Cop Car's Beat

Cleaning out the Clutter

A few months ago, I took Hunky Husband into our workshop to see what he wanted done with piles of stuff that were sitting about, not having been moved since we moved into this house 20 years ago. He didn't see anything without which he couldn't live, so I started getting rid of the stuff - partly through placing it in recycle/hazardous waste/ecycle, partly by taking it to Goodwill or the Disabled American Veteran resale shops, and partly through trashing. I made great progress in the first couple of weeks, then my time got diverted to other projects - and I forgot all about it.

Thursday, I decided to replace a towel ring in my bathroom with an 18"-long towel bar. To do this, I retrieved level, steel tape, screw drivers, hex drivers etcetera from the workshop (plus my drill and bits from my sewing room - don't ask!) In the process, I realized that there was still much "stuff" to get out of the workshop. Today, I've focused on getting rid of a large box of stuff that was sitting on the floor and, somehow, stumbled across some vacuum tubes. Well...I've long (perhaps 65 years) had a soft heart for vacuum tubes. But...they gotta go! We have only one piece of equipment that uses vacuum tubes and it, too, is on the "get rid of" list.

Above is a photo of the tubes - and a handful of crystals (at the bottom of the photo) that would be used in fixed-frequency radio frequency oscillators. Woo-hoo. Some of the vacuum tubes are possibly from among a large box of tubes that I bought (at the price of a month's rent) as a freshman in college. That would have been 1955-56. I'm smart enough, now, to realize that the guy who sold them to me had probably stolen them from the US Army (Ft Leonard Wood - near our school); but, I was naïve in those days. And, no, I had no real use for the vacuum tubes at the time, but they were cute! HH has told me that, having imbibed too much one evening during the months in which we dated, I regaled him with my design for a transmitter that I would build to use some of those tubes.

How did the towel bar installation go? Well, the towel bar came with plastic inserts for use in hollow-wall construction. As it happened, one end of the towel bar was to be situated into an area that had something inside the hollow wall. Since I was unsure what was inside that part of the wall and didn't wish to injure the sewer pipe that might possibly run through that area, I came up with a work-around. I used heftier plastic sleeves than had been supplied, cut them off at the pointy end, installed them to act as bearings on the drywall, and used shorter (and larger diameter) screws than had been supplied.

Since I am rarely forethoughtful enough to take "before" photos, I'll give a photo of another towel ring that is in that bathroom. The ring in the photo normally holds a clean wash cloth. The "after" photo shows the installed towel bar. A hand towel gets bunched up in the towel ring, slowing down drying of the towel. (Since the wash cloth that is kept in the towel ring is always dry, being replaced, daily, drying time is not an issue.) The towel bar is long enough that the towel can be spread out, if required, or another wash cloth would fit in the available space.

 

 
 

Three Body Problem

This artist's concept illustrates Kepler-47, the first transiting circumbinary system.

NASA/JPL-Caltech/T. Pyle

One graduate-level course, alone, nearly convinced me to give up the study of physics altogether. I felt that I spent 30 years in a one-semester class on the three body problem; thus, I found the following item from Slashdot.org really interesting - if 50 years too late!

AI Cracks Centuries-Old 'Three Body Problem' In Under a Second (livescience.com) 122

Posted by EditorDavid on Saturday November 09, 2019 @02:34PM from the matters-of-great-gravity dept.

 

Long-time Slashdot reader taiwanjohn shared this article from Live Science: The mind-bending calculations required to predict how three heavenly bodies orbit each other have baffled physicists since the time of Sir Isaac Newton. Now artificial intelligence (A.I.) has shown that it can solve the problem in a fraction of the time required by previous approaches.

Newton was the first to formulate the problem in the 17th century, but finding a simple way to solve it has proved incredibly difficult. The gravitational interactions between three celestial objects like planets, stars and moons result in a chaotic system -- one that is complex and highly sensitive to the starting positions of each body. Current approaches to solving these problems involve using software that can take weeks or even months to complete calculations. So researchers decided to see if a neural network -- a type of pattern recognizing A.I. that loosely mimics how the brain works -- could do better.

The algorithm they built provided accurate solutions up to 100 million times faster than the most advanced software program, known as Brutus. That could prove invaluable to astronomers trying to understand things like the behavior of star clusters and the broader evolution of the universe, said Chris Foley, a biostatistician at the University of Cambridge and co-author of a paper to the arXiv database, which has yet to be peer-reviewed.

 

Slashdot.org's wise saying of the day: "Numeric stability is probably not all that important when you're guessing."

