JimsAstronomy

Wednesday, March 25, 2020

ANTIMATTER - what happens when we find it?

- 2679 - ANTIMATTER - what happens when we find it? One of the biggest mysteries in Physics remains, why is there more matter than antimatter? The Conservation of Energy tells us that at the time of the Big Bang, when matter was first created from energy, there should have been equal amounts of matter and antimatter created.
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--------------------- 2679 - ANTIMATTER - what happens when we find it?
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- When matter and antimatter come back together again they annihilate each other and everything returns back to energy again, according to E = mc^2, Energy is Conserved. Energy and matter are to forms of the same thing , and matter and antimatter can not live together. They must return to energy.
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- Antimatter is not found naturally on Earth. Exceptions are, very briefly, during radioactive decay and when Cosmic Rays collide with atoms in the upper atmosphere. Also, very small amounts of antimatter, such as anti-hydrogen, can be produced in our particle accelerators. The small amount of antimatter produced by the largest particle accelerator, CERN in Geneva, Switzerland, would light a 100 watt bulb for only 3 seconds.
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- Anti-hydrogen produced at CERN has one positron and one antiproton in each atom. If the atoms remain suspended in a perfect vacuum they survive indefinitely. However, if the anti-hydrogen comes in contact with ordinary matter, such as the walls of a container, the atoms quickly annihilate each other and turn into energy in the form of gamma ray radiation and high energy particles called pions. The pions decay quickly into muons, neutrinos, positrons, and electrons. It all happens in a flash.
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- Antimatter is made of 12 fundamental anti-particles. Just as matter is made of 12 fundamental particles. The Standard Model for Particle Physics defines all matter being made of 6 varieties of quarks and 6 varieties of leptons. Quarks come in threes and make up protons and neutrons. Leptons come in three varieties of electrons and three varieties of neutrinos. So the 12 fundamental particles make up “ordinary matter”.
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- The Standard model also includes the anti-particles for each of these fundamental particles of matter. A total of 24 fundamental particles with mass. Particles and anti-particles have the same mass but opposite signs of charge. For example, the electron has a negative charge and the positron has the same mass but carries a positive charge. If an electron and a positron collide they vaporize in a flash of energy.
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- The Standard Model does include four “force carrying” particles, the photons, W-Z bosons, gluons, and gravitons but these are massless and only travel at the speed of light. Since they are massless they have no anti-particle counterpart.
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- In 1928 Paul Dirac predicted that anti-particles existed. He developed equations of motion for the waveforms of electrons using Einstein’s theory of relativity. His equations required that there be negative electrons as well as positive electrons. Therefore he predicted that a positive electron twin of the same mass must exist. It was in the math.
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In 1932 this particle was actually discovered in cloud chambers that were studying cosmic ray collisions in the upper atmosphere. The first anti-particle was called a positron. In 1955 the antiproton was discovered. In 1956 the anti-neutron was discovered. In 1995 the anti-hydrogen atom was created.
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- Today antiprotons are routinely produced in particle accelerators. Protons traveling at near light speed are smashed into a block of copper or iridium metal. ( Any material would work as a target. It is just that these are easy to cool and beefsteak would be too sloppy.)
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- The energetic protons are stopped so abruptly very high temperatures are created. Temperatures high enough to create matter-antimatter pairs. The anti-protons with their negative charge are pulled off from the collision using powerful magnets that direct the beam of anti-protons into their experiments.
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- Positrons are created by radioactive decay and are used in PET scans, or brain scans for medical diagnoses. PET scans are “Positron Emission Topography“. The positrons are injected into the body. They then annihilate electrons in nearby atoms in the brain.
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- The energy emerges as two gamma rays that shoot off in opposite directions at 510,000 electron volts. The angles of projection are precisely aligned to conserve the angular momentum.
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- The gamma ray beams are detected in a ring of detectors very similar to a particle accelerator. The speed and angles are recorded in a computer and topography techniques are used to reconstruct an image of the brain and show the doctors if a tumor is there.
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- No one has ever observed the production of a particle or an anti-particle by themselves. They always come in pairs. To create a pair you need lots of energy. Your body is made of ordinary matter particles. These particles have been around for a long time. In fact, they were created 13,700,000,000 years ago.
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- These particles were created from the energy of the Big Bang. At that time they were created as pairs. An equal number of particles and anti-particles were produced. But, somehow, and we don’t know how, things got lopsided. When the annihilation of particle/antiparticle were over a small amount of matter was left over.
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- That is what everything we know is made of, matter, but we do not know what happened to the anti-matter Maybe there was an anti-gravity and the anti-matter shot off to form some other anti-Universe. Of course aliens in an anti-Universe would think they were ordinary matter and we were made of anti-matter. If you ever meet, just don’t shake hands with these guys.
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- If there were not this lopsided result with the Big Bang all matter would not exist the and Universe would consist only of light radiation in empty space.
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- When electrons and positrons annihilate each other they change into photons. In other words fermions change into bosons. Or, in other words mass changes into energy. We know that because E=mc^2.
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------------------------------ Energy = mass * 90,000,000,000,000,000.
