TEMPERATURE - absolute zero degrees

 -  3065  -  TEMPERATURE   -  absolute zero degrees.  Physicists at the National Institute of Standards and Technology in Boulder, Colorado, chill an aluminum membrane to 0.00036 Kelvin, lower than theory predicted possible for the material. The experiment suggests a way to see quantum effects, like a single object coexisting in two places at once

---------------  3065   -  TEMPERATURE   -  absolute zero degrees

-  What we call temperature, or heat, is just an easy way to measure “thermal energy“. Everything in the universe has thermal energy, which exists in the form of vibrations in atoms and molecules.

-

-   If you add thermal energy to an object, its atoms and molecules vibrate more, and it warms up. If you remove thermal energy, its atoms and molecules vibrate less, and it gets colder.

-

-  How cold can it get?   Start at a nice warm temperature, say 75 degrees Fahrenheit (24 degrees Celsius). You only need to wear a shirt and shorts, and you might even want a cold drink. 

-

-   Except that now, you're starting to feel a little chill in the air. The temperature is dropping to 45 degrees F (7 degrees C). You'd better grab a coat and long pants.  

-

-  A few more minutes, and we're at 32 degrees F (0 degrees C). You need a hat and gloves, and you can see your breath in the air as the water vapor from your lungs condenses in the cold, fogging up your windshield.

-

-    We reach 0 degrees F (-18 degrees C). Your body is shivering, using muscular energy to generate heat to keep you warm. And your cold drink has frozen solid.

-

-  We have reached -44 degrees F (-42 degrees C). Time to switch to the Kelvin scale, where it's 231 Kelvin. Regular thermometers don't work anymore because their mercury has frozen solid.

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-   You've probably never felt cold like this. You're numb, and your extremities are frostbitten. As the temperature drops further, substances that were once pliable become brittle. Your leather seat begins to crack and crumble under your weight, and a rubber tire wouldn't bounce on the floor, it would shatter.

-

-  Our next stop is 184 K (-129 degrees F or -89 degrees C), the lowest temperature ever recorded on Earth. Now things really get strange. The air itself starts to condense. First, carbon dioxide condenses, forming tiny frost-like crystals.

-

-   Then, at around 90 K (-298 degrees F or -183 degrees C), oxygen condenses. Pretty soon, the air that once filled your car is a pool of liquid on the floor. But don't worry about that. You're no longer breathing anyway. Even the warmest parka in the world couldn't save you at this temperature.

-

-  There is some good news, though. Your car's electric system just improved. Usually, even really conductive materials like copper wire lose energy because of electrical resistance. 

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-  But at about 133 K (-220 degrees F or -140 degrees C), as vibrating molecules slow down, certain metal-oxide ceramics lose their resistance, becoming superconductive. At even lower temperatures, metals like lead and tin become superconductive, too.

-

-  Eventually, the inside of your car reaches the temperature of the darkest parts of space, about 3 K (-454 degrees F or -270 degrees C). This is as cold as the universe gets. 

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-  There is just enough ambient thermal energy bouncing around to keep us from ever shedding those last three degrees. Naturally, at least. In the lab, scientists have managed to drop the temperature below 3 Kelvin down to just a few billionths of a degree above absolute zero (0 K or -460 degrees F).

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-----------------  Here is how low temperatures have been in a race to the bottom:

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-  Year 1926: Chemists first describe a method, called “adiabatic demagnetization“, that uses magnetic fields to cool materials below 1 kelvin. 

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-  Year  1933, scientists employ it to chill a salt to 0.25 Kelvin. That’s low, but not as low as laser cooling can go.

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-  Year 1978: First demonstration of laser cooling takes materials to 40 Kelvins; 10 years later, physicists use laser cooling to achieve 43 millionths of a Kelvin.

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-  Year 1997: Three physicists share the Nobel Prize for inventing laser cooling.

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- Year  2015: Stanford University researchers chill a gas made of rubidium, a soft metal used to make solar cells, to 50 trillionths of a degree above absolute zero, setting a new record.

-

- Year  2017: Physicists at the National Institute of Standards and Technology in Boulder, Colorado, chill an aluminum membrane to 0.00036 kelvin, lower than theory predicted possible for the material. The experiment suggests a way to see quantum effects, like a single object coexisting in two places at once.

-

---------------------------------  Other Reviews available:

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-  2946  -  TEMPERATURE  -  a race to the bottom?  -   Scientists are probing the extreme ends of the spectrum of what’s called “absolute temperature“. At the upper limit, absolute hot is a theoretical furnace where the laws of physics melt away. On the flip side, absolute zero is cold,  so cold there’s nowhere to go but up.  This absolute zero is almost within scientists’ grasp.

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-  2564  -  TEMPERATURE  -  calculating global Warming?    How to measure the temperature of stars? Knowing the temperature of the Earth how to calculate the total energy being radiated?   We live on the surface of  a  2,000,000,000,000,000 one hundred light bulbs.  And, the Sun that is warming us has a surface temperature of 6,000 degrees Kelvin.  How do we know these things?

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-   2563  TEMPERATURE  -  Getting Temperature from Light?  If we measure the  frequency emitted we know the energy gap between orbits for that particular atom.  And , if we know the energy gaps for each element we can measure the frequency of radiation and identify the element that created. it.  That is how astronomers know the makeup of stars and gas nebulae that are billions of light years away.  

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-  Review  505  How small is the Atom”

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-  Review 983  -  “How an Atom Works”

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-  Review  985 -   “Measuring How an Atom Works“.

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-  Review  986 -   “How a Molecule Works“.

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-  Review  924 -   “Rutherford’s Atom”

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-  Review  1740  -  “Temperature of the Earth”

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-  Review 2377  -  “Defining the Atom”

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-  Review 2333  -  “Rainbows can Tell Us What the Universe is Made Of.”

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-  Review 2555  -  History of the Atom to 1925

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-  Review  2555  -  History of the atom after 1925

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February 27, 2021     TEMPERATURE   -  absolute zero degrees     727        3065                                                                                                                                                         

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3064 - INTERFEROMETERS - light and atoms

 -  3064  -  INTERFEROMETERS  -  light and atoms?    In astronomy we can put light and atom interferometers in space to be used to detect gravity waves.  Gravity waves radiate from binary Blackholes and binary Neutron Stars.  These gravity wave “telescopes” could see back to the beginning of the Universe.

----------------------------  Light spectrograph

---------------  3064  -  INTERFEROMETERS  -  light and atoms

-  Photons behave both as waves and as particles.  So do atoms.  So does everything.  It is just that in a larger mass the waves are too small to be detectable.  You have to get to small masses, atomic size, and waves become predominant. 