Photon momentum - linear and angular

Johanne Kepler, German astronomer, suggested that "ships and sails proper for heavenly air should be fashioned" to allow space travel. That was about 400 years ago. He was a bit off in his analysis; but, about 250 years later, James Clerk Maxwell demonstrated that photons imparted momentum to the surfaces on which they impinged.¹

I recall reading a science fiction story, "The Winds of Space", in my teenage years; but, I can find no evidence that it actually existed. Somehow in the succeeding years, I may have become confused with a short story that was published in 1963².

Yesterday, Slashdot.com led me to an article in Science³ that contains the latest news on the properties of light. Below are excerpts from the article.

Structured Abstract

INTRODUCTION

Light beams carry both energy and momentum, which can exert a small but detectable pressure on objects they illuminate. In 1992, it was realized that light can also possess orbital angular momentum (OAM) when the spatial shape of the beam of light rotates (or twists) around its own axis. Although not visible to the naked eye, the presence of OAM can be revealed when the light beam interacts with matter. OAM beams are enabling new applications in optical communications, microscopy, quantum optics, and microparticle manipulation. To date, however, all OAM beams—also known as vortex beams—have been static; that is, the OAM does not vary in time. Here we introduce and experimentally validate a new property of light beams, manifested as a time-varying OAM along the light pulse; we term this property the self-torque of light.

….

CONCLUSION

We have theoretically predicted and experimentally generated light beams with a new property that we call the self-torque of light, where the OAM content varies extremely rapidly in time, along the pulse itself. This inherent property of light opens additional routes for creating structured light beams. In addition, because the OAM value is changing on femtosecond time scales, at wavelengths much shorter than those of visible light, self-torqued HHG [High Harmonic Generation] beams can be extraordinary tools for laser-matter manipulation on attosecond time and nanometer spatial scales.

In conclusion, I'll have to say that I just don't see it ; ) Thankfully, I don't have to understand all of the new developments to realize how valuable they may come to be. Well done to the huge team responsible.

__________________________

1. Historical data are from A Brief History of Solar Sails
2. Clarke, Arthur C. The Wind From the Sun. 1963
3. Generation of extreme-ultraviolet beams with time-varying orbital angular momentum. Science

Elusive Neutrino - 10 fun facts

A couple of years ago, I had a short posting, Elusive Neutrino¹, which included reference to a couple of books^{2, 3} that I had found interesting. Just for fun, today, I'm posting an excerpt from the All Things Neutrino website developed and owned by Fermi National Accelerator Laboratory  |  Managed by Fermi Research Alliance, LLC for the U.S. Department of Energy Office of Science. (The link to the website is included in the right-hand sidebar under 4 Fun & Enlightenment.)

Ten quick facts about neutrinos:

1. Trillions of the harmless particle stream through you every second, night or day.
2. They are the second most abundant particle in the universe (after particles of light called photons).
3. Neutrinos rarely interact with anything—a lightyear of lead would stop only about half of the neutrinos coming from the sun.
4. About 15 billion neutrinos from the Big Bang are in the average room.
5. Neutrinos interact only through two of the four known forces: the weak force and gravity.
6. So far, scientists have discovered three flavors of neutrinos: electron (ν_e), muon (ν_μ), and tau (ν_τ).
7. They oscillate, or change flavor, as they travel.
8. Their masses are very tiny, but not yet known.
9. Their speed is very close to the speed of light, but also not known exactly.
10. They could be the reason that matter exists in the universe.

I had been noodling about various places on the Internet to see if the next solar eclipse will provide an opportunity "to look for lunar neutrino occultation, getting a tomograph of the moon's interior" as Stu of Eunoia had opined in a comment to my previously cited posting. Alas, I think not.

_______________________________

1. List of particles - Wikipedia
2. Solomey, Nickolas. The Elusive Neutrino: A Subatomic Detective Story; ISBN-13: 978-0716750802; ISBN-10: 0716750805
3. Al-Khalili, Jim. Quantum: A Guide for the Perplexed

Helium hydride

From NASA's SOFIA page, an excerpt:

April 17, 2019

 

The Universe’s First Type of Molecule Is Found at Last

Illustration of planetary nebula NGC 7027 and helium hydride molecules. In this planetary nebula, SOFIA detected helium hydride, a combination of helium (red) and hydrogen (blue), which was the first type of molecule to ever form in the early universe. This is the first time helium hydride has been found in the modern universe.

Credits: NASA/SOFIA/L. Proudfit/D.Rutter

The first type of molecule that ever formed in the universe has been detected in space for the first time, after decades of searching. Scientists discovered its signature in our own galaxy using the world’s largest airborne observatory, NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, as the aircraft flew high above the Earth’s surface and pointed its sensitive instruments out into the cosmos.