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------------------------------ Energy = kilograms * meters^2 /seconds^2.
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------------------------------ Force = mass * acceleration
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------------------------------ Force = kilograms * meters / second^2
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------------------------------ Energy = Force * Distance
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- A particle thought to be moving faster than the speed of light, by another observer would be seen as a particle traveling backward in time and having the opposite charge. So, according to Richard Feynman, professor at Caltech, a positron can be viewed as an electron traveling backwards in time. Sorry, I can’t explain that one. Over my head.
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- Physicists believe that other than having an opposite charge antimatter follows all the laws of physics the same as matter. But it is hard to prove. One piece of evidence comes from the Supernova explosion 1987A.
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- Astronomers detecting neutrinos and anti-neutrinos from this explosion found them to be arriving Earth at the same time. The Supernova is 164,000 lightyears away. If gravity was affecting matter differently than anti-matter then we would not expect both types of neutrinos to arrive simultaneously.
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- Particle physicists are studying antimatter to learn if all the laws equally apply. We still don’t know for sure.
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- The starship Enterprise in Star Trek is powered by matter- antimatter fuel. It would be the ideal fuel. There is no better efficiency that creating matter into 100% energy. Especially with E=mc^2.
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- One kilogram would give you 90,000,000,000,000,000 kilogram*meter^2 / second^2 of energy. One ounce would light every light bulb in the United States for 24 hours. A kilogram*meter^2 / second^2 is a joule of energy and a joule is a watt of energy per second. We have just not figured how to mine antimatter yet.
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--------------------------------- To learn more about Antimatter see Reviews:
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- 2562 - ANTIMATTER - mystery in physics? Why is there more matter than antimatter? The Conservation of Energy tells us that at the time of the Big Bang, when matter was first created from energy, there should have been equal amounts of matter and antimatter created. When matter and antimatter come back together again they annihilate each other and everything returns back to energy again, according to E=mc^2, Energy is Conserved.
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- 2561 - ANTIMATTER BLACKHOLES - what happens when they meet? Antimatter is not science fiction, it is all around us. Antimatter is a mass that has the opposite electric charge but otherwise is exactly the same as ordinary matter, its counterpart. What makes antimatter fascinating is that when it meets up with matter the two annihilate each other back into energy, according to E = mc^2.
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- 2560 - ANTIMATTER - is all around us? Anti-matter is a term that most people relate to science fiction. It is the ultimate fuel used to power space ships traveling at near light speed. Few people realize that anti-matter is all around us, all the time, everyday. Anti-matter is created naturally in nature through radioactivity.
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- 2376 - ANTI-MATTER - Why does it exist? Present theory suggests that if particles outnumbered antiparticles in the Big Bang by as little as one part in 100 million, then the present universe could be explained by those extra particles that were not annihilated by an antiparticle counterpart.
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- 2244 - Matter is a mystery that we do not know how to explain. When the Big Bang occurred, our standard model predicts that there should have been an equal amount of matter and antimatter created. If it all came from nothing it has to add up to nothing. There needs to be equal amounts of matter and antimatter.
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- 1892 - Energy is converted into matter every day in our upper atmosphere.
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- 1746 - Does antimatter really exist?
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- 1393 - Does antimatter really exist? We know that the center of our Milky Way Galaxy is still producing antimatter, and the resulting Gamma Rays.
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- 1303 - Why look for antimatter in he Antarctic.
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- 1272 - Teaching the science of antimatter.
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- 1149 - Why does matter outnumber antimatter?
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- 971 - Notes from lecture about the Standard Linear Accelerator lecture on antimatter.
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- 607 - Antimatter is all around us.
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- March 25, 2020 730 2679
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----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
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--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
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--------------------- Wednesday, March 25, 2020 -------------------------
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BIG BANG - almost did not happen?

- 2678 - BIG BANG - almost did not happen? - The goal of the Big Bang theory is simply to understand the origin and the evolution of the Universe. Basically, how am I here? I read the theory but I have some questions?
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----------------------------- 2678 - BIG BANG - almost did not happen?
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- Here are my questions:
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- If all of the distant galaxies are moving away from us, in all directions, all at the same speed relative to their distances, I must be at the center of the Universe. Right?
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- True, the galaxies are moving away and the more distant the galaxy the faster it is receding, but, this is not the galaxy moving through space. It is space expanding between us. All the galaxies are just riding along a wave of growing space.
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- Light waves traveling through expanding space become stretched out. They get longer wavelengths. And, longer wavelengths have lower energy. Wavelengths shift toward the red end of the spectrum. They become redshifted.
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- The Cosmic Microwave Background radiation left the expanding Universe 380,000 years after it started. The radiation has been traveling through expanding space for 13,300,000,000 years. The Gamma Rays that left in the beginning have been stretched out to Microwave wavelengths that we are receiving now.
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- The radiation started when its temperature was 3,000 Kelvin and it arrives at much lower energy, a thermal energy of only 2.73 Kelvin. During that time the Universe has expanded by a factor of 1,000 and the temperature has dropped by a factor of 1,000.
