Are there Blackholes in our own Galaxy?

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--------------------- #1508 - Are there Blackholes in our own Galaxy?

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- Most people have learned by now that there is an enormous Blackhole at the center of the Milky Way Galaxy. It has the name Sagittarius A*. ( pronounced A star ). You can find it on the southern horizon in the Constellation Sagittarius the Archer. The shape of the star constellation is a perfect “teapot”. The Blackhole is at the spout of that teapot just 26,000 lightyears away.
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- Most people will probably be surprised to learn the astronomers have found 18 other Blackholes in our Galaxy. Blackholes are hard to find. Astronomers estimate that there are millions more Blackholes that remain undetected. Blackholes are invisible because no light can escape. Astronomers can only find Blackholes due to their gravitational effects on neighboring objects. When gas or stars are orbiting an invisible center at abnormally fast speeds, or when the orbiting gas gets superheated and emits X-rays or Gamma Rays, then the invisible center could be a Blackhole.
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- The invisible center could also be a Neutron Star that is very small and emits almost no radiation. In order to determine which is right astronomers need to make accurate measurements of the mass and the radius of the orbiting gas or star.
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- Neutron Stars are created when an 8 Solar Mass star ends its life exhausting all of its nuclear fuel. With no fuel to create outward radiation the inward pressure of gravity causes the star to collapse. When all of the star’s mass reaches the center it rebounds into a giant shockwave. It becomes a brilliant supernova explosion that is 10 billion times the brilliance of our Sun. What is left behind is a Neutron Star that is less that 3 Solar Mass and 12 miles in diameter.
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- Blackholes are created when a 30 Solar Mass star ends its life. The supernova explosion is much greater and the core left behind is greater than the 3 Solar Mass. A dead star of mass greater than 3 Solar Mass has so much gravity not even the neutrons at the core can withstand the pressure. The radius collapses even further. The mass / radius ratio passes the threshold that even light speeds can not achieve the escape velocity needed to leave the core. The core becomes a Blackhole with an Event Horizon right at the point that light is bent backwards into the core never to escape. ( See footnote 2 to learn more about Escape Velocity and why the ratio mass / radius determines when the star becomes a Blackhole. )
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- Beyond the edge of the Event Horizon gas and particles, and stars, can orbit without being pulled into the Blackhole. However anything that passes inside the Event Horizon is removed from the Universe never to return. How big is the Event Horizon?
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- For a non-spinning 10 Solar Mass Blackhole the Event Horizon is 37 miles across. For a 20 Solar Mass Blackhole the Event Horizon is 74 miles across. Doubling the mass doubles the diameter. If the Blackhole is spinning and it is spinning at its maximum rate the diameter is half that of a non-spinning Blackhole of the same mass.
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- Astronomers can never see the Blackhole itself. However, they can see the accretion disk of material that is orbiting beyond the Event Horizon. The friction created by the rapid rotation of gas and particles heats up the gas to millions of degrees. The extremely hot gas begins emitting X-rays. Astronomers detect the X-rays and can make measurements of velocities and radii that will be used to calculate the mass at the center. If it is more than 3 Solar Mass the center must be a Blackhole. Binary Stars orbiting a Blackhole are the easiest to measure and all 18 discovered so far have been X-ray binaries.
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- A binary pair of stars orbiting each other, and one of the stars is invisible, and, the companion star is the telltale indicator of the mass of the invisible star. Measurements are made of the orbiting speed of the companion star. Distances are measured of the orbits about the center. Knowing the mass and radius will allow calculations to be made of the mass of the invisible star. If it is less than 3 Solar Mass it is a Neutron Star. If it is more than 3 Solar Mass it is a Blackhole.
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- These measurements have been made accurately on 18 binary Blackholes. 20 more have X-ray signatures of invisible orbiting binaries but measurements are not yet precise enough to definitely say they are Blackholes and not Neutron Stars. Many more Blackholes exist in our Galaxy. But, unless there is a binary star or orbiting X-ray material there is no way to tell the Blackhole is there.
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- The Blackhole at the center of our Galaxy is 4 million Solar Mass. Its Event Horizon is 15 million miles across, which is the diameter of 17 Suns side by side. The Blackhole is 26,000 lightyears away. 4 million Solar Mass is an enormous mass. But the Galaxy in total is 10^12 Solar Mass. So, 4*10^6 Solar Mass is only 0.0004% of the total Galaxy‘s mass.
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- Sagittarius A* has a spinning accretion disk that is 140 million miles in circumference completing a rotation ever 24 minutes. The material is traveling 34 million miles per hour. The radius of the orbiting material is 22 million miles.
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- One other Blackhole among the other 18 is 37,000 lightyears away. It is 10,000 Solar Mass and has a diameter of 4.7 Earths.
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- Another is 10 Solar Mass and has a diameter of 37 miles, about the size of Rhode Island.
