Much Ado Podcast with Lisa and Tom

My wife, Lisa, and I just started a new podcast called the Much Ado Podcast.  We have released two episodes so far.  The focus will be books we are reading and TV shows and movies we are watching, but these are just jumping off points leading to discussions of many other topics that interest us.  Some things we have talked about so far include neuroscience, the Hollows book series by Kim Harrison, the Twilight books and movies, the Monte Hall problem, American Idol, Fringe, Worst Ideas Ever, and the Game of Thrones.  If you are a TV or movie junkie or if you like to read this podcast may be of interest to you.  Lisa primarily reads fiction and I primarily read non-fiction so between the two of us we cover a broad array of interests.  I have posted a permanent link to our podcast on the right.

Conquering Mount Wilson

Ever since I moved to Southern California I have wanted to climb Mount Wilson.  Edwin Hubble discovered the expansion of the universe in 1929 using the observatory on Mount Wilson.  From the trail head in Sierra Madre it is a seven mile hike with a net vertical climb of about one mile.  I have started up the trail twice before with my kids, but only made it as far as First Water, 1.5 miles from the start.  The first time, we had to turn around before First Water because my then 12-year-old daughter did not wear socks.  The second time, I went with my two youngest sons who were 18 and 16 at the time.  I wanted to get at least as far as Orchard Camp, 2 miles beyond First Water, but my 18 year old prevailed in encouraging us to turn around after we reached First Water.

On Saturday January 5, 2013 my youngest son (now 18) and I made our third attempt.  This was actually our first serious attempt.  We never intended to push all the way to the summit the two previous times.  We only wanted to familiarize ourselves with the trail and go on a short hike.  We had no idea what to expect beyond First Water, except for the information we could glean from reading the blogs of other hikers that my wife found for us.  Our research seemed to indicate that many hikers only hiked up and then got a ride at the top.  We planned to hike up and back down for a total of 14 miles.  At least two blog authors actually hiked 18 miles because they could not find the continuation of the trail after the toll road and were not convinced that a 7-mile route to the top existed.  It was good that we read these blogs so that we could be alert to find the trail off the toll road and ask questions of other hikers.  It is an easy mistake to make.

The weather was clear the day of our hike.  The temperatures were mild for this time of year.  The high on Mount Wilson was expected to be 50 degrees while the high at the trail head in Sierra Madre was in the 60s.  We started at 7 a.m. when the temperature was about 38 degrees.  The cool temperatures allowed us to carry less water than a summer hike would have required.  We carried 2 liters each.  For food, we each packed two peanut butter sandwiches, two snickers bars, and trail mix.  This all turned out to be adequate, although by the end of the hike I wished that I had brought another liter of water.  On the other hand, my son only drank about 1.5 liters.

I will share just a bit of information about us so that our perception of the difficulty of this hike can be put into perspective.  I am 49 years old and need to lose at least 30 pounds, but I am quite active.  I exercise about an hour daily with a routine that includes resistance training and running anywhere from 3-7 miles.  I have run as far as 12 miles, but not recently.  My son was on his high school cross country team, but he has just recently recovered from a stress fracture.  He has been able to get back to running only about a month before our hike.  I ran two 5K races this year and my best time was 28:30.  My son's best 5K time is around 22 minutes.

Since our starting time was roughly at sunrise, I figured that we needed to turn around by noon to make it back before dark.  I was willing to stretch it to 1 p.m. if necessary since I thought the descent might be a little faster than the ascent.  Having no idea what to expect or how my body would respond to this hike, I did not put our chances of success very high.  My son, on the other hand, was much more optimistic.  I think we both understood that success depended on whether I could do it since he is much younger, in better shape, and not overweight like me.

Sunrise over the San Gabriel Valley from the Mount Wilson Trail

The first quarter mile of the hike left me winded and with my calves threatening to cramp up.  At that point, I did not see how I could possibly keep this up for 14 miles.  However, the farther we went the more I began to settle into a pace that seemed a little more maintainable.  Occasional relief from the relentlessly steep grade provided a welcome opportunity for recovery.  I found that even brief periods of rest were extremely beneficial.

