2956 - GAMMA RAY BURSTS

 -  2956  -  GAMMA  RAY  BURSTS  -  -  Long ago and far across the universe, an enormous burst of gamma rays unleashed more energy in a half-second than the sun will produce over its entire 10-billion-year lifetime.  ½ second versus 10,000,000,000 years!  The light got here on May 22, 2020,

-   This is a test.  How many of your 4th graders can get the right answers?  How many of the faculty?

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-  5 questions, you are allowed 10 seconds for each, the most right answers with the fastest times is the honor student for the day.

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-  Question 1:  You are participating in a race.  You overtake the second person.  What position are you in?

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-  Question 2:  What about if you overtake the last person in the race?

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-  Question 3:  Math in your head, no calculators allowed.  Take 1000 and add 40 to it.  Now add another 1000.  Now add 30.  Add another 1000.  Now add 20.  Now add another 1000.  Now add 10.  What is the total?

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-  Question 4:  Mary’s father has five daughters  Nana, Nene, Nini, Nono, what is the name of the 5th daughter?

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-  Question 5:  A mute person who wants to buy a toothbrush begins imitating the action of brushing one’s teeth.  He successfully expresses himself to the shopkeeper who helps him with the purchase.  Next a blind man comes in wishing to by a pair of sunglasses, how can he express himself to the shopkeeper?

-

-  Times up: 

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------------------------------------

-

-  (1)  You are second

-  (2)  How can you overtake the last person?

-  (3)  4100

-  (4)  Mary

-  (5)  Simply ask the shopkeeper.

-  

----------------------------- 2956 -  GAMMA  RAY  BURSTS  -  

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-  After examining the incredibly bright burst with optical, X-ray, near-infrared and radio wavelengths, astrophysists believe it potentially spotted the birth of a “magnetar“.

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-  They believe the magnetar was formed by two neutron stars merging, which has never before been observed. The merger resulted in a brilliant “kilo nova“, the brightest ever seen, whose light finally reached Earth on May 22, 2020. The light first came as a blast of gamma-rays, called a short gamma-ray burst.  

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-  Gamma Rays are high energy light that has very short wavelengths and therefore high energy.

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-    When two neutron stars merge, the most common predicted outcome is that they form a heavy neutron star that collapses into a blackhole within milliseconds.   For this particular short gamma-ray burst, the heavy object survived. Instead of collapsing into a blackhole, it became a “magnetar“

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-   A magnetar is a rapidly spinning “neutron star” that has large magnetic fields, dumping energy into its surrounding environment and creating the very bright glow that we can see.

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-  After the light was first detected by NASA's Neil Gehrels Swift Observatory, scientists quickly enlisted other telescopes, including NASA's Hubble Space Telescope, the Very Large Array, the W.M. Keck Observatory and the Las Cumbres Observatory Global Telescope network, to study the explosion's aftermath and its host galaxy.

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-  Compared to X-ray and radio observations, the near-infrared emission detected with Hubble was much too bright, 10 times brighter than predicted.

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-  As the data were coming in from the Hubble observations astronomers had to figure out about what that meant for the physics behind these extremely energetic explosions.  This was a magnetic monster.

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-  There were several possibilities to explain the unusual brightness, known as a short gamma-ray burst, that Hubble saw. Researchers think short bursts are caused by the merger of two neutron stars, extremely dense objects about the mass of the sun compressed into the volume of a large city like Chicago.

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-  While most short gamma-ray bursts result in a blackhole, the two neutron stars that merged in this case may have combined to form a magnetar, a supermassive neutron star with a very powerful magnetic field.

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-  This magnetar-powered kilonova, whose peak brightness reaches up to 10,000 times that of a classical nova. 

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------------------  1) Two orbiting neutron stars spiral closer and closer together. 

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-----------------   2) They collide and merge, triggering an explosion that unleashes more energy in a half-second than the Sun will produce over its entire 10-billion-year lifetime. 

-

-----------------   3) The merger forms an even more massive neutron star called a magnetar, which has an extraordinarily powerful magnetic field.

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-----------------   4) The magnetar deposits energy into the ejected material, causing it to glow unexpectedly bright at infrared wavelengths. 

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-  Magnetic field lines are anchored to the star and are whipping around at about 1,000 times a second, and this produces a magnetized wind.  These spinning field lines extract the rotational energy of the neutron star formed in the merger, and deposit that energy into the ejecta from the blast, causing the material to glow even brighter.

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-    Most magnetars are formed in the explosive deaths of massive stars, leaving these highly magnetized neutron stars behind. However, it is possible that a small fraction form in neutron star mergers.

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-  Kilonovae, which are typically 1,000 times brighter than a classic nova, are expected to accompany short gamma-ray bursts. Unique to the merger of two compact objects, kilonovae glow from the radioactive decay of heavy elements ejected during the merger, producing elements like gold and uranium.

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-   The unexpected brightness seen by Hubble came from a magnetar that deposited energy into the kilonova material, then, within a few years, the ejected material from the burst will produce light that shows up at radio wavelengths. Follow-up radio observations may ultimately prove that this was a magnetar, leading to an explanation of the origin of such objects.

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-  The  final chapter of the historic detection of the powerful merger of two neutron stars in 2017 officially has been written. After the extremely bright burst finally faded to black, an international team led by Northwestern University painstakingly constructed its afterglow—the last bit of the famed event's life cycle.

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-  Not only is the resulting image the deepest picture of the neutron star collision's afterglow to date, it also reveals secrets about the origins of the merger, the jet it created and the nature of shorter gamma ray bursts.

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-  This is the deepest exposure we have ever taken of this event in visible light.  Many scientists consider the 2017 neutron-star merger, dubbed GW170817, as LIGO's (Laser Interferometer Gravitational-Wave Observatory) most important discovery to date. 

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-  It was the first time that astrophysicists captured two neutron stars colliding. Detected in both gravitational waves and electromagnetic light, it also was the first-ever multi-messenger observation between these two forms of radiation.

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-  The light from GW170817 was detected, partly, because it was nearby, making it very bright and relatively easy to find. When the neutron stars collided, they emitted a kilo nova, light 1,000 times brighter than a classical nova, resulting from the formation of heavy elements after the merger. But it was exactly this brightness that made its afterglow, formed from a jet traveling near light-speed, pummeling the surrounding environment.

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-  100 days after the merger, the kilonova had faded into oblivion, and the afterglow took over. The afterglow was so faint, however, leaving it to the most sensitive telescopes to capture it.

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-  Starting in December, 2017, NASA's Hubble Space Telescope detected the visible light afterglow from the merger and revisited the merger's location 10 more times over the course of a year and a half.  At the end of March 2019 Hubble was able to obtain the final image and the deepest observation to date. 

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-  Over the course of seven-and-a-half hours, the telescope recorded an image of the sky from where the neutron-star collision occurred. The resulting image showed, 584 days after the neutron-star merger, that the visible light emanating from the merger was finally gone.

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-  By using all 10 images, in which the kilonova was gone and the afterglow remained as well as the final, deep Hubble image without traces of the collision. The team overlaid their deep Hubble image on each of the 10 afterglow images. Then, using an algorithm, they meticulously subtracted, pixel by pixel, all light from the Hubble image from the earlier afterglow images.

