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Sunday, August 31, 2014

The Richard Feynman Lectures

Richard Feynman was a Nobel Prize winning physicist that started working on the Manhattan Project and ended his career as one of the preeminent and most sought after physics sages.


Bill Gates, in an act of pure kindness to humanity, bought the rights to Feynman's famous Cornell University Physics lecture series entitled, "The Character of Physical Law" and opened them for everyone.

If you never got physics or hated the math, you can understand Richard Feynman. In these lectures he is presenting to students and his respected professor colleagues so he is explaining things in an unpretentious way for anyone to listen.

I urge you to watch these videos.

Here's where I got the story:
http://www.openculture.com/2012/08/the_character_of_physical_law_richard_feynmans_legendary_lecture_series_at_cornell_1964.html


Here are the videos.

Enjoy!










 

Thursday, August 28, 2014

Science is wonderful in it's own right

Schrödinger's cat caught on quantum film by NewScientist



One cat is outlined by outgoing photons, the other made by photons travelling the opposite direction but influenced by the first beam of light - influenced by quantum entanglement.

Spooky action at a distance as it was called.  Two things passing each other and exchanging information without touching. Neither photons slow down or are bumped. 

Science can be this wonderful!  You don't need to understand the math to appreciate how weird this is.

This experiment was done by

http://doi.org/10.1038/nature13586


Tuesday, August 26, 2014

Electronic passports

If people are concerned about the location of Western converts fighting for ISIS, then all nations should make electronic passports complete with GPS transponders.  Cell phones cost almost as much as a passport these days so it is economically viable. 

Electronic passports have many advantages:
  • Easy to find someone lost in a foreign land. 
  • Easy to track if people went into a dangerous country. 
  • Easier to track drug mules.
  • Easy to estimate how many foreigners are in a country.
  • Easy to determine when and where someone was kidnapped. 
 It's defeatable, but it makes things easier.

Technology can help lots of problems if people can conceive it.

Police militarization versus Army nonlethalizaion

How ironic.

The US Army is funding research into non lethal crowd suppression weapons using heat wave and sound wave devices to quell large protesting crowds.

Why? The US Army learned in Iraq that to use lethal force against protesters would make them more prone to violence and hence turn peaceful demonstrators into angry frustrated terrorists.



At the same time, local police forces are misusing tactical weaponry meant to respond to terror cells that attack small town America. The media is unfair   blaming a reasonable program on the actions of a few police forces. The goal was to give small police forces the equipment to take on a well-armed and well-organized terror cell.  To be fair to Department of Homeland Security, this was a sound plan that makes sense. 

But what happens when you use tactical equipment against protesters? Same response as in Iraq.


Did those police forces read the lessons learned by the Army in Iraq?

Saturday, August 23, 2014

When you contract Ebola, you are saved by a virologist, not a physician.

Physicians, general practice medical doctors, are the most shameless exploiters or other people's work.

Example.  You contract Ebola and are infected. Your doctor gives you a shot.  You recover.  Who saved you?  For simple people, the answer is the doctor that stabbed you.  But did he make the vaccine?   No, he used the research of a virologist that solved the weaknesses of the Ebola virus. He used the pharmaceutical company that did the trials and human experiments to prove that the dosage and compounds were safe or safe enough. He is merely the vaccine pusher, in the strictest sense. His knowledge of whether or not you'd recover is a reading of the pharmacological information provided with the dose.  In other words, a crap shoot.  I know statistics, if mortality rate with a vaccine is 10% then he expects to lose 10 in a hundred. He can't tell you who or when. How miraculous is that?

The doctor gets to look good but he didn't do the work.  General practice physicians make millions of dollars a year and save maybe a few hundred people a year.  Virologists struggle for years to get funding, and in the end can save millions of people.  Why?

Look at why this is on my previous post here. Most people are thinking about the short term selfish horizon. They appreciate people that help their best interest. But who helps society the most?



Being apart is not being alone, morality at the highest stage drives the few

Some people do not need or seek out the attention or validation of the group. Some people participate in society by what they do for society and not what they show society. They consider society as a whole: a sum of the parts.

Consider Kohlberg' stages of moral development .  Some people attain level / stage six. At this level some people realize that all action in the specific towards one person or family is meaningless in the extremes of time and space.   That person or family may exist for a hundred years but eventually the influence on society and even history fades into nothingness. So why work in temporal matters, why work towards one goal?  This is a hard thing for most people to understand but people at this stage, people with this understanding of morality in the abstract, understand how decisions affect everyone over vast time periods, are not trying to help Steve down the street with his move but help everyone with pivotal problems.  Doing the abstract work gives them no credit or appreciation from Steve or his neighbours. Also none of the back problems.