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-   Light interferometers were invented over 200 years ago.  Just recently science has began using this old technology in new ways.

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-  Radios have been around a long time too.  They are everywhere today.  Your cell phone is a radio.  Your remote control is a radio.  AM and FM radios operate at frequencies of 1000 kilohertz and 300 Megahertz.  

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-  These frequencies correspond to wavelengths of 300 yards down to 4 inches.  The TV remote uses infrared waves that have wave lengths of 0.000001 meters, which is about the size of a bacteria.

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-    Radio waves and light waves are the same electromagnetic medium as radio waves, why don’t we have radios that operate at light wave frequencies?  In fact ,we do, and simple ones are operating in fiber optic cables. 

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-   Science is learning how to use light wave frequencies to build comb generators, and heterodyne mixers that are very analogies to traditional radios.  The frequencies are 10^15 cycles per second, 1,000,000,000,000,000 oscillating cycles in each second.  This corresponds to wavelengths of 3*10^-7 meters, 0.0000003 meters.

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-  The light wave interferometer is one of the most accurate instruments known.  The new comb generators will make them more accurate then today’s atomic clocks.   A radio’s simple comb generator generates a comb of harmonic frequencies by pulsing energies into a simple diode. 

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-  The rapid on and off pulse is a square wave containing all the harmonics of the original signal.  The optical comb generator does the same thing only at light frequencies.  Using these optical comb generators will allow more precise atomic clocks to be invented.  

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-  Also, there will be new ultra sensitive chemical detectors.  Lasers will control chemical reactions.  Higher capacity telecommunications will be possible at higher frequencies.  Improved light detectors and light range finders will be invented.  And, there will be more applications that we have not thought of yet.

-  Optical Comb generators start with mode-locked lasers that can create ultra-short pulses of light.  The shortest pulses from these lasers have durations less than 10 femtoseconds.  ( See Review 361   “Time is Getting Short”).

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-    The carrier frequency for the light consists of one pure frequency, or color.  The amplitude pulse of this single frequency consists of light of many frequencies all traveling together.  The shorter the pulse, the broader the spread of frequencies.  

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-  The mode-locked laser is set to emit a train of these pulses at a regular rate, called the “Repetition Frequency“.  If you plot these frequencies the spectrum appears as the teeth on a hair comb, spaced precisely at the laser’s Repetition Rate. 

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-   Typically the repetition rate is set at 1 GHz, or 1,000,000,000 cycles per second.  The optical comb has 400,000 teeth spaced out at 1 GHz apart.  High-speed photodiodes can accurately measure frequencies at 1 GHz.  Now, with this optical comb we can translate the accuracy up into the frequencies of light.

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-  One problem that had to be overcome was the phase shifting that occurred with a train of pulses.  This amounted to creating an Offset Frequency after a multiple of pulses.  Scientists had to know this “Offset Frequency” in order to calibrate their instrument for ultra-precise measurements. 

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-   Using a cesium beam atomic clock one second is defined as a cesium oscillation of 9,192,631,770 cycles, exactly.  A cesium clock is based on 9 GHz microwaves being absorbed by cesium atoms.  An optical comb generator could be calibrated to 60,000 times the cesium frequency. 

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-   To calibrate out the Offset Frequency the scientists needed a mode-locked laser that had a bandwidth of at least one octave.  An octave is a factor of 2 in frequency.  An octave spanning spectrum enables the comparison of frequencies of two comb lines at opposite ends of the spectrum. 

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-   Any deviation from the second frequency being exactly twice the first frequency is a measure of the phase shift and the Offset Frequency.  This is called “self-referencing” because you are comparing the comb frequency against itself.  If these two frequencies are mixed together, or beat together, the difference frequency is the Offset Frequency, and this process is called “heterodyne detection“.  The same as in an old heterodyne radio.

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-  Another new tool is the atom interferometer.  It is similar to the light interferometer except it uses the waves from atoms instead of the waves from photons.  Gyroscopes using this system will improve 200 fold.  This will allow navigation cross country that is more accurate than GPS.

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-    Interferometers use interference patterns from mixing two waves to calculate the differences in the distances that the two waves travel.  In the 1890’s Albert Michelson and Edward Morley tried this experiment to detect if Earth’s orbit was passing through an ether.  

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-  Science at that time thought that an ether medium was needed for light waves to travel across space.  They discovered there was no ether. 

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-   In 1920 Louis-Victor de Broglie discovered that all particles behaved as waves depending on the particles mass and its velocity.  The heavier and faster the particle the shorter its wavelength.

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-    An atoms wavelength is around 1/100th of a nanometer.  Visible light has wavelengths of 400 to 700 nanometers.  If the path of an atom varies 1/1000th of a nanometer an atom interferometer can detect it.  To detect these waves of atoms they must be cooled to nearly absolute zero Kelvin temperature.

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-  On the Earth’s surface, gravity’s acceleration is 9.8 meters / second.  But, this varies slightly depending on the composition of the rock at the surface.  By detecting the variations in the strength of gravity these instruments can detect underground oil.  

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-  100,000 tons of oil buried 1 kilometer underground will decrease gravity by a few hundred thousands of a  percent.  Not just oil.  The same technique can detect underground diamonds.  Not just diamonds,  The atom interferometer can detect underground caves where terrorists are hiding. 

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-   However, the most immediate use will be the military using it for accurate navigation without the use of satellites.  They can even navigate under the Artic ice with precision.

-

-  In astronomy we can put light and atom interferometers in space to be used to detect gravity waves.  Gravity waves radiate from binary Blackholes and binary Neutron Stars.  These gravity wave “telescopes” could see back to the beginning of the Universe.

-

-    The Cosmic Microwave Background allows us to see back to 300,000 years after the Big Bang.   But, gravity waves could see past that opaque wall even further back in time to the Big Bang.  

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-  Whenever you have a greater ability to see, you are bound to see something new.  Light interferometers and atom interferometers are ultra-precise measurements that will discover new things.  Get ready to learn.

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-  See  Review 2684  - Wave-Particle Duality

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February 27, 2021       INTERFEROMETERS  -  light and atoms    915      3056                                                                                                                                                          

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-----  Comments appreciated and Pass it on to whomever is interested. ---- 

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--  email feedback, corrections, request for copies or Index of all reviews 

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Saturday, February 27, 2021  ---------------------------

3062 - DARK MATER - is it real?

 -  3062  -  DARK  MATER  -  is it real?  We have known about Dark Matter for a long time  Back in the 1930’s, a Swiss astronomer named Fritz Zwicky noticed that galaxies in a distant cluster were orbiting one another much faster than they should have been given the amount of visible mass they had. He proposed than an unseen substance, which he called “dark matter“, might be tugging gravitationally on these galaxies.          