When the universe was still very young, only a few kinds of atoms existed. Scientists believe that around 100,000 years after the big bang, helium and hydrogen combined to make a molecule called helium hydride for the first time. Helium hydride should be present in some parts of the modern universe, but it has never been detected in space — until now.

SOFIA found modern helium hydride in a planetary nebula, a remnant of what was once a Sun-like star. Located 3,000 light-years away near the constellation Cygnus, this planetary nebula, called NGC 7027, has conditions that allow this mystery molecule to form. The discovery serves as proof that helium hydride can, in fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe and how it evolved over billions of years into the complex chemistry of today. The results are published in this week’s issue of Nature.

….

Helium hydride is a finicky molecule. Helium itself is a noble gas making it very unlikely to combine with any other kind of atom. But in 1925, scientists were able to create the molecule in a laboratory by coaxing the helium to share one of its electrons with a hydrogen ion.

….

ADDITION OF 4/27/2019 - Ethan Siegel's further treatment on the subject is quite interesting. He blogs at Starts with a Bang!

Upcoming Total Lunar Eclipse

Ethan Siegel, astrophysicist and science writer, of Starts With A Bang! has a fine posting concerning the total lunar eclipse that will be visible to many of us, tomorrow night (20th/21st). I've excerpted portions of his posting, below.

The Supermoon lunar eclipse of 2015 was the first such combination since 1982, and was the largest diameter Moon to be seen in lunar eclipse in more than three decades. 2018 had one, and so will 2019 on January 20/21. (JIMMY BAIKOVICIUS FROM URUGUAY)

Supermoon Lunar Eclipse To Become The First Pan-American Total Eclipse in 19 Years: On January 20/21, half of Earth will experience a total lunar eclipse. For the first time in 19 years, this includes all of North and South America.

….

Total lunar eclipses are relatively common; we get about one per year, on average. But something special is happening on the night of January 20th/21st: the entirety of the North and South American continents will get to experience the full show of the eclipse. This includes the penumbral, partial, and total stages from everywhere in the Americas. It’s the first time this will happen since the year 2000, and the last time it will occur until 2058.

The area shown in red, here, will get to observe the total lunar eclipse of January 2019 from Earth. This includes everyone in North and South America with clear skies. (TIMEANDDATE.COM)

….

Remarkably, binoculars or a telescope will allow you to see incredible features of the Moon with no additional filters. Normally, viewing the Moon through binoculars or a telescope is very harsh on the eyes, and impossible without a special lunar filter due to the Moon’s overwhelming brightness.

….

Small portions of northern Europe and northern Asia will experience the entirety of the eclipse, but all of North and South America will get to view the entire thing. This marks the first Pan-American eclipse of the 21st century!

….

________________

I've undoubtedly mentioned, previously, having observed a red moon during an eclipse as a child. At age 4, (I believe that I observed the eclipse of August 25/26, 1942) I feared that the moon was bleeding to death!

NASA Photos

NASA has been posting information on Hurricane Michael. Among their photos are two that show the Florida Gulf Coast, at night, before (October 6) and after (October 12) Hurricane Michael made landfall. It is easy to track Michael's path. (The black at the bottom of each photo is the Gulf of Mexico, with North being at the top of each photo.)

For more information:  https://weather.msfc.nasa.gov/sport

Credit: NOAA/NASA MSFC, SPoRT 

Having nothing to do with a hurricane, Nature posted a NASA photo of a penny that has spent some time on mars. Curiosity was launched on November 26, 2011 and landed on Mars on August 6, 2012.

Credit: NASA/JPL-Caltech/MSSS

An image taken by the Curiosity rover on 4 September shows a US 1-cent coin covered in Martian dust. The coin is used as a target by Curiosity to calibrate the Mars Hand Lens Imager, a camera fastened to the end of the rover’s robotic arm. (NASA/JPL-Caltech/MSSS)

See more of the best science photos of the month, chosen by Nature’s picture editors

More on the penny coin may be found on Science.com posting One Red Cent: Curiosity Rover Totes Penny on Mars.

TRESTLE

In a comment on Not exactly...., Stu asked us to consider the electromagnetic pulse produce by the sudden collapse of a large magnetic field when the energy source self-destructed. He brought to mind the TRESTLE program that ran for some years at Kirtland Air Force Base in Albuquerque. TRESTLE came to mind, not because of any self-destruction but because TRESTLE provided electromagnetic pulse (EMP) simulation against full-scale aircraft in order to assess survivability in the event of nuclear war. (In fact, since that time, non-nuclear EMP weapons have been developed.) The companies for which Hunky Husband and I worked, Boeing Wichita and BDM, respectively, were intimately involved in TRESTLE. HH actually observed some of the B-52 testing while the closest I ever came was rooming with one of the BDM engineers, who did work on TRESTLE, for a few months when she and I were working on a very different program in California.