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- It is space that is expanding and not objects that are moving through space. Since the expansion is the same everywhere it appears to us it is in all directions and we are at the center. We are not. Regardless of where you go inside the Universe it looks the same. We are not special. Everyone things they are at the center.
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- OK, space is expanding, but, what is it expanding into?
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- The Universe can expand without expanding into something. Space itself can curve, warp, shrink and grow without being embedded in something else, without going into some higher dimensional space. That is the answer, but it still does not make sense. I never thought that 3 dimensions could be that mysterious.
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- Was the Big Bang some kind of enormous explosion? True, space and time expanded, grew, and cooled, but, it was not an explosion. The Big Bang was a creation of space and time. It was a creation of matter and energy.
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- An explosion blows things apart. The Big Bang created things. True, the Universe was smaller, hotter, and denser earlier in time. When the Observable Universe was 50% it current size, it was twice as hot and 8 times as dense. When it was 1% its current size it was 100 times hotter. And, when it was 0.00001% its current size it was 273,000,000 Kelvin.
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- At that time it was about as dense as Earth’s atmosphere at sea level. But, it was so hot that all the gas and matter, all the atoms were flying around as free protons and free electrons. Run all this forward in time and things are coming together, not flying apart.
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- Again, running time backwards, what was there before the Big Bang? The Big Bang is when space and time first started. So, the question is what happened before time started? There is no way to know that. In fact, we can not get back past 10^-43 seconds.
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- The theories in physics, relativity, and quantum mechanics all fail to work when the dimensions of time and space become very small, less that 10^-43 seconds.
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- We have four known forces in the Universe, gravity, electromagnetic, strong and weak nuclear forces. When the Universe was 10^-12 seconds old the electromagnetic force and weak nuclear force combined to form a single force. Maybe, going back even further the Electroweak force combines with the strong nuclear force.
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- And, maybe even closer to the Big Bang gravity combined with the other three forces. However, none of our theories or observations work this far back in time. So, we do not know what really happens. Physics can not get us back beyond 10^-43 seconds let alone back to negative time beyond zero.
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- OK, last question. What is on the other side of the Observable Universe? Well, our current theories suggest the answer is more universe. The Universe is 13.7 billion years old. Because light has always , everywhere, traveled at the same speed of 186,000 miles per second, we can see 13.7 billion lightyears in every direction, theoretically. Well that is what you would think.
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- However, while light was traveling for 13.7 billion years the Universe has been expanding. When we see a galaxy that is 13.7 billion lightyears away, at that moment, it is actually 46.5 billion lightyears away. So, astronomers want to say the Universe is 93 billion lightyears across.
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- Saying this causes a problem. The Universe is the same looking in opposite directions. Light could not possibly have traveled between these opposite places. How could they be in thermal equilibrium, every where the same temperature?
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- Astronomers invented the theory of Cosmic Inflation in order to explain how the Universe could be uniform everywhere. This inflation, faster than the speed of light, could have happened when gravity split off from the other three forces.
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- In that instant of time the Universe expanded by a factor of 1,000. This would mean that the Universe is 1,000 times bigger than the Observable Universe. We can never see this part of the Universe because its light will never reach us.
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- As the Universe continues to expand at an ever increasing rate more and more of the Universe will be outside what we can observe. In 100 billion years from now our little Local Group of gravity captivated galaxies will have merged and be all alone in a much smaller Observable Universe.
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- The poor astronomers of the world have a dead end job. In no time there will be nothing to see. Better enjoy it while you can.
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---------------------- Other Reviews available:
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- 2334 - The Expanding Universe. As our Universe expands every cubic centimeter of new space creates invisible energy, called “dark energy“. The energy of expansion increases with time as the average density of matter in the cosmos falls more rapidly toward zero.
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- 2335 - The Universe Almost Didn’t Happen. The Universe is expanding today, so, running backwards in time it must have been denser and hotter than it is today. Gravity is constantly trying to pull all the matter back to a Singularity.
- 2603 - Universe - shape of he Universe. This Review list dozens of other reviews about the Universe. See appendix:
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- March 25, 2020 1127 2678
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----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
--------------------- Wednesday, March 25, 2020 -------------------------
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Tuesday, March 24, 2020

The Universe Almost Didn’t Happen

- 2335 - The Universe Almost Didn’t Happen. The Universe is expanding today, so, running backwards in time it must have been denser and hotter than it is today. Gravity is constantly trying to pull all the matter back to a Singularity.
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---------------------------- - 2335 - The Universe Almost Didn’t Happen

- By the Universe I mean the “reality” we observe and that we are a part of. We believe that this “reality” is the same everywhere. Physics is the same everywhere. Physics is the same backwards in time.
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- The Universe is expanding today, so, running backwards in time it must have been denser and hotter than it is today. Gravity is constantly trying to pull all the matter back to a Singularity.
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- However, as the Universe continues to expand the pull of gravity is weaker and weaker. It all depends on the relative density of matter in the Universe. A lot of matter will stop the expansion and cause it to contract. Too little matter and the expansion will continue forever. There is a balancing point were the density of matter is just “critical” to slow the expansion to a stop at an infinite point in time. This is called the “ Critical Density”.