-----------------------  3062  -  DARK  MATER  -  is it real?                       

-  Astronomers have confirmed that this mysterious dark matter material can be found throughout the cosmos, and that it is six times more abundant than the normal matter that makes up ordinary things like stars and people.

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-   Despite seeing dark matter throughout the universe, scientists still do not know what it is?  Or is it even real? 

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-  Originally, some scientists conjectured that the missing mass in the universe was made up of small faint stars and black holes, though detailed observations have not turned up nearly enough such objects to account for dark matter's influence.  The laws of gravity tell us this.

-

-  The current leading contender for dark matter's mantle is a hypothetical particle called a “Weakly Interacting Massive Particle“, or WIMP, which would behave like a neutron except would be between 10 and 100 times heavier than a proton. 

-

-  If dark matter is made from WIMPs, they should be all around us, invisible and barely detectable. So why haven't we found any yet? While they wouldn't interact with ordinary matter very much, there is always some slight chance that a dark matter particle could hit a normal particle like a proton or electron as it travels through space.

-

-   Researchers have built experiment after experiment to study huge numbers of ordinary particles deep underground, where they are shielded from interfering radiation that could mimic a dark-matter-particle collision. 

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-  After decades of searching, not one of these detectors has made a credible discovery.

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-  Ordinary matter is made up of particles like protons and electrons, as well as a whole zoo of more exotic particles like neutrinos, muons and pions. So, some researchers have wondered if dark matter, which makes up 85 percent of the matter in the universe, might also be just as complicated.  Only 15% is “ordinary matter”

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-   There is no good reason to assume that all the dark matter in the universe is built out of one type of particle. Dark protons could combine with dark electrons to form dark atoms, producing configurations as diverse and interesting as those found in the visible world of “ordinary matter”

-

-   Along with additional particles of dark matter, there is the possibility that dark matter experiences forces analogous to those felt by regular matter. Some researchers have searched for "dark photons," which would be like the photons exchanged between normal particles that give rise to the electromagnetic force, except they would be felt only by dark matter particles. 

-

-  Physicists in Italy are gearing up to smash a beam of electrons and their antiparticles, known as “positrons“, into a diamond. If dark photons do exist, the electron-positron pairs could annihilate and produce one of the strange force-carrying particles, potentially opening a brand-new sector of the universe.  A positron is a mimic of an electron except it has the opposite electrical charge.

-

-  One of the leading alternatives to WIMPS is a hypothetical particle known as an “axion“, which would be extremely light, perhaps as little as 10 raised to the 31st power less massive than a proton. 

-

-  Axions are now being searched for in a few experiments. Recent computer simulations have raised the possibility that these axions could form star-like objects, which might produce detectable radiation that would be quite similar to mysterious phenomena known as “fast-radio bursts“.

-

-  Astronomers originally discovered dark matter through its gravitational interactions with ordinary matter.   Dark Matter particles should be their own antiparticles, meaning that two dark-matter particles would annihilate with one another when they meet. 

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-  The “Alpha Magnetic Spectrometer” (AMS) experiment on the International Space Station has been searching for the telltale signs of this annihilation since 2011 and has already detected hundreds of thousands of events. Scientists still aren't sure if these are coming from dark matter, and the signal has yet to help them pin down exactly what dark matter is.

-

-  Because it so massively outweighs ordinary matter, dark matter is often said to be the controlling force that organizes large structures such as galaxies and galactic clusters. 

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-  A long-standing mystery in particle physics are the puzzling results of a European experiment known as DAMA/LIBRA. This detector, located in an underground mine below the Gran Sasso mountain in Italy, has been searching for a periodic oscillation in dark matter particles. 

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-  This oscillation should arise as the Earth moves in its orbit around the sun while flying through the galactic stream of dark matter surrounding our solar system,  called the “dark matter wind“. Since 1997, DAMA/LIBRA has claimed to see exactly this signal, though no other experiment has seen anything like this.  

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-  A signal from the beginning of time has led some physicists to suggest that dark matter might have an electrical charge. Radiation with a wavelength of 21 centimeters was emitted by stars in the universe's infancy, just 180 million years after the Big Bang. 

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-  It was then absorbed by cold hydrogen that was around at the same time. When this radiation was detected in February, 2021, its signature suggested that the hydrogen was much colder than scientists had predicted. 

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-  Astrophysicist  hypothesized that dark matter with an electrical charge could have drawn heat away from the all-pervasive hydrogen. But this conjecture has yet to be confirmed.

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-  Can ordinary particles decay into dark matter?  Neutrons are regular matter particles with a limited lifetime. After around 14.5 minutes, a lone neutron unmoored from an atom will decay into a proton, an electron and a neutrino. 

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-  Two different experimental setups give slightly different lifetimes for this decay, with the discrepancy between them about 9 seconds  . In 2021 physicists suggested that if 1 percent of the time, some neutrons were decaying into dark-matter particles, it could account for this anomaly.   These physicists monitored neutrons for a signal that could be dark matter but were unable to detect anything so far.

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-  Given the difficulties that scientists have faced trying to detect and explain dark matter, one might wonder if we are going about it all wrong. For many years, a vocal minority of physicists have pushed the idea that perhaps our theories of gravity are simply incorrect, and that this fundamental force works differently on large scales than we expect. 

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-  Often known as "modified Newtonian dynamics," or MOND models, these suggestions posit that there is no dark matter and the ultrafast speeds at which stars and galaxies are seen to rotate around one another is a consequence of gravity behaving in surprising ways defying the math that we are familiar with.

-

-   "Dark matter is still an unconfirmed model,"  yet the latest evidence suggests that dark matter is real.  We still have more to learn, stay tuned.  Here are other review:

-  

-  3049  -    DARK  MATTER  -  is real but what is it?    Dark matter is still an unconfirmed model, yet , the detractors have yet to convince the larger field of their ideas. And the latest evidence? It also suggests that dark matter is real.  But what is it?

-

-   2931  - DARK  MATTER  -   explorations?  -  Researchers remain unsure about what exactly dark matter is. Originally, some scientists conjectured that the missing mass in the universe was made up of small faint stars and black holes, though detailed observations have not turned up nearly enough such objects to account for the significant amount of dark matter's influence.   

-  

-   2897  -  DARK MATTER   -  produces many new theories?    When something seems a little mysterious or we just don’t understand what is going on we like to describe it with the adjective ‘dark’.  This is one of the reasons why the term ‘dark’ matter got coined which was first proposed to explain the anomaly observed in the rotational velocities of galaxies.