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-  The final time-series of images, showing the faint afterglow without light contamination from the background galaxy. Completely aligned with model predictions, it is the most accurate imaging time-series of GW170817's visible-light afterglow produced to date.

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-  The brightness evolution perfectly matches our theoretical models of jets.  It also agrees perfectly with what the radio and X-rays are telling us.

-

- 

-  The cosmic explosions known as short gamma ray bursts are actually neutron star mergers, just viewed from a different angle. Both produce relativistic jets, which are like a fire hose of material that travels near the speed of light. Astrophysicists typically see jets from gamma ray bursts when they are aimed directly, like staring directly into the fire hose. But GW170817 was viewed from a 30-degree angle, which had never before been done in the optical wavelength.

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-  GW170817 is the first time we have been able to see the jet 'off-axis. The new time-series indicates that the main difference between GW170817 and distant short gamma-ray bursts is the viewing angle.

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December 29, 2020            GAMMA  RAY  BURSTS  -                  2956                                                                                                                                                             

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--------------------- ---  Tuesday, December 29, 2020  ---------------------------

2955 - UNIVERSE - how do we know it is expanding?

 -  2955  - UNIVERSE  -  how do we know it is expanding?  -   The Universe hasn't existed forever but only for a finite time since the Big Bang, and that it's been expanding ever since that event took place. The matter and energy in the Universe began in a hot and dense state all at once, and then expanded and cooled as all the various components sped away from one another. 

-  Before we get to the Universe let’s start with a simple school classroom.  It was empty, there were no desks.

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-  September, 2005, on the first day of school, Martha Cothren, a social studies school teacher at Robinson High School in Little Rock , did something not to be forgotten. 

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-  On this first day of school, with the permission of the school superintendent, the principal and the building supervisor, she removed all of the desks out of her classroom. When the first period kids entered the room they discovered that there were no desks. 

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-  Looking around, confused, they asked, "Ms. Cothren, where're our desks?" 

She replied, "You can't have a desk until you tell me what you have done to have

earned the right to sit at a desk."

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-  They thought, "Well, maybe it's our grades." 

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-  "No," she said.

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-  "Maybe it's our behavior." 

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-  She told them, "No, it's not even your behavior."

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-  And so, they came and went, the first period, second period, third period. 

Still no desks in the classroom. By early afternoon television news crews

had started gathering in Ms. Cothren's classroom to report about this crazy 

teacher who had taken all the desks out of her room. 

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-  The final period of the day came and as the puzzled students found seats on 

the floor of the deskless classroom, Martha Cothren said, "Throughout the

day no one has been able to tell me just what he or she has done to earn the 

right to sit at the desks that are ordinarily found in this classroom. Now 

I am going to tell you." 

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-  At this point, Martha Cothren went over to the door of her classroom and 

opened it. Twenty-seven (27) U.S. Veterans, all in uniforms, walked into

that classroom, each one carrying a school desk. 

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-  The Vets began placing the school desks in rows, and then they would walk over and stand alongside the wall. 

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-  By the time the last soldier had set the final desk in place those  kids started to understand, perhaps for the first time in their lives, just how the right to sit at those desks had been earned. 

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-  Martha said, "You didn't earn the right to sit at these desks. These heroes 

did it for you. They placed the desks here for you. Now, it's up to you to 

sit in them. 

-

-  It is your responsibility to learn, to be good students, to be

good citizens. They paid the price so that you could have the freedom to 

get an education. Don't ever forget it."   This is a true story....

- 

----------------------------- 2955 -  UNIVERSE  -  how do we know it is expanding?

-

-  The Universe expanding is not an explosion.  Here’s why:

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-  An explosion always begins at a specific location in space.  An explosion initially occupies a small but finite volume.  And an explosion expands rapidly outward in all directions, limited only by the external forces and barriers it encounters.

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-  When you have an explosion, some material will often be caught up and/or affected by it, and will be pushed radially outward, with some of that material (typically the lightest stuff) moving outward the fastest. 

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-  That fastest-moving material will spread out more quickly and farther than the rest of the material, and will become less dense as a result. Even though the energy density drops everywhere, it drops fastest farthest away from the explosion, because more energetic material becomes less dense faster: at the outskirts. Just by measuring the trajectories of these different particles, you can always reconstruct where the explosion occurred.

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-  If you look farther and farther away, you also look farther and farther into the past. The farthest we can see back in time is 13.8 billion years, our estimate for the age of the Universe. It's the extrapolation back to the earliest times that led to the idea of the Big Bang. While everything we observe is consistent with the Big Bang framework, it's not something that can ever be proven.

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-  But this picture of an explosion doesn't match up with our Universe. The Universe looks the same here as it does a few million or even a few billion light-years away. It has the same densities, the same energies, the same number of galaxies in a given volume of space, etc.

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-  The objects that are very far away do indeed appear to move away from us at greater speeds than the nearby objects, but they also don't appear to be the same age as the slower, closer objects.

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-   Instead, as we go to extreme distances, the farther ones appear younger, less evolved, greater in number, and smaller in size and mass. Despite the fact that we can see galaxies out to distances in excess of 30 billion light-years, if we track how everything is moving and reconstruct their trajectories back to a common origin, we see the most unlikely of outcomes: the perceived "center" lands right on us.  Wow, did not know we were that important?

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-  Our of all the trillions of galaxies in the Universe, what are the odds that we would just happen to be right at the center of the explosion that began the Universe? What are the odds, on top of those minuscule ones, that the initial explosion was configured in just such a way, complete with irregular, inhomogeneous densities, varying start times for star formation and galaxy growth, energies that vary tremendously from place-to-place in just the right, fine-tuned fashion, and a mysterious 2.7 K background glow in all directions,

to conspire so that we're exactly at the center? 

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-  The explosion scenario isn't just unrealistic; it's in defiance of the known laws of physics.  An explosion in space would have the outermost material move away the fastest, which means it would get less dense, would lose energy the fastest, and would display different properties the farther away you went from the center. It would also need to expand into something, rather than stretching space itself. Our Universe doesn't support this.

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-  Instead, however, the law of gravity that governs our Universe, Einstein's General theory of Relativity, predicts that a Universe full of matter and energy doesn't explode, but instead expands.

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-   A Universe that's full of equal amounts of stuff everywhere, with the same average densities and temperatures, must either expand or contract; since we observe an apparent recession, the expansion solution is the only one that's physical. 

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-  There's a misconception that an expanding Universe can be extrapolated back to a single point; this isn't true! Instead, it can be extrapolated back to a region of finite size with certain properties , filled with matter, radiation, the laws of physics, but then must evolve according to the rules that our theory of gravity lays out.

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-  What this leads to is a Universe that has similar properties everywhere. This means that in any finite, equally-sized region of space, we should see the same density to the Universe, the same temperature to the Universe, the same number of galaxies, etc. 

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-  We would also see a Universe that appeared to evolve with time, as more distant regions should appear to us as they were in the past, having expanded less and having experienced less gravitational attraction and smaller amounts of clustering.

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-  Because the Big Bang happened everywhere at once a finite amount of time ago, our local corner of the Universe will appear to be the oldest corner of the Universe that there is. From our vantage point, what appears to us nearby is almost as old as we are, but what appears at great distances is much more similar to what our nearby Universe was like many billions of years ago.

