Physics – Page 3 – Stone Fig

Golden Apples

Planned obsolescence, a one-way trip, will be the demise of the Parker Solar Probe. It will burn up. But that’s ok; it’s all part of the plan. NASA’s probe will collect information on the Sun’s corona. The information to be gathered and beamed back to Earth is important to our understanding of solar processes.

The probe will make 24 orbits of the Sun over seven years. In its final seven orbits the probe will swing out past Venus and then slingshot back in towards the Sun to descend further through the heat of the Sun’s corona on each of its final orbits. Eventually it will pass within 3.8 million miles of the Sun’s surface.

The corona is the upper layer of the Sun’s atmosphere, extending millions of miles beyond the visible surface of the Sun, the photosphere. Photons released by nuclear fusion deep in the interior of the Sun are emitted by the photosphere, giving light. The corona lies millions of miles above this but is curiously hotter than the Sun’s surface. Solar winds generated in the polar and equatorial regions of the Sun lash out from the corona and send massive amounts of electrically charged particles streaming away from the Sun. These winds and other solar activities are the solar weather which reaches across the 93 million miles between the Earth and the Sun and can cause havoc on Earth. The particles of the solar wind travel at speeds over one million miles per hour and can cover the distance between the Sun and the Earth in about ten days. This is much slower than the light from the Sun which can cover that distance in about eight minutes.

The most visible aspect of the solar winds is the generation of aurora, curtains of glowing colors of light, that appear near the Earth’s magnetic poles. In the northern hemisphere, these displays are often called Northern Lights. They shimmer in the Earth’s upper atmosphere when the particles of the solar wind hit the lines of the Earth’s magnetic field. The strongest of these solar winds can also destroy the electronic capability of satellites. The winds can wipe out power grids on the Earth’s surface plunging cities into blackouts which can last for days. When the bursts of energy that generate the solar winds are detected, warnings can be made so that delicate equipment can be turned off or otherwise protected. Life on Earth is protected from the charged particles of the solar wind by the Earth’s own magnetic field. But astronauts above the Earth, or perhaps on a mission to Mars, or living on the moon, are not protected from the massive stream of charged particles.

The Parker Solar Probe is helping us to develop a deeper understanding of the fundamental processes of the Sun. By studying the data received from the probe, we will be able to better forecast solar weather and protect life and property. This knowledge will also provide important information regarding how to protect astronauts when we go out to build colonies off Earth.

Recently the probe reached a milestone on it mission; it began its second orbit of the sun. Important data has already been sent by the probe and received by NASA scientists. On the second orbit, protected by its 4.5 inch carbon-composite solar shield, the probe will pass within 15 million miles of the Sun’s surface. It will go deeper. With each orbit it will transmit more data on the solar wind, and it will continue to find information related to solar eruptions which accelerate particles dangerous speeds, and will plumb the mystery of why the corona is several 100’s of time hotter than the surface of the Sun. The probe will descend deeper and deeper into the heat to discover the depths of the plasma of the Sun’s corona.

These are the golden apples of the Sun, to gain knowledge, to know, to understand.

The picture is based on NASA imagery.

Information on the Parker Solar Probe found at https://www.nasa.gov/sites/default/files/atoms/files/parkersolarprobe_presskit_august2018_final.pdf .

Golden Apples of the Sun based on collection of Ray Bradbury stories of that name and from W.B. Yeats The Song of Wandering Aengus

Le Grand Kilogram

“The world is changed.” – opening narrative, “The Lord of the Rings: The Fellowship of the Ring”

The international kilogram mass, or Le Grand K, will no longer the world’s standard. There will no longer be a physical object protected from human touch and wayward air currents under triple bell jars. Now the standard mass for the kilogram will be defined as something ethereal.

I think the first time I heard about “Le Grand K I was in 3^rd grade. An article in my Weekly Reader spoke of a weight stored in a vault outside of Paris. I was fascinated! Since the time I was small, I had seen weights used on scales at feed stores and general stores in old rural North Carolina. They were handled by hardy men and women as they talked about the weather and their families. They moved them onto and off the scale-balance with careless ease as they weighted out feed or flour or nails. But this weight in Paris was completely different. This was a piece of metal that had been carefully made and even more carefully protected. It defined, for all other weights in the world, what a true kilogram actually was. It was handled not with bare, sweaty hands but only with gloved hands. It was covered in a glass bell jar. That bell jar was covered by another, larger glass bell jar. And that bell jar was covered by a larger, third bell jar. Le Grand K did not hang on a nail on the wall next to the scale. It was in a vault, kept behind closed and locked doors.

But over the years corrosion and dust and decay have affected the weight of this world standard. There had to be a better way. So now, all these years later, the old metal standard is just a museum piece. Perhaps if I wander far enough I may find it in a flea market in some distant corner of Europe. It is now detritus of a past age.