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- The 18 Blackholes so far discovered are all X-ray Binaries ranging is size from 4 to 15 Solar Mass.
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- They range in distances is from 3,400 lightyears away to 86,000 lightyears away.
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- The companion stars range in brightness magnitudes form 8.9 to 18.2 Magnitude. They have orbiting periods ranging from 4.1 hours to 155.3 hours.
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- The second biggest Blackhole, outside of Sagittarius A*, is Cygnus X-1 having a 15 Solar Mass. Its companion star is a Blue Supergiant Star of 19 Solar Mass. It has a magnitude of 8.9 and can be viewed in the Constellation Cygnus the Swan with an amateur telescope. It is 6,100 lightyears away.
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- The companion Blue Star orbit’s the Blackhole in 134.4 hours ( 5.6 days ). The average distance between the binaries is half the distance between the Sun and Mercury. The orbiting velocity is 90% of the theoretical maximum and it is the brightest X-ray source in the sky.
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- Unless a Blackhole actively feeds on material from another star or other material it will not have an accretion disk and it will not be visible. Lonely Blackholes are truly black. Outside our Galaxy almost every other large galaxy has a massive Blackhole at its center. In 1990 most astronomers were not convinced Blackholes even existed. Now, we are convinced they are more common than every imagined. An announcement will be made shortly, stay tuned.
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(1) Other reviews available #1441, # 1350 about Cygnus X-1, and still 11 others if you want the index.
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(2) The definition of a Blackhole is a mass of so much gravity even light can not escape. We can calculate Escape Velocity. And, we know the velocity of light is 186,282 miles per second.
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- Escape Velocity squared is directly proportional to the mass and inversely proportional to the radius.
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------------------------------ (Ve)^2 = constant * M / r
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- The bigger the mass the faster the velocity needed to escape its gravity. The smaller the radius the faster the escape velocity needed. Any proportionality can be turned into an equality with the proper “constant of proportionality“. In this case the constant is 2 * the Gravitational Constant.
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------------------------------- (Ve)^2 = (2*G) * M / r
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-------------------------- The Gravitational Constant, G = 6.67*10^-11
-------------------------- If we make the Escape Velocity, Ve = the speed of light, then (Ve)^2 = 9*10^16
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------------------------- 9*10^16 = ( 13.3*10^-11 ) * M / r
------------------------- r = ( 1.5*10^-27 ) * M
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- If we normalize this equation to us Solar Mass as the unit in kilograms, which is 2*10^30 kilograms, the equation reduces to:
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--------------------- r = 3 * M
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- r is in kilometers and M is in Solar Mass.
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- This becomes a very simple formula to calculate the radius of the Event Horizon of the Blackhole. The Milky Way Blackhole is 4,000,000 Solar Mass. The radius of its Event Horizon is 12,000,000 kilometers. A diameter of about 15 miles.
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(3) Why is the Escape Velocity squared equal to the ration of Mass to radius?
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------------------------------- (Ve)^2 = (2*G) * M / r
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- We get this equation setting the balance or the equality of two opposing Energies, the Kinetic Energy needed to escape the pull of gravity and the Potential Energy of gravity trying to push towards the center not allowing any escape.
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------------------ The equation for Kinetic Energy = ½ * mass * (velocity)^2
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------------------ The equation for Potential Energy = G *mass * Mass / radius.
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- The Event Horizon occurs when these two energies cancel out being equal to each other.
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------------------ ½ * mass * (velocity)^2 = G * mass * Mass / radius.
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------------------- ( velocity ) ^2 = (2*G) 8 Mass / radius.
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- Use this formula to determine how fast you would have to throw a baseball in order to escape Earth’s gravity? From the Earth = 25,000 miles per hour.
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--------------------------- From the Sun = 1,375,716 miles per hour
-------------------------- From a Blackhole = 670,633,500 miles per hour, but nothing can travel faster than the speed of light so the baseball could never escape.
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(4) CAUTION: It is important to note that these calculations are illustrative. They are all Isaac Newton’s physics. When we approach the speed of light, when gravity becomes as intense as a Blackhole, light and space bend, time slows, and Albert Einstein’s equations come into play. You need to employ equations of Relativity to get more precise answers to these questions.
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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.
or, use: “Jim Detrick” www.facebook.com, or , www.twitter.com.
707-536-3272, Saturday, November 3, 2012