This level of abstraction is known in many fields, in mathematics, and science and even in art. Did Monet make fifty versions of the same painting, or just one? Logically, if he wanted to make the most money from one painting idea then reproducing it many times is what an average person would do. But what if he, or anyone else like him, thought in the abstract?  To create art that defines a period is a longer lasting mark than selling 50 times as many. This is why people dedicate their lives creating things most people don't understand to care about. It's because those creators understand morality on the highest level of abstraction.

Think on it this way, some people are satisfied if they get up every day and build bridges.  In forty years you can construct maybe hundreds of bridges. But in fifty years, they will all disappear to be replaced with bigger better bridges that carry more with the latest technology.

What if instead you dedicate your life to figuring out the calculus of how to make all bridges stronger and last longer?  Then your work lives on forever.

So who is the nobler man, the doctor that heals one patient or the mathematician that discovers the infection rate of Ebola?  Whose mark is greater?

Monday, August 18, 2014

The 5% Solution

If life was 5% harder on the 1%, would that stop waiters from urinating in their vichysoisse?

Wednesday, August 13, 2014

Simple Car Model; Part 2

Last time we ended with these equations:

$$  \dot{\vec{p}} = ( \frac{F(t)}{m } ) * t + C $$



$$ \int \dot{\vec{p}} dt  = ( \frac{F(t)}{m } ) \int ( t + C_{0}) dt $$

$$ {\vec{p}}  = ( \frac{F(t)}{m } )  ( t^{2} +  C_{0}t +  C_{1}) $$



$$ (\dot{x} = \dot{p}\cos (\theta) ,  \dot{y} = \dot{p}\sin (\theta) )$$



This represents a simple 2-wheeled car that is pushed by a force along a 2D plane. Now with this model if we pushed the car with a force it would sail forever along the path of the wheels.

Instead, to make it realistic, we add in friction.  Kinematic friction is really the reason why objects coast to a halt rather than moving forever.

Kinematic friction creates a force - a drag if you will but not drag that is another force that resists the motion of an object moving over another.  When a wheeled vehicle coasts to a stop the friction we are talking about is not the rubber wheels on the road, because that friction must be almost 100% of the normal force (more on this later) to push off the surface and cause motion.

What I am talking about is the friction force created by an object traveling at velocity that resists forward motion.  It is generated in the axles of wheels by the tire rim rotating around the drive axle.  In this case, the kinematic friction is very small.  But that is good and it's a real life force.

I researched online and found some experimental numbers for steel on  greased steel friction that is about what we need.

I got them here http://www.school-for-champions.com/science/friction_coefficient_greased.htm#.U-vXOZUzBBI



Coefficient of Sliding Friction (greased surfaces)

Material 1

Material 2

Static

Kinetic

Steel (mild) Steel (mild) - 0.09 - 0.19

Since there are two axle and wheels on our simple car, let's use the high end number once instead of an average number twice.  It would be about the same in the end. $$\mu = 0.19 $$

Let's use Newton's Third Law:
For every action, there is an equal and opposite reaction.

Written another way;  The sum of all forces on an object must be zero.


$$  \sum{F(t)} = 0 $$

Otherwise we could create or destroy energy, we can't so the mass and energy must all be transfered into other ways.

The friction force resists motion so we apply the vector in the opposite direction to the pushing force we apply,  so they subtract.  The nice thing here is that since the push force and friction will always be opposite we can ignore the vector addition and simply subtract them.  That won't happen when we stop applying force, but then the vehicle will coast to a halt.  Which is realistic. That is not to say we shouldn't state the special exception, but that is the reason why in the next equation there should be:

$$  \sum{F(t)} = F_{push} - F_{friction} = 0 = m  \cdot \ddot{\vec{p}}    $$

The equation for friction is  $$ F_{friction} = \mu* F_{normal} $$

which in a 3D plane must be normal towards gravity and in a magnitude that represents the total mass under friction. The wheels push down with the total force of the mass they carry.  So,

$$ F_{friction} = \mu* F_{normal} = \mu* mg $$

Going back to the acceleration equation,

$$  \ddot{\vec{p}}  =  \frac{F(t) - \mu*mg}{m }  $$

$$ \int \ddot{\vec{p}} dt  = \int ( \frac{F(t) - \mu*mg}{m } ) dt  $$ 

Friction is constant as well.