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-  When you look at a region of the sky with the Hubble Space Telescope, you are not simply viewing the light from distant objects as it was when that light was emitted, but also as the light is affected by all the intervening material, and the expansion of space, that it experiences along its journey.

-

-   Hubble has taken us farther back than any other observatory to date, and has shown us a Universe that evolves in galaxy type, size, and number density with time.

-

-  The distant galaxies that exist are constantly emitting light, and we are seeing the light that has arrived only after it has completed its journey to get to us through the expanding Universe. 

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-  Galaxies whose light took a billion or ten billion years to get here appear as they were a billion or ten billion years ago. If we go all the way back, towards almost the moment of the Big Bang itself, we'd find that the Universe when it was that young was dominated by radiation, and not matter. It has to expand and cool for matter to become more important, energy-wise.

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-  Over time, as that Universe expands and cools, neutral atoms can finally, stably form without being immediately blasted apart. The radiation that once dominated the Universe, however, still persists, and continues to cool and redshift due to the expansion of space. 

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-  What we perceive today as the “Cosmic Microwave Background” is consistent with being the leftover glow from the Big Bang, but is also observable from anywhere in the Universe.  (See reviews about the CMB to learn more)

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-  The large-scale structure of the Universe changes over time, as tiny imperfections grow to form the first stars and galaxies, then merge together to form the large, modern galaxies we see today. 

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-  Looking to great distances reveals a younger Universe, similar to how our local region was in the past. Going back past the earliest galaxies we can observe, we find the leftover glow from the Big Bang itself, which appears in all directions and should be visible from anywhere in the Universe.

-

-  There isn't necessarily a center to the Universe at all; it's only our biased intuition that tells us there ought to be one. We can set a lower limit on the size of the region where the Big Bang must have occurred.  It can be no smaller than the size of a soccer ball, but there is no upper limit; the region of space where the Big Bang occurred could even have been infinite.

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-  If there truly is a center, it could literally be anywhere, and we would have no way to know. The portion of the Universe that is observable to us is insufficiently large to reveal that information, even if it could be true. 

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-  We would need to see an edge to the Universe, or observe a fundamental anisotropy where different directions appear different (but we see the same temperatures and galaxy counts), and we'd need to see a Universe that appeared to be different from region-to-region on the largest cosmic scales (but it appears to be homogeneous instead).

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-  The Universe, particularly on smaller scales, is not perfectly homogeneous, but on large scales the homogeneity and isotropy is a good assumption to better than 99.99% accuracy.

It sounds so reasonable to ask the question, "where did the Universe begin expanding from?"

-

-   But once you realize all of the above, you'll recognize that's the wrong question entirely. "Everywhere, all at once," is the answer to that question, and that's largely because the Big Bang isn't referring to a special location in space, but rather a special moment in time.

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-  That's what the Big Bang is: a condition that affects the entire observable Universe all at once at one specific moment. It's the reason why looking at objects that are farther away in space means that we're seeing that object as it was at a moment in the distant past.

-

-   It's why all directions appear to have rough properties that are uniform regardless of where we look. And it's why we can trace back our cosmic history, through the evolution of the objects we see, as far back as our observatories enable us to go.

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-  Galaxies comparable to the present-day Milky Way are numerous, but younger galaxies that are MilkyWay-like are inherently smaller, bluer, more chaotic, and richer in gas in general than the galaxies we see today. For the first galaxies of all, this ought to be taken to the extreme, and remains valid as far back as we've ever seen.

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-  Despite all that we have access to, despite all that our theories and observations tell us,  there's still a tremendous amount that remains unknown to us. We don't know what the actual size of the entire Universe is; we only have a lower limit that it must now be at least 46,100,000,000 light-years in radius in all directions from our perspective.

-

-  We don't know what the shape of the fabric of space is, and whether it's positively curved like a sphere, negatively curved like a saddle, or perfectly flat, like a sheet or a cylinder. We don't know whether it curves back on itself or whether it goes on forever. 

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-  All that we know is based on all we can observe. From that information, we can conclude that it's consistent with being infinite in size, it's consistent with perfect flatness, but information to the contrary may lie in the next significant digit of data or just beyond our observable cosmic horizon.

-

-  On a logarithmic scale, the Universe nearby has the solar system and our Milky Way galaxy. But far beyond are all the other galaxies in the Universe, the large-scale cosmic web, and eventually the moments immediately following the Big Bang itself. 

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-  Although we cannot observe farther than this cosmic horizon which is presently a distance of 46.1 billion light-years away, there will be more Universe to reveal itself to us in the future. The observable Universe contains 2 trillion galaxies today, but as time goes on, more Universe will become observable to us, perhaps revealing some cosmic truths that are obscure to us today.

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-  The reason we cannot know the true nature of the Universe the entire, unobservable Universe is because the portion that we have access to is finite. There's a finite amount of information we're capable of gleaning about our cosmos, even if we develop arbitrarily powerful instruments and detectors.

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-   It is plausible that even if we wait an infinite amount of time, we'll never know whether the Universe is finite or infinite, or what its geometric shape is.

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-  Whether you view the fabric of space as a leavening loaf of raisin bread or an expanding balloon with coins glued to the surface, you must keep in mind that the part of the Universe we can access is likely only a tiny component of whatever it is that actually exists.

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-   What is observable to us only sets a lower limit on the entirety of what's out there. The Universe could be finite or infinite, but the things we're certain of is that it's expanding, getting less dense, and that more distant objects appear as they were a long time ago. 

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-  The Universe is expanding the way your mind is expanding. It's not expanding into anything; you're just getting less dense.

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December 29, 2020        UNIVERSE  -   it is expanding?                 2955                                                                                                                                                             

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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”  -----------

--------------------- ---  Tuesday, December 29, 2020  ---------------------------

2954 - SPACETIME - how did it come from math? -

 -  2954  -  SPACETIME  -  how did it come from math?  -   All measurements of space and time are only meaningful relative to the observer in question, and depend on the relative motion of the observer to the observed.  The spacetime interval remains invariant. No matter who is doing the observing or how quickly they’re moving, the combined motion of any object through spacetime is something all observers can agree on.

---------------   Then there are written jokes that put the visual in your brain:

-  Tomorrow is my birthday, it is important that I approach it with a sense of humor.  If I knew that I was going to live this long I would have taken better of myself.

-

-  My pharmacist asked me my birthday again today, I think she is going to get me something.

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-  I notices the half the stuff in my shopping cart was labeled “ For Fast Pain Relief”

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-  Some mornings I can’t tell the differences in the noises from my stomach and my coffee maker.

-

- I am chronologically gifted.  I was taught to respect my elders.  Now, I don’t respect anyone.

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-  The things I remember with the most clarity never really happened.

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-  Happy Birthday, and don’t forget to flush.

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---------------------- 2954 -  SPACETIME  -  how did it come from math?

-

-  Here’s a question that most of us have been asked at some point in our lives, “what’s the shortest distance between two points?” By default, most of us will give the same answer that Archimedes gave more than 2,000 years ago: a straight line.  Why is that part of math class?

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-  If you take a flat sheet of paper and put two points down on it absolutely anywhere, you can connect those two points with any line, curve, or geometrical path you can imagine. So long as the paper remains flat, uncurved, and unbent in any way, the straight line connecting those two points will be the shortest way to connect them.  Now , we are into geometry.