Geology of the Solar System

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--------------------- #1507 - Geological History of the Solar System

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- See Review # 1506 for the geological history of the Earth. To carry our lineage back further this review is about the geological history of our Solar System. We do not have many rocks to work with, a few meteorites, so the history lesson takes more imagination.
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- By studying the rocks, gas , and stars within 6,500 lightyears of Earth with detailed observations astronomers believe:
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--------------The Sun formed in a nebula of 1,000 to 10,000 other stars. An example can be seen today in the Orion Nebula ( M42 ) in the Constellation Orion the Warrior.
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------------- One very large star, 25 Solar Mass, exploded in a supernova within the nebula. It was only 1 lightyear from our cluster of dense gas and clouds that became a nursery for stars to be born. An example today is the Star Cluster Pleiades ( M45 ).
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- The cloud of dust and gas has a temperature of 10 to 20 Kelvin. That is cool, only 18 to 26 F above Absolute Zero temperature. The surrounding interstellar medium has a density of one atom per cubic centimeter but an average temperature of 100 Kelvin. Atoms and particles in the colder cloud pack together to densities of million of atoms per cubic centimeter.
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- Atoms began to join together to form molecules. the molecular cloud was dozens of lightyears across. Gravity begins to have its effects the cloud begins contracting as it is brought together by the shockwave of the close exploding supernova.
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- The cloud does not contract evenly. It fragments into smaller pieces. Over a million years the cloud separates into individual clumps. Each clump is likely to become an individual star looking like the Star Cluster Pleiades.
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- Our Sun evolved without a binary star. Only 30% of the stars form without a binary. Our star has a higher percentage of the elements heavier that helium. Astronomers call all these elements metals.
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- Of the 50 closest stars only Sirius and Procyon are more massive than our Sun. Using the wider survey only 12% of the stars are more massive than our Sun. Only 25% of the stars have a higher percentage of metals.
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- Our Sun has a solar system with 4 giant gas planets and 4 smaller rocky planets. astronomers have discovered over 1,000 planets around other stars, but, they have to learned enough to define how common our type of solar system is. Some put the probability at 0.2%. However, this small probability would still mean that amongst the 200 billion stars in the Milky Way Galaxy there would be 400 million Solar Systems like ours.
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- Evidence for the supernova blast that started the evolution of our Sun and its Solar System comes form meteorites (geology), dating the radioactive isotopes of Nickel-6 and iron-60. Iron-60 has a half-life of 1.5 million years. Therefore, these meteorites had to be delivered form a nearby source during the Solar System’s earliest days.
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- It takes a massive star to have the gravity and explosive power to create the element iron-60. Other radioactive elements, aluminum-26 and calcium-41 were also found. All this implies that the supernova star was a massive 25 Solar Mass. Such a massive star has a lifetime of 7.5 million years.
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- The distance away from the supernova could not be too close or too far away. It needed to occur about 1 lightyear away.
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- A few million years later our Sun began fusing hydrogen and helium. the accretion disk surrounding the Sun began to form planets. This all started 4,600 million years ago.
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- To help your imagination turn your binoculars on the Orion Nebula tonight. Search out the Pleiades Star Cluster. Our Sun was like one of these bright stars born in the nursery of the nebula. To see an animation of this event see www.astronomy.com/toc.-
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- To learn what happened starting 4,600 million years ago see Review #1506 The Geology of the Earth
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- #1157 Mysteries of Our Solar System
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- #15 The Sun and the Planets in Six Easy Pieces.
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- #1150 What is New and Extreme in Our Solar System?
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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.
or, use: “Jim Detrick” www.facebook.com, or , www.twitter.com.
707-536-3272, Wednesday, October 31, 2012

Gelogical history of the Earth?

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--------------------- #1506 - Geological History of the Earth

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- The planet Earth was formed 4,600 million years ago ( MYA) along with the nine other planets and a whole lot of other debris. ( See Review #1507 for the astronomical geological history of the Solar System.)
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- The oldest rocks found to date are the debris from the formation of the Solar System that have arrived as meteorites. These oldest rocks are called “ Chondrites” and they have been dated at 4,568 MYA.
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- Chondrites are stony meteors containing Chondrules, and Chondrules are small spheres of olivine or pyroxene. Olivine being a mineral found in igneous rocks containing the elements consisting of magnesium iron silicates. Pryoxene is a very similar group of minerals that are silicates of magnesium, iron, calcium and other elements.
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- Minerals are molecules and compounds of the elements which were formed in supernovae explosions. We know our Solar System accretion disks was composed of debris from 2^nd or 3^rd or 4^th generation stars that died as supernovae. The larger the star the shorter its lifetime and the sooner supernova occurs. We know that because our Solar System is rich in the heavier elements it came from the generational stars.