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- Mass and Energy are the same thing according to E=mc^2. Energy is mass in kilograms times 90,000,000,000,000,000 meters^2 per seconds^2. So, we really mean the mass-energy density of the Universe.
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- If the pull of gravity and the push of expansion are exactly in balance at the Critical Density, then this is an unstable condition. It is like balancing a pencil upright on its point. The slightest force in any direction will cause the pencil to fall in that direction. If the Universe is exactly in balance then the slightest perturbation will cause it to either contract or expand again.
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- If the mass-energy density is greater than Critical it will stop expanding and begin contracting until the density becomes infinite at a single point ( a Singularity). If the mass-energy density is less than Critical then the Universe will continue expanding causing density to become less and less and colder and colder into the Deep Freeze. All the measurements astronomers are able to make confirm that the actual mass-energy density is almost exactly Critical.
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- Astronomer’s calculations make the density so close to Critical that if you added or subtracted 10% of the mass of a “dime” to the total mass of the Universe conditions would change to make the Universe physically impossible for life.
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- This is called the Universe’s Fine- Tuning Problem. If you run the calculations backwards in time to one second after the Big Bang the density would be extremely high. If you continue calculating back to a billionth or a second, one nanosecond, after the Big Bang you get the density of the entire Universe to be:
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------------------- 447,225,917,218,507,401,284,016 grams per cubic centimeter
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- Adding just 0.2 grams per cubic centimeter to this number and the Universe would have collapsed into a Big Crunch by now, 13.7 billion years after the Big Bang. If you take away only 0.2 grams per cubic centimeter the matter density would be so low by now we could not even detect it. The Fine-Tuning Problem! If any of the constants in physics were slightly different life could not exist.
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- When the Universe is at Critical Density astronomers say the geometry of the Universe is “flat”. The measurements to date tell us the Universe appears to be flat to one part in 10^60.
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- This is a very small number:
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------- 0.000000000000000000000000000000000000000000000000000000000001
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- But, the Universe could not be exactly flat because that would be an unstable condition. It is so close to Critical Density, but not exactly Critical Density. The Fine-Tuning Problem AGAIN!!!
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- Only a flat geometry Universe meets two essential requirements for life. First, a flat Universe survives long enough for generations of stars to form. The elements in the periodic table are formed in supernovae explosions. These elements in chemistry and biology are essential for life to form.
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- Secondly, a flat Universe expands slowly enough for matter to clump into stars, galaxies, planets, moons, asteroids. But, not so slowly that only Blackholes and Neutron Stars are formed.
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- Because the Universe is flat to one part in 10^60, astronomers must conclude that the matter we see is only 4% of the mass-energy of the Universe. 23% must be Dark Matter and 73% must be Dark Energy. We do not know what 96% of the Universe is but it must the there because we are here.
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- One explanation for the flat Universe is the “Theory of Inflation”. Between 10^-34 and 10^-32 seconds after the Big Bang, when the force of gravity split off from the other three forces, the Universe expanded be a factor of 10^50, expanding from 10^-50 meters to 1 meter in size.
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- This faster than the speed of light expansion explains why the Observerable Universe is homogenous and isotropic. It also explains why it appears flat. Just like the Earth appears flat in the part we observe from 2 meters off the ground. The more we see the more we learn. The more we learn the more we can see.
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- April 18, 2019. 1050
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----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
--------------------- Tuesday, March 24, 2020 -------------------------
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Monday, March 23, 2020

PIONEERS - exploring the universe?

- 2660 - PIONEERS - exploring the universe? The Pioneer spacecraft reached escape velocity from the Sun and would ultimately leave the solar system but were slowing down more than the data predicted they would. Also if we were in a kind of gigantic 'bubble, where the density of matter was significantly lower than the known density for the entire universe, it would have consequences on the distances of supernovae and, ultimately, on determining the expansion of the Universe.
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----------------------------- 2660 - PIONEERS - exploring the universe?
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- Before Voyager 1 and 2 explored the outer solar system, Pioneer 10 and 11 paved the way. Launched in 1972 and 1973, respectively, these spacecraft were the first to transit the asteroid belt and the first to make close observations of Jupiter (both Pioneer 10 and 11) and Saturn (Pioneer 11).
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- Like their successors, the Voyagers and New Horizons, both Pioneers are past the orbit of Pluto and will continue speeding outward from the center of the solar system.
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- Powered by four plutonium-238 radioisotope thermoelectric generators each, the Pioneer spacecraft carried several scientific devices that allowed them to take photographs and make detailed measurements of the environments around Jupiter and Saturn and in the outer solar system.
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- The Pioneers also famously carried the Pioneer plaque, with a pictorial message for any extraterrestrials who may someday encounter the craft; this would give them information as to the origin of the probes.
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- The Pioneers had some unique design features that allowed them to be very precisely tracked by Earth-based receiving stations. Both Pioneers were spin stabilized (which means that they rotate around a central point to keep them from wobbling or changing trajectory) and required very few course corrections that could perturb their motion.