There is no longer a physical presence of a defining Kilogram. There is no more tactile experience of grasping the bell jar and lifting it away, being careful not to hit the precious mass. There is no more grasping the mass with gloved hands or padded tongs and feeling the weight of that mass pulling against bone and sinew and muscle of the hand and arm. Now it is ghostly. Now there is an ethereal determination of the pull of something that we cannot readily see as we would the weight.

The device now used to determine the mass of the test object measures electricity. For the test object, the question, “How much does this weigh?” is answered in a vacuum with the soft vibrations of electrical current and the resistance and magnetism of a conductor. There are two forces to be measured. The first is a measurement of value of an applied electrical current in a conductive coil in a Watt-Balance. The second is a measurement of induced voltage in the coil while moving through a stationary magnetic field.

Each of the measurements can be converted into the units of power (watts) by a known and proven mathematical formula, hence the name of the device, the Watt-Balance. The mass to be measured is placed in a pan which pulls down against the stiffness of a conductive, metal coil. A current is applied to the coil. This current stiffens the coil until the upward force in the coil balances the downward pull of the mass being measured. The value of the current required to balance the mass is recorded. The current is then turned off, the subject mass is removed, and the coil is now tested. The coil, a conductor of electric current, is passed through a magnetic field of known strength at carefully controlled, constant velocity. The value of the induced voltage in the coil is recorded. Based on the values of the measured current from the first stage and the value of the induced voltage from the second stage, two mathematical equations can be compared. Through this process the mass of the item being measured can be established with an extremely high degree of accuracy.

The Washington Post article on the redefined kilogram may be found at https://www.washingtonpost.com/science/a-massive-change-nations-will-vote-to-redefine-the-kilogram/2018/11/15/b5704b0a-e6c7-11e8-b8dc-66cca409c180_story.html

The National Institute of Standards and Technology (NIST) information on the Watt-Balance (Kibble-Balance) may be found at https://www.nist.gov/si-redefinition/kilogram-kibble-balance

Cylindrical Sails

Modern ocean-going vessels are mostly propelled by diesel or diesel-electric engines with mechanical connection to the propeller shaft. Now these engines can get an assist from sails installed on the ship’s decks. These are not fabric sails with rigging. The sails being installed are rotor sails. To an observer the sail looks like a large, vertical pipe. When in operation these vertical pipes are spun using power from the mechanical plant in the ship. The spinning cylindrical sail works together with the wind in utilizing Magnus effect to push the ship forward.

These sails work in a manner similar to the wing of an airplane. An airplane’s wing is shaped so that the air passing over the top of the wing exerts less downward pressure on the wing than the upward pressure from the air that is passing under the wing. This creates an upward lift applied to the wing and to the aircraft.

To show this take a narrow strip of paper about 1 inches wide, and using both hands hold it by the near corners with the thumb and fore-finger of each hand. Blow across the top of the paper. Even a gentle blow causes the piece of paper to rise. The air pressure over the top of the paper is less than the air pressure below the piece of paper, so the paper rises up. This also applied to the spinning rotor sails. The rotor sails are smooth vertical cylinders. They do not “catch” the wind; rather, they work by air pressure.

If you were a sea gull flying above the ship and looking down you would see the vertical cylinder as a spinning circle. Let’s say that the ship is sailing North, or towards the top of your screen. For this example, the wind is blowing from the West; from your left to your right. The cylinder is spinning in a clockwise direction so that the North edge of the spinning circle, as you look down on the spinning cylinder (remember you are a gull above the ship), is rotating to the East and so is moving in the same direction as the wind. The South edge of the spinning cylinder is rotating towards the West, in the direction that the wind is coming from, and so is spinning against the wind. This creates a higher pressure on the South side of the spinning cylinder which exerts a pressure in the northerly, or forward, direction. This is the wind assist for the ship heading North.

The rotor sails can be spun in either direction, clock-wise or counter clock-wise to take advantage of favorable winds. The winds do not have to be 90-degrees to the course of the ship as the wind and the Magnus effect can be used even with the wind off the forward or after quarters of the ship. Unfavorable winds that cannot be utilized are those that are blow from approximately twenty degrees on either side of the bow or stern of the vessel.

The pressure difference between the high-pressure side and the low-pressure side of the spinning, cylindrical rotor sail is magnified by the Magnus effect. Based on the influence of this force, studied and described by Heinrich Magnus, a spinning object causes the air on one side to exert a force on the object so that it moves in a direction perpendicular to the axis of the spin. The use of the Magnus effect in rotating sails was first demonstrated in the 1920s. At that time it was not found to be more efficient than the normal means of the ship’s motive power.