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- In the beginning it was just the elements hydrogen and helium. The supernovae created the heavier elements. Then these elements began growing into molecules and compounds called minerals. A small number of elements in the beginning have grown to over 4,500 minerals found today. And, the list grows at the rate of about 12 new minerals per year being discovered.
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- 4,550 MYA: There were about 150 minerals on the planet. Minerals are inorganic substances having definite chemical composition and often a definite crystalline structure.
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- 4,500 MYA: The Moon was formed. It was believed to be created by the Earth’s crust being splashed into orbit after being hit by a meteor or a sub-planet, about the size of Mars. (footnote 2).
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- 4,400 MYA: The second oldest rocks to be found were zircons. Zircons are zirconium silicate minerals, ZrSiO4, having a tetragonal shaped crystalline structure. Zircon crystals are hard enough to resist erosion. They have a high melting point and can withstand most chemical attacks.
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- 4,200 MYA: Most of Earth’s atmospheric oxygen was in the form of water vapor.
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- 4,000 MYA: The list of minerals had grown to about 350 different minerals. The Earth’s crust was forming new compounds and molecules out of the elements churned in the caldron of volcanoes and tectonic lava flows.
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- 3,900 MYA: Earth and the Moon experienced very heavy meteor bombardments. (footnote 1).
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- 3,800 MYA: Earth’s surface solidifies, liquid water first appears, and the oceans formed.
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- 3,700 MYA: Coarse-grained igneous rocks formed called Granites. These Granites were composed of feldspars, and quartz with some mica, hornblende, and augite. feldspars are a group of minerals composed of aluminosilicates of potassium, sodium, and calcium. Quartz is silicon dioxide, SiO2. It is the chief constituent of sand. By now 550 minerals existed on the Earth.
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- 3,600 MYA: The planet’s first super continent formed.
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- 3,500 MYA: The planet’s first life arrived in the form of single-celled cyanobacteria .
Cyanobacteria began the first photosynthesis. ( Spring Lake has had an algae bloom this summer. Green algae has filled the lake. Mats of algae formed on the surface and blue-green moss-like colors formed on the mats. This was cyanobacteria that is toxic if ingested. I had to be careful to keep my dog out of the water. We walk around the lake every day. Dogs lick their fur that gets wet and can get poisoned.) (See footnote 1)
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- 2,500 MYA: The Earth has now created 1,500 different minerals.
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- 2,400 MYA: The algae and photosynthesis in the oceans have created oxygen in the atmosphere. ( See footnote 1).
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- 1,500 MYA: Oxygen has reached the concentration of 10% of the gas in the atmosphere.
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- 1,000 MYA: The super continent “ Rodina” has formed.
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- 310 MYA: The oxygen content in the atmosphere reaches 30%.
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- 250 MYA: The oxygen content has dropped to 12%.
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- 200 MYA: The Pacific Ocean forms.
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- 180 MYA: North America separates from Africa.
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- 110 MYA: The Atlantic Ocean forms.
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- 60 MYA: The Rocky Mountains form.
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- 0 MYA: Today, there are over 4,500 minerals in the Earth’s crust and the atmosphere has 21 % oxygen.
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- (1) 2.400 MYA: was the greatest climate change Earth has ever experienced. the primordial methane-rich atmosphere changed to an oxygen content level that we can still breath today. This change occurred because primitive , single-celled cyanobacteria began the process of photosynthesis to be alive.
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- The bacteria took in carbon dioxide and warm sunlight to grow while exhaling oxygen into the atmosphere. The rocks in the Earth took on the oxygen and “ rust” until there were no more unoxidized metals left. After that there was a runaway build up of oxygen in the atmosphere.
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- (2) The six Apollo missions to the Moon brought back 842 pounds of lunar rocks. All the rocks were dated to 4,000 MYA to 3,850 MYA. This is hundreds of millions of years after the Moon was formed. The conclusion: The Earth and the Moon were bombarded with these rocks for a period of 100 million years. The bombardment almost completely remade the surface of the Moon by 3,850 MYA.
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- (3) What caused this immense meteor bombardment?
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- There are several theories still under study. A likely scenario has the outer planets orbiting nearer to each other and nearer to the Sun when the Solar System first formed. Originally the giant planets were 5 to 17 astronomical units from the Sun. ( The Earth is 1 AU). The asteroid belt was 35 AU distant. After a few hundred million years Jupiter and Saturn passed through orbits that had 2:1 resonance. Jupiter made 2 revolutions around the Sun for every 1 revolution Saturn made. The combined gravitational effects of these resonances caused Uranus and Neptune to pass through the asteroid belt scattering the small bodies everywhere. These meteors entered the inner Solar System and created the bombardments on the Earth, Moon , and inner planets.
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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.
or, use: “Jim Detrick” www.facebook.com, or , www.twitter.com.
707-536-3272, Tuesday, October 30, 2012