We arrived at First Water, 1.5 miles from the trail head, after about 40 minutes.  At that point I finally felt like I could make it.  We were averaging better than two miles per hour and it now seemed manageable.  My son was having no trouble at all.  He would get ahead of me and then stop and wait for me to catch up.  Our next milestone was making it to Orchard Camp, the halfway point 2 miles beyond first water.  This leg felt easier than the first.  The trail flattened out and even occasionally descended providing rest periods without the necessity of stopping.

My son at about the halfway point

If we divide the ascent roughly into quarters, the third leg is the most difficult.  Between Orchard Camp and Manzanita Ridge is a distance of 1.7 miles, but the grade is relentlessly steep and often over rocks.  In one spot the trail entirely disappears and hikers must negotiate a tricky corner on hands and feet.  For me, it also required a short jump after which I nearly lost my balance.  If I had not caught myself I might have fallen about six feet onto a steep, rocky, slope below.  It probably would not have been catastrophic, but could have easily resulted in injury.

Me at the same spot

We spoke with an experienced hiker at Manzanita Ridge who had made this climb many times.  He passed us while we were resting and having a snack just before, and he was still at Manzanita Ridge when we arrived.  We had not realized how close we were or we would have pressed on.  He assured us that we had just made it through the most difficult part of the trail.  From here to the top, another 1.8 miles, was much easier than what we had just been through.  I made sure to ask him about finding where the trail continues from the toll road so we did not do the 18 mile version of the hike I found in other blogs.  I do not remember the details he told us, but we were able to find it by watching for it.

Part of the toll road covered with snow

The toll road begins just a half mile beyond Manzanita Ridge.  We started looking for the trail continuation immediately once we were on the toll road.  After we did not see it right away, we thought we might have gone the wrong way.  We went back a ways, double checked the signs, and asked other hikers before we were convinced that we were going the right way.  It took quite a while before my son finally spotted it.  I do not know the exact distance that we hiked on the toll road, but I believe it was around three quarters of a mile.  The toll road comes to a T intersection.  It is tempting to turn right and continue on the road, but I believe that this is the mistake the other hikers made.  Just before the T intersection on the right side of the toll road is the trail continuation.  This final leg of the trail is steep, but short.  My son hiked ahead.  A short time later he called out and I could see him above me, assuring me that he had reached the top.  I continued up to where he was and found myself in the parking lot where I had parked two summer ago when my kids and I drove to the top.

The view from near the top

So close to the top that we can see the TV towers

We finally made it

Proof that I made it too

From the parking lot, there is still a little more of a climb along a paved trail to reach the actual summit.  At the very top, there is a pavilion with picnic tables and the Cosmic Cafe in the center.  The cafe is only open April through November so we had to eat the food we brought.  The restrooms are also closed so we had to resort to nature for those needs.  These inconveniences and the cool weather were well worth it to avoid the large insects that are active in the summer, as we learned when we drove up two summers ago.  Summer hikers are advised to bring ample insect repellant.

The trail up to the pavilion

Lunch at the pavilion

A modern sculpture at the summit

The trail head from Mount Wilson for the descent

We arrived at the top around 11:30 a.m. and stayed for about half an hour.  The descent took less time.  We arrived back at our car in Sierra Madre by 3 p.m.  At first the descent was a welcome relief to all that climbing.  I never got winded as on the ascent, but it did not take that long for an entirely different set of muscles to become fatigued.  Going up it was my calves that got most tired, but it was my thighs on the way down.  When we had barely made it as far and Manzanita Ridge I had trouble re-tying my shoes after emptying the gravel out.  The problem was that when I brought my leg up to tie my shoe my thigh would immediately begin to cramp up.  I had to have my son help me tie one of them.  If I did not run regularly I think this hike would have been impossible for me.  As it was, it was still very challenging.  It was like doing four hours worth of calf raises on the way up, and then another three hours worth of leg extensions on the way down.  My legs were just not quite accustomed to this level of activity.  Running on a flat surface does not quite cut it.  On the way down I found myself longing for something flat to walk on.  Even the short segments where the trail goes up were a relief because they used different muscles than the constant descending.

