Friday, April 2, 2021

Index of Astronomy and physics reviews:

I:   Partial index of recent reviews:  Request number to get a particular copy.

-

-  3076 -  PARALLAX  -  measures distance to the stars?  -  In 200 B.C.  Hipparchus Nicea , an astronomer using only his naked eyes measured the position and brightness of 1,080 stars.  Today the science he started is called “ astrometry”  In August 8, 1989 the High Precision Parallax Collecting Satellite was launched, “Hipparcos”, to carry on the science of astrometry.  

-  3077  -  MAGNETARS  - and Gamma Ray Burster stars?  Magnetars could be the natural end product of [main-sequence] and probably also pre-[main-sequence] mergers. Astronomers may finally understand the origin of magnetars and their strong magnetic fields.

 -  3078  -  -  BIRD  POOP  -  can it break a car windshield?   A woman with a cracked windshield claimed a bird had done it.  The car was parked.   The bird poop over the cracked windshield was 4 inches in diameter.  To break a car windshield you need in excess of 50 million Pascal of pressure.   Is the bird guilty?

-  3079  -  DARK  ENERGY  -  Could the Astronomer’s Math be Wrong?  -   Therefore, the Universe is not expanding at a constant rate, it is accelerating in its expansion.  Astronomers do not know what could cause this so they call it “Dark Energy” and their calculations are that Dark Energy composes 73% of all the mass-energy in the Universe.

-  3080  -  ATOMS  - Stability with Uncertainty?   The stability of all atoms, in all the elements, in all of matter, depends on the “Principle of Uncertainty” and the “wave-particle duality” of all matter.   How can stability depend on uncertainty? 

-  3081  -  BRAIN  -    Understanding Yourself -  If the brain were simple enough to understand we would all be too simple to figure it out.  The brain gets it complexity from having many parts, each having a specialized function.  It gets its complexity from the communications network that coordinates all of the parts through biochemical means.  It gets its complexity through evolving throughout a lifetime and over many lifetimes.

 -  3082  -  UNIVERSE  -  how to create one?  The beginning is the easy part.  First you start with nothing. Who would have thought of that? This all happened around 13,700,000,000  years ago.  That was when the universe sprang out of nothing. We still don't know the conditions under which the universe first formed, and whether there was a time before time. But, here is our best scientific guess.

 -  3083 -   EXOPLANETS  -  recent planet discoveries?   Astronomers  have confirmed the discovery of a “planetoid” that is almost four times farther from the Sun than Pluto, making it the most distant object ever observed in our solar system.

 -  3084  -  NEUTRON  STARS  -  how can they carry charges?  Can we have a super-strong magnetic field coming from the inside of a blackhole?  We see blackhole magnetic fields, but are they generated inside the event horizon or outside, such as in the accretion disk?   And if they do come from the inside, what’s the physics behind that? 

 -  3085 -  UNIVERSE  -  explaining it s rate of expansion?  Determining how rapidly the universe is expanding is key to understanding the fate of the Universe.  But with more precise data this fate has become a mystery.  Estimates based on measurements within our local universe don't agree with extrapolations from the era shortly after the Big Bang 13.8 billion years ago.

-  3086  -  DARK ENERGY -  What is the Universe Made of?  Dark Energy was not known until 1998 so we  have only 30 years to think about it.  The most likely answer is vacuum energy.  A vacuum is not really a vacuum but a see of virtual particles and anti-particles going into and out of existence in such a short time they do not defy the laws of physics and cannot be detected using the laws of physics.  

 -  3087  -  COSMIC  INFLATION  -   needed to explain the universe?  What is Cosmic Inflation?  Cosmic Inflation is a theory to help astronomers explain the observations they have of the Universe.  The theory is that the Universe expanded faster than the speed of light very early in its evolution.  

 -  3088  -  GRAVITY  -  will we ever understand it?   Experimental results are extending the parameter space of gravity measurements to small, single source masses and low gravitational field strengths. Further improvements to this methodology will enable the isolation of gravity as a coupling force for objects below the Planck mass. 

-  3089  -  SUPER SYMMETRY  -    Our best model of particle physics can not contain all the weirdness in the universe.  The reigning physics model is the Standard Model.  Its replacement has been predicted for decades.

 -  3091 -  ASTEROID  -   near miss and a perfect hit?  One of the larger stones that hit was about 5 centimeters long. Its crust is the remainder of the surface that got heated as the meteorite came through the atmosphere.  “Winchcombe meteorite” may look a bit like a broken barbecue briquette, but to scientists, it is absolutely beautiful.

 -  3092  -  ANTIMATTER  -  Teaching the Science.   If you do not know the answer it must be science.  Science is a process to learn answers to questions..  When you are curious about something, you observe its characteristics, you form a hypothesis, and then confirm it right or wrong with objective means.

 -  3093 -  NEUTRINOS  -  discoveries in Antarctica IceCube?  Earth’s South Pole was struck by a ghostly particle from some unknown corner of the universe.  This “antineutrino, the neutrino’s antimatter twin that has the opposite spin, collided with an electron at nearly the speed of light, and the ensuing particle shower lit up a network of detectors buried beneath the ice at an observatory in Antarctica appropriately named “IceCube“.

 -  3094  -  BLACKHOLES   -  the path to discovery?  The closest confirmed blackhole is “A0620–00“, about 2,800 light-years away, but it’s likely there are many others much closer that we haven’t yet found. Astronomers estimate that our Milky Way may hold as many as 100 million stellar-mass blackholes. 

-  3095  -   DARK  ENERGY  -   into WIMPs and MACHOs?   The more we learn the more we know the less we know.   That is certaintly true with astronomy.   We have come to the most recent conclusion that 95% of the Universe is “dark”.  We call it Dark Energy and Dark Matter.  Of course Matter is Energy too, according to energy = mass*c^2 .