-

-  This is how the three dimensions of space work in our Universe: in flat space, the shortest distance between any two points is a straight line. This is true regardless of how you rotate, orient, or otherwise position those two points. 

-

-  But our Universe isn’t made up merely of three space dimensions, but of four spacetime dimensions. Three of them are space and one of them is time, and that’s where we get spacetime. The shortest distance between two spacetime events isn’t a straight line any longer. Here’s the science of why.

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-  The “distance’ between two points depends on the path taken; ‘displacement” does not.

Normally, we measure the distance between two points by the distance traveled, such as that along a geodic of the planet Earth.

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-  For most of us, our first exposure to the idea of a straight line being the shortest distance between two points comes from a place we might not realize: the Pythagorean theorem. The Pythagorean theorem as a rule about right triangles, that if you square each of the short sides and add them together, that equals the square of the long side. In math terms, if the short sides are a and b while the long side is c, then the equation relating them is

-

---------------------------------   (  a² + b² = c²).

-

-  Think about what this means, however, not from the perspective of pure mathematics alone, but in terms of distances. It means that if you move through one of your spatial dimensions by a certain amount (“a“, for example) and then move through a perpendicular dimension by another amount (“b“, for instance), then the distance between where you began and where you wound up is equal to “c“, as defined by the Pythagorean theorem. In other words, the distance between any two points on a plane, where those points are separated by “a” in one dimension and “b” in another dimension, is “c“, where:

-

----------------------------------   c = √(a² + b²).

-

-  In our Universe, of course, we’re not restricted to living on a flat sheet of paper. We have not just length and width (or the “x” and “y” directions, if you prefer) dimensions to our Universe, but depth (or the “z” direction) as well. If you want to figure out what the distance is between any two points in space, it’s the exact same method as it was in two dimensions, except with one extra dimension thrown in. Whatever amount your two points are separated by in the “x” direction, the “y” direction, and the “z” direction, you can figure out the total distance between them just the same as earlier.

-

-  Only, because of the extra dimension, the distance between them, “d”,  is going to be given by: 

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---------------------------   d = √(x² + y² + z²). 

-

-  This might look like a scary equation, but it just says that the distance between any two points is defined by the straight line connecting them: the line that accounts for the separation between your two points in all three dimensions: the x-direction, the y-direction, and the z-direction combined.

-

-  One of the interesting and important realizations about this relationship, the distance between two points being a straight line, is that it absolutely does not matter how you orient your visualization of the x, y, and z dimensions. You can either:

-

--------------------------  change your coordinates so that the x, y, and z dimensions are in any (mutually perpendicular) directions you like, or

-

--------------------------  rotate these two points by any amount in any direction,

and the distance between them will not change at all.

-

-  Sure, the individual components will change if you either rotate your perspective or rotate the line connecting those two points, as your definitions of length, width, and depth will change relative to one another for that line as the rotation occurs. But the overall distance between those two points doesn’t change at all; that quantity of the distance between those points remains what we call “invariant,” or unchanging, regardless of how you rotate them.

-

-  Now, let’s not simply consider space, but time as well. You might think if time is just a dimension, too, then the distance between any two points in spacetime will work the same way. For example, if we represent the time dimension as “t“, you might think the distance would be the straight line connecting two points through the three spatial dimensions as well as the time dimension. In mathematical terms, you might think that the equation for the separation between any two points would look something like:

-

------------------------------   d = √(x² + y² + z² + t²).

-

-  After all, this is pretty much the same change we made when we went from two dimensions to three dimensions, except this time we’re going from three dimensions to four dimensions. It’s a reasonable step to attempt, and describes exactly what reality would look like if we had four dimensions of space, rather than three.

-

-  But we don’t have four dimensions of space; we have three dimensions of space and one dimension of time. And despite what your intuition may have told you, time isn’t “just another dimension.”

-

-   There are two ways that time, as a dimension, is different from space. The first way is a small one: you can’t put space (which is a measurement of distance) and time (which is a measurement of time) on the same footing without some way to convert one to the other. 

-

-  One of the great revelations of Einstein’s “theory of relativity” was that there is an important, fundamental connection between distance and time: the speed of light, or equivalently, of any particle that travels through the Universe without a rest mass.

-

-  The speed of light in a vacuum is 299,792,458 meters per second.   This velocity tells us precisely how to relate our motion through space with our motion through time: by that fundamental constant itself. When we use terms like “one light-year” or “one light-second,” we’re talking about distances in terms of time: the amount of distance that light travels in one year (or one second). If we want to convert “time” into a distance, we need to multiply it by the speed of light in a vacuum.

-

-  But the second way requires an enormous leap to understand: something that eluded the greatest minds of the late 19th and early 20th centuries. The key idea is that we’re all moving through the Universe, through both space and time, simultaneously. If we’re simply sitting here, stationary, and not moving through space at all, then we move through time at a very specific rate at which we’re all familiar: one second per second.

-

-  However, and this is the key point, the faster you move through space, the slower you move through time. The other dimensions are not like this at all: your motion through the “x” dimension in space is completely independent of your motion through the “y” and “z” dimensions. But your total motion through space, and this is relative to any other observer, determines your motion through time. The more you move through one (space or time), the less you move through the other.

-

-  Time appears to run slower and distances appear smaller close to the speed of light.

-

-  This is why Einstein’s relativity gives us concepts like “time dilation” and “length contraction“. If you move at very low speeds compared to the speed of light, you won’t notice these effects: time appears to move at one second per second for everyone, and lengths appear to be the same distance for everyone at speeds normally achievable on Earth.

-

-  But as you approach the speed of light, or rather, as you perceive an object where the relative speed between you and it is close to the speed of light, you will observe that it’s contracted along its direction of relative motion, and that clocks appear to run at a slower (dilated) rate relative to your own clocks.

-

-  The reason underlying this, as realized by Einstein, was straightforward: it’s because the speed of light is the same for all observers. If you imagine that a clock is defined by light bouncing back and forth between two mirrors, then watching someone else’s clock as they move close to the speed of light will inevitably result in their clock running slower than your own.

-

-  There is an even deeper insight here, which initially eluded even Einstein himself. If you treat time as a dimension, multiply it by the speed of light, and treat it as though it were imaginary, rather than real, then we can define a “spacetime interval” the same way we defined distance earlier. Only, since the imaginary number “I” is just “√(-1)”, this means that the spacetime interval is actually:  [Note the minus sign attached to the time coordinate!]

-

--------------------------   d = √(x² + y² + z² - c²t²)

-

-  The transformation from “motion through or separation in space” to “motion through or separation in time” is also a rotation, but it’s a rotation not in the “cartesian coordinates” of space (where x, y, and z are all real numbers), but through the “hyperbolic coordinates” of spacetime, where if the space coordinates are “real“, then the time coordinate must be “imaginary“.

-

-  In a great twist of fate, the person who first put these puzzle pieces together was Einstein’s former teacher, Hermann Minkowski, who noted in 1907/8 that:

-

-  “Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.”

-

-  With Minkowski’s mathematical rigor behind it, the concept of spacetime was not only born, but was here to stay.

-

-  What’s remarkable about all of this is that Einstein, despite lacking the mathematical insight to understand exactly how the dimension of time was related to the three conventional dimensions of space, was still able to piece together this key physical insight. Increasing your motion through space decreased your motion through time, and increasing your motion through time decreased your motion through space.