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- The combination of the type of transceiver aboard the spacecraft and ground-based Doppler tracking used on the missions allowed their acceleration to be tracked to an almost unbelievable accuracy of 10^–10 meters per second squared (m/s2).
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- The Voyager spacecraft, which were not spin stabilized and relied on more frequent use of thrusters, cannot be tracked to this level of precision.
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- The Pioneers are considered the most precisely tracked and navigated spacecraft to date. This astonishing accuracy with regards to measuring the acceleration of the Pioneers led to an unusual discovery. It was understood that the probes would slow down to some extent due to the Sun’s gravitational attraction.
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- But while the Pioneers had reached escape velocity from the Sun and would ultimately leave the solar system, by 1980 a researcher at NASA’s Jet Propulsion Laboratory noticed the Pioneers were slowing down more than the data predicted they would. This occurred in both Pioneers, manifesting as a sunward acceleration of 8.74 ± 1.33 × 10^−10 m/s2.
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- While this may seem like a very small difference in measured acceleration from predicted acceleration, it led to the Pioneers remaining thousands of kilometers closer to Earth per year than they should have been. The cause greatly puzzled the scientists who studied the problem. Even such a small, unexplained sunward acceleration suggested a possible breakdown in the principle of gravitation as described by general relativity.
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- Why were the Pioneers slowing down? Many factors were considered as possible causes for this unexplained deceleration, which became known as the “Pioneer anomaly“. Could our understanding of the fundaments of physics be flawed?
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- Could gravitational forces from the surrounding interstellar medium that fills the space between stars be different than had been expected? Could dust produce drag on the spacecraft? Was the anomaly possibly secondary to solar radiation forces?
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- Could our calculations regarding the exact position of Earth relative to the spacecraft be incorrect? Was something related to the spacecraft, waste heat, a faulty thruster, or a gas leak, causing the anomaly?
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- Beyond the theoretical problems facing researchers, another more concrete problem stood in their way: The technical information and recordings of Pioneer data needed to solve the problem were stored either on paper or on 7- and 9-track magnetic data tapes.
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- Identifying these data sources (some of which were literally in boxes under stairwells and in dumpsters on their way to being destroyed), recovering the hardware needed to read the tapes, and converting all of this information to modern media formats was a daunting challenge on several levels, most notably the cost and manpower involved.
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- When all of these possibilities were considered, one potential cause of the Pioneer anomaly repeatedly came to the fore: thermal effects, mostly originating from the four RTGs aboard each Pioneer. To fully analyze this possibility scientists used predicted and actual thermal measurements to create a highly accurate thermal model of the spacecraft.
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- They first modeled the effects of heating from the Sun on the trailing face of the Pioneers. Then they turned to heat sources on the spacecraft. Heat from the RTGs radiated toward the leading edge of the spacecraft, in the direction of its motion, and heat from the electronics box also primarily radiated in this same direction. This generated a sunward (backward) pressure on the entire spacecraft.
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- As a result, the overall heating of the craft, when all factors were included, was asymmetric. Ultimately that radiation forces from the differential heating of the spacecraft, known as thermal recoil forces, from the RTGs and electronics were enough to explain the entire Pioneer anomaly.
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- Additional analysis showed that the Pioneer anomaly also appears to be decreasing in intensity with time, likely as a result of the RTGs’ radioactive decay and slow decline in power output.
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- In the end, the theory of relativity was not overthrown, our understanding of physics is not flawed, the Pioneer anomaly was explained to people’s satisfaction, and, for now, the question has been put to rest.
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- But the story of the Pioneer anomaly shows how exacting measurements in science can generate new questions, challenge old ideas, and stimulate new ways to solve complex problems. Here is an even bigger problem to solve far beyond our Solar System
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- The Earth, solar system, the entire Milky Way and the few thousand galaxies closest to us move in a vast "bubble" that is 250 million light years in diameter, where the average density of matter is half as high as for the rest of the universe.
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- This is the hypothesis advanced by a theoretical physicist from the University of Geneva to solve a conundrum that has been splitting the scientific community for a decade: At what speed is the universe expanding?
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- Until now, at least two independent calculation methods have arrived at two values that are different by about 10% with a deviation that is statistically irreconcilable.
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- The universe has been expanding since the Big Bang occurred 13.8 billion years ago—a proposition first made by the Belgian canon and physicist Georges Lemaître (1894-1966), and first demonstrated by Edwin Hubble (1889-1953). The American astronomer discovered in 1929 that every galaxy is pulling away from us, and that the most distant galaxies are moving the most quickly.
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- This suggests that there was a time in the past when all the galaxies were located at the same spot, a time that can only correspond to the Big Bang. This research gave rise to the Hubble-Lemaître law, including the Hubble constant (H0), which denotes the universe's rate of expansion.
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- The best H0 estimates currently lie around 70 (km/s)/Mpc (meaning that the universe is expanding 70 kilometers a second more quickly every 3.26 million light years). The problem is that there are two conflicting methods of calculation.