Evolution of dogs over 120 million years

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---------------- #1505 - Molly’s Grandpa was a Llama?

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- Molly is a Golden Retriever, 7 months old and 50 pounds. My brother, Bob, wanted to know her pedigree. She came from a flea and burr infested farm in Napa at 3 months and was considered a rescue dog. Her lineage goes back to Scotland where her ancestors were bred for retrieving water fowl and game birds. In the 18^th century guns were getting better and the downed game was too hard to find. Golden Retrievers were ideal for the job. Her lineage goes back to over 120 million years. Then, they were called Llamas.
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- Science now knows that mammals and dinosaurs lived together for millions of years. 65,000,000 years ago dinosaurs died out and mammals took over and began to diversify. Mammals began as small, shrew-like creatures, some up to the medium sized dog. From there, evolution created a diversity of mammals where today we have 4,316 different species of mammals.
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- Mammals are different from other creatures in that they have fur, or hair, are warm-blooded, and produce milk. They have live births, with a few mammals that lay eggs ( platypus), and a few that have a mother’s pouch (kangaroos), but 90% are placental mammals.
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- Of these placental mammals there are at least 23 categories, called orders, and within these orders there are 4,316 different species. Each has a Latin name but I will just use a few representatives with common names for each species. For example the largest number of species is in the order “Rodentia” which has 1,995 species of mice, squirrels and guinea pigs. Here is a table of the order and species:
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---------- 1 ------------ mice, squirrels ---------- 1,995 species
---------- 2 ----------- rabbits ------------------------ 80
---------- 3 ------------ bats -------------------------- 925
---------- 4 ----------- bears, cats, dogs, seals ---- 280
---------- 5 ----------- monkeys, men -------------- 233
---------- 6 ----------- whales, dolphins ------------- 78
---------- 7 ------------ cows, pigs, deer ------------ 215
---------- 8 ------------ horses, rhinos ------------- -- 18
---------- 9 ------------ sloth’s, anteaters ------------ 29
---------- 10 ----------- pangolins (1) ----------------- 7
---------- 11------------ flying lemurs ---------------- 2
---------- 12------------ aardvarks (5) ----------------- 1
---------- 13------------ manatees ---------------------- 4
---------- 14------------ hyraxes (2) ------------------- 11
---------- 15------------ elephants ---------------------- 2
---------- 16------------ elephant shrews ------------- 19
---------- 17------------ hedgehogs ------------------- 21
---------- 18------------ moles ------------------------- 42
---------- 19------------ tree shrews ------------------ 19
---------- 20------------ shrews ---------------------- 312
---------- 21------------ tenrecs, moles (footnote 3) - 24
---------- 22------------ golden moles ---------------- 18
---------- 23------------ solenodons (footnote 4) ----- 2
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- We can try to combine these orders into groups that have common characteristics in order to determine a common ancestor. Common characteristics might be similar teeth, similar toes or hooves, similar spines, etc. Another way to combine these species into a family tree is to group those with the most similar DNA. This review does not go into the details of mutations in DNA. But, evolution has occurred through mutations in the DNA code. The mutations that improve the species, or create another species that are better survivors, live on. Those with the poor mutations die off. Only the strong survive.
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- The DNA string is unique to each species as it is passed on to generation after generation. When you get back to common ancestors of species they have common DNA mutations. So, without going into the explanations here are the results:
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The genetic differences in DNA between:
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---------------- humans -------------- chimpanzes ------------ 1.24%
---------------- humans -------------- gorillas ---------------- 1.62%
---------------- humans -------------- orangutans -------------- 3.08%
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----------------- chimps ----------------gorillas ---------------- 1.63%
----------------- chimps -------------- orangutans -------------- 3.13%
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----------------- gorillas ------------ orangutans --------------- 3.09%
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- Using DNA results, humans are more like chimps than any other species. And, humans are to gorillas almost as chimps are to gorillas. Using this data from the DNA we conclude that humans and chimps had a common ancestor from which both species diverged 6,500,000 years ago. And, humans and chimps diverged from gorillas some 7,500,000 years ago. These species of humans, chimps and gorillas diverged from orangutans with a common ancestor 16,000,000 years ago.
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- It is important to note that only males were included in this DNA survey, ha, ha.
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- We are interested in Molly’s common ancestors. Together dogs and bears are in the species “ Carnivores”. The number of nucleotide differences between dogs, bears, llamas, and antelope are:
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-------------------- dogs --------------- bears ------------- 36 different nucleotides
------------------- dogs --------------- llamas ------------ 35
-------------------- dogs --------------- antelope ---------- 46
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-------------------- bears -------------- llamas ------------ 45
-------------------- bears -------------- antelope ---------- 50
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- It looks like dogs are more closely related to llamas than to bears. But, comparing dogs and bears to llamas they are 10 differences apart. Comparing them to antelope they are only 5 differences apart. Dogs and bears had a common ancestor with llama and antelope some 80,000,000 years ago.
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- As best we can determine there evolved two basic groups of mammals. One from Africa and one from the Northern Latitudes.
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From Africa common ancestors existed:
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65,000,000 years ago for:
------------elephants
----------- hyraxes (footnote 2)
----------- manatees
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and 80,000,000 years ago for:
---------- aardvarks (footnote 5)
---------- elephant shrews
---------- tenrecs (footnote 3)
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- As best we can determine from Northern Latitudes common ancestors existed:
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80,000,000 years ago for:
------------rabbits
---------- mice
---------- tree shrews
------------flying lemurs
---------- primates, you and me Leroy
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and 90,000,000 years ago for:
---------- hedgehogs
---------- bats
--------- dogs and bears
---------- pangolins (footnote 1)
----------- horses
----------- pigs, whales
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- This grouping certainly had something to do with continental drift when Africa separated from Gondwana some 120,000,000 years ago. South America separated from Africa some 105,000,000 years ago. South America joined up with North America some 90,000,000 years ago. The categories for these mammals come together with a common mammal ancestor some 110,000,000 years ago when they were all shrews. Then, the dinosaurs died off some 65,000,000 years ago. Interesting!
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(1) Pangolons are a scaly anteater. They look like a walking pine cone that is up to 3 foot long. They can curl up into an armored ball with razor sharp scales for protection. Its claws are also sharp for climbing and burrowing.
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(2) Hyrax is a small rabbit-like mammal said to be the closest living relative to the elephant. Found in Africa and the Middle East it has fossil records dating back 40,000,000 years ago.
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(3) Tenrecs are found in Madagascar and Africa. They vary in size from shrew-like to opossum-like. They are omnivorous and nocturnal and usually live in groups.
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(4) Solenodons are shrew-like mammals that resemble a species very closely to those living with the dinosaurs. They have long snouts and eat insects. Their tits are on their butts and their saliva is venomous. Once adult they are solitary animals.
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(5) Aardvarks are called the ant-bear because it is the size of a pig. It is a living fossil. It is nocturnal and feeds on ants and termites. It has a long, sticky tongue. It borrows out a home. Its predators are lions and leopards and for defense it will lie on its back and slash with its long claws.
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- From review #873 written January 15, 2008.-
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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.
or, use: “Jim Detrick” www.facebook.com, or , www.twitter.com.
707-536-3272, Monday, October 29, 2012

MRIs use Nuclear Magnetic Resonance imaging?