The sign back at the Sierra Madre trail head

Back in Sierra Madre

It took about five days for my legs to recover from this hike.  This was much more than normal workout soreness.  The first few days I found it easier to go down the stairs in our home backwards.  In spite of the pain, the sense of accomplishment was exhilarating.  I want to do it again.

Can Aliens Watch TV?

We live in a world of perception that our minds create.  While there is a real world out there, what we perceive of it is highly filtered and interpreted.  Our technological devices are tuned to our minds and senses to recreate something like what we experience from our perceptions of the real world.  They do not reproduce nature exactly, but only good enough to fool our senses.  An intelligent alien species visiting our world would not necessarily perceive the output of our technological devices the same way we do, nor would this output necessarily match their direct perceptions of the world.

Our TVs only produce three different colors: red, green, and blue.  With these three colors, our TVs are able to reproduce the sensation of any color we are capable of sensing.  This little economical trick is made possible not because of the inherent properties of light, but because of the inherent properties of our eyes.  In other words primary colors have nothing to do with the physics of light, but everything to do the eyes and the brain.

Our eyes have four different types of light-sensitive cells.  One type of cell, commonly called a rod, is very sensitive to visible light but can only distinguish varying levels of intensity.  Three other types, the cones, require higher levels of light, but they allow us to distinguish different colors because each type of cone is sensitive to a different range of frequencies.  One type of cone is most sensitive around the red range, another is sensitive near green, and a third near blue.  There is overlap.  Both the red cones and the green cones are stimulated by spectral yellow.  This allows our devices to fool our eyes and minds into seeing yellow by mixing red light and green light.  From a physics standpoint, red and green mixed is not the same as yellow, but we cannot distinguish these two cases.  The graph below shows the approximate range of sensitivity for each of the three types of cone cells.

Primary colors come in two types as shown in the image below.  Mixing light has an additive effect (shown on the left) while mixing pigments has a subtractive effect (shown on the right).

Because TVs mix light, this effect is additive (i.e. red and green make yellow, red and blue make magenta, and blue and green make cyan).  To make white we mix all three primary colors (red, green, and blue) at their full intensity.  Mixing them evenly at lower intensity levels produces gray while black is merely no light at all.  White from the TV has a fundamentally different quality compared with white from the sun.  White from the sun contains all frequencies while white from the TV only has red, green, and blue, but these whites still look the same to our eyes.

Mixing pigments takes away light.  Each pigment absorbs different frequencies so mixing them together combines these effects.  Magenta pigment absorbs green light and yellow absorbs blue light.  When these pigments are mixed, all but the red light are absorbed.  Magenta, yellow, and cyan are the three primary pigment colors used by modern printers.  There are many possible primary color schemes for pigment, but the magenta-yellow-cyan scheme works better than the red-yellow-blue scheme most of us learned in grade-school art class.  Artists know very well that you cannot mix every possible color with only red, yellow, blue, black, and white paint.  This is why oil paints come in so many different colors.

Once again, the reason mixing colors works, whether light or pigment, is because of the way our eyes work.  Our intelligent alien visitors may have eyes that work differently.  They might have a wider or narrower range of frequencies they can see.  They might see infrared or ultraviolet, or they might not even see the red or violet that we see.  They might only distinguish intensity, or they may have greater or lesser color acuity because they have more or fewer light sensitive cells analogous to our cones.  For example, if they had four cones, they might need a primary color scheme of four colors to display all the colors they can perceive.  There is no guarantee that they will look at our TVs and at the corresponding natural scene and perceive them as the same scene.

Besides color, there are other considerations as well.  We view TV at 30 frames per second and movies at 24 frames per second.  This works with the frame rate and persistence of vision characteristic of our brains to create the illusion of smooth motions.  Our alien visitors' brains may have a faster frame rate and they might see the flicker in our devices, which could be so distracting to them that they do not see or enjoy the action the way we do.  All this would also be true of our visitors' technological devices.  Their devices would be tuned to their brains and we might not perceive the output of their devices at all they way the aliens perceive it.

