrate far into the cloud of gas and dust grains.
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- Two of the most famous globules are the Horsehead Nebula, ( B33) and the Eagle Nebula ( M16)
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- These nebulae globules are star forming regions that astronomers are studying. Stars form from the fragmentation and eventual collapse of interstellar molecular clouds. The collapse of clouds is usually caused by shockwaves from nearby supernova explosions.
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- The Bok Globule Bernard 68 is in the Constellation Ophiuchus, The Serpent Bearer, and is between 100,000 and 1,000,000 years old. It is 350 lightyears from Earth. The temperature of the cloud has been measured to be 10 Kelvin. The surrounding interstellar medium is 50 Kelvin.
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- Bernard 68 is oscillating like a beating heart which is believed to have been caused by being hit by something. The globule is denser towards the center than on the edges which suggest it is slowly collapsing into a star. Calculations are that in another 100,000 years B68 will be a low mass Red-Dwarf star.
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- Other globules suggest that multiple star formations are common. Star formations may take a few million years. The outward push of heated gas balances the inward pull of gravity. The core can reach a few thousand Kelvin causing molecules of hydrogen to break down into individual atoms of hydrogen. Gravity will eventually win, a protostar will form, and nuclear fusion will light up the star. A star is born.
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- Globules are chemically rich. The gas inside the globules freezes into dust grains. An analogy would be blowing your breath on a cold window and the frost will form on the window. Ultraviolet radiation will break down the dust grains into molecules that can come back together to form new compounds. Laboratories that try to simulate this process have created protein molecules and even cell membranes. If it can happen in the lab maybe it can happen in space.
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- Some of the compounds that have been identified in globules include methanol, carbon dioxide, and ammonia.
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- This is exciting stuff to study. Astronomers are building more sensitive spectroscopy equipment in the hopes of detecting complex organic molecules. Globules are good for study and hopefully easier to understand that the giant molecular clouds that form hundreds of star clusters.
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An announcement will be made shortly, stay tuned
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RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copies to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email and with requested reviews at http://jdetrick.blogspot.com/ Please send feedback, corrections, or recommended improvements to: jamesdetrick@comcast.net.
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707-536-3272, Wednesday, June 13, 2012
--------- #1488 - End of the world according to Mayan Calendar
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- According to the Mayan “ long count” linear calendar, today, June 5, 2012 is predicted to be the end of the world. ( At least I voted before this happened)
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- The earliest recorded historical date that is known for certainty is May 28, 586 B.C. We know this because there was an historical battle between the Lydians ,who were the allies of the Greek Spartans ( Not the Herbert Slater Spartans ), and the Medes, who were ruled by the Persian king Cyrus.
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- These enemies had been locked in a war for 5 years. One day during their face to face confrontation a solar eclipse occurred. This was taken as a sign of the god’s disapproval and the Lydians and Medes agreed to end their fighting then and there.
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- Astronomers can accurately calculate when this eclipse occurred. They know that at that location it took place on May 28, 586 B.C.
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- Now the B.C., birth of Christ, part of that date is much less certain. In fact, December 25th was not decided as the right day until 440 A. D. , after the death of Christ. December 25th was selected because it coincided with the birth day of Mithias, the Persian sun-god and it was during the festival of the Pagans of Yule.
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- In 534 A.D. Dionysius Exiguus created the system we use today counting the years from the birth of Christ, we are 2,012 years since the birth of Christ. Unfortunately he slipped up on his calculations and did not get the math right. Attempts to correct things and get as close as possible put the birth of Christ at 6 B.C. But, for sure it occurred before the death of Herod the Great in 4 B. C.
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- Now, I am just waiting for the asteroid to hit! An announcement will be made shortly, stay tuned.
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RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copies to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email and with requested reviews at http://jdetrick.blogspot.com/ Please send feedback, corrections, or recommended improvements to: jamesdetrick@comcast.net.
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707-536-3272, Tuesday, June 5, 2012Calendars are curious with today being the end of the world according to the Mayans and I just happened to stumble on to it the same day. That is something I did not want to miss in my lifetime. It least it did not happen on Friday the 13th. If a month begins on a Sunday it will always have a Friday the 13th in it. And, every month in recorded history has had at least one Full Moon in it, except one. That happened in February 1865. I missed it.