$$ \int \ddot{\vec{p}} dt  =( \frac{F(t) - \mu*mg}{ m } ) \int  dt  $$

$$  \dot{\vec{p}}   =( \frac{F(t) - \mu*mg}{m } )(  t   + C_{0}  )$$

and

$$ \int \dot{\vec{p}} dt   =( \frac{F(t) - \mu*mg}{m } ) \int (  t   + C_{0}  ) dt $$



$$ {\vec{p}} dt   =( \frac{F(t) - \mu*mg}{m } ) (  t^{2}   + C_{0}t + C_{1}  ) $$

We are going to ignore static friction, that is the special force that stops an object from motion just as it lifts off contact.  It is normally higher but for mild steel it was measured in experiment above as negligible.  For steel rims and steel axles this is the friction force added.

We have not solved for any terms, or simplified the equations.  That is the strictly correct way to represent the solutions of an ordinary differential equation. 
Let's make a very generic initial value problem.  Imagine that the simple car always starts off at zero acceleration and zero velocity.  Like real life.

Then the initial value solution is




Tuesday, August 12, 2014

A Meaningful Physics Model - Simple car on 2D plane

Very often people try to describe how things work to students using very simple examples.  One of my disliked versions is the simple nonholonomic ( don't worry about this I'll explain later) car model. When someone tries to explain how a car works, they make examples so simple, these examples never work like anything real.  This causes students - including me - real problems understanding harder models.

Imagine you are trying to understand how mechanics - simple Newtonian physics - works.  Imagine a card like object, something that drives forward along it's front wheels direction of travel.  OK, seems simple enough.  We all know that when you push an object with wheels it moves forward (perpendicular to the wheel axis) over ground.

Let's assume some simple things that don't change Newton's Laws of Motion.  Let's assume the entire world is flat.  If so, we can ignore gravity so this makes a 2D force equation.  Let's just move in X and Y and forget Z.  Imagine an x-y plane. The car drives over it.  These are huge real world assumptions that don't apply but to start off they are critical.

Now how we push anything is to hit it with a force. Punch your brother, he moves. How, you transfered momentum to him but that started as accelerating a mass.
 Here are my variables:  P represents the position of the car model.  Let's say that $$p$$ is the point midway through the wheel axle along the travel direction. P consists of an x and y component.
$$\vec{p} = (x, y)$$
The angle of wheels when measured from my imaginary origin at (0,0) is theta
$$\theta$$
 Angle can change independently of the velocity applied to the system.
Now let's call the force I apply to the vehicle as
$$F(t)$$
where t is time. The force applied can vary over time.  But the force does not depend on the vehicle it is pushing.  When we add friction, that will change.
 Let the car have a mass of $$m$$ or it's weight at the Earth's surface (another assumption).

Most people start with a kinematic model, one that ignores how mechanical systems work by ignoring Newton's Laws.

Here is Newton's Second Law of Motion in terms I used:

$$ m \otimes  \ddot{\vec{p}} = F(t)   $$

Forces applied at all times to an object equals that mass cross product acceleration. Let's apply force at the center of the mass, so this simplifies to

$$ m  \cdot \ddot{\vec{p}} = F(t)   $$

Another way to say this is:
$$  \ddot{\vec{p}} = \frac{F(t)}{m }   $$
This puts it into a second order ordinary differential equation.


Now, instead of just claiming that the car has a velocity in the x and y directions let's derive how you get that.  Since the mass is a constant, we can ignore a change in mass.  We will make one more assumption, that during one tiny infinitessimal period the amount of force applied to the mass does not change.  This is wrong, because it's possible that Force varies instantaneously but in reality this is a small error term for the area under the integral curve.  This is a big departure from other people's interpretation.  On the other hand, I don't make the small angle assumption which estimates $$ \theta \approxeq \sin \theta $$
to make the equations linear.  You can work with nonlinear systems, they don't bite.