-

-   2886  -  DARK  MATTER  -  mysteries?   When something seems a little mysterious or we just don’t understand what is going on we like to describe it with the adjective ‘dark’.  We do not understand 95% of the universe we live in.  The 5% that is left is everything we know about and are still learning about.  

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-  2861  -  DARK  MATTER  - how we know it is there? -  The big idea of dark matter is that there’s something other than these known particles contributing in a significant way to the total amounts of matter in the Universe.  We look at the motions of these objects, we look at the gravitational rules that govern orbiting bodies, whether something is bound or not, how it rotates, how structure forms, and we get a number for how much matter there has to be in there.

- 

-  2823  - DARK  MATTER  -  needs to be a new 2020 discovery?  Researchers remain unsure about what exactly dark matter is. Originally, some conjectured that the missing mass in the universe was made up of small faint stars and black holes, though detailed observations have not turned up nearly enough such objects to account for dark matter's influence.

-

-  2790  -  DARK  MATTER  -  to discover what it is?  -  There is a race to discover “dark matter“. Dark matter is that elusive substance that has mystified science since the 1930s, when astronomers first realized galaxies needed some kind of invisible gravitational glue to hold them together. No one knew what it was, so it was named “dark matter“. 

-

-  2768 -  DARK  MATTER  - What is the Universe Made of?  Since 1970 astronomers have believed Dark Matter existed because studying the orbits of galaxies and stars around galaxies could not be calculated based on the stars and matter they could see.  Either Kepler’s and Newton’s formulas for the laws of gravity and motion were incorrect, or there was matter there that they could not find. 

-

February 25, 2021           DARK  MATER  -  is it real?                       3062                                                                                                                                                          

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--  email feedback, corrections, request for copies or Index of all reviews 

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--------------------- ---  Thursday, February 25, 2021  ---------------------------

3061 - MARS - how to find life?

 -  3061  -  MARS  -  how to find life?   NASA’s Perseverance rover is there on Mars, February 21, 2021.  One part of the Perseverance rover mission is to search for fossilized microscopic life on Mars.  How will scientists know whether they've found it?

--------------------------  3061  -  MARS  -  how to find life?

-  NASA's Mars Perseverance rover will be the agency's ninth mission to land on the Red Planet. Along with characterizing the planet's geology and climate, and paving the way for human exploration beyond the Moon, the rover is focused on astrobiology, or the study of life throughout the universe. 

-

-  Perseverance is tasked with searching for telltale signs that microbial life may have lived on Mars billions of years ago. It will collect rock core samples in metal tubes, and future missions would return these samples to Earth for deeper study.

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-  Mission scientists believe that Jezero Crater, the landing site for Perseverance, could be home to such evidence. They know that 3.5 billion years ago, Jezero was the site of a large lake, complete with its own river delta. They believe that while the water may be long gone, somewhere within the 28-mile-wide crater, or perhaps along its 2,000-foot-tall  rim, biosignatures could provide the evidence that life once existed there.

-

-   Biosignatures could be in Jezero's lakebed or in shoreline sediments that could be encrusted with carbonate minerals, which are especially good at preserving certain kinds of fossilized life on Earth. 

-

-  NASA's fifth rover to the fourth planet from the Sun carries a new suite of scientific instruments to build on the discoveries of NASA's Curiosity rover, which has found that parts of Mars could have supported microbial life billions of years ago.

-

-  The hunt for biosignatures will include the rover's suite of cameras, especially Mastcam-Z (located on the rover's mast), which can zoom in to inspect scientifically interesting targets. The mission's science team can task Perseverance's SuperCam instrument - also on the mast - to fire a laser at a promising target, generating a small plasma cloud that can be analyzed to help determine its chemical composition. 

-

-  Perseverance will rely on one of two instruments on the turret at the end of its arm. PIXL the Planetary Instrument for X-ray Lithochemistry) will employ its tiny but powerful X-ray beam to search for potential chemical fingerprints of past life.

-

-   The SHERLOC (the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instrument has its own laser and can detect concentrations of organic molecules and minerals that have been formed in watery environments. 

-

-  Together, SHERLOC and PIXL will provide high-resolution maps of elements, minerals, and molecules in Martian rocks and sediments, enabling astrobiologists to assess their composition and determine the most promising cores to collect.

-

-  An enduring hope of the science team is to find a surface feature that couldn't be attributed to anything other than ancient microbial life. One such feature could be something like a stromatolite. 

-

-  On Earth, stromatolites are wavy, rocky mounds formed long ago by microbial life along ancient shorelines and in other environments where metabolic energy and water were plentiful. Such a conspicuous feature would be difficult to chalk up to geologic processes.

-

-  Perseverance's sample caching system is a trunk-size collection of motors, planetary gearboxes, and sensors is among the most complex, capable, and cleanest mechanisms ever sent into space. 

-

-  With  this the science team will collect the most intriguing samples they can find, store them in samples tubes, and, later, deposit them so that future missions can collect the sample tubes and fly them back to Earth for analysis.

-

-  The instrumentation required to definitively prove microbial life once existed on Mars is too large and complex to bring to Mars.  Samples returned from Mars' Perseverance rover may tell us that at one time billions of years ago life existed elsewhere in the universe. 

-

-   There is strong evidence that Jezero Crater once had the ingredients for life.  Whether or not Mars was ever a living planet, it's essential to understand how rocky planets like ours form and evolve. Why did our own planet remain hospitable as Mars became a desolate wasteland?

-

-  Perseverance may not provide the final word on if the Red Planet ever contained life, but the data it collects and the discoveries it makes will play a key role whenever that result is reached.

-

-  The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.

-

-  Subsequent missions by NASA in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

-

-  The Mars 2020 mission is part of a larger program that includes missions to the Moon as a way to prepare for human exploration of the Red Planet. Charged with returning astronauts to the Moon by 2024, NASA will establish a sustained human presence on and around the Moon by 2028 through NASA's Artemis lunar exploration plans.

-

February 24, 2021       MARS  -  how to find life?                            3061                                                                                                                                                          

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-----  Comments appreciated and Pass it on to whomever is interested. ---- 

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--  email feedback, corrections, request for copies or Index of all reviews 

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Thursday, February 25, 2021  ---------------------------

3060 - COMETS - hit the Earth?

 -  3060  -  COMETS  -  hit the Earth?  -    The Chicxulub impactor , a comet,  crashed into Earth about 66 million years ago.  It left behind a crater off the coast of Mexico that spans 93 miles and runs 12 miles deep.

--------------------------------------   Comet ISON

------------------------------  3060  -  COMETS  -  hit the Earth?