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--------- #1487 - Birthday Puzzle
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- How did I know it was Sam’s birthday yesterday? It was easy.
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- I asked Sam NOT to tell me anything except the final number off his calculator. I said take the number of the month you were born, January = 1 , February = 2, …….. June = 6 , but don’t tell me.
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- Just multiply that number by 5 and add a 6 . ( 6*5 + 6 = 36).
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- Ok, now don’t tell me but multiply that number by 4 and add 9 ( 36*4 + 9 = 153).
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- Ok, now don’t tell me but multiply that number by 5 ( 153 * 5 = 765)
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- Now don’t tell me but add the number for the day you were born ( 765 + 4 = 769).
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- Ok , now tell me what is the number. He says 769. I subtract 165 ( 769 - 165 = 604) and I tell Sam based on the number you gave me, 769, I know you were born on June 4th. ---------- 604 is June 4.
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- Always subtract 165 and you will get the right answer.
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- If you want to know why this always works let me know and I will tell you.
--------- #1486 - Free-floating planets adrift in space?
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- We have 8 planets in our Solar System. There may have been more orbiting our Sun at one time and maybe a few escaped during the chaos of planetary evolution. Some may have just been far outside in the Kuiper Belt and the Sun’s gravity just let go of them.
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- We lost Pluto by committee. A group of astronomers decided Pluto could no longer be a planet in our Solar System. It now must be referred to as a Dwarf Planet in the Kuiper Belt of comets. The reason is that there were bigger Dwarf Planets further out in orbit around the Sun than Pluto. We either had to call them planets too or demote Pluto to a Dwarf.
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- But, what happens to planets that do loose contact with their star. If a planet looses gravitational contact with its star its velocity and momentum carries it off to freely float in space. There is lots of space out there. It is not as if planets would be bumping into each other. Are there planets drifting freely in free space? Astronomers think there are.
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- There is strong evidence that hundreds of billions of these free-floating planets, un-tethered for any star, are wandering through the Milky Way Galaxy. Un-tethered planets are the natural result of the inevitable chaotic gravitational interactions that evolve in every solar system.
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- Surveys suggest that there are twice as many rogue planets as there are stars in the galaxy. Planets are far easier to make than they are to keep. Solar systems often become unstable with planets flung out of their orbits and place of birth.
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- These rogue planets are being detected using a technique called “ micro-lensing. When telescopes focus on a particular star using very sensitive light meters and an unbound planet passes in front of the star the micro gravitational lensing temporarily increases the brightness of the background light source star. By determining the peak brightness from two different perspectives, an Earth telescope and a space telescope, astronomers can determine how far away the planet is. The duration of the brightening correlates with the mass of the planet that is acting as a lens.
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- A Jupiter- size planet will create a micro-lens brightening that last less than 2 days. A Brown Dwarf star would micro-lens brightness for weeks. The height of the brightening light curve tells astronomers how on-target the alignment is between the light source, the planet lens, and the observations from Earth. A perfect alignment will create a circular brightening ring called the Einstein Ring, which was predicted by Einstein in his General Theory of Relativity.
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- Micro-lensing events are rare because they rely on a chance alignment of a background star and a passing planet. Astronomers must monitor a large number of stars over a longer period of time in order to find this transient stellar brightening event.
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- However, astronomers have surveyed the brightness of 50,000,000 stars over 2 years. They have detected 474 microlensing events. 10 of these lasted less than 2 days indicating a Jupiter-size planet. Their analysis suggests that 75% of new objects detected are floating freely through space. You would think these would be cold, dark, rocks, or gas not suitable for any life. Astounding predictions are that blanketed by a thick hydrogen atmosphere and warmed by radioactivity and geothermal sources these rogue planets could support life.
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- Objects larger than planets but too small to become stars are called Brown Dwarfs. 100’s of these Brown Dwarfs have been found in the Galaxy. They have been classified into 3 types: “L” Dwarf stars have surface temperatures of 2,600 F. They are not massive enough to have enough gravity, to have enough pressure, to have a high enough temperature, to start hydrogen fusion into helium. Our Sun’s surface temperature is 8,000F. “T” Dwarf stars are cooler, 1,700 F. “Y” Dwarf star are the coolest, < 350 F and some have been found as cool as 80 F.