An article in The Guardian in 2016 describes the installation and efficiency of rotor sails developed and installed by NorsePower on the MS Estraden. Using these rotor sails as a wind assist on its routes across the North Sea resulted in a reduction of 6% in fuel costs.

In 2018, an article on the Maritime Executive website described a more recent installation of rotor sails on the Maersk Line tanker, Maersk Pelican. The installation was further reported in 2018 in the World Maritime News, which stated that Maersk sees a potential fuel savings of up to 10% in using the rotor sails for wind assist. When wind conditions are favorable the rotor sails can provide sufficient forward thrust which allows the ship’s primary engines to be throttled back. This results in less fuel burned resulting in less combustion exhaust from the engines.

The electrical power that is used to spin the rotor sail is less than the energy required by the ship’s normal propulsion to generate the forward thrust generated by the rotor sail. When the savings in fuel and the reduced emissions is multiplied across many ships and many thousands of miles of ocean transport, the reduction of fuel burned and the reduction of the resultant pollution is significant.

https://www.theguardian.com/sustainable-business/2016/aug/16/shipping-emissions-low-carbon-wind-power-climate-change

https://www.maritime-executive.com/article/two-wind-power-rotor-sails-installed-on-lr2-tanker

https://worldmaritimenews.com/archives/259777/rotor-sails-fitted-on-board-maersks-tanker-in-a-worlds-1st/

The Big Toss

I think that we have all done it, boys and girls alike. Maybe it starts with tossing pine cones at a tree. Or maybe by tossing a rock or ball into the air to see if you can hit it with a handy stick. This game often changes into one of, “How high can I throw this ball?” And then it becomes, “Can I throw it so high that it won’t come down?” To our vast disappointment, no. It always comes back down. And it always will thanks to gravity (g). No matter how much force (F) we put into it, no matter how hard we throw it, it always comes down.

A recent NASA/AP article published in the online Herald out of Rock Hill, SC provided a picture of Russian astronaut Sergey Prokopyev flinging a small satellite into orbit from outside the International Space Station (ISS). The ISS is itself in orbit around the Earth at a velocity of about 5 miles per second. Sergey’s sturdy “fling” (the word used to describe the launch) imparted additional velocity (V) to the satellite as it traveled away from the ISS.

The satellite is …. – wait! What is the satellite for? That information is hard to find; I will keep looking for it. But the interesting part of the NASA/AP release (no pun intended) is the novel approach to the satellite launch. When I think of a satellite launch I picture massive engines belching fire and towering rockets boosting bus-size devices to be hurled into space. In the time since satellites were first launched in the 1960’s, improvements in technology have allowed satellites to shrink so that now there is a distinct class of satellites that go by various names such as cube-sats, mini-sats, and nano-satellites. NASA Ames Research Center (ARC) has been working to guide the development of this area of space science over the last decade or more, and since 2016 ARC has hosted the Small Spacecraft Systems Virtual Institute (S3VI). The S3VI provides information on the state of the art of small space craft technology which includes nano-satellites and other space craft weighing less than 180 kg (up to about 400 pounds). The larger satellites at the higher end of this scale dwarf the nano-satellites such as the tissue-box size Sirius recently launched from the ISS. All these “small” satellites still need to be carried above the Earth’s atmosphere by some rocket, but for these Sirius satellites I find their final launch/release quite amazing.

The Sirius “nano” satellite is described in the NASA/AP article as being about the size of box of tissues. “Nano” means one-billionth of a unit, but in this case it is used as a word for tiny or diminutive. The satellite is small enough to be held by one hand. According to the NASA released video (https://www.youtube.com/watch?v=APko4n4H8fc) it has a handle to make it easier to hold and launch.

“OK Sergey, you are a ‘Go’.” says the director. “Hold it by the handle and just deploy it.” And with that Astronaut Prokopyev achieves the dream of every child that has ever tossed a ball into the air; it does not come down. Of course it will eventually come down as gravity (g) plays its ruthless role and overcomes the imparted forces of the velocity (V) of the ISS and the force (F) of Sergey’s “fling”. Eventually gravity will tug the little satellite down into Earth’s atmosphere where it will burn up on re-entry.

But if Sergey was five years old and continued to look up after he had tossed the nano-sat, he would be excited to see the small, gleaming satellite continually traveling away from him until it disappeared from sight.

How thrilling to feel that you have won against gravity.

The picture is based on a Charles Schultz drawing of the ”Peanuts” character Charlie Brown. I know we all wish Charlie Brown the best of luck in hitting the big toss.

Watch for my article reporting back on what the satellite is for. Perhaps we will use a sling shot next time. Why not?

8 BILLION !! What are YOU doing?

By the time we reach the next quarter century World Population will reach 8 BILLION people.

This is a troubling number as each one of us will need food and shelter and health care and should have the opportunity to lead a productive and happy life.