- 3096  -  ELECTROMAGNETIC  RADIATION  -   We are Immersed in Electromagnetic Radiation?   Electromagnetic Radiation is going through your body all the time.  The spectrum of electromagnetic radiation ranges from Radio Waves, Microwaves,  Infrared,  Light, Ultraviolet , X- Ray, and Gamma Rays. 

 -  3097  - ASTEROIDS  -  start life on Earth?  -  When the Earth was first formed in he solar System with the other planets it was pummeled by asteroids. Thousands of these space rocks slammed into the young Earth, sometimes with a force powerful enough to vaporize the seas.

 -  3098  - ASTRONOMY  -  unsolved mysteries?  -  These were some of the major unsolved problems in astrophysics. 

 -  3099  -   UNIVERSE  -  why is it expanding?   Determining how rapidly the universe is expanding is key to understanding our cosmic fate, but with more precise data has come a mystery.   Estimates based on measurements within our local universe don’t agree with extrapolations from the era shortly after the Big Bang 13.8 billion years ago.  Which is the correct picture?

 -  3100  - GALAXIES  -  Don’t  Follow the Laws of Gravity?    Astronomers do not have a good idea of what Dark Matter really is.  It is something that has mass and is an attractive force for gravity.  But, it does not interact with the electromagnetic forces.  It does not absorb or emit light or any other part of the electromagnetic spectrum.

 -  3101  - UNIVERSE  -  Is it spinning, or, is it just me?  An initial spinning Universe could cause parity-violating asymmetry where gravity is allowing matter to dominate over anti-matter.  Bold theories still need a preponderance of evidence.  A spinning Universe is a new idea.  What does it all mean? 

-  3102  -  TEMPERATURE  -  dimensional analysis to Big Bang?     The math used is called “dimensional analysis.”  It is a simple concept.  To learn it we will try it out on a pendulum before we try it out on the Universe.   Measurements in physics and astronomy can involve 3 dimensions:  length (space), time, and mass (energy).  We refer to these as dimensions and they are measured in units: meters, seconds, kilograms.

 -  3103  -  LASER  -  Laser Light is cool.    Science is trying to use light pressure to cool objects by slowing down the vibration of atoms.  The goal is to reach Absolute Zero temperatures and the ‘Ground State” of atom vibrations.  The new science is called “optomechanics“.

 -  3104  -   LIGHT  -  The Power of Light?   We can not learn all about the Universe using “ light”.  There is just too little of it.  Even if we expand the meaning of ‘light” beyond visible light to the entire electromagnetic spectrum our vision is limited.  95% of the Universe does not respond to electromagnetic radiation or forces.

-  3105 --  EARTH  -  finely tuned for life?    How did it get that way?  Are we here as a result of random collusions and mutations?  We only know life that is us.  That is a sample size of one. Regardless,  Earth's history demonstrates that life can take root and evolve.  Here is what we have  learned.

 -  3106  -   UNIVERSE  -  The Universe you live in?  Space is completely silent. Sound needs an atmosphere to travel through, and since space has no atmosphere, it has no sound. The biggest, most awe-inspiring exploding star wouldn’t even make a peep. Astronauts are able to communicate up there thanks to radio waves, which can travel through space.

- 3107  -  Thinking what time is?  Everything you see is younger when you see it.  It takes time for the light to reach you and it is the speed of light that is constant.  Time is variable it depends on where you are and how fast you are moving.  It even gets more complicated. 

 -  3108  -   EVOLUTION  - Common sense is not is simple thing.  It is an immense society of hard-earned practical ideas of life learned lessons, rules, and exceptions, dispositions and tendencies, checks and balances.   We express common sense and knowledge through language that I am typing and you are reading.

 -  3109  -  CMB  -   measuring the Cosmic Microwave Background.  We have a Universe with 5% normal matter, 27% dark matter, and 68% dark energy. At last, we can state, with extraordinary confidence, what the Universe is made of.  The curvature of the Universe is no greater than 1-part-in-1000, indicating that the Universe is indistinguishable from perfectly flat.  Where have I heard that before?  Christopher Columbus did not believe it either.

 -  3110  -  BLACKHOLE  -  first picture.  The first image of a blackhole's magnetic fields is of Galaxy M87's supermassive blackhole in polarized light. The lines mark the orientation of polarization, which is related to the magnetic field around the shadow of the blackhole. 

 -  3111 -   EINSTEIN -  Why does energy equal mass?  If you extrapolate all the way back, the universe gets smaller and smaller, it gets denser and denser, and warmer and warmer. Finally you get to a point where it's really small, really hot and dense. That's actually the Big Bang theory: that the universe started in such a condition. That's where you really have to stop.

 -  3112  -  TIME  -  think about it?    Using both optical fibers and invisible laser transmission of data, the researchers have measured the meaning of a second more accurately than ever before. They did it by looking at minute, the measure of size, not time, differences between time kept by the atoms.

 -  3113  -  NEUTRON  STARS   -  We have much more to learn about Neutron Stars.  Each property shows itself a little differently depending on our observations and the instruments we use to make the discoveries.   It is possible that Neutron Stars become Quark Stars before they become Black Holes.  

 -  3114  -  BROWN  DWARF  -  stars that do not shine so bright.  Their brightness depends on their size.  The bigger stars are the brighter they are and the shorter their lives.  We are fortunate that our Sun is in the middle of the pack and should live for 10,000,000,000 years.

-

-  April 1, , 2020                                                                               3114                                                                                                                                                   

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

-----  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

 ---------------------   Friday, April 2, 2021  -------------------------

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

No comments:

Post a Comment