Sunday, May 20, 2012

Will Future Aircraft be Fueled by Natural Gas?

   If you could really make more economical vehicles, what would you do in order to maximize the impact on our society?  One approach would be to use such technology in an ultra-ultra economy car, such as the so-called Smart Car. It would be one thing if you could get people to trade in their Hummers for such a car, but if you are going to compete against Honda Civics and other traditional subcompacts, it's not going to really be all that much cheaper, in my opinion.  The cost of gasoline is going to be about the same per mile driven, and in fact these cars are not going to be driven much anyway. 

How much of an economic impact will tiny economy cars have?  Some, but not very much.  

   If you were really going to make a serious economic impact, you would probably try to use your more economical technology (whatever it is) on vehicles that really consume a lot of energy, such as taxicabs , delivery trucks, fleet vehicles, city buses, locomotives and even aircraft. These vehicles are used for tens if not hundreds of thousands of miles per year, and so if you really have a way to save money, this is where the big bucks are to be found.  

   In that regard, I was interested to see the Boeing is designing an aircraft that would use liquefied natural gas (LNG) in place of jet fuel. Published articles are focused on a very advanced concept in which the LNG would actually be frozen.  That offers the highest performance, but even using today's technology (cryogenic liquids), using LNG in aviation should be a no-brainer.  LNG has more energy per unit weight than gasoline (54 MJ/kg versus about 44 MJ/kg for current aviation fuel).  This extra bang per unit weight means that planes are going to weigh less and travel farther and faster than they can today. Plus natural gas combustion emits less carbon than current jet fuel, it's cleaner than petroleum, and it is about half the cost compared to  aviation fuel. 

    Plus, if you want to continue to rely on petroleum fuel, you have to buy it from countries run by idiots, who like threatening the US with nuclear warfare among other things.  What a great idea that is!
   Nevertheless, a great number of Americans believe economic growth is bad for the economy, and moreover they are very comfortable with an occasional ten-year war in the Middle East.  On that basis, there will no doubt be considerable opposition to switching to LNG fuels, as we continue our policy of supporting corrupt foreign despots whenever possible.  Nevertheless, my guess is that common sense will prevail,and thus it will probably happen sooner rather than later. 

If the world starts using liquefied natural gas for aircraft, it's going to be cheaper and faster to fly. 

Post Script

For what it's worth, the modifications needed to run a turbine on natural gas instead of liquid jet fuel are relatively simple, and in fact in the 1990's the Soviet Union built a modified Tupolev 155 jet aircraft that ran on natural gas.  So don't even try to say that it can't be done.  It can be done, and it is a straightforward conversion. 

The use of natural gas for a jet aircraft was successfully demonstrated on a Tupolev 155.

For additional reading:

Andrew Webster, Boeing's SUGAR Freeze plane concept runs on cryogenically frozen natural Gas, The Verge, Mar 21, 2012,

Saturday, May 19, 2012

The Rising Fastball-Myth or Fact?

     "Nolan Ryan has two out in the ninth inning, oh and two on Reggie Jackson.   Here's the windup...and the pitch....STRIKE THREE ON A RISING FASTBALL!!"

 Robin Ventura offers his theory to Nolan Ryan that there is no such thing as a rising fastball. 

    Or was it?  This has been a debate for many years, with technology seeming to support those who believe that baseballs do not rise. Physicists have weighed in the analysis.  Even Mythbusters, one of my favorite shows, did a segment which says that the ball does not rise. 

   However, let me offer a bit of a rebuttal.  First, as a physicist of sorts, let me offer some advice on when to trust physicists.  

   a.  Trust them to determine nuclear transitions, discover quarks, design semiconductors, estimate the age of the universe or measure spectra of atoms.

   b.  Do not trust them to change a light bulb,  select a restaurant for dinner, and never ever let them jump start a car.  And do not trust their opinions about sports. 

   Physicists, you see, do not become physicists because they love physics.  They become physicists because no one will pay them to play sports, and they have no other way to attract a mate.  