  Photo supplied by Hunky Husband - unsure whether photo was taken by Boeing or USAF

What made TRESTLE so astounding to many people was the size of the support structure (B-52 and C-5A aircraft had to sit on it) and the fact that it was made mostly of wood. In DOCUMENTATION OF THE TRESTLE at Kirtland Air Force Base, New Mexico, we are told that, "AFWL awarded a contract to Boeing Company (Contract Number F29601-72-C-0028) to test the following systems:

1) B-52;

2) EC-135;

3) Airborne Warning and Control System (AWACS);

4) E-4 (Boeing 747), Advanced Airborne National Command Post (AABNCP);

5) Short-range attack missile (SRAM);

6) B-52 electro-optical viewing system (EVS);

7) Rivet Ace–electronic countermeasure equipment aboard the B-52; and

8) Hound Dog I."

Later in that document, we are told, "The primary subcontractors under the MDAC [McDonnell Douglas Aircraft Company] contract were:

2) Maxwell Laboratories, Inc. (MLI) for pulser design and construction;

3) Braddock, Dunn and McDonald (BDM) for electromagnetic analysis, timing and

control equipment;

4) W.C. Kruger & Associates for architectural and engineering design;

5) R.D. Krause Engineering Company for engineering design; and

6) Hunt Building Company for general construction (Jedlicka 1977:3)."

Below is a rather long video from YouTube that tells more than anyone wants to know about TRESTLE. I found the section up to about minute 20 to be mildly interesting as a reminder of the history of the weaponry on hand and developed during the Cold War. Minutes (about) 20-28 are of interest only to structural engineers. At about minute 28, airplanes start to be covered to a greater extent. Credits start to roll at about minute 42 and the video ends somewhere after minute 43. To see HH, onsite, check out time stamp 38:49. Well...not really. I didn't see anyone I knew during the length of the video.

 

More information may be found at NATIONAL REGISTER OF HISTORIC PLACES: HISTORIC CONTEXT AND EVALUATION FOR KIRTLAND AIR FORCE BASE: Albuquerque, New Mexico

 

Not exactly....

In a case that is not exactly cutting off one's nose to spite one's face, is a record-setting achievement reported on the Physics and Physicists website. (Perhaps a better analogy would be a queen sacrifice?) That posting is excerpted, below. The video is less than 10 seconds long.

Saturday, September 29, 2018

Record 1200 Tesla, and then, BANG!

Hey, would you sacrifice your equipment just so you can break the record on the strongest magnetic field created in a lab? These people would.

Speaking with IEEE Spectrum, lead researcher Shojiro Takeyama explained that his team was hoping to achieve a magnetic field that reached 700 Tesla (the unit of measurement for gauging the strength of a magnetic field). At that level, the generator would likely self destruct, but when pushed to its limits the machine actually achieved a strength of 1,200 Tesla.

To put that in perspective, an MRI machine — which is the most intense indoor magnetic field most people would ever encounter — comes in at just three Tesla. Needless to say, the researchers’ machine didn’t survive the test, but it did land them in the record books.

 

 

Addition of 10/6/2018

 

From BigThink:

 

This image explains it a bit better, from the IEEE institute. "The University of Tokyo's 1,200-Tesla magnetic field generator is powered by a bank of capacitors [on left, white] capable of storing 5 megajoules. The capacitors' energy flows into the primary coil [bottom left, gray] and induces a counteracting current and magnetic field in the liner [orange]. This implodes the liner in 40 microseconds, compressing the magnetic field [bottom right]."

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Image by University of Tokyo

Why would I do this to you?

This is one of those postings that I expect about half of my blog friends to skip over - those who have no reason to know what a partial differential equation is or why they would want to know. I understand, and think none the less of those who feel that way. As a freshman in college, I was among that group. However, the next year, as a physics major, I was required to start thinking about thermodynamics. I would bet even money that you have heard of the First Law of Thermodynamics and can even tell me that it has to do with conservation of energy. (See how smart we are?)