Now how do you figure out how the position changes over time based on a force applied to the car?  We can solve the acceleration differential equation twice, integrate once to get the velocity equation and twice to get the position equation.

$$ \int \ddot{\vec{p}} dt = \int \frac{F(t)}{m } dt  $$

Force and mass constant:


$$ \int \ddot{\vec{p}} dt = \frac{F(t)}{m } \int dt  $$


$$  \dot{\vec{p}} = ( \frac{F(t)}{m } ) * t + C $$

When you integrate, this multiplies the constants by t and adds a constant term.  You need initial conditions to know what C should be.  For example, if your wheeled car was already accelerating there would be a constant velocity applied.  This is the velocity equation.



 $$ \int \dot{\vec{p}} dt  = ( \frac{F(t)}{m } ) \int ( t + C_{0}) dt $$

 $$ {\vec{p}}  = ( \frac{F(t)}{m } )  ( t^{2} +  C_{0}t +  C_{1}) $$

This is the position equation.  If the car's angle is used to determine the velocity in the x and y directions, then the velocity is the projection of vector velocity along the axes.

$$ (\dot{x} = \dot{p}\cos (\theta) ,  \dot{y} = \dot{p}\sin (\theta) )$$


$$\dot{\vec{p}} = (\dot{x},\dot{y}) = (   )$$

Ok this is complicated, but now you can apply a force to the wheeled vehicle and it will move like a real object would.


Death of a Famous Person

If only depressed people could see the aftermath of their death BEFORE they die: the hurt and sadness their passing causes. Perhaps knowing that they truly matter would help avoid a tragedy. 





Why did we lose such a man? He was not alone. He could have slept on my couch.  I could have listened. He meant a lot to me, his humour made it ok to laugh at ourselves.


We should make remembrance walls to people BEFORE they die, show them how much they mean to us, perhaps the outcome would not be so tragic then.

Saturday, August 9, 2014

Existing is not contributing. It's consuming.

The earth has a limited mass, limited resources, limited space, and time. We exist as a species racing against the inevitable end of what we know. Lifetimes are short. On universal scale, one life isn't remarkable.  This all seems dreary and unpleasant.

In the midst of this bleak reality, we possess the free will to change how we live and what that brief life means. We can simply exist, taking up precious resources to feed ourselves and amuse our sensibilities. Coasting along while others toil simply consumes resources. Or, we can find a way to contribute.

Does a supreme creator or pantheon of deities exist?  To me, the probabilities approach zero. However, we do know that humans exist, they struggle to survive and they need all the help they can get. Life is hard enough for most people.  A life dedicated to contributing to humanity will never be wasted.

The choice is yours, existing is not contributing.

Thursday, August 7, 2014

Species are not invasive, our concept of habitat is flawed.

Biologists confuse some of their key scientific concepts when they mix emotional attachments to some organisms with their knowledge of biology.  The human side of scientists is revealed when they speak about invading species. Really? Someone found aliens?  No, they are all rightful inhabitants of this planet whether we fondly remember them from our childhood or not as being local inhabitants.

What is the habitat of any one species on the Earth? Answer: anywhere it can eek out existence in accordance with Darwin's Law of Evolution. They are born to adapt and flourish or die. No animal has a zip code.

To say that one species is a pest or a weed, or is invading is to make a moral human judgment on a fellow creature where no value judgment is needed.  If trees from Asia can survive in North America then they are now local. At one time most trees were tropical, another time they were mostly coniferous.  Everything changes. Habitats change with speciation but their home is still theirs.

Guard against denying species access to their habitat, Earth.

Monday, August 4, 2014

Morality is an animal quality

For those who don't believe it, or were told something different, I present one small example of the fact that morality is an inherited animal characteristic.

Bear saves crow.

Well fed bear expends minimal effort, a quick grapple, and a gentle touch to rescue a fellow creature. This is altruism. What can the bear gain from the crow?  What does it matter if the crow dies? Sure if the bear was starving that crow might be dinner. But we would all act desperately if we were desperate.

This is a moral code in its raw animal form. It does not come from a book, nor from a gathering. It is in our nature. We can be kind to others innately.  Only what we teach one another changes what we used to understand.

Sunday, August 3, 2014

My dream: an open science consortium.

My hope, my dream, is one day an organization dedicated to open science, with fair treatment to all scientists is created.

Science must compete in the economic forum as a discretionary, competitive, selfish enterprise because that is what society expects. But each of these descriptors is counter productive to mankind. Even to the goals of science in general.

Society would go farther if scientists worked in a commune. A kibbutz if you will. There are so many ideas to uncover there is enough work to go around for all scientists to contribute.

However, the system is set up to reward less than free exchange of ideas.