   Historically, if you go back 80 years ago, physicists used to argue that there was no such thing as a curve ball, because their simple models didn't predict that.  They tried to argue that it was just an optical illusion caused by the spin of the ball.  Hah!  Later on, the aerospace engineers used wind tunnels and measured the rotation rate of the baseball and calculated that in fact baseballs did curve. Today there is very little doubt that balls do in fact curve. 

    Back in the day, the Village Elliot used to play baseball, as ridiculous as that may seem to anyone who knows the rotund research scientist now.  He never had any real ability to play except for one thing:  he could visually track an 80 mile an hour (amateur level) baseball as well as anyone, and thus was a respectable contact hitter even after age 40.  And I know darn well that there IS such a thing as a rising fastball and that it is not an illusion.  If you don't believe me, go to your local amateur league and try to catch one of these kids that throws at near-professional velocity.  Ask for the four seam fastball and see if you don't wind up catching it in your teeth.
   When I played baseball, we had a kid named Brian Rasay who had pitched for Cedarville University and he definitely threw a hard riser.  I wouldn't catch him without a catcher's mask for that reason.  

   So what gives?  I think first of all, the physicists need to ask what defines the "straightball."   A trivial case would be an underhand fastball, which starts out from a release point of a foot and which can obviously be thrown with an upward trajectory.  But that is not what is meant by a rising fastball.

    The "straightball" would be thrown on a downward trajectory.  
Keeping in mind that the pitchers' mound is about a foot high, the release point may be around six to six and a half feet for a typical (overhand) pitcher, relative to the batter.

Here's a graphic of Brandon Morrow of the Blue Jays, from an excellent article by Mike Fast in Baseball Prospectus,

     Now the batter calls it a straightball if the ball comes in at belt high, or about 3 feet from ground level, without any additional weird movement.  Obviously, the ball is travelling down about 3 or 4 feet.  

    The physicist can note at this point that the actual trajectory is kind of a parabolic path, with some correction because air resistance slows down the ball a few mph on its way to the plate.  Given that a pitched baseball has a speed of 95 miles per hour, the predicted effect of gravity is that it will deviate by about 1 meter (3 feet) by the time it gets to home plate.  The effect of air resistance is that it will slow down a tad as it gets closer to the plate.  So in other words, the initial trajectory is such that the fastball starts out as if it is going to pass six feet above home plate, but it actually winds up at the three foot level.  The baseball pitcher does not need to study physics to figure this stuff out.  He knows from experience where to release the ball to put it where he wants it.  Similarly, the batter is not a physicist and does not get out a calculator to determine the trajectory of the ball.  He knows what the ball looks like and how it should behave.  The point is that "straight" is defined in some kind of modified parabolic coordinate system, which is simple to the ballplayer but very complicated to describe using mathematical physics. 
    What about the effect of spin?  The four seam fastball has maximum air resistance because of its orientation, and if thrown by an overhand pitcher, has a backspin, which results in an aerodynamic force being put on the ball.  The aerodynamicists estimate that the Magnus force on the four seamer is probably about half the force of gravity, and would result in the baseball changing its trajectory by about a foot and a half by the time it crosses home plate.  This is comparable to the distance that a curveball can move, incidentally.  

  The Magnus Force is known to affect the trajectory of spinning baseballs, including the curve ball...AND the rising fastball. 

The Magnus force causes the ball to deviate from the normal trajectory by as much as a foot and a half. This is a real effect, not an optical illusion.  However, since the ball is thrown from a release point of about six feet above the ground, the physicist is probably right that it does not actually have a net rise with respect to ground. 

In Cartesian Coordinates, the normal fastball travels downward from the pitcher's release point to the strike zone, and follows a roughly parabolic trajectory.  The riser has less of a downward break. (the y-scale is exaggerated).

Referenced to the "normal" trajectory, the riser's trajectory can be altered by about 1.5 feet due to the Magnus effect. (y-scale greatly exaggerated). 

   So, the altitude of the baseball does not go from level flight to a rising trajectory.  So if that's how you want to define the rising fastball, it does not exist under normal conditions.  But that is not right way to look at the problem, as baseball players can automatically view the "straight" trajectory in distinctly non-Cartesian systems.  So if you are going to call the rising fastball unreal, the "straightball" or flat trajectory is even more unreal.  
  So I think that the physicists have actually calculated the right answer, but interpreted it incorrectly.  The point is that aerodynamic forces can in fact cause a well pitched four seamer to cross home plate at a higher point than a normal two-seam fastball, by about a foot and a half.  It is not an optical illusion. It is a physical change in the trajectory caused by its spin and orientation.    It is usually not a net rise, however, because the pitcher's release point is about six or seven feet above the elevation of home plate.  