A 2011 comic take on the game version of the laws by American chemical engineer Rich Byrnes

Byrnes, Rich. (2011). “Boil’s Laws: the Laws of Thermodynamics and Casinos”, Funnybone, ChEnected, Apr. 08

By my second semester junior year, I was required to take a course in thermodynamics. Although I don't recall the exact title of the book we used in Introduction to Thermodynamics, I recall that it was a thin book with a grey cover. As I recall (but, I wouldn't bet too much money on this, it was in 1958, after all) I believe that little book was by Sears (not & Roebuck!) That was a difficult course for me. As it turned out, the course and book were super-saturated with partial differential equations, a course that, at that time, I had not gotten around to attempting. Somehow, my math always seemed to be behind my physics coursework. I needed matrix algebras long before I got to a math course that included them.

One of the more interesting things about my taking thermo was that Elder Brother and Hunky Husband were also taking thermodynamics - and - we were all living together (along with EB's late wife). Funny thing was, the three of us could not compare notes or even converse cogently about our respective classes. EB took thermo in the chemical engineering department and HH took thermo in either the mechanics department or the mechanical engineering department. HH wanted to talk steam tables, I wanted to talk partial differential equations (PDE), and who recalls what a chemical engineer wanted to talk about? I do recall the two guys playing catch (thereby destroying) my clay model that I had built of the pressure/volume/temperature (better known as a PVT) diagram for water. Grr!

Cop Car's Roomies - Elder Brother, Hunky Husband, Expert Seamstress - Spring 1958

Fast forward to 1981 at which time I interviewed for a job at Tyndall AFB, Florida, working on USAF's HAVE BOUNCE program - part of the Rapid Runway Repair program to which BDM was contracted. (This was actually my second interview - BDM had first asked me to come to McLean VA, to their corporate headquarters.) I recall someone's bragging to me that the USAF computer being used for aircraft simulations would do xxxx fast Fourier transforms (FFT) per second. "What's a fast Fourier transform", you may ask. Well, it is a faster way of computing the same answers as one gets using the old, standard Fourier transform - which is now called a discrete Fourier transform (DFT). Did I hear you mutter, "Ask a silly question...."? Either FFT or DFT should give the same answer in solving (drum roll) differential equations, including PDEs!

Fourier Transform (FT)

Why did HAVE BOUNCE need to use FFTs at all? Because the HAVE BOUNCE program involved testing of various aircraft (F-4, C-130, C-141, C-5, B-1, A-10, Boeing 747, Douglas DC-10 are the ones which I recall) to measure their response to operations over a surface that was shaped as a 1-cos wave of known maximum amplitude. The measurements were made in the time domain, that is, one would plot out the data along a time axis. We needed to know the response as a function of frequency - plots along a frequency axis.

BTW: In case I didn't mention it, FFT solutions/second was/is used in comparing speeds of computers in practical terms.

 

Why did I bring up the whole subject? Because, I visited the Improbable Research website this morning only to find the following posting.

How Aesthetically Pleasing Is Your Country’s Diffraction Pattern?

September 19th, 2018

You may be wondering how aesthetically pleasing is your country’s diffraction pattern. This new physics study proves that Albert F. Rigosi shares your mental hobby:

“Analysis of Fraunhofer Diffraction Patterns’ Entropy Based on Apertures Shaped as National Borders,” Albert F. Rigosi, Optik, vol. 172, November 2018, pp. 1019-1025. (Thanks to John Ng for bringing this to our attention.) The author, at Columbia University and the National Institute of Standards and Technology, reports:

“How aesthetically pleasing is your country’s diffraction pattern? This work summarizes the calculated and experimental Fraunhofer diffraction patterns obtained from using apertures lithographically formed into shapes of national borders. Calculations are made based on the fast Fourier transform of the aperture images. The entropy of a diffraction pattern image, based on its two-dimensional gradient, for each of 113 nations has also been computed. Results suggest that most nations’ diffraction patterns fall under one of two prominent trends forming as a function of geographical area, with one trend being less entropic than the other.”

The top images here shows shows a diagram of the experimental setup. The bottom collection of images show: “Three example nations. (a) The aperture for the continental USA is depicted. (b) is the FFT calculation of the aperture above, and the corresponding experimental data is shown below in (c). (d) The aperture for Egypt is depicted, along with its FFT and experimental data in (e) and(f), respectively. (g) The aperture for Papua New Guinea is shown with its (h) calculated FFT and (i) experimental diffraction data.”

Additional everything can be found in an appendix.    

posted by Marc Abrahams in Arts and Science, Research News | Comments Off on How Aesthetically Pleasing Is Your Country’s Diffraction Pattern? 

I have zero interest in fractal patterns of the outlines of various countries. They have no need to be pleasing as far as I am concerned; but, perhaps you can understand how it sent my mind off in a mathematical direction?