So whose version of reality would be more correct?  Both and neither.  Both we and our alien visitors evolved perception mechanisms suitable to our respective worlds which enabled us to survive and develop a technological society.  In a practical sense, perception is reality, just as in politics.  At the same time, it is not possible for either of our perception mechanisms to completely represent the real world.  That would be too much information to process.  Instead, evolution gives us just enough to survive better than the alternative while working within practical limits.

Comparing ourselves with a hypothetical alien species is an exercise in imagining whether things are as they must be, or only as they happen to be in our particular case.  This is just another way of moving us further from the position we once occupied at the center of the universe before Copernicus and Galileo removed us from that spot more than 400 years ago.

Why Don't We Just Run Cars on Hydrogen?

Sometimes when I talk to my kids about energy-related issues, they may propose a solution that seems quite simple and obvious to them.  The problem is that the real issues may be more complex than they appear on the surface and may require some foundational knowledge to fully understand.  One such potential solution to our energy needs is hydrogen-powered cars.  Hydrogen is a clean burning fuel and is certainly plentiful given all the hydrogen that exists in Earth's oceans.  Why do we not just use hydrogen to solve our energy problems?

To understand why we do not use hydrogen more as a fuel, we need some basic chemistry knowledge.  Burning is a chemical reaction where energy is released.  When hydrogen is burned, oxygen atoms from the atmosphere each combine with two hydrogen atoms to form water as a waste product while giving off heat in the process.  Other chemical reactions consume energy rather than release energy.  The problem with hydrogen is that it is very light and very reactive.  All of the hydrogen on earth has either floated away into space because it is so light, or it has bonded with other atoms and requires at least as much energy to release as what we get from burning it.

Hydrogen then can be a convenient way to store energy, like a battery, but it is not a source of energy.  Extracting hydrogen from water takes as much energy as we recover from burning it.  It is like using boulders rolling down a hill as a source of energy.  The problem is they are all currently lying at the bottom of the hill.  We could push them to the top of the hill and then use them, but then we might as well just use the energy directly that we used to push them up the hill.

The only reason we might prefer the rolling boulders is that they give us a lot of energy fast while the process of pushing them up is longer and slower even though the total energy is equivalent (minus whatever is lost through inefficiency).  This is why hydrogen is sometimes used as rocket fuel.  The real source of energy was the coal that generated the electricity that was used to extract the hydrogen from water.  But the hydrogen works much better as rocket fuel because it can release its energy much faster.

Backing up even further, the energy in the coal ultimately came from the sun.  Prehistoric plants used photosynthesis to convert sunlight into chemical energy that was eventually buried, becoming the fossil fuels we use as our primary energy source today.  The energy from the sun comes from hydrogen, so in essence we are already running everything on hydrogen.  The difference is that the process that generates energy in the sun is nuclear rather then chemical.  Chemical processes only rearrange atoms.  Nuclear reactions change one kind of atom into another either by combining nuclei (fusion) or splitting nuclei (fission).  For elements lighter than iron, fusion releases energy, while elements heavier than iron release energy with fission.  The amounts of energy are several orders of magnitude greater than those involved with chemical reactions.

Unlike regular burning of hydrogen, nuclear fusion could provide us with all the energy we would ever need.  The problem is that extremely high temperatures and close proximity are required to start and sustain a reaction.  Stars do this with gravity, but it is not so easy on earth.  So far the only way we have been able to use the energy of nuclear fusion is in thermonuclear (hydrogen) bombs.  These blow themselves apart by design.  To sustain the reaction and produce usable energy we would have to hold it together.  This is a challenge we have yet to resolve.

Orbital Dynamics

As a follow up to some of my previous posts about space flight, I have decided to discuss orbital dynamics.  The general public is grossly misinformed about real space flight thanks to so much misinformation in movies and on TV.  The Jet Propulsion Laboratory has an excellent tutorial here for those who want to get into even more detail about space flight.