-

-   All measurements of space and time are only meaningful relative to the observer in question, and depend on the relative motion of the observer to the observed.

-

-  The spacetime interval remains invariant. No matter who is doing the observing or how quickly they’re moving, the combined motion of any object through spacetime is something all observers can agree on. 

- 

December 28, 2020             SPACETIME  -  the math?                     2954                                                                                                                                                             

----------------------------------------------------------------------------------------

-----  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”  -----------

--------------------- ---  Tuesday, December 29, 2020  ---------------------------

2951 -QUASARS - and other strange stars.

 -  2951  -  QUASARS  -  and other strange stars.    Hubble Space Telescope was recently focused on “NGC 6302“, known as the "Butterfly Nebula" to observe it across a more complete spectrum of light, from near-ultraviolet to near-infrared, helping researchers better understand the mechanics at work in its technicolor "wings" of gas. 

----------------------------- Predictions for the new year 2021:

-  President Biden gets Congress authorization to raise debt whenever he wants.  He  discontinues term limits for his office.  Medical staff promises he can live to 120 with new virus protections.

-

-  Ozone created by electric cars now killing millions in the seventh largest country in the world, Mexifornia , formerly known as California .  White minorities still trying to have English recognized as Mexifornia's third language. 

-

-  Spotted Owl plague threatens Mexifornia and northwestern United States crops and livestock. 

-

-  Couple petitions Supreme court to reinstate heterosexual marriage. 

-

-  Last remaining Fundamentalist Muslim dies in the American Territory of the Middle East (formerly known as Iraq , Afghanistan , Syria and Lebanon ). 

-

-  Iran still closed off; physicists estimate it will take at least 10 more years before radioactivity decreases to safe levels. 

-

-  France pleads for global help after being taken over by Jamaica 

-

-  Castro’s brother finally dies at age 112; Cuban cigars can now be imported legally, but President Biden has banned all smoking. 

-

-  George Z. Bush says he will run for President in 2036. 

-

-  Postal Service raises price of first class stamp to $17.89 and reduces mail delivery to every other Wednesday only. 

-

-  Biden government sponsors  $75.8 billion study that concludes diet and exercise is the key to weight loss. 

-

-  Biden oversees Massachusetts as state executes last remaining Conservative. 

-

-  Supreme Court rules punishment of criminals violates their civil rights. 

-

-  Average height of NBA players is now nine feet, seven inches. The basket height remains at 10 feet.

-

-  New federal law requires that all nail clippers, screwdrivers, fly swatters and rolled-up newspapers must be registered by January 2022. 

-

-  Congress authorizes direct deposit of formerly illegal political contributions to campaign accounts. 

-

-  IRS sets lowest tax rate at 75 percent. 

-

-  Seventeen states still having trouble with voting machines.  No one every learns who rally won the elections.  Results just get published on FunnyBook, formerly Facebook

-

------------------  2951  -  QUASARS  -  and other strange stars? 

-

-  The 2019 Hubble observations highlight a new pattern of near-infrared emission from singly ionized iron, which traces an S-shape. This iron emission likely traces the central star system's most recent ejections of gas, which are moving at much faster speeds than the previously expelled mass. 

-

-  The star, or stars,  at its center are responsible for the nebula's appearance. In their death throes, they have cast off layers of gas periodically over the past couple thousand years. The "wings" of NGC 6302 are regions of gas heated to more than 36,000 degrees Fahrenheit that are tearing across space at more than 600,000 miles an hour. NGC 6302 lies between 2,500 and 3,800 light-years away in the constellation Scorpius.

-

-  As nuclear fusion engines, most stars live placid lives for hundreds of millions to billions of years.  But near the end of their lives they can turn into crazy whirligigs, puffing off shells and jets of hot gas. 

-

-   Astronomers have employed Hubble's full range of imaging capabilities to dissect such crazy fireworks happening in two nearby young planetary nebulas. “NGC 6303”” is dubbed the “Butterfly Nebula” because of its wing-like appearance.   “NGC 7027” nebula, resembles a “jewel bug“, an insect with a brilliantly colorful metallic shell.

-

- The researchers have found unprecedented levels of complexity and rapid changes in jets and gas bubbles blasting off of the stars at the centers of both f these nebulas. Hubble is allowing the researchers to converge on an understanding of the mechanisms underlying the chaos.

-

-  The new multi-wavelength Hubble observations provide the most comprehensive view to date of both of these spectacular nebulas.  By examining this pair of nebulas with Hubble's full, panchromatic capabilities, making observations in near-ultraviolet to near-infrared light. 

-

-   The new Hubble images reveal in vivid detail how both nebulas are splitting themselves apart on extremely short timescales allowing astronomers to see changes over the past couple decades. Some of this rapid change may be indirect evidence of one star merging with its companion star.

-

- The nebula NGC 7027 shows emission at an incredibly large number of different wavelengths, each of which highlights not only a specific chemical element in the nebula, but also the significant, ongoing changes in its structure. 

-

-  The research team also observed the Butterfly Nebula, which is a counterpart to the "jewel bug" nebula: Both are among the dustiest planetary nebulas known and both also contain unusually large masses of gas because they are so newly formed. 

-

-  Hubble's broad multi-wavelength views of each nebula are helping the researchers to trace the nebulas' histories of shock waves. Such shocks typically are generated when fresh, fast stellar winds slam into and sweep up more slowly expanding gas and dust ejected by the star in its recent past, generating bubble-like cavities with well-defined walls.

-

-  Researchers suspect that at the hearts of both nebulas are two stars circling around each other. Evidence for such a central "dynamic duo" comes from the bizarre shapes of these nebulas. Each has a pinched, dusty waist and polar lobes or outflows, as well as other, more complex symmetrical patterns.

-

-  A leading theory for the generation of such structures in planetary nebulas is that the mass-losing star is one of two stars in a binary system. The two stars orbit one another closely enough that they eventually interact, producing a gas disk around one or both stars. The disk is the source of out flowing material directed in opposite directions from the central star.

-

-  Similarly, the smaller star of the pair may merge with its bloated, more rapidly evolving stellar companion. This also can create out flowing jets of material that may wobble over time. This creates a symmetric pattern, perhaps like the one that gives NGC 6302 its "butterfly" nickname. Such outflows are commonly seen in planetary nebulas.

-

-  The suspected companion stars in NGC 6302 and NGC 7027 haven't been directly detected because they are next to, or perhaps have already been swallowed by, larger red giant stars, a type of star that is hundreds to thousands of times brighter than the Sun.

-

-  The Butterfly Nebula is like a lawn sprinkler spinning wildly, tossing out two S-shaped streams. At first it appears chaotic, but if you stare for a while, you can trace its patterns. The same S-shape is present in the Butterfly Nebula, except in this case it is not water in the air, but gas blown out at high speed by a star. And the "S" only appears when captured by the Hubble camera filter that records near-infrared emission from singly ionized iron atoms.

-

- The S-shape directly traces the most recent ejections from the central region, since the collisions within the nebula are particularly violent in these specific regions of NGC 6302.  The iron emission is a sensitive tracer of energetic collisions between slower winds and fast winds from the stars. 

-

-  The fact that the iron emission is only showing up along these opposing, off-center directions implies that the source of the fast flows is wobbling over time, like a spinning top that's about to fall. So we need lawn sprinklers and spinning tops to visualize the nebula.  Ok!