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- An announcement will be made shortly , stay tuned.
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RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copies to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email and with requested reviews at http://jdetrick.blogspot.com/ Please send feedback, corrections, or recommended improvements to: jamesdetrick@comcast.net.
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707-536-3272, Tuesday, June 5, 2012
--------- #1485 - Where is the Dark Matter??
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- Astronomers and physicists are trying hard to find Dark Matter. Astronomers have convincing evidence that the entire Universe is made up of matter and energy, time and space with 73% of the energy being used to fill space and expand the Universe at 47,000 miles per hour for every million lightyears of space. Residing in the space is concentrated energy called matter, 23% of which we can not see. 4% of matter-energy we can see. The 4% is all that we know and love, the rest is all “ Dark”.
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- When astronomers use light to detect what is in the Universe they come up far short, only 4% of what they find interacts with electromagnetic energy. So, astronomers are trying to use gravity to detect what is out there. Dark Matter and Dark Energy do interact with gravity.
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- So, just looking at matter alone 85% is Dark Matter, 23% out or 27%. You would think with that much out there we should be able to find it. Astronomers think that Dark Matter is made up of particles that we have yet to discover. We have discovered the fundamental particles like electrons and quarks that make up protons and neutrons. We have discovered neutrinos and the force carrying particles like gluons and bosons. Dark Matter must be another one of these fundamental particles. To make up so much of the matter out there they must be massive particles. They must be weakly interactive because they do not interact with electromagnetic energy. Call them “ WIMPS” for weakly interactive massive particles.
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- WIMPS due interact with gravity. We should still be able to detect them. One way they are detected is in studying the rotation of galaxies. Something is holding galaxies together and that is gravity. The center of galaxies are the most dense and therefore provide the strongest source of gravity. Stars rotating around the center with a shorter radius should be traveling faster than the stars out at the edge of the galaxy with a radius of thousands of lightyears distance.
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- Our Solar System for example contains the Sun with 99% of the mass and planets like Mercury that has rotational velocity at 48 kilometers / second versus Saturn that has a rotational velocity of 10 kilometers per second. Orbital velocities are directly proportional to mass and inversely proportional to radius of their orbit , v^2 = G*M / r. The outer stars should be orbiting at a slower velocity than the inner stars. However, that is not the case. The orbiting velocities seem to be constant out to the edge of the galaxy.
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- In order to explain this with our physics we conclude that there is no central mass. There must be a halo of invisible mass that completely surrounds the galaxy. Let’s try to find it around the Milky Way. Astronomers have explored out to 13,000 lightyears and have found no evidence that Dark Matter is there.
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- Astronomers ought to be able to detect the gravitational effects of Dark Matter mass. Light passing from a distant star should be warped or bent as it passes by this mass. It is called gravitational micro-lensing. Distant stars should vary in brightness as the lensing effect passes in front of the traveling light beam. So far, no effect of Dark Matter has been detected.
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- Astronomers have also studied over 400 red giant stars that hover above the galactic plane supposedly in the Dark Matter halo. Again, the effects of gravity from Dark Matter has not been detected.
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- The microlensing effect is a difficult measurement to make and there could be other explanations as to why we do not see the results expected. For one, the calculations assume the Dark Matter halo is spherical. If it were cigar shaped, or squashed beach ball shaped, the Dark Matter could still exist inside the calculations. We can not tell for sure because we do not know the Dark Matter distribution.
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- The Earth is orbiting the Milky Way center every 225 million years. We should be passing through the Dark Matter particles. Physicists are trying to detect these fleeting particles by putting measurements deep underground. The mass of Earth around the measurements is to separate surface noise and random particles that are buzzing around the surface. Here are some of the experiments in process. Google them to learn more:
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------------------- CDMS, is the Cryogenic Dark Matter Search using germanium / silicon detectors in an old mine shaft in Soudan, Minnesota
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------------------ CoGeNT is a wedge germanium detector that is in the same mine. The hope is that these detectors should capture a WIMP as it is passing through the Earth. Remember the WIMP is unaffected by the electromagnetic forces that hold the atoms together. It must collide with another fundamental particle to be detected.