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--------------------- #1504 - Nuclear Magnetic Resonance
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- Nuclear magnetic resonance has nothing to do with radioactivity. Nuclear refers to the nucleus of atoms which are made up of charged particles called “protons.” Protons spin on a rotational axis. They carry a positive charge of 1.9*10^-19 Coulombs, the same as the negative charge of an electron. A spinning electric charge creates a magnetic moment.
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- We do not usually detect this magnetic moment because all the protons are lined up in random directions. However, if the atoms are placed in an external magnetic field they can be made to all line up in the same direction. Using this phenomenon allows medicine to create Magnetic Resonance Imaging, an MRI, of the tissues in the body. Medicine drops the “Nuclear” in the names because patients would not stick their head in a machine that was called “ nuclear”.
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- The external magnetic field aligns all nuclei’s magnetic moments to point in the same direction. The north poles of the spinning protons have an axis of rotation in parallel with the magnetic field lines of the external field. The next step is to get the rotating axes to tilt and precess around this true north axis. The rotating protons also have angular momentum and this can cause a wobble like a spinning top with the rotational axis making a circle around the true vertical.
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- To inner act with this precession we use a radio wave at right angles to the magnetic field lines. The electro-magnetic wave has a magnetic field that aligns perpendicular to the precessing magnetic moment causing it to tilt even further than its natural precession when the wave frequency is exactly the same as the precession frequency. When this happens it is called frequency resonance. Energy is absorbed in the angular momentum of the rotating proton. When the radio wave is turned off the proton returns to its original precession angle and emits that fixed amount of energy corresponding to the resonant frequency. This is what is detected as a unique signal in the frequency spectrum representing the particular atom that is doing the precessing. The resonant frequency is unique for every element.
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- The precession angle is a function of the strength of the magnetic field. The resonance frequency is 42 Megahertz per Tesla of magnetic strength. An MRI machines uses a very strong magnetic field, say 5 Tesla. So , the resonant frequency is 210 Megahertz for the hydrogen that it is detecting to form the image. Thus, that is the reason a radio frequency orthogonal to the magnetic field is the what is chosen.
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- The MRI technology uses hydrogen as the atom nucleus to be detected. The radio frequencies used in other application varies from 60 to 1,000 Megahertz. These are the familiar range of frequencies used in VHF and UHF television broadcasting. Each atomic structure has a unique resonant precession frequency and detecting it can identify the element or the molecule involved.
-
- Atomic elements that have an odd number of protons, or an odd number of neutrons (called isotopes) have natural magnetic moments of precession that are easier to detect. If the atomic nucleus has an even number of protons or neutrons its spin is zero and balanced lacking a magnetic moment.
-
- Our bodies are mostly water ( H2O) so looking at the tissues in the body works well using the resonant frequency of hydrogen. Carbon 13 is also used with its 6 protons and 13 neutrons. But, Nuclear Magnetic Resonance has many different applications other than MRI, imaging. There are many isotopes that can be detected in any number of elements and molecules found in poisons, toxins, environmental pollution, explosives, etc. Here is a list of some of the elements having natural magnetic resonances:
-
--------------------- hydrogen 1
--------------------- carbon 13
--------------------- hydrogen 2
--------------------- lithium 6
--------------------- boron 10
--------------------- boron 11
--------------------- nitrogen 14
--------------------- nitrogen 15
--------------------- oxygen 17
--------------------- fluorine 19
--------------------- sodium 29
--------------------- silicon 29
--------------------- lead 31
--------------------- cadmium 113
--------------------- xenon 129
--------------------- platinum 195
-
- A significant application for NMR is having a non-intrusive way of identifying these elements and their molecules. To get to 3-dimensional imaging we need a few more tricks.
-
- A constant uniform magnetic field works well in detection in 1-dimension to simply identify that a target element is there. However, to locate the target in 2-dimensions we need to very the magnetic field intensity over space and time. Then, when the resonant frequency is emitted matching the correct magnetic field intensity we also have its location in space. This gradient in the magnetic field allows us to create a 2-dimensional image throughout the target. The image represents a “slice” of detected hydrogen protons. Where there is more water the image is white, less water in fat is gray, still less water in muscle is dark gray, bone with little water and is black.
-
- To get a 3-dimensional image we simply move the target slightly and get another “slice”. After passing through the entire target we put the slices together and create a 3-dimensional image of the inside of the body. Medical experts can study the MRI image and complete a diagnosis. The non-intrusive image is very similar to an X-ray image, but much safer for the patient.
-
- NMR also works in chemistry to determine the structure of molecules. For example, NMR was used to discover the structure of the “ buckyball”, a carbon 60 atoms structured to form a sphere. In biology it is used for non-destructive study of proteins, including DNA.
-
- NMR is used in oil drilling, the magnetic resonance detection is lowered into the drill hole to discover oil and natural gas. Once the oil is in the refinery NMR is used again in process control to produce the oil products.
-
- Someday NMR may be used in quantum computing
-
- Lasers can be used to align magnetic moments in place of strong external magnetic fields. NRM technology is on the verge of many new discoveries. An announcement will be made shortly, stay tuned.
- --------------------------------------------------------------------------
-
- 2 learn more Wikipedia has excellent animations and videos that explain nuclear magnetic resonance.
-
- Google Alex Pine, University of Berkeley, California for several links to the state of the art in NMR. I attended his lecture at Sonoma State on October 22, 2012.
-
- The Earth has a magnetic field that can be used in NMR with sensitive enough detectors. The Earth is also a precessing magnetic axis with its north pole pointed exactly at the star Polaris, The North Star. The planet is not a balanced sphere and it is influenced by gravitational fields from the Sun and the Moon. The magnetic axis precesses in a giant circle. In a few thousand years the north pole axis will be pointing at the star Vega. It takes 26,000 years for precession to complete one cycle back to Polaris.
( See Review # 622 to learn more about Polaris.)
-------------------------- ------------------------------------------------------------------
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.
or, use: “Jim Detrick” www.facebook.com, or , www.twitter.com.
707-536-3272, Monday, October 29, 2012

How you can measure the speed of light?