-

-  The 'Jewel Bug' Nebula  NGC 7027 had been slowly puffing away its mass in quiet, spherically symmetric or perhaps spiral patterns for centuries until relatively recently. Something recently went haywire at the very center, producing a new cloverleaf pattern, with bullets of material shooting out in specific directions.

-

-  New images of NGC 7027 show emission from singly ionized iron that closely resembles observations made by NASA's Chandra X-ray Observatory in 2000 and 2014.   The iron emission traces the southeast-to-northwest-oriented outflows that also produce the X-ray-emitting shocks imaged by Chandra.

-

-  Astronomers have discovered the second-most distant quasar ever found.  It is the first quasar to receive an indigenous Hawaiian name, Pōniuā`ena, which means "unseen spinning source of creation, surrounded with brilliance" in the Hawaiian language.

-

-  Pōniuā`ena is only the second quasar yet detected at a distance calculated at a cosmological redshift greater than 7.5 and it hosts a blackhole twice as large as the other quasar known in the same era. The existence of these massive blackholes at such early times challenges current theories of how supermassive black holes formed and grew in the young universe.

-

-  Quasars are the most energetic objects in the universe powered by their supermassive blackholes and since their discovery, astronomers have been keen to determine when they first appeared in our cosmic history.

-

-   By systematically searching for these rare objects in wide-area sky surveys, astronomers discovered the most distant quasar (J1342+0928) in 2018 and now the second-most distant, Pōniuā`ena (or J1007+2115, at redshift 7.515). The light seen from Pōniuā`ena traveled through space for over 13 billion years since leaving the quasar just 700 million years after the Big Bang.

-

-  Spectroscopic observations from Keck Observatory and Gemini Observatory show the supermassive blackhole powering Pōniuā`ena is 1.5 billion times more massive than our Sun.

-

-  Pōniuā`ena is the most distant object known in the universe hosting a blackhole exceeding one billion solar masses.

-

-  For a blackhole of this size to form this early in the universe, it would need to start as a 10,000 solar mass "seed" blackhole about 100 million years after the Big Bang, rather than growing from a much smaller blackhole formed by the collapse of a single star.

-

-  How can the universe produce such a massive blackhole so early in its history?  This discovery presents the biggest challenge yet for the theory of blackhole formation and growth in the early universe.

-

-  Current theory holds the birth of stars and galaxies as we know them started during the “Epoch of Reionization‘, beginning about 400 million years after the Big Bang. The growth of the first giant blackholes is thought to have occurred during that same era in the universe's history.

-

-  The discovery of quasars like Pōniuā`ena, deep into the reionization epoch, is a big step towards understanding this process of reionization and the formation of early super massive blackholes and massive galaxies. Pōniuā`ena has placed new and important constraints on the evolution of the matter between galaxie’s intergalactic medium in the reionization epoch.

-

-  "Pōniuā`ena acts like a cosmic lighthouse. As its light travels the long journey towards Earth, its spectrum is altered by diffuse gas in the intergalactic medium which allowed astronomers to pinpoint when the Epoch of Reionization occurred.

-

-  In 2019, the researchers observed the object using “Gemini Observatory's GNIRS” instrument as well as “Keck Observatory's Near Infrared Echellette Spectrograph” (NIRES) to confirm the existence of Pōniuā`ena.  In case you want to learn more.

-

-   The Near Infrared Echellette Spectrograph (NIRES) is a prism cross-dispersed near-infrared spectrograph built at the California Institute of Technology.  Commissioned in 2018, NIRES covers a large wavelength range at moderate spectral resolution for use on the Keck II telescope and observes extremely faint red objects found with the Spitzer and WISE infrared space telescopes, as well as brown dwarfs, high-redshift galaxies, and quasars. 

-   

December 28, 2020        QUASARS  -  and other strange stars          2951                                                                                                                                                             

----------------------------------------------------------------------------------------

-----  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”  -----------

--------------------- ---  Tuesday, December 29, 2020  ---------------------------

ETA CATENAE - an exploding star?

 -  2953  - ETA  CATENAE  -  an exploding star?   Astronomers using NASA's “Far Ultraviolet Spectroscopic Explorer” satellite made the first direct detection of a companion star of Eta Carinae.  Eta Carinae is one of the most massive and unusual stars in the Milky Way galaxy. The detection was made possible by the high temperature of the companion star and the unique sensitivity of the satellite at the shortest ultraviolet wavelengths. 

---------------  Husband and wife decide who does what;

-  

 -  A man said to his wife one day, "I don't know how

 you can be so stupid and so beautiful all at the same time.

-

 "The wife responded, "Allow me to explain.

 God made me beautiful so you would be attracted to

 me;

-

 God made me stupid so I would be attracted to you! 

 -

 -  A man and his wife were having an argument about who

 should brew the coffee each morning.

-

 The wife said, "You should do it because you get up

 first, and then we don't have to wait as long to get our

 coffee.

-

 The husband said, "You are in charge of cooking

 around here and you should do it, because that is your job, and I

 can just wait for my coffee."

-

 Wife replies, "No, you should do it, and besides, it

 is in the Bible that the man should do the coffee."

-

 Husband replies, "I can't believe that, show me."

 So she fetched the Bible, and opened the New

 Testament and showed him at the top of several pages, that it indeed says 

 ...........

 "HEBREWS" 

-

- 

----------------------------- 2953 -  ETA  CATENAE  -  an exploding star

-

-  Eta Carinae is an unstable star thought to be rapidly approaching the final stage of its life. It is clearly visible from the southern hemisphere and has been the subject of intense studies for decades.

-

-   This mysterious star is located about 7,500 light-years from Earth in the star  constellation Carina. Scientists thought a companion star in orbit around Eta Carinae might explain some of its strange properties, but researchers lacked direct evidence a companion star existed. 

-

-   Evidence that Eta Carinae might be a double star system was inferred from a repeating pattern of changes in visual, X-ray, radio and infrared light over approximately 5 light years radius. Astronomers thought a second star in a 5 light year orbit around Eta Carinae might cause the repeated changes in its light. 

-

-  The strongest indirect evidence supporting the double star theory is that once every 5 light years, the X-rays coming from the system disappear for about three months. Eta Carinae is too cool to generate X-rays, but it continuously blasts a flow of gas into space as a stellar wind at about 300 miles per second. 

-

-  If its companion has a similar wind, their stellar winds would collide with enough force to generate the X-rays. This collision region must lie somewhere between the two stars. 

-

-  As Eta Carinae moves in its orbit, it passes in front of the region where the winds collide, as viewed from Earth. When this occurs, Eta Carinae eclipses the X-rays once every 5 light years, causing them to disappear. 

-

-  The last X-ray eclipse began on June 29, 2003. The 5 light year orbit places the companion star only about 10 times farther from Eta Carinae than Earth is from the sun. Eta Carinae is too far away for telescopes to distinguish two stars in such a close orbit. 

-

-  Another way to find evidence of a double-star system would be to detect the light of the second star, which in this case is much fainter than Eta Carinae. Several scientists searched for light from Eta Carinae's companion using ground-based telescopes, but none have succeeded.