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------------------ XENON 100 is a detector using liquid xenon beneath Gans Sasso Mountain in Italy.
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----------------- CRESST is in the same location using calcium Tung state crystals as detectors.
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----------------- DAMA is still another detector using sodium iodide.
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- Detections have occurred but confirmation remains illusive. Dark Matter is still eluding us. An announcement will be made shortly, stay tuned.
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RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copies to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email and with requested reviews at http://jdetrick.blogspot.com/ Please send feedback, corrections, or recommended improvements to: jamesdetrick@comcast.net.
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707-536-3272, Monday, June 4, 2012
--------- #1482 - Our Milky Way’s Gamma Ray Bubbles.
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- If you travel far out into space and look back at the Milky Way Galaxy edge-on with a camera that detects light in the Gamma Ray frequency range your image includes two enormous “ bubbles”, “tear drops” above and below the galaxy center. And, there are two jets shooting up at a 15 degree angles to the perpendicular. How to explain this ?
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- Our Milky Way Galaxy is relatively quiet and not consider an “active galaxy”. We know there is a Blackhole at the center of the Galaxy. It is called Sagittarius A* and it weighs 4,000,000 Solar Mass. That is enormously massive but small compared to other active galaxies. Other active galaxies have super massive blackholes that are billions of Solar Mass. These Blackholes are still consuming material, stars, planets, interstellar gas and dust. As this material is annihilated at the edge of the Blackhole twin jets shoot off in opposite directions at the poles of rotation.
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- The Gamma Ray Bubbles at the rotation poles of our Milky Way Galaxy are evidence that our galaxy was more active in the past.
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- The jets and bubbles extend 27,000 lightyears above and below the galactic plane. The Gamma Ray bubbles are perpendicular to the galactic plane, however, the jets are tilted at an angle of 15 degrees. This tilt is likely the result of the Blackhole’s accretion disk being tilted in its rotation.
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- The Blackhole’s accretion disk can warp as it spirals in toward the Blackhole’s spinning event horizon. The magnetic field created by the electric charges in the spinning disk accelerate the charged jet material out the spin axes of the Blackhole. The jets are produced by a plasma of electric charged particles, electrons and nuclei ions, that are squirted out from the axes following a corkscrew magnetic field that is tightly focused.
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- The Gamma Ray Bubbles are created by a “ solar wind of sorts” of hot material blowing outward from the spinning accretion disk. As a result the bubbles are much broader than the narrow jets that are focused by the magnetic field.
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- The Gamma Ray radiation is created when electrons moving near the speed of light collide with low energy light. The energy of light is directly proportional to the oscillation frequency. Gamma Rays have more energy than ultraviolet light because they have higher frequency. Ultraviolet light has more energy than red light. The collisions are of high energy and generate high energy photons in the Gamma Ray frequency range.
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- Astronomers are studying these recently discovered phenomena with great interest. They hope to learn more about the evolution of galaxies? When was our galaxy last active? How much material falling into the central Blackhole would make our galaxy active again?
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- Astronomers estimate that it would take 10,000 Solar Mass of material to make the Blackhole active again. Today, it appears to have a scant amount of material to feed on. However, there is a sizeable gas cloud on a collision course with the galaxy center. Astronomer’s hope to see the collision happen and to learn the results as the gas intercepts the event horizon of the Blackhole.
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- There is a Blue-White star, named S2, that orbits within a whisker of the Blackhole swinging by at 2% of the speed of light. Traveling at 5,000 kilometers per second. S2 is blue-white bright and therefore a young star no more than 10,000,000 years old. What will happen when this star gets eaten by the Blackhole?
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- We have seen thermonuclear flare ups occur on other stars. V838 Monocerotis star is 20,000 lightyears away and on February, 2002, it had an enormous flare up that was millions of time more luminous that our Sun. The flare up repeated in March and again in April. How can 3 successive flare ups of this magnitude occur in sequence? Are stars colliding? Did this single star swallow 3 giant planets? Is this predictable behavior of an end-of-life for a giant star?
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An announcement will be made shortly, stay tuned. Astronomers have a lot to learn.
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(1) To learn more : Picture was taken by the Fermi Space Telescope, google it.