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- The first is based on the cosmic microwave background: This is the microwave radiation that comes at us from everywhere, emitted at the time the universe became cold enough for light to be able to circulate freely (about 370,000 years after the Big Bang).
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- Using the precise data supplied by the Planck space mission, and given the fact that the universe is homogeneous and isotropic, a value of 67.4 is obtained for H0 using Einstein's theory of general relativity to run through the scenario.
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- The second calculation method is based on the supernovae that appear sporadically in distant galaxies. These very bright events provide the observer with highly precise distances, an approach that has made it possible to determine a value for H0 of 74.
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- These two values carried on becoming more precise for many years while remaining different from each other. It didn't take much to spark a scientific controversy and even to arouse the exciting hope that we were perhaps dealing with a 'new physics.
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- To narrow the gap the idea that the universe is not as homogeneous as claimed, a hypothesis that may seem obvious on relatively modest scales. There is no doubt that matter is distributed differently inside a galaxy than outside one. It is more difficult, however, to imagine fluctuations in the average density of matter calculated on volumes thousands of times larger than a galaxy.
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- If we were in a kind of gigantic 'bubble, where the density of matter was significantly lower than the known density for the entire universe, it would have consequences on the distances of supernovae and, ultimately, on determining H0.
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- All that would be needed would be for this "Hubble bubble" to be large enough to include the galaxy that serves as a reference for measuring distances. By establishing a diameter of 250 million light years for this bubble, the physicist calculated that if the density of matter inside was 50% lower than for the rest of the universe, a new value would be obtained for the Hubble constant, which would then agree with the one obtained using the cosmic microwave background.
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- The probability that there is such a fluctuation on this scale is one in 20 to one in 5, which means that it is not a theoretician's fantasy. There are a lot of regions like ours in the vast universe.
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- The best part of astronomy is learning something you don’t agree with. What are you missing? What more is there to learn? It is like picking up small pebbles of knowledge up on the beach with the whole ocean of the unknown extending over the horizon.
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- March 23, 2020 2677
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----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
--------------------- Monday, March 23, 2020 -------------------------
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UNIVERSE - Wrap Your Mind Around the Universe?

- 2676 - UNIVERSE - Wrap Your Mind Around the Universe? - We create the Universe in our heads. It is similar to how we create “ rainbows’ in our heads. Rainbows are not objects that really exist. They are not actually there. If someone sees a rainbow from a different location, she is seeing a different rainbow from the one you are seeing.
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------------------- 2676 - UNIVERSE - Wrap Your Mind Around the Universe?
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- The Universe is much different that what we see. It is like a rainbow that we create in our minds. Let’s wrap our mind around the Universe?
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- Light coming from the stars is traveling very fast, 670,633,500 miles per hour. But space is very, very big. The nearest star is 4.4 lightyears away.
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------------ There are 25,280,000,000,000 miles in a single lightyear
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------------ Alpha Centauri is 5,880,000,000,000 miles away
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------------- Time = Distance / Velocity
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------------- Time light has traveled = 25.28 *10^12 miles / 6.7 * 10^8 miles / hour
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------------- Time = 37,000 hours for light to reach us
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------------ There are 8,760 hours in a year
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------------ Time light has traveled = 3.7*10^4 hours / 8.7*10^3 hours / year = 4.4 lightyears
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- That is how far the closest starlight has to travel and how long it takes to reach us even when traveling at 670 million miles per hour.
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- When we are looking at the star Alpha Centauri we are viewing what it looked like nearly 4 ½ years ago. It is 4 ½ years older now. It could have blown up and disappeared and we would not know about it for another 4 ½ years. ( although this explosion is unlikely).
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- It turns out the Universe is always giving us old information.
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- You hear that expression that the stars of the heaven could have gone supernova and not even be there anymore. This is unlikely. The stars we can see with the naked eye are likely within 3,000 lightyears distance. These are the stars in our neighborhood of the Milky Way Galaxy. So, all these stars could not have lived more than 3,000 additional years. Stars live for millions and billions of years so 3 thousand is merely a blink of the eye in star time.
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- You can only see about 6,000 stars in the night sky. But, who’s counting? It is very unlikely that one of these will have gone supernova exactly 3,000 years ago, or whatever fewer lightyears it is away from us.
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- The most likely supernova we are likely to have in our Galaxy is Eta Carinae ( just guessing) and it is 250,000,000 lightyears away. It would have had to have exploded 250,000,000 years ago in order for us to see it now. ( See other Reviews to learn more about Eta Carinae.)
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- Astronomers have discovered over 1,000 Quasars that are billions of lightyears away. They are extremely bright lights created by active Blackholes at the cores of massive galaxies. These astronomers are most assuredly looking at ghosts.
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- Quasars only occurred in the early Universe. The Universe has since expanded so much that more recent Quasars do not exist anymore. The light we are seeing is information about a long bygone Universe.
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- We have read about massive stars collapsing into a Blackhole. We visualize it happening in our minds. Artist depict renderings and computer simulations of what it would look like. Our imagination can see it but in fact we could never see such an event.
