Month: March 2015

Magnetic Reconnection & Why it Matters to You

Recently, NASA launched the Magnetospheric Multiscale (MMS) mission to detect a phenomenon known as magnetic reconnection. Unless you have taken a course in space physics, chances are you have not run across the concept. However, magnetic reconnection plays a key role here on Earth as well as throughout the universe. To understand why NASA wants to learn more about reconnection, we’ll start off with a few basics.

All magnetic fields are dipoles, that is, they have two poles, north and south. The flow of the magnetic field runs from the North Pole to the South Pole. The Earth itself acts like a giant bar magnet. The Earth’s magnetic North Pole lies near the geographic South Pole and vise versa. Hence, geographically, the flow of Earth’s magnetic field runs from south to north as seen below:

Courtesy: NASA

Three things to consider regarding electric and magnetic fields:

A changing magnetic field creates an electric field.

An electric current creates a magnetic field.

A particle with an electric charge will travel along the path of a magnetic field line.

Space itself consists mostly of particles with an electric charge called plasma. The intense heat of the Sun separates the atomic bonds between electrons (negative charge) and the nucleus that has protons (positive charge). Thus, normally electrically neutral atoms are broken apart and spread throughout the Solar System as an electrified gas (plasma) via the solar wind.

The Sun’s magnetic field is embedded in the solar wind and expands past the most distant planets. This magnetic field is thus known as the Interplanetary Magnetic Field or IMF. As this plasma travels out into the Solar System, some of it will encounter the Earth’s magnetic field on the day side. This is one of two areas where reconnection occurs around Earth.

Reconnection is when the IMF field lines merge with the Earth’s magnetic field lines to transfer mass and energy from the solar wind into Earth’s magnetic field. The possibility of reconnection is most strong when the IMF and Earth’s magnetic field lines flow is opposite of one another. Remember that Earth’s magnetic field flows from the geographic South Pole to North Pole. Thus, reconnection occurs most often when the IMF is flowing southward.

In physics, the letter B signifies a magnetic field. A three dimensional coordinate field is signified by the letters x, y, and z. The z-axis is up and down with negative z values running southward. When the IMF has a strong negative Bz direction, this means the IMF is flowing opposite of the northward flow of the Earth’s magnetic field and the potential for reconnection is high.

So why does any of this matter to us? When reconnection occurs the probability for magnetic storms on Earth is high. These storms create the aurora, which is the most aesthetic feature of these events. The plasma from the IMF is transferred to the Earth’s magnetic field during reconnection and follows the solar wind over to the night side.  Here, reconnection occurs a second time as the Earth’s magnetic field is stretched out by the solar wind.  Opposing magnetic field lines reconnect and unleash plasma at a high velocity.  The process is diagrammed below:

mms_graphic

Courtesy: NASA

The unleashed plasma then follows the Earth’s magnetic field lines into the Polar Regions. Unabated, the kinetic energy of these particles would be harmful to life. However, oxygen and nitrogen atoms in the upper atmosphere absorb the kinetic energy lifting their electrons to a higher energy orbit. When the electrons recede back to a lower energy orbit, the harmful kinetic energy is converted into harmless light radiation resulting in the aurora at the Polar Regions.  The aurora as seen from the International Space Station is below:

The story does not end there. As mentioned above, a changing magnetic field produces electric currents. Reconnection causes disturbances in the Earth’s magnetic field that can induce electric currents in both orbiting satellites and ground based power grids. These currents can cause expensive damage to electrical systems. A better understanding of the process of reconnection can provide more accurate forecasts of magnetic storms. These forecasts can inform satellite operators when to go into protective shutdown mode to prevent damage and allow power grids to take preventative action against blackouts.

The potential for damage is not insignificant. The 1989 magnetic storm caused a blackout across Quebec for nine hours. During that event, auroras were seen as far south as the Gulf Coast. The Carrington event of 1859 was much stronger than the 1989 storm. The electrical currents induced by this magnetic storm were so strong that telegraphs were able to operate even when disconnected from their batteries. A similar event today would, of course, result in much more significant damage given how much more reliant we are on electronics than in 1859. This is the most pressing reason NASA wants to understand the nature of reconnection. There are many other astrophysical applications as well.