-

-   Because the companion is thought to be much hotter than Eta Carinae, astronomers reasoned it should be brighter at shorter wavelengths like ultraviolet light. However, it still escaped detection when it was searched for using the ultraviolet capabilities of the Hubble Space Telescope. 

-

-  Finally the companion could be seen at even shorter ultraviolet wavelengths than Hubble. Astronomers observed the far-ultraviolet light from Eta Carinae with the satellite on June 10, 17 and 27, 2003, right before the expected X-ray eclipse.

-

-   The disappearance of far ultraviolet light so close to the X-ray eclipse implies when Eta Carinae eclipsed the X-rays, it also eclipsed the companion star. The far-ultraviolet light observed prior to the eclipse was from the hotter companion, because Eta Carinae is too cool to emit much far-ultraviolet light. 

-

-  This far ultraviolet light comes directly from Eta Carinae's companion star, the first direct evidence that it exists.  The companion star is much hotter than Eta Carinae, settling a long-standing mystery about this important star. 

-

-  Here is some history on this exploding star.  170 years ago, Eta Carinae, one of the brightest, most massive stars in the Milky Way, erupted with a titanic blast, releasing almost as much energy as a supernova explosion and becoming at one point the second brightest star in the night sky. Somehow, the star survived the “Great Eruption”, providing an intriguing mystery for astronomers.

-

-  Light from the outburst has rebounded, or “echoed,” off interstellar dust and has only now reached Earth, researchers have found the original explosion created a huge 10-solar-mass cloud of debris expanding 20 times faster than expected more than 20,000,000 miles per hour, fast enough to travel from Earth to Pluto in just a few days.

-

-  Velocities that high are seen in the aftermath of supernova explosions, but not in events that leave a star intact.  These really high velocities in a star that seems to have had a powerful explosion, but somehow the star survived.  The easiest way to do this is with a shock wave that exits the star and accelerates material to very high speeds.

-

-  Researchers first detected the light echoes from Eta Carinae in 2003, initially using telescopes at the Cerro Tololo Inter-American Observatory in Chile. Using the larger Magellan telescopes and the Gemini South Observatory, also in Chile, the researchers collected spectra to determine the velocity of the expanding debris.

-

-  The data did not jibe with accepted ideas about stellar evolution.  Massive stars normally die when their cores run out of nuclear fuel. When the outward pressure of fusion-generated energy suddenly stops, gravity takes over and the core collapses, generating a tremendous shock wave that blows the outer layers of the star into space.

-

-  Depending on the original mass, the core becomes a compact neutron star or a black hole.   In the case of Eta Carinae’s eruption, some process must have produced a supernova-like shockwave that came just shy of the energy needed to destroy the star. What might have happened?

-

-   Eta Carinae likely started out as a triple star system with two massive stars orbiting close together and a third star farther away. When the more massive of the two closely orbiting suns neared the end of its life, it began to expand, allowing the slightly less massive star to suck in an enormous amount of material.

-

-  That less massive star could swell to about 100 solar masses, in the process stripping away the dying sun’s outer atmosphere and leaving an exposed helium core about 30 times more massive than the Sun.

-

-  From stellar evolution, there is a firm understanding that more massive stars live their lives more quickly and less massive stars have longer lifetimes.   So the hot companion star seems to be further along in its evolution, even though it is now a much less massive star than the one it is orbiting. That doesn’t make sense without a transfer of mass.

-

-  That mass transfer would have changed the gravitational architecture of the system, allowing the helium-core star to move away from its huge partner, so far, in fact, that it eventually interacted with the outer third star, kicking it inward. That star finally crashed into the supermassive star at the heart of the triple system in a cataclysmic merger f the three stars.

-

-  In its initial stages, ejected material moved relatively slowly as the two stars spiralled closer and closer together. When the stars finally merged, debris was blown away 100 times faster, catching up and ramming into the slower-moving material and generating the light seen in Eta Carinae’s eruption.

-

-  The helium-core star, meanwhile, ended up in an elliptical orbit that carries it through the giant central star’s outer atmosphere every five-and-a-half years, generating X-rays and shock waves.

-

-  The now-binary star system shines five million times brighter than the Sun with two enormous, symmetrical lobes of expanding debris expanding to either side. The large star will likely exhaust its nuclear fuel in the near future, astronomically speaking, and explode as a supernova.

-   

-  So, now you know the story of an exploding star.  Here are some more reviews on this star:

-

-  1731  -  Learn more about astronomy by using more of the electromagnetic spectrum. Here are 2 views of galaxies and stars using X-rays and Radio waves converted to light waves.

-  1347  -  What is the Next Supernova to Go Boom?  The biggest supernova recorded was in 2006.  It was 250,000,000 lightyears away.  The picture is a star ready to blow. It is 8,000 lightyears away.  

-

-  775  -  Eta Carinae Supernova?   Press Democrat May 8, 2007, headlines:  “Supernova awes astronomers”.  Suprenova SN 2006gy was an exploding star 5 times brighter and more powerful than astronomers have ever seen before.  Fortunately, it was 240,000,000 light years away and that is how long ago it exploded. The light got here last September but what amazes astronomers is that it is still as bright.

-

-  49  -  409  -  Eta Carinae  -  The biggest, brightest star.

-

December 26, 2020        ETA  CATENAE  -  an exploding star?             2953                                                                                                                                                             

----------------------------------------------------------------------------------------

-----  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”  -----------

--------------------- ---  Sunday, December 27, 2020  ---------------------------

ATOM - what happens on the inside?

 -  2951  -  ATOM  -  what happens on the inside?  No one really knows what happens inside an atom. But two competing groups of scientists think they've figured it out. And both are racing to prove that their own vision is correct. Here's what we know for sure: Electrons whiz around "orbitals" in an atom's outer shell. Then there's a whole lot of empty space. Right in the center of that space, there's a tiny nucleus, a dense knot of protons and neutrons that give the atom most of its mass.

-  But first you need to here the story of the nun who went to a Hooter’s Bar.

-  

-  A nun, badly needing to use the restroom, walked into a local Hooters.

-

-  The place was hopping with music and loud conversation and every once in a while "the lights would turn off."

-

-  Each time the lights would go out, the place would erupt into cheers.

-

-  However, when the revelers saw the nun, the room went dead silent.

-

-  She walked up to the bartender, and asked, "May I please use the restroom?

-

-  The bartender replied, "OK, but I should warn you that there is a statue of a naked man in there wearing only a fig leaf."

-

-  "Well, in that case, I'll just look the other way," said the nun.

-

-  So the bartender showed the nun to the back of the restaurant.

-

-  After a few minutes, she came back out, and the whole place stopped just long enough to give the nun a loud round of applause. !

-

-  She went to the bartender and said, "Sir, I don't understand.  Why did they applaud for me just because I went to the restroom?"

-

-  "Well, now they know you're one of us," said the bartender, "Would you like a drink?"

-

-  "No thank you, but, I still don't understand," said the puzzled nun.

-

-  "You see," laughed the bartender, "every time someone lifts the fig leaf on that statue, the lights go out.

-

-  Now, how about that drink?"

-

----------------------------- 2951 -  ATOM  -  what happens on the inside?

-  

-   Those protons and neutrons at the center of the astom cluster together, bound by the “strong force“.   The number of those protons and neutrons determine whether the atom is iron or oxygen or xenon, and whether it's radioactive or stable.