    Let me add one trivial point.  If the pitcher is a submarine (underhand) pitcher, with a release point about two feet above the home plate level, do we mean to say that the ball cannot be thrown up around the letters?  Of course not.  The pitcher can throw the ball with an upward trajectory and the ball clearly rises.  The physicist should not be locked into the math to miss the point that the initial trajectory can be upwards.

     So, in summary, the rising fastball is not quite a myth. The elevated mound and the preferred release point of most pitchers ensures that a pitch thrown for a strike is basically downward.  With a hard backspin, the four seamer can deviate from its normal trajectory by as much as a foot and a half by some credible estimates.  This is rising action relative to its normal trajectory.  Moreover, if the pitch is thrown from a low release point (i.e., underhand), it is trivially obvious that the ball can have a net rise by the time it crosses home plate.  The physicists are correct, however, that a pitch thrown from an overhand pitcher to the belt level of the batter does not actually have a net upwards trajectory relative to the level of home plate.  

Saturday, May 12, 2012

The Medieval Warming Period and the Climate Stasis Hypothesis

 Did Eric the Red really colonize Greenland?  If so, was the weather warmer back then, or was it all a conspiracy?

    The historicity of the Medieval Warming Period is a minor controversy these days.  Almost everyone accepts the data from the 20th Century which shows that global average temperature has increased by about 1.0 degrees Celsius since about 1908.  By the same token, there is only a minor embarrassment that the temperature rise leveled off from about 1946 through 1975, and that once again the temperature rise has slowed since 2002.  This data is not in serious dispute, or at least it is not disputed by the Village Elliot. 

   Given that global temperatures have risen, the next question is whether human activity has been the primary cause.  Conventional wisdome is that human activity is absolutely implicated, based on the presumption that the average temperature of the earth has remained constant, plus or minus about 0.5 degrees Celsius, for thousands of years (referred to as the Climate Statis hypothesis; i.e., that climate change is definitely not natural or at least not on the timescale of "only" 100 years or so).  Hence a temperature rise of 1.0 degrees Celsius is too much to attribute to non-anthropogenic causes, and thus the CO2 Greenhouse Effect can safely be identified as the sole cause for the temperature rise.  Moreover, many mainstream climatologists argue that the world is headed for a climate catastrophe, and major changes are required in the global hydrocarbon economy in order to avert disaster.  

    The Village Elliot is not on board with some of these key principles, despite the fact that the persons making these assements are much better qualified and well studied in these matters.  In particular, I suggested in my last blog that historical climatology is basically blind as a bat if it could not see much unusual about 1816, the Year Without a Summer, in which snow fell year round.  It is thought that tree ring data provides information about the temperature in any given year, which I find amazing, given that on three continents trees reportedly failed to even grow rings that year because they stayed dormant.  The cooling of 1816 was caused by a massive volcanic eruption at Tambora, Indonesia and does not directly affect the CO2 Greenhouse hypothesis.  It does call into account whether the historical records of the 19th century are worth a darn, and specifically whether they allow us to rule out climate change caused by factors other than carbon dioxide.  

    Let us then turn our attention to the Medieval Warming period.  As is the case with the Year Without  a Summer, the Medieval Warming period used to be a historical fact.  Eric the Red colonized Greenland  at the end of the 10th century.  The Vikings flourished there, so that by the 13th century there were over 3000 colonists in 300 farms.   

Some historians have suggested that Eric named Greenland simply as a propaganda ploy to attract new residents.  Maybe so, but someone had to convince crops to grow in a short growing season, and people and livestock to not freeze to death once they did settle there.  These seem close to being historical facts which can not be easily overturned. 

Yet, according to conventional wisdom, global average temperatures changed only slightly during this period, and even the localized temperatures in the North Atlantic were cooler than they are today.