Why discuss orbital dynamics?  Because every body in the universe is in orbit around something. Furthermore, orbital dynamics are interesting because they are so non-intuitive when it comes to maneuvering a space ship. Understanding orbital dynamics is essential to real space flight.

Johannes Kepler discovered by observation that planets follow elliptical orbits around the sun.  Isaac Newton showed that elliptical orbits are a consequence of the inverse square law of gravity.  More generally, orbits are conic sections.  When you throw a baseball, its path is a parabola.  A comet that only approaches the sun once, and then heads for interstellar space is following a hyperbolic curve.

If two space craft are orbiting the earth in the same orbit, but separated by some distance, how can they rendezvous or send items back and forth.  MIT Professor Walter Lewin discusses this problem in his ham sandwich lecture, which is posted online here.  As Lewin states it, how do you throw a ham sandwich to the hungry astronaut in the space ship that is in orbit ahead of you?  You might want to just throw it toward him, but that would put the ham sandwich into a higher orbit, thus ultimately slowing it down and sending it further away from the hungry astronaut.  The right way to send him the ham sandwich is to throw it backwards, away from his space ship.  This would initially slow down the ham sandwich, but then it would pick up speed as it fell into a lower orbit.  If done just right, the elliptical orbit of the ham sandwich would intersect the more circular orbit of the hungry astronaut's space ship at just the right time on the next orbit.

The astronauts in the Gemini program in the 60s, the first to execute a rendezvous in earth orbit, had to learn to go contrary to their intuition.  The first required maneuver was to match the plane of the target.  Next, it was necessary for the perusing ship to be in a lower orbit so it could gain on the target.  Once the target was in sight, the astronauts had to fight their natural tendency to fire thrusters to move their space ship toward the target.  Instead, they needed to maintain their lower orbit, only pulling up into the same orbit as the target at exactly the right moment.  Of course, this is all old hat now for real astronauts, but the complex and intricate details are not always fully appreciated by a general public fed with a steady diet of Star Trek and Star Wars.

Orbital dynamics also come into play in planning trajectories for interplanetary travel, but that is a subject for another post.  If you can't wait until then, check out the JPL Space Flight Tutorial I mentioned previously.

Common Sense

Everyone seems to know what common sense is, but no one has ever been able to fully explain to me exactly what they mean by it.  One idea about common sense that I have gleaned from the various opinions I have surveyed is that it is something that cannot be taught.  You either have it or you don't.  Another is that it is somehow inversely related to formal education.  Often people who are lauded as having common sense do not have much formal education while the highly educated are sometimes thought to lack it.  Common sense seems to be a type of knowledge, but which specific knowledge constitutes common sense seems to vary from one individual to another.

My ex-father-in-law was someone who was said to have a lot of common sense.  He did not have formal education beyond high school, but he ran successful businesses and made wise investments, and thus accumulated enough money to retire very early and be quite comfortable.  He also had the fortune to invest in real estate during a time when values were always rising, a condition that no longer always holds true.  My impression of him was that he was very intelligent, hard working, and constantly learning about things that were important to him.  I don't think he was born with the knowledge he had.  Perhaps common sense in this case means learning from life experience and from paying attention to things rather than in a formal classroom setting.  I am not sure why we need to make this distinction.  To me, knowledge is knowledge regardless of how we acquire it.

When my oldest son was preparing to take the written driving exam to get his learner's permit, his friend dissuaded him from studying by telling him that it is all just common sense.  My son took the test and failed.  Then he studied the material and passed it.  So does he lack common sense because could not pass the test without studying?  Did he acquire common sense after he studied, or does that not count?  Maybe only those who pass the test without the need for study are the ones with common sense.  I suspect that this friend had already acquired the knowledge in other ways.  Maybe his parents talked to him about things and he paid attention.  This same son is very good at strategy games.  No one can ever beat him.  He seems to have an intuitive knack for it.  This probably just seems like common sense for him.