-
--------------------- #1503 - How did we learn the speed of light?

-
- How you can learn the speed of light by using some astronomy. You will need some binoculars or a telescope. Find Jupiter in the night sky high above the Constellation Orion. With binoculars you can easily see the four moons of Jupiter:
-
------------------------ Ganymede
------------------------ Io
------------------------ Callisto
------------------------ Europa
-
- The moons in orbit around Jupiter change positions every night. Io is the closest and orbits every 42.5 hours. Pick any monthly astronomy magazine and it will show a chart of the positions of Jupiter’s moons each day of the month. I will pick October 31, 2012 at 12:45 AM Viewed through the telescope the south pole of Jupiter is up, not down. This is because the telescope lens flips the image, north to south. At that time the moons are located:
-
---------------------- Callisto is far to the left, west
--------------------- Europa is not as far to the right, east
--------------------- Ganymede and Io are closer to Jupiter about the same distance, 15 arc seconds to the right, east
-
- I picked this time for the unusual event that you can see Ganymede’s shadow on the face of Jupiter. It is the black dot at the top near the south pole. When Io passes behind Jupiter, is eclipsed by Jupiter, it repeats every 42 hours, 30 minutes. It is like a pendulum in a clock.
-
- If you continue these measurements throughout the course of the year there will be a time delay of 22 minutes, from the shortest time to the longest time. This represents the point that the Earth orbit is closest to Jupiter, and when it is farthest from Jupiter six months later. That 6 months represents one half a complete orbit which spans the distance of the diameter of an Earth orbit. The distance to the Sun is 93,000,000 miles. Therefore the diameter is 186,000,000 miles.
-
- The 22 minute delay is the time it takes light to travel that extra distance across the diameter of Earth orbit. We can calculate the velocity:
-
-------------------- Velocity = 186,000,000 miles / 22 minutes
-
-------------------- Velocity = 8,450,000 miles per minute
-
--------------------- Velocity = 141,000 miles per second.
-
- Well that was with 25% of the right answer. Close is good for astronomy measurements. The speed of light is 186,282 miles per second.
-
----------------------- 141,000 / 186,282 = 76%
-
- We need to realize that Jupiter is in orbit too. Io’s eclipses actually appear to follow a 13 month cycle. So, we need some refinements in our calculations.
-
- In the 17^th century when mariners first tried to use Io eclipses as a clock, they found the time to be earlier and later than expected depending on the time of year. The clock turned out to be not accurate enough to avoid the rocks. They did not realize that they had to take into account the Earth’s orbit about the Sun. Astronomers first realized that the time difference was actually the greater distance across the diameter of Earth’s orbit. They got their answer with about 5% for the speed of light.
-
- To get even better accuracy astronomers started to measure the parallax of distant stars. In 1728 the astronomers began measuring the parallax shift as the Earth orbited the Sun. One particular star’s position, that of Gamma Draconis, shifted by an angle of 0.006 degrees. Basic trigonometry was used to calculate how fast light traveled between the Sun and the Earth. The result of 8 minutes and 12 seconds was only 7 seconds shorter than the right answer. They estimated that light travels 10,210 times faster that Earth’s orbital velocity. This overestimate of light speed is with 1% correct.
-
- In 1850 an electric motor was used to spin a disk having fine teeth with gaps between. A mirror was placed 5 miles away. Returning light pulses with a slow moving disk returned through the same slot. Spinning the disk faster allowed a tooth to block the returning light pulse. Spinning still faster and the returning light pulse passes through the adjacent gap. Using this method the round trip journey for the light pulse could be measured. The result only overestimated the speed of light by 4%.
-
- In 1920 scientists bounce light beams off a rotating mirror that was located 21 miles away. The mirror was a spinning octagonal mirror. It would reflect the light beam back to the source only when the mirror face was exactly perpendicular to beam. By varying the speed of the rotation they could calculate the time for each reflecting beam. This measurement put the speed of light at 299,796 + or - 4 kilometers per second,
186, 208 miles per second.
-
- Today’s best measurements put light speed at:
-
----------------------------- 299,792.458 kilometers per second
-
---------------------------- 186,282 miles per second.
-
- When radar was used during World War II precise speeds were needed to calculate accurately incoming planes, missiles, and ships. To get even more accuracy scientists combined microwaves inside a cavity of precisely known dimensions. The standing waves produced by the microwaves were known to within 0.8 microns. Measuring the frequency accurately allowed the calculation of the speed of light multiplying frequency times wavelength:
-
------------------------- c = f * w
-
- This measurement got the result to within 299,792.5 + or - 3 kilometers per second. You could make the same measurement in your microwave oven if you could measure accurately the standing wave on a pad of butter and you knew the frequency of the magnetron to be 2.45 GHz. c = f * w
-
- By 1980 light speed was one of the most accurate constants known. It became the standard to determine the length of one meter. A meter became the distance the light travels in a vacuum in 1 / 299,792.458 seconds.
-
- All attempts to date to prove that light is not this constant speed in a vacuum have failed. Electromagnetic radiation instantly travels at this constant speed, and is usually abbreviated as “c”.
-
------------------ as in: E = m * c^2
-------------------------------------------------------------------------
Want to learn more about light?
Here are some more reviews available upon request:
# 1386 Light speed
# 1389 The power of light
# 940 Not enough light
# 934 Light’s mysteries
# 915 Light - atomic interferometer
# 1335 Light spectrum
# 1043 The strangeness of light
# 1044 Light to matter, stranger still
# 615 The energy of a quantum of light
# 912 Wave-particles, anti-matter, and entanglement.
# 768 The wave-particle duality of light
# 34 Getting light from electricity and magnetism
# 589 Light
# 645 How far away is the Sun.
--------------------------- ------------------------------------------------------------------
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.
or, use: “Jim Detrick” www.facebook.com, or , www.twitter.com.
707-536-3272, Wednesday, October 24, 2012

Protons made of Quarks made of Preons?