The MMS Senior Project Scientist Tom Moore describes how the mission will research magnetic reconnection below:

The MMS mission will cost $850 million.  To put that in perspective, it cost $1.6 billion to build MetLife Stadium and $1.3 billion for the luxury high rise at 432 Park Avenue.  Space is not cheap, but not more expensive than major construction projects back here on Earth.

Replicate, Replicate, Replicate

Typically, during grade school we are introduced to the scientific method with the following steps:

Hypothesis

Gather Data

Experiment – test hypothesis

Reject or accept hypothesis

However, there is one extra step that is very important and that is replication of the original research result. Replication of results never gets the headlines, or wins a Nobel, but without it, science cannot advance. This is a vital, if often overlooked, aspect of the scientific process that guards against fraudulent work and/or erroneous findings. One such example of the replication process nullifying an original research result is the vaccination/autism link. In the late 1990’s, a research paper was published indicating a link between vaccinations and autism. Those results could not be replicated independently and were later discovered to be fraudulent.

Another controversial science paper was published around the same time as the fraudulent vaccine/autism study. That being, the hockey stick graph indicating a rapid rise in global surface temperatures during the 20th century. Unlike the vaccine/autism link, the hockey stick result was replicated independently. Also, an investigation of fraud charges against the author, Michael Mann, cleared him of any wrongdoing. Hence, the vaccine/autism link was fraudulent science that is not valid, but the hockey stick graph is a valid result confirmed independently and cleared of fraudulent charges.

In astronomy, the replication process recently nullified a discovery that attracted quite a bit of publicity. In 2014, a team of astronomers announced the detection of gravity waves in the cosmic background radiation left over from the Big Bang. This had huge implications, as this would have confirmed the inflationary model of the Big Bang as well as gravity being transmitted via waves as predicted by Einstein in 1916. However, the replication process determined the signal the team detected in the form of polarized light was actually caused by dust in the Milky Way.

It happens, another case was the exoplanet Gliese 581g. When discovered, it was thought to be a habitable planet and garnered quite a bit of press coverage. However, subsequent observations determined the signal received was caused by hyperactivity of the star itself and not an exoplanet at all. Nor is this restricted to the natural sciences. In economics, there was a notable failure to replicate a research result that had significant policy implications during the height of the worst economic downturn since the Great Depression.  As you can tell, a failure to replicate does not necessarily mean the original work was fraudulent, sometimes it is caused by a breakdown in methodology or misunderstanding of cause and effect.

All this can be very confusing to students and can lead to disillusionment with science unless the process is understood properly. We cannot be experts at everything, so how do we know if a scientific report is trustworthy or not? How do we know if that latest nutrition study the press is hyping will pan out in the long run? I tell my students to see if the results have been verified independently. For example, the link between lung cancer and smoking has been replicated by many studies and thus, can be trusted to be quality info. That is the hallmark of good science.

The lesson here is, never jump on an initial finding (no matter how interesting) as a conclusive result. Best to wait for replication of the original study as confirmation of those results.  Failure to do that with the autism/vaccine link has caused a significant increase in measles cases the past year.  And as we have discovered, once a concept gets lodged in a mindset, it can be very difficult to dislodge it.

So, another bit of advice on how to do good science. If we develop a “rooting” interest in a scientific result as we do at a sporting event or in politics, we have already gone off the rails are far as the scientific method goes. Nature will not bend to our wishes. We can only employ the scientific method to understand it better.

*Image at top of post is replication of Mann’s hockey stick graph courtesy NOAA.

Solar Eclipse

For those of us unable to make it to the North Atlantic here is a most excellent video of totality during today’s eclipse.

I have to say, the Faroe Islands would have made for a great trip to view this eclipse.

Here in the U.S. we will have an opportunity to view a solar eclipse on August 21, 2017.  The path of totality moves from the Northwest, across the Midwest, and finally South Carolina before heading out into the Atlantic.

In 2024, my hometown of Buffalo, NY will experience a total eclipse on April 8th at 3:18 PM.  Totality will last almost 4 minutes.  Below is a map of totality for New York State.

eclipse

Horseshoes and Hand Grenades

Sports quotations often find their way into the classroom and the workplace. Usually it is the hackneyed kind such as the one this post is named after and is of little value. However, if you dig into the work of the most successful coaches there are often little nuggets that go way beyond the value of say, “Giving it 110%.”