Reflecting on these and other experiences, I think I might be seeing a common thread to what people mean when they speak about common sense.  The best I can figure out is that it means "what is obvious to me."  Any two people will have some knowledge in common, and other knowledge that is unique.  My wife was playing a game on a mobile device and called her daughter for help on one of the levels.  Her daughter's response was, "You're having trouble with that one?!"  She found one of the levels difficult that her daughter found easy.  The rest of the story is that her daughter had already gone through a similar game consisting of maybe 100 levels and this was my wife's first one and she was perhaps on level 16.  There are many other subjects where the roles would have been exactly reversed.  We all know different things.

This leads me to the main reason for writing this post in the first place.  People sometimes express incredulity that someone else does not know something that is obvious to them.  This is often what gets labeled as common sense.  I think that this reaction is unkind and unnecessary.  In almost every case, the roles could be reversed if the subject were different.  The concept of common sense seems to be very egocentrically defined.  A better reaction would be kindness, patience, and the willingness to share our knowledge without making any value judgements about what others ought to know.  The flip side of this is the willingness to learn something from every person we meet.  Ralph Waldo Emerson summed up this idea very well.  “In my walks, every man I meet is my superior in some way, and in that I learn from him."

Navigating an Asteroid Field

In "The Empire Strikes Back" Han Solo navigates his Millennium Falcon through an asteroid field to escape star destroyers.  Since then, a number of other TV shows and movies have depicted similar crossings through asteroid fields where a space ship weaves through to avoid collisions.  How likely is a scenario such as this?

We do not have first hand knowledge of any actual asteroid fields similar to the one from Star Wars.  In our solar system, we have an asteroid belt between the orbits of Mars and Jupiter, but it is far more sparsely populated than the one depicted in Star Wars.  The average distance between asteroids is about 1 million miles.  All of our space probes have passed through it without incident and with no course corrections needed.  The probability of encountering even a single asteroid is remote, unless we explicitly set out to do so.

The asteroid belt was denser in the early solar system, but still nothing like the asteroid field from Star Wars.  Structures like that would be unstable.  Collisions would tend to knock asteroids further apart until they were far enough apart to make collisions a much more rare occurrence.  There are stable points of gravitational equilibrium called Lagrange points where debris could accumulate forming something as dense as that depicted in Star Wars, but these would not extend over a large area and would be very easy to avoid altogether.  Lagrange points are in known locations relative to large celestial bodies.

Perhaps it is possible for a dense asteroid field to exist for a short time before repeated collisions drive the asteroids further apart.  If so, it would always be much simpler to navigate around it rather than through it.  If it was uncharted and you came upon it suddenly, the speed differential between you and the asteroids would likely be so great that there would be no time to react before your spaceship was obliterated.  Bodies in space travel at extremely high velocities relative to each other unless they are in the same orbit around a planet or star.

The only way to produce the scene from Star Wars is to nearly match the speed of the asteroids with your spaceship before attempting to navigate through.  However, it would not look anything like that depicted on Star Wars.  The Star Wars spaceships fly more like airplanes than spaceships, which real spaceships cannot do because there is no air to push against (see blog post Spaceships That Fly Like Spaceships).  It would be more like navigating the spaceship in the old arcade game, Asteroids, but more complex because you would be dealing with three dimensions rather than two, and without the option of shooting the asteroids.

Remember also that if you have to flee from an enemy in space, you have many more possibilities than you do on the surface of the earth because you can fly in three dimensions.  It is difficult to get our minds wrapped around the possibility of traveling freely in three dimensions because we are too accustomed to traveling gravity-bound on the surface of the earth.  It is true that we can go short distances in the third dimension, but our travel on earth is predominantly in only two.  In space you could travel forever in a third dimension.

If you just need to get from point A to point B, it should be no problem to simply plan your course around the asteroid field.  Because of the way these type of structures might form, they are likely to lie in the same plane, meaning that you could just adjust your plane of travel by a small amount to get around it.

So even though the scene from Star Wars would likely never need to occur, no matter how advanced our technology, it still makes for an exciting action sequence.