-  The Chicxulub comet’s devastating impact brought the reign of the dinosaurs to an abrupt and calamitous end by triggering their sudden mass extinction, along with the end of almost three-quarters of the plant and animal species living on Earth.

-

-  The enduring puzzle is where did the asteroid or comet originate, and how did it come to strike Earth? 

-

-  Using statistical analysis and gravitational simulations astrophysicists calculated that a significant fraction of long-period comets originating from the Oort cloud, an icy sphere of debris at the edge of the solar system, can be bumped off-course by Jupiter's gravitational field during orbit.

-

-  Jupiter, the most massive planet, kicks incoming long-period comets into orbits that bring them very close to the sun.  During close passage to the sun, the comets,  "sungrazers", can experience powerful tidal forces that break apart pieces of the rock and ultimately, produce cometary shrapnel.

-

-  In a sungrazing event, the portion of the comet closer to the sun feels a stronger gravitational pull than the part that is further, resulting in a tidal force across the object.  You can get what's called a tidal disruption event, in which a large comet breaks up into many smaller pieces. And crucially, on the journey back to the Oort cloud, there's an enhanced probability that one of these fragments hit the Earth."

-

-  The new calculations  increase the chances of long-period comets impacting Earth by a factor of about 10, and show that about 20 percent of long-period comets become sungrazers.  This new rate of impact is consistent with the age of Chicxulub, providing a satisfactory explanation for its origin and other impactors like it.

-

-   If you break up an object as it comes close to the sun, it could give rise to the appropriate event rate and also the kind of impact that killed the dinosaurs.

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-  Evidence found at the Chicxulub crater suggests the rock was composed of carbonaceous chondrite. The hypothesis is that this might explain this unusual rock composition.

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-  The theory on the origin of Chicxulub claims that the impactor originated from the main belt, which is an asteroid population between the orbit of Jupiter and Mars. However, carbonaceous chondrites are rare amongst main-belt asteroids, but possibly widespread amongst long-period comets, providing additional support to the new “cometary impact hypothesis“.

-

-  Other similar craters display the same composition. This includes an object that hit about 2 billion years ago and left the Vredefort crater in South Africa, which is the largest confirmed crater in Earth's history

-

-   And the impactor that left the Zhamanshin crater in Kazakhstan, which is the largest confirmed crater within the last million years. The researchers say that the timing of these impacts support their calculations on the expected rate of Chicxulub-sized tidally disrupted comets.

-

-  The hypothesis can be tested by further studying these craters, others like them, and even ones on the surface of the moon to determine the composition of the impactors. Space missions sampling comets can also help.

-

-  Aside from composition of comets, the new Vera Rubin Observatory in Chile may be able to observe tidal disruption of long-period comets after it becomes operational next year, 2022.

-

-  Understanding this is not just crucial to solving a mystery of Earth's history but could prove pivotal if such an event were to threaten the planet.

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February 25, 2021       COMETS  -  hit the Earth?                            3060                                                                                                                                                         

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--  email feedback, corrections, request for copies or Index of all reviews 

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Thursday, February 25, 2021  ---------------------------

3059 - NEURAL NETWORKS - doing the thinking for you?

 -  3059  -  NEURAL  NETWORKS  - doing the thinking for you? One common example of a neural network is your smartphone camera’s ability to recognize faces.  Another example is driverless cars which are equipped with multiple cameras to recognize other vehicles, traffic signs and pedestrians using neural networks to turn or adjust their speed accordingly.

---------------  3059  -  NEURAL  NETWORKS  - doing the thinking for you? 

-  Neural networks are also behind the text suggestions you see while writing texts or emails, and even in the language translations tools available online.

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-  The networks do need to have prior knowledge of something to be able to classify or recognize it.  That’s why there is a need to use big data in training neural networks. They work because they are trained on vast amounts of data to then recognize, classify and predict things.

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-  In the driverless cars example, it would need to look at millions of images and video of all the things on the street and be told what each of those things is. When you click on the images of crosswalks to prove that you’re not a robot while browsing the internet, it can also be used to help train a neural network. Only after seeing millions of crosswalks, from all different angles and lighting conditions, would a self-driving car be able to recognize them when it’s driving around in real life.

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-  More complicated neural networks are actually able to teach themselves how to perform a task after being given basic instructions.

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-  Some neural networks can work together to create something new. For example, the networks create virtual faces that don’t belong to real people when you refresh the screen. One network makes an attempt at creating a face, and the other tries to judge whether it is real or fake. They go back and forth until the second one cannot tell that the face created by the first is fake.

-

-  Humans take advantage of big data too. A person perceives around 30 frames or images per second, which means 1,800 images per minute, and over 600 million images per year. That is why we should give neural networks a similar opportunity to have the big data for training.

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-  A neural network is a network of artificial neurons programmed in software. It tries to simulate the human brain, so it has many layers of “neurons” just like the neurons in our brain. The first layer of neurons will receive inputs like images, video, sound, text, etc. This input data goes through all the layers, as the output of one layer is fed into the next layer.

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-  For example a neural network can be trained to recognize dogs and cats. The first layer of neurons will break up this image into areas of light and dark. This data will be fed into the next layer to recognize edges. The next layer would then try to recognize the shapes formed by the combination of edges. The data would go through several layers in a similar fashion to finally recognize whether the image you showed it is a dog or a cat according to the data it’s been trained on.

-

-  These networks can be incredibly complex and consist of millions of parameters to classify and recognize the input it receives.

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-  Neural networks were invented in 1943, when Warren McCulloch and Walter Pitts created a computational model for neural networks based on algorithms. Then the idea went through a long hibernation because the immense computational resources needed to build neural networks did not exist yet.

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-  Recently, the idea has come back in a big way, thanks to advanced computational resources like “graphical processing units” (GPUs). They are chips that have been used for processing graphics in video games, but it turns out that they are excellent for crunching the data required to run neural networks too. That is why we now see the proliferation of neural networks.  More to come.

-  

February 24, 2021       NEURAL  NETWORKS  - doing the thinking?    3059                                                                                                                                                          

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--  email feedback, corrections, request for copies or Index of all reviews 

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--------------------- ---  Thursday, February 25, 2021  ---------------------------

3058 - PERSEVERANCE - Mars gives us more to learn?

 -  3058  -  PERSEVERANCE  -  Mars gives us more to learn?    As we begin to understand the most ancient history of Mars, researchers are ready to directly search of any signatures that life might have once existed on ancient Mars.

---------------  3058  -  PERSEVERANCE  -  Mars gives us more to learn?

-  The name “Perseverance” was chosen by a seventh grader  who won nationwide  naming contest.  Perseverance needed to take off within the launch window of July 30-August 15, otherwise, NASA would have to wait until September 2022 to try again.