Bear in mind, for all the publicity and money athletes make, the work your students will do in their lives will have much greater impact on society than most sports figures. If the Seahawks gave the ball to Marshawn Lynch and he crashed into the end zone at the end of this year’s Super Bowl, outside the NFL bubble, it really would not have changed anyone’s life. That is not the case for a paralegal taking information for a legal case, a business manager making decisions that will affect the company’s employees, or a nurse taking care of a hospital patient.

That being said (another cliché) here it goes:

Red Auerbach: “It’s not what you tell your players, its what they hear.” In the book, On & Off the Court, Auerbach tells the story of his first few days as a coach at St. Albans Prep in D.C. After the first three days of practice, Auerbach realizes his players are not absorbing the techniques being taught. Finally, he pulls the team aside and says, “The object of the game is to take this ball and stick it into the hole over there…and make sure the other team doesn’t stick the ball into this hole over here.” A teacher has to meet the students on their level.

Earl Weaver: As described by Bill James in the book, Guide to Baseball Managers, Weaver was not interested in what his players could not do, only in what they could do. I tell my students that I do not want them to think about what they don’t know or are unable to do. The focus in the class should be on what they do know and can do. That is used as a foundation upon which to build their knowledge of the subject.

Bill Polian: “Ignore the noise.” In The Game Plan, Polian recalls the decision to draft Peyton Manning over Ryan Leaf. At the time, the consensus in the media was that Leaf was the better prospect due to his physical stature. However, Polian had interviewed and observed private work-outs with both quarterbacks. The information culled from these sessions made it clear Manning was the better pick despite all the howling it would bring from the fans and media. For your students, remind them not to be swayed in their decision making by those who do not have all the facts, no matter how loud they may be. And that leads to:

Chuck Noll: About Three Bricks Shy of a Load is, to this day, the best sports read I have come across. In it, Noll describes his decision making process as follows: “I don’t like to speculate…I like to make decisions based on real facts, and if you haven’t got enough facts to make a decision, you obviously can’t make it.” You might get lucky making a single gut-feeling decision, but not over the course of a lifetime. The process of decision-making should be based on facts and information rather than a feeling what might be the best way to proceed.

Vince Lombardi: From When Pride Still Mattered, former Packer lineman Bob Skoronski describes a speech Lombardi gave to his team on the meaning of love. It went, “Anybody can love something that is beautiful or smart or agile. You will never know love until you can love something that isn’t beautiful, isn’t bright, isn’t glamorous. It takes a special person to love something unattractive, someone unknown. That is the true test of love. Everybody can love someone’s strengths and somebody’s good looks. But can you accept someone for his inabilities?” Given the caricature of Lombardi we have been presented with, it’s hard to imagine him saying this. But then again, would Lombardi have been able to motivate his players year after year by simply yelling at them? Lombardi obviously had more going for him than that. And you’ll need more going for you than that in any sort of leadership position.

It’s easy to be dismissive of sports culture given the scandals of recent years. And sports alone will not prepare one for life. The fact that 78% of NFL players file bankruptcy within two years of leaving the game makes that painfully obvious. However, as in most things in life, if you look deep enough, you’ll find something useful. In the big picture sports are not everything, as Marv Levy once said, World War II was a must win. Nonetheless, coaches are teachers, and the best will have techniques and philosophies that can be applied in the classroom and in life.

Remagen

March 7th was the 70th anniversary of the capture of the Ludendorff Bridge crossing the Rhine River at Remagen. Hitler had ordered all the bridges across the Rhine to be demolished to stop the American advance into Germany. The U.S. Army 9th Infantry Division managed to capture the bridge while the German Army was attempting to blow it up.

Remagen
Ludendorff Bridge, 1945. Photo: National Archives.

General Omar Bradley said the bridge was worth its weight in gold as the American Army poured personal and equipment across the Rhine. In fact, so much tonnage crossed the bridge the overuse caused its collapse ten days later.  Twenty-eight were killed during the collapse which is described by Army Engineer John Morgado below.