-

-  No one knows how those protons and neutrons (together known as nucleons) behave inside an atom. Outside an atom, protons and neutrons have definite sizes and shapes. Each of nucleons is made up of three smaller particles called “quarks“, and the interactions between those quarks are so intense that no external force should be able to deform them, not even the powerful forces between particles in a nucleus.

-

-   This theory is in some way wrong. Experiments have shown that, inside a nucleus, protons and neutrons appear much larger than they should be. Physicists have developed two competing theories that try to explain that weird mismatch, and the proponents of each are quite certain the other is incorrect. Both camps agree, however, that whatever the correct answer is, it must come from a field beyond their own.

-

-  Since the 1940s, physicists have known that nucleons move in tight little orbitals within the nucleus. The nucleons, confined in their movements, have very little energy. They don't bounce around much, since they are restrained by the strong force.

-

-  In 1983, physicists at the European Organization for Nuclear Research (CERN) noticed something strange: Beams of electrons bounced off iron in a way that was very different from how they bounced off free protons. That was unexpected.  If the protons inside hydrogen were the same size as the protons inside iron, the electrons should have bounced off in much the same way.

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-   Scientists came to believe it was a size issue. For some reason, protons and neutrons inside heavy nuclei act as if they are much larger than when they are outside the nuclei. Researchers call this phenomenon the “EMC effect“, after the “European Muon Collaboration”, the group that accidentally discovered it. It violates existing theories of nuclear physics.

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-  While quarks, the subatomic particles that make up nucleons, strongly interact within a given proton or neutron, quarks in different protons and neutrons can't interact much with each other. The strong force inside a nucleon is so strong it eclipses the strong force holding nucleons to other nucleons.

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-  At any given time, about 20% of the nucleons in a nucleus are outside their orbitals. Instead, they're paired off with other nucleons, interacting in "short range correlations." Under those circumstances, the interactions between the nucleons are much higher-energy than usual. That's because the quarks poke through the walls of their individual nucleons and start to directly interact, and those quark-quark interactions are much more powerful than nucleon-nucleon interactions. 

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-  These interactions break down the walls separating quarks inside individual protons or neutrons. The quarks making up one proton and the quarks making up another proton start to occupy the same space. This causes the protons (or neutrons) to stretch and blur. They grow a lot, albeit for very short periods of time. That skews the average size of the entire cohort in the nucleus thus producing the “EMC effect“.

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-  Other scientists think the EMC effect is still unresolved. That's because the basic model of nuclear physics already accounts for a lot of the short-range pairing. 

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-  What is clear is that the traditional model of nuclear physics cannot explain this EMC effect.   We now think that the explanation must be coming from QCD.  Quantum Chromodynamics is the system of rules that govern the behavior of quarks. 

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-  Shifting from nuclear physics to QCD is a bit like looking at the same picture twice: once on a first-generation flip phone, that's nuclear physics,  and then again on a high-resolution TV, that's quantum chromodynamics. The high-res TV offers a lot more detail, but it's a lot more complicated to build.

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-  The problem is that the complete QCD equations describing all the quarks in a nucleus are too difficult to solve. Modern supercomputers are about 100 years away from being fast enough for the task. And even if supercomputers were fast enough today, the equations haven't advanced to the point where you could plug them into a computer.

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-  That suggests we need a different model.  We know that inside a nucleus are these very strong nuclear forces. These are a bit like electromagnetic fields, except they're strong force fields.  The fields operate at such tiny distances that they're of negligible magnitude outside the nucleus, but they're powerful inside of it.

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-  These force fields, which we call "mean fields" (for the combined strength they carry) actually deform the internal structure of protons, neutrons and pions (a type of strong force-carrying particle). 

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-  Just like if you take an atom and you put it inside a strong magnetic field, you will change the internal structure of that atom. 

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-  An experiment underway at Jefferson National Accelerator Facility in Virginia  will move nucleons closer together, bit by bit, and allow researchers to watch them change. 

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-  A "polarized EMC experiment" that would break up the effect based on the spin (a quantum trait) of the protons involved. It might reveal unseen details of the effect that could aid calculations.

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-  We still have a lot more to learn about atoms…………..  Here are some more reviews:

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-   2913  -  ATOM  -  can we see an atom?   Well, that really depends on what we mean by “see.” We see something when light emitted or reflected from an object reaches our eyes and the signal is conducted to our brain. 

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-  2867  -  ATOM  - and the electron cloud?  The picture of the atom you were taught in high school is wrong, mainly because electrons aren’t point-like particles.  Electrons are a‘fuzzy’ . They are tough to pin down due to their ‘Quantum Wave Function’, which is a complicated way of saying they exist as a field of “probability“, not as an individual particle. 

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-  2709 -  ATOMS  -  measuring how atoms work?  -  An atom can be viewed as a tiny electron orbiting a tiny nucleus at a certain radius.  Let’s start with the hydrogen atom which is a single proton orbited by a single electron.  

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-  2694  -  ATOM  -  How can mathematics tell us how an atom works?  It is 100 years of discovery.  -  It is how physicists were able to figure out the mathematics that defines the behavior of an atom.  They are still figuring, but, we have come a long way. 

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- 2685  -  MOLECULE  -  how a molecule works?  When there is more than one proton in the nucleus and more than one atom in orbit this classical physics math just becomes overwhelming.  That is the reason the math of Quantum Mechanics was invented. When Quantum Mechanic’s math is used, the concept of the electron orbiting the proton completely disappears.  The electron’s position around the nucleus becomes a probability distribution

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-  2452  -  ATOMS  -Michael Discovers Atoms.  My grandson, Michael, was looking at pond water under his microscope.  He could see small plants and animals moving around in the water.  But, he also saw all the little pieces of dust jiggling, almost vibrating, in a zigzag manner.  He asked me what causes everything to move like that?

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-  2377 - ATOM  -  defining the atom  All the other elements in the periodic table above hydrogen and helium were created in the nuclear fusion of the stars  The first stars formed with only hydrogen and helium.  When they burned all their fuel and exploded as supernova they splattered the surrounding space with all the atoms in the higher level elements.  

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-  2333  -  Rainbows can tell us what the Universe is made of.  Introduction to the science of spectroscopy.

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-  2318  -  Brownian motion from atoms you can not see.    My grandson, Michael, was 9 years old when he was looking at pond water under his microscope.  He could see small plants and animals moving around in the water.  But, he also saw all the little pieces of dust jiggling, almost vibrating, in a zigzag manner.  He asked me what causes everything to move like that?

-  2315  -   About how atoms were first discovered.  How was the atom discovered,  This review covers the first 100 years of discovery that started in 1808.  John Dalton conclusively argued for the existence of the indivisible atom, and at the same time as Einstein was provided a way to directly measure those atoms, Thomson and Rutherford discovered that the atom wasn't indivisible at all. Instead, it was made of even tinier bits

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-  2307 -  How small is the atom?   An atom is very small.  However, all atoms are about the same size, 10^-10 meters.  Atoms of all the elements have different atomic weights but they still are about the same size in diameter.

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-  2255  -  History of the atom. 

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-  2256 -   Atom’s stability and uncertainty?

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-  2147 -    Rutherford’s atom.   How the atom was discovered in 1911.  

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December 25, 2020      ATOM  -  what happens on the inside?        2952                                                                                                                                                             

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