The Village Elliot wonders how this could be true.   Even with today's agricultural technology, it is very difficult to farm in Greenland.  To think that thousands of Vikings could be farming in a wintry wasteland does not make sense.  Morever,  Antactic Ice core data supports the notion that this period was indeed warmer than the later period.  This, plus the general dominance of the Vikings during those centuries, strongly implies that the temperatures were much warmer during that period.

Moreover, the Vikings were not the only group that settled Greenland.  It turns out that the aboriginal Tuniit and Inuits also greatly expanded their territory in Greenland coming from from the northwest, and thrived for a time before receding significantly during what historians can the Little Ice Age (but which most climatologists call a 0.5 degree temperature dip).     

Why it Matters

   The existence or nonexistence of the Medieval Warming period does not contradict the reality of the CO2 Greenhouse effect.   Rather, the reality of absorption of thermal energy by carbon dioxide is pretty much undisputed.   The advancement of the Climate Stasis hypothesis, or the notion that the climate never changed much prior to the 20th century. mainly serves to confuse the modelers and perhaps impart some errors into the assumptions that go into current climate models.  Namely, we may be left with a model of a robust terrestrial climate, which suggest that the earth's average temperature is not strongly affected of volcanos such as Tambora.  The models further suggest that the Year Without a Summer and the Medieval Warming Period never happened, or at least that they were greately exaggerated.  Hence this might lead to understimation of effects other than carbon dioxide.  Moreover, most climate historians seem content with the view that recent climate has been fairly static. 

   The Village Elliot, however, is a habitual contrarian.  Certainly I do not have the tools to prove or disprove the consensus views of professional climatologists.    Nevertheless, in my opinion--and it's just an opinion--future  more objective reviews of history will lead probably climatologists to conclude that there are indeed other factors worth worrying about in addition to  carbon dioxide.   From the standpoint of politics, however, this is a heretical prediction, as we've pretty much settled on a policy of reducing carbon emissions even if it retards economic growth.  

Oct 30, 2012 Post Script:  It turns out that at least one recent peer reviewed study in fact has in fact vouched for a warmer Warming Period and a cooler Little Ice Age.  You may read about  it here:

Additional Reading

Check out the present average monthly temperatures in Greenland, and tell us how Vikings were able to grow crops there if the temperatures were lower in the 10th century than they are now...

Kim, B.; Yoon, Ho Il; Kang, Cheon Yun; Bahk, Jang Jun (2002). "Unstable Climate Oscillations during the Late Holocene in the Eastern Bransfield Basin, Antarctic Peninsula". Quaternary Research 58 (3): 234

J. Fabres et al., Branfield Basin fine-grained sediments:  Late Holocene Sedimentary Processes and Antarctic Oceanographic Conditions, The Holocene vol. 10 no. 6 703-718

Intergovernmental Panel on Climate Change Working Group I: The Physical Science Basis of Climate Change    

Climate Change in the Baltic Sea Area, HELCOM Thematic Assessment in 2007, Baltic Sea Environment Proceedings No. 111 Helsinki Commission, Baltic Marine Environment Protection Commission


Saturday, May 5, 2012

Stan Lee is a Mutant


Today I tried to take my daughter to see The Avengers (well, actually, she was taking me).  We went to the local theater, that had something like 20 showings scheduled, but they were sold out and there was a line about a mile long.  I don't know much about movies, but it looks to me like they have another Mega-hit on their hands.  Like, Marvel Comics might make as much money as some entire nations.  

    What is even more amazing is that the amazing characters of Marvel Comics were created by Stan Lee, who has been doing this since 1939!  1939?  That couldn't be right, could it?   That would mean the guy has been working on comics for 73 years???  He would have to be a mutant for that to be true.

    Well, that's exactly right.  Stan Lee started to work as a child prodigy at the age of 17, at which time he created Captain America, the Human Torch, Prince Namor the Sub-Mariner and others. Now, as a cheery 90 year old, he's still at it. Along the way, he created Thor, Spider-Man, Daredevil and probably a thousand other amazing characters and super villains.  It's incredible to think about doing something you love for such an amazing long time. 