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- A Blackhole is so dense with so much gravity that light never escapes. Its gravity bends space-time back on itself. If somehow we were viewing this event from outside it would simply look like time was slowing to a stop. The event becomes frozen in time. It just stops. There is nothing more ever to be seen.
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- The Universe is expanding at 47,000 miles per hour for every million lightyears distance. Therefore the galaxies are no longer located where we see them. And, of course, by now they may look much different.
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- There may even have been mergers and collisions by now. They may even be so far away by now that the light will never reach us. We may never know what these galaxies look like today.
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- We create the Universe in our heads. It is similar to how we create “ rainbows’ in our heads. Rainbows are not objects that really exist. They are not actually there. If someone sees a rainbow from a different location, she is seeing a different rainbow from the one you are seeing.
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- Your eyes witness a specific light beam that gets bent in the rain drops and enters only your eyes. If no one was looking the rainbow would not be there. In fact, throughout history rainbows did not exist until animals evolved with color vision. Your eyes and your eyes alone personally create the colors you see. Each rainbow is personally yours.
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- Rainbows do not have shadows or reflections. If you see a rainbow reflected of the still surface of a lake it is a different rainbow because it is being created by different beams of light. Rainbows are not real, we make them real in our heads.
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- So it is with much of the Universe. It is as we perceive it. The finite speed of light requires that we use the laws of physics to learn what “is”. For sure, it “ is” not what we “ see”.
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- A good student will be able to “ see” with “ understanding”. You have to learn to see what is. An announcement will be made shortly, stay tuned.
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- March 23, 2020 1398 2676
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----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
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--------------------- Monday, March 23, 2020 -------------------------
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Sunday, March 22, 2020

EYE TRICKS - Your Eyes are Playing Tricks

- 2673 - EYE TRICKS - Your Eyes are Playing Tricks? - Your eyes are how you perceive the outside world. But, what you see does not exist in your eyes. Your eyes are the detectors that send data to your brain. What actually exists as an image is in the occipital lobes of your brain. In a very real sense there is no outside world, everything that exists for you is inside your head.
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--------------------- 2673 - EYE TRICKS - Your Eyes are Playing Tricks?
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- The eyes are detecting and sending to our brains just a very, very small part of the radiation data that exists in the outside world. The environment is packed full of radiation, electromagnetic radiation. Radio waves, microwaves, infrared rays, red light, blue light, ultraviolet radiation, X-rays, gamma rays are all over the place. They are all filling the same space that you can see.
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- What would it be like if we could stair out the window and see all the radiation that is out there. It would be information overload for sure. The wavelengths of radiation that we can detect with instruments extends from miles long down to nanometers in length (10^6 meters to 10^-12 meters) with visible light wavelengths only 400 to 700 nanometers (4*10^-10 meters).
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- The retinas in your eyes have two kinds of detectors, cones and rods. Images from the outside world are focused through your pupils onto the fovea, the center spot of the retina.
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- There are 8,000,000 cones in the center of your retina. Cones work sort of like prisms, due to their triangular shape they are sensitive to different wavelengths of light, in the 400 to 700 nanometer range. Therefore, cones see colors from blue to red. But, cones require bright light. They do not work well in dim light.
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- Around the fovea are 20,000,000 rod shaped cells. Because of their cylindrical shape they can not distinguish colors. But, they work well in dim light . Rods are 15 degrees to 20 degrees from the fovea center. Cones cover 1 degree in the center.
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- So, in dim light we suffer from a 1 degree blind spot in the center of our eyes. However, we can see quite well with “averted vision“. Look 15 degrees away from the object and in dim light you can see it better, but only in black and white. Your color vision is gone in dim light.
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- In fact, rods are totally blind to red light. Check out the Christmas tree lights next time. Put a dimmer on the lights and slowly turn the brightness down. At some point colors vanish and you only see gray lights. At that point your cones no longer work and you rods are seeing the gray lights.
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- However, the red-lights will disappear entirely. We can not see dim red light, even as gray. Also, if a dim object is smaller than one degree it vanishes when we look at it directly. Only averted vision can pick it up.
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- Cones respond quickly to bright light but rods respond slowly to dim light. It can take up to 20 minutes for you eyes to acquire night vision sensitivity. Almost everything in the night sky and through the telescope requires night vision sensitivity.
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- Once acquired night vision is 10 times sharper than daylight vision. That is the reason galaxies appear as a smudge of light and the full Moon appears sharp with lots of detail.
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- That is the great thing about CCD’s. Charge Coupled Diodes can continue to accumulate photons to acquire an image over time. Even in the dimmest light, stair at one spot with a long enough time exposure and every object becomes visible. Hubble’s Deep Field view of far away galaxies took a time exposure of 400 days.
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- Use your averted vision to see objects in the night sky. The Beehive Cluster (M44) will first appear as a blob, a nebula. With averted night vision normal eyesight can resolve individual stars.
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- It’s weird, and takes practice, but in dim light the clearest vision materializes only when you don’t look at it.
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- That is an eye trick for you.
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- March 18, 2020 780 2673
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----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
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--------------------- Saturday, March 21, 2020 --------------------
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FRAME DRAGGING - bending space time?