-

-  The launch to Mars was dependant on planetary alignment between Earth and Mars, which takes place during three crucial weeks every 26 months.

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-  Perseverance made the 64-million-mile journey to Mars in about six months landing on the Red Planet February 2021.

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-  NASA previously sent three rovers to Mars, Spirit, Opportunity, and Curiosity, which landed on Mars in 2012 and is still roaming the Red Planet today.

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-  Perseverance landed in the Jezero Crater, a 500-meter-deep crater located in a basin slightly north of the Martian equator.   The crater once housed a lake estimated to have dried out 3,500,000,000 years ago.  It is the ideal location for Perseverance to hunt for signs of past microbial life.

-

-  The mission will test out conditions for possible human exploration of Mars by trialing a method of producing oxygen from the Martian atmosphere, characterizing environmental conditions such as water and dust on Mars, and looking for resources.

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-   It takes14 minutes for the team in San Diego to send and receive a signal from the rover on Mars, considering there's a lag since Mars is millions of miles away.   Communication with Perseverance use the Deep Space Network, a global network of antennas that were built in the 1960's.

-

-  The rover will collect at least 20 samples from Mars using a handy drill, literally attached to the robot's arm.  The rock samples will be stored away in tubes in a well-identified place on the Martian surface, and left there to be returned to Earth by a future sample return mission to the Red Planet.

-

- The Ingenuity helicopter will hitch a ride with the rover, and allow NASA to test out its ability to fly a helicopter on a planet other than Earth for the first time.

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-  The team behind Perseverance redesigned its wheels, giving the rover narrower wheels than its predecessor Curiosity, but bigger in diameter and made of thicker aluminum in order to handle the wear and tear of driving around the Martian terrain.

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-  Perseverance’s instruments S.H.E.R.L.O.C., (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) and WATSON, Wide Angle Topographic Sensor for Operations and eNgineering instrument, will look for microscopic clues in Martian rock.

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-  Perseverance has 23 cameras, more cameras than any other interplanetary mission in history.

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-  The names of 10,932,295 people were etched onto Perseverance as part of NASA's "Send Your Name to Mars" campaign.  Perseverance rover is set to spend at least one Martian year on the planet, the equivalent of 687 days on Earth.

-

-  A microphone on the rover also has provided the first audio recording of sounds from Mars.

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-  From the moment of parachute inflation, the camera system covered the entirety of the descent process, showing some of the rover's intense ride to Mars' Jezero Crater. The footage from high-definition cameras aboard the spacecraft starts 7 miles above the surface, showing the supersonic deployment of the most massive parachute ever sent to another world, and ends with the rover's touchdown in the crater.

-

-  The six-wheeled robotic astrobiologist, the fifth rover the agency has landed on Mars, currently ( February 2021) is undergoing an extensive checkout of all its systems and instruments.

- 

-  The world's most intimate view of a Mars landing began  230 seconds after the spacecraft entered the Red Planet's upper atmosphere at 12,500 mph. The video opens in black, with the camera lens still covered within the parachute compartment. 

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-   Within less than a second, the spacecraft's parachute deploys and transforms from a compressed 18-by-26 inch cylinder of nylon, Technora, and Kevlar into a fully inflated 70.5-foot-wide  canopy. The tens of thousands of pounds of force that the parachute generates in such a short period stresses both the parachute and the vehicle.

-

-    The video captures the heat shield dropping away after protecting Perseverance from scorching temperatures during its entry into the Martian atmosphere. The downward view from the rover sways gently like a pendulum as the descent stage, with Perseverance attached, hangs from the back shell and parachute.

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-   The Martian landscape quickly pitches as the descent stage, the rover's free-flying "jetpack," which decelerates using rocket engines and then lowers the rover on cables to the surface  breaks free, its eight thrusters engaging to put distance between it and the now-discarded back shell and the parachute.

-

-  Then, 80 seconds and 7,000 feet (2,130 meters) later, the cameras capture the descent stage performing the sky crane maneuver over the landing site, the plume of its rocket engines kicking up dust and small rocks that have likely been in place for billions of years.

-

-  The EDL camera system not only provided for the opportunity to gain a better understanding the spacecraft's performance during entry, descent, and landing, but also to take the public along for the ride of a lifetime  landing on the surface of Mars. 

-

-  The footage ends with Perseverance's aluminum wheels making contact with the surface at 1.61 mph, and then pyrotechnically fired blades sever the cables connecting it to the still-hovering descent stage. The descent stage then climbs and accelerates away in the preplanned flyaway maneuver.

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-  Five commercial off-the-shelf cameras located on three different spacecraft components collected the imagery. Two cameras on the back shell, which encapsulated the rover on its journey, took pictures of the parachute inflating. A camera on the descent stage provided a downward view, including the top of the rover, while two on the rover chassis offered both upward and downward perspectives.

-

-  February, 2021, the rover team continues its initial inspection of Perseverance's systems and its immediate surroundings.  The team will check out five of the rover's seven instruments and take the first weather observations with the Mars Environmental Dynamics Analyzer instrument.

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-   A 360-degree panorama of Jezero by the Mastcam-Z should be transmitted down, providing the highest resolution look at the road ahead.

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-  A key objective of Perseverance's mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet's geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.

-

-  Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

-

- Jet Propulsions Laboratories, JPL, manages the mission for NASA from Caltech in Pasadena, California.

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-  Both Earth and Mars currently have oxidising atmospheres, which is why iron-rich materials in daily life develop rust (a common name for iron oxide) during the oxidation reaction of iron and oxygen. The Earth has had an oxidising atmosphere for approximately 2.5 billion years, but before that, the atmosphere of this planet was reducing, there was no rust.

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-  The transition from a reduced planet to an oxidised planet is referred to as the Great Oxidation Event . This transition was a central part of our planet's evolution, and fundamentally linked to the evolution of life here, specifically to the prevalence of photosynthesis that produced oxygen.

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-   Planetary geologists have discovered that Mars underwent a great oxygenation event of its own, billions of years ago, then the red planet was not so red.

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-  The researchers used infrared remote sensing and spectroscopy to measure the molecular vibration of the material on the Martian surface from orbit, in order to reveal the mineralogy and geochemistry of ancient rocks on Mars.

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-   Through detailed comparisons of infrared remote sensing data and data collected in the laboratory here on Earth, the team showed that ancient rocks on Mars exposed at the surface had been weathered under reducing conditions, indicating a reduced atmosphere did exist.

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-  Mars is cold and dry now, but  3.5 billion years ago, it was warmer and wetter. It was warm enough to allow the formation of river channels, lakes and minerals that formed by interaction with water.