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--------------------- #1502 - Atoms with Protons, with Quarks, with Preons?

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- The ancients in Greece first proposed the atom as the smallest indivisible particle that makes up matter in the natural world. Science later discovered the electron which turned out to be the basis for chemistry. Later, the nucleus of atoms were discovered to contain protons and neutrons. Then, more recently protons and neutrons were found to each contain 3 Quarks. Today, do you suppose we will find that Quarks contain even more elementary particles?
-
- In today’s Standard Model of Particle Physics Quarks are considered “ fundamental particles”, point like in size with a spin of ½. Spin ½ means that they have a “quantum” spin. It is either +½ or -½ . It is like the magnetic moment of spin is either the north pole or the south pole. There is nothing in between. Here are the sizes we are talking about:
-
------------------------- Hydrogen atom --------------- 1.1*10^-10 meters
------------------------- Proton ------------------------- 1.7 * 10^-15 meters
------------------------- Quark -------------------------- less than 10^-18 meters
-------------------------- Preon -------------------------- smaller still.
-
- Could the Quark be composed of these even smaller “fundamental particles”, Preons?
-
- No evidence measured to date will give us the answer. But, that does not stop physicists from imagining such particles and developing the theories for there existence. They have even given them a name, “ Preons”.
-
- Here is how the theory might work and still match the Standard Model:
-
----------------------------- STANDARD MODEL OF PARTICLE PHYSICS -----------
-
------------------- 12 Fermions ------------------------------ 4 Bosons plus the Higgs
-
--------------- 6 Quarks and 6 Leptons -------------------- 5 Force Carriers
-
- Lowest Energy Generation of Quarks and Leptons:
-
--------------------------------------------------- Charge --- Mass in million electron volts.
-
-------------------------------- Up Quark ------ +2/3 ----------------- 2.3
------------------------------- Down Quark --- -1/3 ----------------- 4.8
------------------------------- Electron --------- -1 -------------------- 0.511
------------------------------ Electron Neutrino -- 0 ------------------ less than 0.000002
-
- Boson, Force Carriers Energy Levels:
-
--------------------------- Photon ----------------- 0 ------------------ massless
--------------------------- Gluon ------------------ 0 ------------------ massless
-------------------------- Z Boson ----------------- 0 ---------------- 91,188
------------------------- W Boson ----------------- + - 1 ------------ 80,385
------------------------- Higgs Boson ----------- 0 --------------- 125,000
-
- If there are two types of Preons one having a charge of +1/3 and the other being neutral. And, an anti-Preon exists at a charge of -1/3, then this Standard Model can be constructed with each Quark containing 3 Preons and each Boson containing 2 , or, 6 Preons. Here is what the table would look like:
-
- Fermions
-
--------------------------------------------------- Charge --- Mass in million electron volts.
-
--------------------------------------------------- +1/3 Preon -----------Neutral Preon
-
-------------------------------- Up Quark ------ 2 ------------------------- 1
------------------------------- Down Quark --- 1 anti ------------------ 2 neutral anti-
------------------------------- Electron ------= 3 anti -------------------- 0
------------------------------ Electron Neutrino - 0 ----------------------- 3
-
- Boson, Force Carriers
-
--------------------------- Photon ----------------- 1+1 anti ------------------ 0
--------------------------- Gluon ------------------ too complicated -------
-------------------------- Z Boson ----------------- 3 +3 anti --------------- 0
------------------------- W Boson ----------------- 3 -------------------------- 0
------------------------- Higgs Boson ----------- too complicated -------
-
- You can see how it would work for Quarks and Leptons to be made up each of 3 Preons having an electric charge of + 1/3.
-
- The future for hunting for structure within Quarks and Leptons is brighter than ever. The Large Hadron Collider in CERN , Switzerland, has already produced a year’s worth of collision data of protons and anti-protons colliding at 7,000 million electron volts. This year it will increase collision energies to 8,000 million electron volts. And, in 2015 to 14,000 million electron volts. Physicists are busy hunting through the debris.
-
- Physics is busy finding the smallest elementary particles. Preons to make up Quarks, Quarks to make up Protons, Protons to make up atoms, atoms to make up molecules, molecules to make up chemistry, chemistry to make up biology, biology to start with a breath of air, learn the alphabet, learn their numbers, grow in knowledge to read this review and figure this stuff out.
-
- There is still more stuff to figure out. The Standard Model does not include gravity. We have no mathematical method of deriving the masses we have discovered. They are all obtained from experiments. The theory for the Higgs Boson started over 50 years ago; experimental evidencewas found just this summer. Another announcement will be made shortly, stay tuned.
------------------------ ------------------------------------------------------------------
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.
or, use: “Jim Detrick” www.facebook.com, or , www.twitter.com.
707-536-3272, Tuesday, October 23, 2012