- 2674 - FRAME DRAGGING - bending space time? The predictions of Einstein’s general theory of relativity is that any spinning body drags the very fabric of space-time in its vicinity around with it. This is known as “frame-dragging”.
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-------------------------- 2674 - FRAME DRAGGING - bending space time?
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- In everyday life, frame-dragging is both undetectable and inconsequential, as the effect is so ridiculously tiny. Detecting the frame-dragging caused by the entire Earth’s spin requires satellites such as the US $750 million Gravity Probe B, and the detection of angular changes in gyroscopes equivalent to just one degree every 100,000 years or so.
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- Luckily for us, the Universe contains many naturally occurring gravitational laboratories where physicists can observe Einstein’s predictions at work in amazing detail. Science studies reveal evidence of frame-dragging on a much more noticeable scale, using a radio telescope and a unique pair of compact stars whizzing around each other at astronomical speeds.
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- The motion of these stars would have perplexed astronomers in Newton’s time, as they clearly move in a warped space-time, and require Einstein’s general theory of relativity to explain their trajectories.
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- The white dwarf-pulsar binary system PSR J1141-6545 was discovered by the CSIRO’s Parkes radio telescope. The pulsar orbits its white dwarf companion every 4.8 hours. The white dwarf’s rapid rotation drags space-time around it, causing the entire orbit to tumble in space.
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- General relativity is the foundation of modern gravitational theory. It explains the precise motion of the stars, planets and satellites, and even the flow of time. One of its lesser-known predictions is that spinning bodies drag space-time around with them. The faster an object spins and the more massive it is, the more powerful the drag.
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- One type of object for which this is very relevant is called a white dwarf. These are the leftover cores from dead stars that were once several times the mass of our Sun, but have since exhausted their hydrogen fuel.
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- What remains is similar in size to Earth but hundreds of thousands of times more massive. White dwarfs can also spin very quickly, rotating every minute or two, rather than every 24 hours like Earth does.
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- The frame-dragging caused by such a white dwarf would be roughly 100 million times as powerful as Earth’s.
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- But we can’t fly to a white dwarf and launch satellites around it. Fortunately, however, nature is kind to astronomers and has its own way of letting us observe them, via orbiting stars called pulsars.

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- Twenty years ago, CSIRO’s Parkes radio telescope discovered a unique stellar pair consisting of a white dwarf (about the size of Earth but about 300,000 times heavier) and a radio pulsar (just the size of a city but 400,000 times heavier).
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- Pulsars are made not of conventional atoms, but of neutrons packed tightly together, making them incredibly dense. The pulsar in this study spins 150 times every minute.
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- This mean that, 150 times every minute, a “lighthouse beam” of radio waves emitted by this pulsar sweeps past our vantage point here on Earth. We can use this to map the path of the pulsar as it orbits the white dwarf, by timing when its pulse arrives at our telescope and knowing the speed of light. This method revealed that the two stars orbit one another in less than 5 hours.
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- This pair, officially called PSR J1141-6545, is an ideal gravitational laboratory. Since 2001 we have tracked Parkes several times a year to map this system’s orbit, which exhibits a multitude of Einstein‘s gravitational effects.
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- Mapping the evolution of orbits is not for the impatient, but the measurements become ridiculously precise. Although PSR J1141-6545 is several hundred quadrillion kilometers away, we know the pulsar rotates 2.5387230404 times per second, and that its orbit is tumbling in space. This means the plane of its orbit is not fixed, but instead is slowly rotating.
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- When pairs of stars are born, the most massive one dies first, often creating a white dwarf. Before the second star dies it transfers matter to its white dwarf companion. A disk forms as this material falls towards the white dwarf, and over the course of tens of thousands of years it revs up the white dwarf, until it rotates every few minutes.
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- A white dwarf is spun-up by the transfer of matter from its companion. Material at the surface of the swollen star falls towards the white dwarf and forms a disk of material traveling so quickly it causes the star to spin rapidly.
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- In rare cases such as this one, the second star can then detonate in a supernova, leaving behind a pulsar. The rapidly spinning white dwarf drags space-time around with it, making the pulsar’s orbital plane tilt as it is dragged along. This tilting is what astronomers observed through our patient mapping of the pulsar’s orbit.
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- Einstein himself thought many of his predictions about space and time would never be observable. But the past few years have seen a revolution in extreme astrophysics, including the discovery of gravitational waves and the imaging of a black hole shadow with a worldwide network of telescopes.
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- See Review - 1260 - Measuring the Space-Time Warp of Earth’s Gravity? Einstein’s Theory of Relativity predicted that gravity would warp the geometry of space-time just like acceleration would. If a satellite orbits the Earth it would follow the least energy path through this modified space-time. This would in turn cause the plane of the satellite’s orbit to wobble, or precess.
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- The effect of precession is very small, one part in a few trillion. This Review 1260 tries to learn how the calculations were made and what the measurement results have been to prove Einstein is right.
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- March 21, 2020 2674
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----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
--------------------- Sunday, March 22, 2020 --------------------
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