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-   Scientists who have used mathematical models to constrain the conditions of an early Martian atmosphere, have concluded that greenhouse warming occurred, but they also concluded from their models that the greenhouse must have included reduced gases rather than carbon dioxide, implied that a reducing atmosphere might have existed. 

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-  Infrared remote sensing of Mars, using infrared spectroscopy to map minerals in exposed, weathered rock. The work was built on detailed analysis of weathered volcanic rocks in Hainan Island in southwestern China, where thick sequences of basalt, similar to volcanic rocks on Mars occur. 

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-  The transition from a reducing to oxidising atmosphere on Earth 2.5 billion years ago was only possible because the existence of life, as oxygen is a waste product of metabolic processes like photosynthesis. Without microbes producing oxygen, it would not accumulate in our atmosphere, and we could not be here.

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- This work demonstrates how spectroscopy and remote sensing lead to fundamental discoveries of significant importance for understanding Mars' history, and even our own.

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-   As we begin to understand the most ancient history of Mars, researchers are ready to directly search of any signatures that life might have once existed on ancient Mars.

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-----------------------  more reviews available:

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-   3054  -   PERSEVERANCE  -  Mars mission with math.    The most advanced rover NASA has sent to another world touched down on Mars Thursday, February 18, 2021,  after a 203-day journey of 293 million miles.

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- 3056  -  PERSEVERANCE  -  the rover has safely landed.   It is the most technologically advanced rover that humans have set on the Mars surface. . The Mars 2020 Mission will use five new technologies to help future missions on Mars, both crewed and uncrewed. Two of these are technology demonstrations.

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-  3023 - MARS  - returning rock samples to Earth?  - Fundamental questions about Mars  remain related to its potential for life; the geological history of the planet; the history of its climate and the driving forces behind these changes; the evolution of geologic processes and the interior composition and structure; and more recent atmospheric, polar, surface, and interior processes

-

-  3010  -  MARS  -  Perseverance  Mars mission.    Scientists unanimously believe that the Mars sample-return program should proceed.   They think its scientific value will be extraordinarily high, with the potential for world-changing discoveries about Earth's nearest planetary neighbor, and possibly about an independent origin of life on another world.

-

-  2974 - MARS  - Perseverance mission in 2021?  Space exploration just took the next giant leap in the search for signs of life beyond Earth.  On July 30, 2020 NASA launched its most sophisticated and ambitious spacecraft to Mars, the  “Perseverance rover“. 

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-  2968 -  MARS  -  exploring robot dogs?  Will Mars exploration be done by robot dogs?  Scientists are equipping four-legged, animal-mimicking robots with artificial intelligence (AI) and an array of sensing equipment to help the robots autonomously navigate treacherous terrain and subsurface caves on the Red Planet.

- 

-  2963  -  MARS  -  20 years of exploration.  Over the past two decades, missions flown by NASA’s Mars Exploration Program have shown us that Mars was once very different from the cold, dry planet it is today. Evidence discovered by landed and orbital missions point to wet conditions billions of years ago. 

-  

February 23, 2021          PERSEVERANCE  -  more to learn?             3058                                                                                                                                                          

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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, February 23, 2021  ---------------------------

3057 - NASA’s - space inventions?

 -  3057  -  NASA’s  -  space inventions?  -  NASA was founding in 1958. Here are some of our greatest space achievements over these past 63 years

------------------------------------  3057  -  NASA’s  -  space inventions?

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------------------------   Voyager 2 speeds past Neptune in 1989.

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-------------------------  The Apollo Moonsuit.  

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------------------------   The Viking Mars Lander. 

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-------------------------  The F-1 Rocket Engine. 

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------------------------   The Space Shuttle.  

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-------------------------  The Apollo Guidance Computer. 

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-------------------------  Mars Rover Curiosity.  

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-------------------------  The Lunar Module.

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-------------------------  The International Space Station.  

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-------------------------   The Apollo Moon Rocket. 

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------------------------   Voyager 2 speeds past Neptune in 1989.  Not content to merely explore Mars and Venus, in the 1960s, NASA hatched a scheme to explore most of the solar system. The major planets, Jupiter, Saturn, Uranus and Neptune, were going into a rough, curving alignment in the 1970s, and NASA wanted to conduct a "Grand Tour" with twin spacecraft. The opportunity to do so would not repeat for about 180 years.

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-  The Jet Propulsion Laboratory (JPL) build two smaller and less ambitious spacecraft called Voyager. The robotic explorers were launched in 1977, racing past Jupiter and Saturn and completing their primary missions by 1980. With a clever twist in trajectory design and a lot of brainpower, JPL managed to divert Voyager 1 to investigate Saturn's largest moon, Titan , and then leave the solar system. Voyager 2 continued onward and visited Neptune and Uranus before heading outward.

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-  Both probes are still transmitting data almost 38 years later, thanks to innovative mechanical and electronic designs, a nuclear fuel source, and the first autonomous computers to fly into space. Voyager 1 officially left the solar system last year, headed for a rendezvous with another star in about 50,000 years.  I will miss that one.

-

-----------------------  The Apollo Moonsuit. What good was flying to the moon if you couldn't walk on it? That was the challenge facing NASA engineers in the early 1960s. They had designed space suits for the X-15 flights, Mercury and then Gemini, and each suit was a little bit better than its predecessors, but all were stiff, bulky and uncomfortable.

-

-  And perhaps worst of all, it was hard to actually do much of anything when the suits were pressurized, they were like wearing stiff, thick balloons. For the Apollo lunar missions NASA innovated quickly, building and testing a dozen designs before settling on the bulky-looking suit used for the Apollo 11 landing.

-

-  That spacesuit, designed specifically for working on the lunar surface, is more nimble than it appears. There are rotating joints on the gloves and other parts of the suit, the fingertips are made of rubber thin enough to "feel," and the shoulders were supported by a clever cable-and-pulley arrangement. And while nobody would call them "comfy," the astronauts were able to use them, protected from the killing temperatures and hard vacuum of the moon, for up to eight hours at a time.

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---------------------   The Viking Mars Lander.  In the late 1950s, NASA's Jet Propulsion Laboratory dreamed up an ambitious mission to send twin robotic landers to Mars. Once there, the machines would conduct geological tests, weather and atmospheric sensing, and perhaps most ambitious of all, a search for life. At the time the mission was being designed, NASA had not even flown past Mars, the planet was merely a red smudge in large telescopes.

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-   NASA engineers were exercising incredible innovation, and had miniaturized life-science labs that should have filled a classroom down to the size of a small washing machine. Two Viking spacecraft, each with an orbiting component as well as a lander, arrived at Mars in 1976.