The Third Reich would end exactly two months after the capture of the bridge.

Remagen Bridge Today
Ludendorff Bridge, 2011. Photo: Gregory Pijanowski

The bridge itself was never rebuilt.  However, the remaining bridge towers are now home to the Remagen Peace Museum. I highly recommend a visit if you find yourself in that region of Germany. Remagen is now a peaceful river town and it is difficult to image all the violence that took place there seventy years ago. However, sitting on a bench on the riverside by the bridge allows one to quietly reflect on the events there that helped end one of the most hideous chapters in human history.

Winter and Global Warming

February clocked out as the coldest month in Buffalo history at 10.90 F. Besides the grumbling about dead car batteries, heating bills, and snow-clogged streets, there are the usual doubts about global warming. In this kind of scenario, how does one address the topic with your students? For starters, do not be dismissive of their qualms. Your students are applying their life experience to reject the concept of global warming. As a teacher, you must utilize your student’s life experience to understand the concept that temperatures are rising globally even while they are shivering on the way to school locally.

The first step is to have a discussion session. The goals of this discussion should be two-fold. One is to expand the student’s perspective beyond a regional basis. Ask the students if they have ever vacationed in Florida during the Spring break. What other travel experiences have they had? Did they note a change in the weather when they traveled? It does not necessarily have to be very far. New York City and the East Coast can be significantly warmer than Buffalo, especially in the Spring.

The second set of questions in the discussion should be geared towards jarring your student’s memories to get a bigger picture on climate. In the case of Buffalo, students can be asked if they recall March of 2012. That month featured 8 days of 70 degree weather and 3 days over 80 degrees. When addressing the issue of climate change, it is important to pull your students out of the here and now. What is happening regionally cannot be extrapolated globally and what is happening now may very well be ephemeral in nature.

This sets the stage for an examination of weather vs. climate. Again, drawing upon a student’s interest may be helpful. If the student is a baseball fan, explain that a game box score is like weather and a batter’s career average is like climate. In the case of Derek Jeter, the 0 for 4’s, 2 for 5’s, 4 for 4’s that show up in the daily box scores is like weather. Jeter’s career average of .310 is like climate. One could take a look at Jeter’s game log from the 1999 season when he hit .349. Twenty-three times that year Jeter went 0-fer. Would one conclude from those games that Jeter was a poor hitter? Should one conclude from a few cold days the climate is not getting warmer or is a larger sample required?

Following this prep work, now is the time to delve into some inquiry based learning. Teaching in Buffalo, I would have the students graph out average annual temperature from 1950 to 2014 and add a moving 5-year average to smooth out the noise. The result is below:

Buff Temp

It is very important to stress this chart does not prove or disprove global warming as the sample size is too small. It is only intended to familiarize the students with the nature of climate vs. weather.

Again, a follow-up discussion with the class is required. What is the average annual temperature in Buffalo? What is the difference between the mean temperature and highest and lowest annual temperature? If the climate were to warm more than 40 F, how would that compare to the hottest year on record? How does 2014, which also featured a very cold winter, compare with other years on the chart? Is there a change in the variations in average temperature after 1980 and is that predicted at all by climate change theory?

Besides getting a feel for the nature of climate statistics, this exercise is intended to enable the class to discern between outliers and trends. Go back to the Jeter example; his 0-fers were outliers (unfortunately, for this Red Sox fan) and were not indicative of his overall hitting skills. This will come up time and time again as climate change contrarians make their case by using outliers. The most recent example is the expanding sea ice in Antarctica, which is a regional phenomenon as ice coverage is declining on the Antarctic continent, in the Arctic, and in mountain ranges around the globe.

At this point, the class should be prepared to deal with global climate. The NASA Climate Change website is an excellent resource for this (A word of caution, global temperatures use Celsius rather than Fahrenheit). The class can explore how the change in Buffalo matches or departs from global climate change. Does the post World War II dip in temperature match what happened globally? Why might that be the case? Does what happened after 1980 match? How about the brief dip in the early 1990’s? What might have caused that? Allow your students to construct their own knowledge of what is happening with the climate. The main objective for the teacher is to ensure the students are applying the Richard Feynman adage, nature will reveal itself to us as it is, not how we wish it to be.