Stan’s superheroes were different from DC Comics’.   Marvel superheros had real problems, ranging from money worries to girl problems, and an occasional hangover from getting too much radiation.  Superman and Batman, on the other hand, were basically super-strong boy scouts in tight longjohns.  Plus, characters like Superman were kind of boring because they had no limitations.  Face it, Superman could fly into the sun and destroy entire planets if he wanted to.  That just didn't make much sense after a while.

   By contrast, Stan Lee created a drama of misunderstood super powered mutants trying to be accepted in a world that just doesn’t seem to care.    That seems to be a theme that others can relate to on some level.  Maybe at times we have all felt that we had some special power or goal in life, only to have it attacked by an ignorant and prejudiced world.   
   Spider-man, in particular, was always going through some kind of crisis.  Poor guy!  If it wasn’t his girlfriend getting mad at him, it was Aunt May having a heart attack, and it was always his fault.  All he wanted to do was save the world...!

 Guys, would you rather have Nastasha (Black Widow) Romanova for a girlfriend, or Lois Lane?  

    Stan must be the most prolific writers of all time. It's one thing to simply create all those characters, but he also wrote stories, dozens per month, for the better part of a century.  Incredible! Definitely, he has to be a mutant, for no one could be that prolific unless some type of super power is involved. 

   One of my professors in Seminary, Tom Boomershine, used to argue that stories of superheros have their roots in the apocalyptic literature in the Judeo-Christian tradition.  Heros like Daniel or Enoch (especially in the non-canonical literature) have some similarity to Peter Parker or Steve Rogers, in that they visit strange new worlds and encounter supernatural creatures.  We tend to view the Biblical stories differently because some of them, after all, are part of the Bible, but from a literary point of view there are some common themes.  These may teach us, in some way, about our own nature.
   My eighth grade English teacher, Mr. Stanton, was appalled by my suggestion that William Shakespeare was simply creating popular entertainment at the Globe Theater, and that nobody recognized that it was great at the time.   Thus, by the same token, popular television shows (like Star Trek) might someday be ranked alongside Shakespeare. Poor Mr. Stanton.  He about passed out at that suggestion, but the fact of the matter is that Star Trek has indeed been enormously influential in the world culture.  

 Stan Lee’s creations are in the same category, and based on early returns, it may be that the latest superhero movie may be ranked among the most popular in world history.  At some point, people are going to have to evaluate the impact of such works on society as a whole.   I hope we don't start worshipping them, but I've seen stranger things in this world.

 I might have expanded that argument to include Stan Lee’s creations, which are going to reach audiences far larger than Bill Shakespeare has.  I believe that people will be discussing Lee’s genius in the 25th Century, along with Billy Shake and others.  Moreover, people will certainly recognize the names William Shatner, Patrick Stewart and Toby Maguire.  Not sure about Richard Burbage, though. 
    Well one of these times, my daughter and I will get to see the Avengers.  I can’t wait.  
Post script
   Well this time the nine year ond I  made it to the show.  It did not disappoint, despite the enormous buildup I gave it.  It lives up to the hype.   The movie succeeds not only in amazing special effects, but also develops the personalities of the superheroes.  I like brilliant inventor Tony Stark (Iron Man), and red blooded true American Hero Steve Rogers (Captain America) the best.  They tend to butt heads a bit.  I think Iron Man is a Democrat, but Captain America is a Republican.  

    The high tech military stuff is incredible.  Basically everything we ever thought of at Air Force Research Labs and then some, it is an engineer's dream.   But ultimately it came down to great acting and the interaction between the characters that outweighed any special effects magic.

    Not sure if the movie reached Shakespearian levels in poetry or plot development, as I had suggested it might.  Nevertheless it will likely have  a certain impact on society.  In particular I think if I were a would-be terrorist, I would hesitate to take on people that make movies like this.  

   On the other hand, The Avengers  is most assuredly not a comedy but there are a few scenes that made me laugh as hard as any movie I have ever seen.  I won't give them away; you'll have to see the movie yourself. 
    Also, if you're thinking about taking kids to see it, my nine year seemed to do okay with it.  It was very intense and the special effects were very exciting, but for the most part it was not really gory or upsetting.  However, the six year did not see it, and I'm sure that was the right call.  He was better off watching the cartoon pirates movie.