(2) Read about Gamma Rays in reviews” #1323, #1238, #1158, # 26 and about Gamma Ray Bursts reviews # 711, # 1267 , #1160, # 542 available upon request.
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RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copies to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email and with requested reviews at http://jdetrick.blogspot.com/ Please send feedback, corrections, or recommended improvements to: jamesdetrick@comcast.net.
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707-536-3272, Sunday, June 3, 2012
--------- #1480 -
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- Venus has not crossed the face of the Sun since 1882 when it did last time in 2004. It will transit the Sun again in 2012, June 5th. We are fortunate in the U.S. to be on the sun-facing side when this happens. The Venus transit will not happen again until 2117, someone needs to take notes for me. I will miss this one.
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- (See footnote 1 for the years of Venus’ transits). On Tuesday, June 5, Venus will cross from one edge of the Sun to the other. It will take 5.7 hours. You will need a welder’s mask or eclipse glasses to witness it.
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- There is a lot of interesting math involved. One is to learn the distance from the Earth to Venus. We use the “ small angle formula” to do the calculations.
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------------------------------------ angle arc seconds = 206,265 Diameter / Distance
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------------------------------------ angle in radians = 57.2958 Diameter / Distance
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- This equation works because for very small angles the cosine = 1 and the sine and tangent = the angle. And, one complete circle is 2*pi radians = 360 degrees. 1 radian = 57.3 degrees. One arc second of angular diameter is a tennis ball 8 miles away.
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- The Moon is about ½ angular degree. The Sun is about the same size in the sky as evidenced by a total eclipse. The angular degree of the Sun is o.5244 degrees. The diameter of the Sun is 139,000 kilometers.
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------------------ 0.5244 angular degrees * 3600 = 1888 arc seconds.
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- The diameter of Venus as it transit’s the Sun is 58.6 arc seconds , which about 3% of the total transit distance. The diameter of Venus is 12,600 kilometers. Using the equation above to calculate the distance to Venus:
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------------------------- Distance = 206,265 / 58.6 * 12,600 kilometers.
------------------------ Venus Distance = 44.3 million kilometers
------------------------ Venus Distance = 27.6 million miles.
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--------------------- Earth is 149.6 million kilometers from the Sun
-------------------- Venus is 108.2 million kilometers from the Sun
-------------------- Distance from Earth to Venus when they are lined up with the Sun = 149.6 - 108.2 = 41.4 kilometers.
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- How long does it take Venus to transit completely across the face of the Su as viewed from the Earth? How fast is Venus and Earth traveling?
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- If we assume the planets orbit in perfect circles the travel distance is 2 * pi * radius. The time is one year to complete one orbit.
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--------------- Earth travels = 2 * pi * 149.6 million km = 940 million km, or 584 million miles.
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--------------- Earth year = 365.24 days * 24 * 3600 = 31.6 million seconds.
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---------------- Earth speed = distance / time = 940 / 31.6 = 29.7 km / sec, or 66,543 miles per hour.
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--------------- Venus travels = 2* pi * 108.2 million km = 680 million km
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--------------- Venus year = 224.7 days * 24 * 3600 = 19.4 million seconds.
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----------------- Venus speed = 680 / 19.4 = 35 km / sec, or, 78,410 miles per hour.
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- The difference in the speed of Venus to the speed of the Earth = 35 - 29.7 = 5/3 km/sec.
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- Traveling at 5.3 km / sec how long does it take to cross the diameter of the Sun, 139,000 km?
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---------------- Time = Distance / time = 139,000 / 5.3 = 26,264 seconds
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---------------- Time to travel diameter = 7.3 hours.
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- The transit on June 5, 2012 does not cross a perfect diameter. The transit time across the cord of the circle is 24,000 seconds or 6.7 hours. Don’t miss it. It will not happen again until 2117.
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- (1) Years Venus transit across the Sun occurs: 1631, 1629, 1761, 1769, 1874, 1882, 2994, 2012, 2117, 2125, 2247, 2255, 2360, 2368. Occurring in the months of June and December.
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RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copies to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email and with requested reviews at http://jdetrick.blogspot.com/ Please send feedback, corrections, or recommended improvements to: jamesdetrick@comcast.net.
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707-536-3272, Friday, June 1, 2012
