Monday, January 31, 2011

A Mechanical Pulse

Can we synthesize a beating heart directly from stem cells?  Did Dorothy’s friend, the Tin Man, have a heart?  Does blood flow through the veins of computer engineers?  Not yet, yes, and not until proven otherwise.

The term pulse has taken on a biological meaning in popular culture.  It is used to describe the gush of blood sent streaming from the heart throughout the body.  You can feel your pulse rate by pressing against your neck.   Fictional characters always check the wrist to see if someone is dead, but the neck seems like a more reliable indicator (if I were a doctor using the wrist to be fancy, I would probably pronounce some living people dead).

In science, a pulse takes on a more general meaning.  It is a single disturbance that propagates through a medium or material.  The source of the pulse may be a beating heart, but it can just as easily be a loud horn.  The loud horn creates a sound of a certain intensity, which travels in all directions through the medium of air.  Sound waves may appear to be mystical, but it is just a game of broken telephone between neighbouring air molecules; information, in this case, longitudinal vibrations on a molecular scale, is being transported. 

Friday, January 28, 2011

Obama Calls for Science

At the 2011 State of the Union Address, President Barack Obama issued a very clear challenge to his nation: “Win the future.”  While the future is something that all nations will share in, it is true that the U.S. does like to have the lion’s share.  Realistically, even if America begins to wake up from its decade-long hibernation, when dreams and ambition were replaced by a sense of entitlement, it will have to share the honour of economic superpower with other nations like China.

Monday, January 24, 2011

Applying a Safety Factor in your Life

Nearly all engineering designs serve a purpose.  When they fail to serve the purpose for which they were designed, they are considered to have failed.  Failure is an expectation, as nothing has an infinite lifetime.  As such, all engineering designs have an expected or intended lifetime after they are built and delivered, which may be thought of as a best-before date. 

Things with moving parts, like cars, may have a lifetime of fifteen years and 200,000 km.  That is because a very popular mode of failure is fatigue.  The strength of a material actually decreases when it is stressed, even at low values.  On the other hand, static objects, like chairs, tend to survive longer than is required – typically, the paint will fade long before a leg breaks.  A chair tends to go out of style before it falls apart.  This is not surprising: whenever it is possible, engineers apply a high safety factor to their designs.

Tuesday, January 18, 2011

Cultural Assimilation: It is the Zeroth Law

There are several laws of thermodynamics, all of which have applications across the various scientific fields.  These laws also have deep philosophical implications, with the second law leading the charge in this regard.  I have already written two articles describing the first law (energy balance).  I will soon cover the depths of the second law, but I feel the need to discuss the most fundamental law beforehand.  Strangely enough, there is a law that comes before the first law.
The zeroth law of thermodynamics states that if two systems are in thermal equilibrium with an external system, then they are also in thermal equilibrium with one another.  Thermal equilibrium means that heat is not being exchanged between two systems.  When two systems having different temperatures come into contact with one another, they will inevitably experience heat transfer.  Once thermal conduction is complete, the collective system will arrive in thermal equilibrium.

Sunday, January 16, 2011

Balancing Relationships and Design Parameters

We all would like to get it just right.  Our soup should not be too hot so as to avoid “leather tongue”, or too cold, because cold chicken soup does nothing for the soul.  Driving either too fast or too slow on the highway is illegal and dangerous.  Shoot the basketball too softly and it does not reach the rim, too hard at it clangs off the backboard.  There is a narrow range of force and angle for which you will score, and with practice, you can find that optimized scenario with regularity.

Goldilocks is not the only person interested in finding the optimal bed or porridge.  It is in fact the primary concern for an engineer to look at a design problem, and optimize its parameters.  The goal is to design a prototype whose safety, mass, volume, cost, and delivery time fall within an appropriate domain.  The optimization problem that ensues may be thought of as a search for balance.  A computer scientist may view this as an interpolation algorithm, perhaps a bisection code, being run until a satisfactory solution is found.

Tuesday, January 11, 2011

What is Time?

Most people are aware that we live in a Universe in which we observe four dimensions.

The three dimensions of space allow us to see three-dimensional shapes, like cubes and spheres.  If we lived in a world of two-dimensional space, we would instead see squares and circles with zero thickness.  Stephen Hawking explained long ago that such a two-dimensional space could not support life, as a two-dimensional being could not both eat and defecate.  A shape with two openings could not hold itself together, and would fall apart or bleed to death (try to draw it and you will get the point).

Of course, the fourth dimension of our Universe is time.  Time is an essential ingredient in the space-time continuum.  Without the dimension of time, the 3D shapes we see would not change.  Everything would be steady state, and there would be no need for the word transient.  Put simply, what is time, but the entity preventing everything from occurring at once? 

Thursday, January 6, 2011

The Defining Moment of Mankind

I recently sat down to dinner with three close friends.  After some time, the conversation entered into some intriguing domain.  The following question was posed: “What moment in history best defines mankind?”  There are so many instances where man has done something of great significance.  How could one choose just one defining moment?  It would need to be an event of upmost importance – one that changed the course of history in a major way.  It should also reflect the nature of our species and set us apart from other ones.  After some pondering, each of us expressed our respective view on the matter.

Tuesday, January 4, 2011

Robo Sapiens

I want to share with you the most engaging talk that I witnessed in recent years.  The lecture, which can be found on, was given by Juan Enriquez in February 2009, as the economic collapse was beginning to be sharply felt in North America.  The eighteen minute presentation shook me to the core.  While it moves along in an entertaining fashion, it eventually ends up in extremely intriguing territory, with fascinating yet plausible predictions for the relative near future of mankind.  I will give a brief summary of the content of the lecture (link for talk).

Among other things, it is unsustainable practices that have led to the economic downturn.  Companies with tunnel vision have taken the shareholders dollar and put it through the shredder.  Today, when trying to move forward from our dark economic situation, we must be very careful where our time, energy, and of course, money, is invested.  More than ever, our focus should be held firmly upon areas with anticipated growth.  According to futurist, Juan Enriquez, our attention should turn to science, and in particular, the fields of cell growth, tissue growth, and robotics.

Saturday, January 1, 2011

A Scientific Resolution

“Everything changes on New Year’s Day,” sings Bono of U2 fame.  I don’t know whether or not that is true, but the first of January does present an opportunity for us all.  If December 31st is a day to reflect on the year that has passed, then the following morning, once the hangover passes, is a time to consider what the coming year will bring.  We often make statements regarding the changes that we will make, known as New Year’s resolutions.