But will we all have that opportunity?

It’s up to YOU!

What are you doing to prepare the world for 8 BILLION? What are you doing to help each man, woman, and child to be fed and sheltered and cared for? What are you doing to help each individual have a life in which they have the opportunity to help their community and to feel the joy of knowing they are contributing to the benefit of others.

During the Renaissance, during the Age of Discovery, during the Reformation, when the French Revolution was taking place, there were less than 1 Billion people on Earth.

But with the industrial revolution and the concurrent increases in the knowledge of science and healthy living conditions more people were being born – and living to be older than in the generations before them. 200 years ago the world population was only 1 Billion. The world passed the 2 Billion mark only about 100 years ago. But by the turn of the century in the year 2000 we nearly TRIPLED that number and we soon passed the 6 Billion mark. Population growth has slowed. But we are still increasing, and by the year 2025 we will reach a world population of 8 BILLION people! And the population will continue to grow from there. Projections of population growth are that by mid-century, in the year 2050, world population will increase by another Billion and we will surpass 9 Billion people on our world.

The increase from 1 Billion to 2 Billion, a doubling, took 100 years. To get from 2 Billion to 9 Billion, more than four times the number, will take less than 200 years. The projections for population increase over the 25 years between 2025 and 2050 are that we will add more than 1 Billion people by mid-century. The 1 Billion increase that took over 100 years to achieve after 1800 will take less than 25 years.

Ask the internet. Ask your neighbors. Ask people where you work. Ask your Government. Ask your church. What can we do – what can I do – so we will be ready?

This is a question for all of us – for you and for me. How am I preparing to help the world at 8 BILLION? And then 9 Billion!

Each of us should rejoice in the Earth. Each of us should go out and experience the world, nature, wild life, birds, crawling things, all of it, including our fellow human-beings.

When we stand in a park or in the woods or next to a flowing stream or pause beside a field of wheat or a bed of sun flowers, we should marvel at it and we should also ask ourselves, “What can I do to preserve and prepare the Earth for all my new neighbors?”

And then act!

The picture of the child is based on a photograph at wallpaperbetter.com.

Keep on Trucking

It happened long before the real “Mr. Natural” stepped into our lives in the 1960s.

A no-name star, perhaps now disappeared over some cosmic horizon, passed through the solar neighborhood and shook things up.

Maybe.

A Space.com article by Meghan Bartels reports on a recent paper published on arXiv.org in which a team of astronomers writes on the possibility of this now long gone star pulling on the early outer solar system and shifting orbits so they are way out of the solar ecliptic plane. The team of astronomers used computer models to study the possibility of the extra-solar visitor – which I am calling Mr. Natural – and the possible results of its passing. Such a pass could have pulled the trans-Neptunian objects (NTO) of the solar system into the eccentric orbits that we can observe today.

Being outside and enjoying what our world offers includes looking up at the night sky. If while looking up at the night sky, we could see the solar system objects that reside beyond Neptune we would see that their orbits are wildly eccentric when compared to the orbits of planets like Earth and Mars. In contrast to our earthly, tight, elliptical orbit of the sun, the orbits for those NTOs are long, stretched-out ellipses. For example, Sedna, which is mentioned in the Space.com article, is a dwarf planet beyond what we would generally consider the edge of our solar system. Its orbit of the sun takes 10,000 years. The closest it gets to the sun is further than 7 billion miles away from the sun. That’s more than 75 times greater than the Earth’s average closest approach to the sun of 93 million miles. Something likely gave Sedna and the other outer solar system objects quite a tug of gravity a long time ago. According to the arXiv.org paper this might have happened as early as 10 million years after the formation of the solar system – which is presumed to be 5 billion years old. So that passing star came and went a long time before the creation of life and a long, long time before even the oldest dinosaur.

The creation of the universe – and of the Earth – and all the life that teems on this Earth is worth considering. When I look at the blossom of a tiny wildflower I can think of its place and my own place in the universe. The flower and I are small parts of the greater cosmos. And we can benefit each other, each giving according to its ability. The flower gives beauty. It accents an open meadow or a shaded woodland glen. It may give nectar to a bird or bee, or be food for the rabbit or the browsing deer. I can see and understand this flower’s part in the greater scheme of life. And for my part, I can be a steward of the flower, and of the meadow, and of the woodland glen. I can respond with joy to the beauty and worth of the flower as well as that of all creation, from this tiny blossom, to the solar system, and to the vast cosmos beyond.

And to Mr. Natural – the presumed passing star of millennia ago – I say “Keep on trucking!”

associated picture is from “Outer solar system possibly shaped by a stellar ﬂy-by”, arXiv.org, S. Pfalzner, et.al., posted July 9, 2018.

Source: https://www.space.com/41212-wandering-star-disturbed-outer-solar-system.html