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-  The twin landers set down on opposite sides of the red planet, and both performed well beyond their primary missions of 90 days.  The Viking 1 lander operated until 1982. While the search for microbial life was ambitious, the results were puzzling and inconclusive.

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-  But in 2008, NASA scientists reevaluated the experiments and ascertained that there may have been microbes, or at least organic substances, present in the Martian soil after all. A new Mars rover mission launch in 2020 may edge us closer to knowing, one way or the other.

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-----------------------  The F-1 Rocket Engine.  In the late 1950s, the Russians always had something bigger and better than the U.S. rockets.  So the U.S. Air Force commissioned a company in California named Rocketdyne to build the largest, most powerful rocket engine ever seen.

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-  It was called the F-1, and would ultimately power the Apollo moon flights. Everything about the F-1 was bold and new and big. The final design yielded 1.5 million pounds of thrust.

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-   Rocketdyne originally built on previous knowledge, but simply scaling-up smaller engines resulted in terrific explosions when tested. One major issue was that the engines were shaking themselves to death due to acoustic vibrations.

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-   Rocketdyne's innovation? Deliberately set off small bombs inside the rocket engine while it was firing, making it vibrate in a controlled fashion, until the engineers understood the problem. That's bold some might say crazy thinking. The F-1 was the most successful rocket engine of its time.

-

---------------------------   The Space Shuttle.  How do you follow-up an amazing space program that landed a man on the moon? With a semi-reusable space plane.

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-  The space shuttle would undergo many redesigns, from a fully-reusable, twin space-plane with a piloted, reusable first stage, to its final incarnation with strap-on boosters and an expendable orange fuel tank. But from its vast cargo capability to its incredible heat-shedding tiles and the ability to fly over 30 times each, America's five shuttle orbiters: Challenger, Columbia, Discovery, Atlantis and Endeavour were amazing machines.

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-  Despite two fatal in-flight accidents, the fleet flew a combined 134 times, and were a study in backing successful innovation into a highly constrained budget.

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---------------------------  The Apollo Guidance Computer inside the Lunar Module was the cigar-box sized machine that could navigate to the moon's surface and back again.   To fly to the moon with 1960’s technology you need a sophisticated navigation computer, and in 1963, when NASA got serious about going to the moon, such devices filled entire rooms.

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-  The Massachusetts Institute of Technology (MIT)'s Instrumentation Laboratory designed the Apollo guidance computer. The result was the first integrated-circuit digital flight computer ever made. The Apollo astronauts used the computers to fly from the Earth to the moon and back nine times, with six successful landings.

-

-  The computer could navigate from the Earth to the moon, from lunar orbit to the surface, then back to lunar rendezvous and a return to Earth on 2 kilobytes of RAM and 36 kilobytes of programming running at one megahertz. It was far less intelligent than a modern washing machine, but so very much more capable, and was the underpinning of today's compact digital computers.

-

-------------------------  Mars Rover Curiosity after a decade-long saga ending with the successful landing on Mars.   The $2.5 billion program was the most ambitious yet, with exponentially more instrumentation and capability than all that had gone before. But all this techno-wonder came at a price, the complex rover weighed a ton and was the size of a small car. Landing it safely was a huge challenge.

-

-  The methods used in previous missions would not be sufficient for this heavy machine. So the engineers hit upon a new, wacky, crazy idea: Slow the craft almost to a hover using parachutes and rockets, then lower the rover using nylon ropes. They called it "sky crane," and the design raised eyebrows, and blood pressures, upon first glance. 

-

-  On August 5, 2012, the only people laughing were the overjoyed engineers, controllers and scientists in JPL's mission control.   Curiosity had made it to Mars, and their adventure was just beginning.  Perseverance would be next in 2021.

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----------------------------  The Lunar Module from Apollo 16 was a remarkable machine operated at the cutting edge of 1960s technology, and never failed in flight.  Lighter, lighter, lighter. That was the mantra of the Grumman Corporation as they struggled to make NASA's Apollo Lunar Module flight worthy. Long a maker of tough fighter aircraft, the company was now tasked with building a small number of true spaceships, machines meant to fly only in space. No streamlining, no aerodynamics.

-

-  The engineers struggled to transform the concept into metal. The final result was a vast departure from early designs: They had stripped out most of the windows, the seats, even the side panels of the lower stage. Everything not absolutely essential to landing on the moon was gone.

-

-  But the machine was still too heavy to fly, so Grumman took to extreme and groundbreaking methods, even chemically etching tiny machined parts until they were barely strong enough to work, in the battle to trim grams. In the end, ten Lunar Modules flew (including the Apollo 13 LM, which saved the crew when their oxygen tank exploded), and every last one of them did their job to perfection.

-

------------------------  The International Space Station  as completed in 2006. It has been continuously inhabited since 2000.   The ISS is the largest and most expensive machine to ever leave Earth, and represents the most complex, successful, and at times, strained international collaboration ever undertaken. 

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-  The ISS is larger than a football field, and expensive, at $150 billion. It is also the longest continually occupied structure in space, with crews serving in rotation for nearly fourteen years. As the station ages, new and inventive solutions are needed to fix ailing parts, such as the recent repair of a faulty air conditioning unit. But the ISS has proven to be robust, and is scheduled to remain in orbit until at least 2024.

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------------------------   The Apollo Moon Rocket  The launch of Apollo 15. The Saturn V remains the most powerful rocket ever flown.  Standing at number one on the list is the mighty Saturn V moon rocket. The three-stage monster was the size of a WWII destroyer, and even more massive at well over 6,000,000 pounds.

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-  The rocket's first stage utilized five F-1 rocket engines producing a combined total of 7.5 million pounds of thrust, that is 160 million horsepower. Had the rocket failed on the launch pad, it would have had the explosive force of a small atom bomb. It was a highly evolved version of smaller rockets that had flown before, with its roots in Wernher von Braun's V2 rockets that pummeled London and Antwerp in WWII.

-

-  The unknowns that faced its creators were immense, and the required innovations in science and technology were titanic. When U.S. President John F. Kennedy announced his intention to land Americans on the moon by the end of the decade in 1961, stunned top NASA brass admitted that they "did not even know what they did not know." 

-

-  Nonetheless, in just eight years, a Saturn V rocket launched the Apollo 11 spacecraft toward a July 20, 1969, landing on the moon. All the crewed Saturn Vs delivered their precious cargo safely, and none failed in flight.

-  

February 22, 2021            -  NASA’s  -  space inventions?                 3057                                                                                                                                                         

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--------------------- ---  Monday, February 22, 2021  ---------------------------