Since I am no longer teaching at Travis High School I will no longer be using this blog.  But I wanted to thank the 34 students that were in my two classes for a wonderful semester.  I’ve learned so much from all of you.

All these photos come from the world’s largest machine.  I think they’re quite beautiful photos.  What does this machine do?  It turns out that it smashes some of the smallest known things in the universe to find out how things work.  They’re smashing atoms together to find out what they’re made of!  It’s called the Large Hadron Collider (LHC) and it’s located on the Swiss-French border near Geneva.  It’s a very very big science experiment!  It cost around 9 billion dollars.

All photos © CERN. They’ve been pulled from The Big Picture

I just read on Seed Magazine’s daily zeitgeist that National Public Radio — the radio station that’s 90.5 on our Austin, Texas dial — has something going on called WONDERSCOPE where us citizen scientists submit a video on a science concept of their choosing.  The first assignment/concept is TIME.  You get EXTRA CREDIT if you make a video for this!  Talk about how it shows up in our class, how it goes beyond what we’ve learned, and what you find interesting about it.  See below for details on submitting.  The link to the wonderscope page.  Ask me for more info or help if you want to do this.  I can help with video editing and stuff like that too.

an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.

EX. natural tendency of objects to keep on doing what they’re doing. All objects resist changes in their state of motion.

f=ma

EX. heavier objects require more force to move the same distance as lighter objects.

for every action there is an equal and opposite re-action.

EX. whenever an object pushes another object it gets pushed back in the opposite direction equally hard

Newton’s Third Law: The law of force pairs is probably the most familiar. It states that every force involves the interaction of two objects. When object A exerts a force on object B, object B also exerts a force back on A. The two forces are equal in strength and oriented in opposite directions.

EXAMPLE: A swimmer pushes off the wall of a pool. The swimmer applies force to the wall but her motion indicates that force is being applied to her too. The force comes from the wall and it is equal in magnitude and opposite direction.

Newton’s second law of motion - the rate of change of momentum is proportional to the imposed force and goes in the direction of the force.

Types of friction:

Dry friction which is caused because of the movement of a solid surface over the other solid surface. It has further two types including static friction and kinetic friction. Secondly, lubricated friction which is because of two solid surfaces separated by liquid or gas layers. Thirdly, there is fluid friction which is because of friction between the layers of fluid. Fourthly there is skin friction which is also known as drag friction. Finally there is internal friction that is between the solid materials when it undergoes the process of deformation.

I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. For Ex. If you push someone on roller blades there going to go forward and not stop.

II. The relationship between an object’s mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector. For Ex. it is like a rocket taking off horizontaly.

III. For every action there is an equal and opposite reaction.For Ex. newton’s cratel thing where one ball hits another 

photo from bbc website.

Tonight there’s a meteor shower called the Leonids.  Read more here and here!

here is an extreme example of air resistance showing up in our normal projectile motion equations.  Actually, this object is moving so fast and so high above the Earth that our equations need to be modified quite a lot — but you asked in class how things would change with air resistance… so here’s an answer.

Sometimes names aren’t what they seem in science and mathematics.  A case-in-point I will use here is an equation that you know very well: the Pythagorean Theorem.  The theorem was well known and understood long before Pythagoras and his secret cult.  Here’s a good page on it.  Besides the equation being used in the west and mideast, it was also used in China around the turn of the century.  This theorem is an example of how scientific and mathematical knowledge know no borders culturally, politically, or otherwise.  Why was it that Pythagoras was named after this most useful formula?  Did he discover it, popularize it, or were his uses of it clever/smart/useful enough to merit applying his name to it?  Is it the same type of situation that the Persian mathematician and astronomer al-Kashi, in some countries, has the ‘law of cosines’ named after him?  In French the law of cosines — a more generalized version of the Pythagorean theorem — is known as “le théorème d’Al-Kashi”.  This ambiguity of naming conventions in science and mathematics is a source of confusion.  For instance, Galileo dealt with the concept of inertia at great length before Newton wrote it down in his famous book on mechanics called the Principia.  Newton included inertia as his first law of motion.  Why isn’t it called one of Galileo’s laws?  Who deserves naming credit?

Also, as an extra credit challenge, can you derive the Pythagorean theorem from the figure above?  Hints: find the areas of all the figures that have to fit into the area of the largest square.

Incidentally, since we’re now speaking of Galileo and inertia, and since one of the questions posed below on the images of Rosetta from three different reference frames, one thing that Galileo’s name stuck to was this technical-sounding tidbit: “Galilean Transformation”.  This falls out of the Newtonian Laws of motion not depending on velocities — only accelerations.  So it doesn’t matter what the velocity is — can we ever detect how fast we’re moving if we’re not comparing to something else (remember the train with no windows question from the homework?).  This idea of being free to choose one’s frame of reference is the basis of Einstein’s Special Relativity.