Physics anyone?

ok,

Mark this on your calender!!

A physics festival is being held at arguably the leading theoritical physics reseach institute in Canada, the Perimeter Institute. It is called Quantum to the Cosmos. It is being held from October 15th to 25th, 2009 in Waterloo, Ontario, Canada.

It has an exciting collection of presentations, guest speakers and displays. Be sure to check it the program and the speaker list book and some time to go visit!!

Or even better you can sign up and be a volunteer to help out durng the festival!!

Oh to corner anyone of those speakers during one of the science at the pub sessions and talk physics over a beer...

mmm, now who would I want to sit down and chat with...

Well, if I must choose, not that I'm picking favourites (and excluding Dr. Hawkings of course, he would be top of the list!!).. Anyone would be a remarkable person to chat with.... heck, I'd even buy the first round or two. ;)

I've been following the X-prize ever since SpaceShip 1 did its thing.. so Dr. Peter Diamandis is a must chat. (that reminds me, I have to do a blog entry on the Goggle Lunar X prize )

the other HAS to be the Dr. Michael Griffin, former NASA Administrator.

UGOTTALUVPHYSICS!!

Rockets and Space

Ok, been a few weeks since last post.

Since I still don't have time to finish off some of the posts I have started, I'll post a two links of presentations that I've done for the Ontario Association of Physics Teachers( OAPT).

The "Trip to Mars" explains some of the physics/Math involved in designing a mission to the Red planet.

The "Rocket for Dummies" explains some of the terms involved in rocket engines and a discussion of how the engines are used.

The links take you to the OAPT web site for now. I'll move the links to a more permanent spot sometime soon.

Hope you learn something new in them...

UGOTTALUVPHYSICS!!

The Hissing Kettle

Ok, so this is what I want you to do.  

Fill a pot with water, put it on the stove, turn the stove on high and then watch and listen.  When you are done come back and read the rest.

I'll wait. Don't worry..

>waiting patiently<

>twiddles thumbs<

Oh, even though you are watching it, the water will still boil.

>Sigh. Me thinks  you shouldn't have put so much water in the pot.  Seems to be taking too long!<

Phew, I'm glad it finally boiled.  So what did you notice?

Notice "air bubbles" forming at the bottom? Well, I hate to admit it, as a kid I always thought it was air sneaking in. The bubbles are really just liquid water turning into a gas.

Did you notice the  bubbles disappearing when they started to float up?  This has to do with energy transfer.  

The temperature of an object is a measure of the average kinetic  energy or basically the speed of the molecules in the object, in this case, water molecules.  So when you add heat to the bottom, the molecules on the bottom get the energy first.  Sometimes they have enough energy to become a gas.  If enough of these molecules come together a gas bubble forms.  If the bubbles are big enough, they will start to float up after breaking the surface tension holding them to the bottom .  

As they rise, they come in contact with colder/slower moving water molecules.  These gas molecules can lose enough energy that they become "liquid" again and the gas bubble collapses. The collapsing bubble create the hiss that you hear.  As more heat is added eventually the gas bubbles make it all the way up to the top, because they don't lose enough energy as they rise, the gas "escapes".  The bubbles never collapse so the hissing stops and a boil soon develops.

One of the interesting aspects of energy transfer is that different materials transmit energy at different rates.  Fibre glass insulation is a poor conductor of heat so it is used to keep the house "warm" during the winter.  Some materials are excellent conductors of heat.  One of the substances is liquid helium.  It  is a VERY cool substances, I mentioned this before here near the bottom of the post.  Liquid helium is a super fluid in certain conditions. One of the properties of a super fluid is that energy is transmitted VERY quickly throughout the fluid so no bubbles get a chance to form.  In one of the series of clips here, it shows the transition from a "normal" liquid to a super fluid state.  In the second video of the 5 segments, at the 4 minute mark (a good explanation continues until the 5 minute mark),  it shows liquid helium going from "boiling" to not boiling.  This represents when the energy in liquid helium gets transferred away almost immediately.

You must admit, UGOTTALUVPHYSICS!!

Viscosity

Ah..gotta love molasses on toast in the morning!

Well at least not the cold mornings.  It takes too long to pour.  A term was developed to talk about how hard a substance is too pour.  It is called viscosity.  An over simplification of the what viscosity is that the longer it takes to pour the greater the viscosity.  

So you ask your self what has the highest viscosity?

Pitch..it has a viscosity of around 100 billion times that of water!! So THAT is slow.   My toast would be cold by then!! It takes around 8 years for a drop to "drip" out of a funnel.

Here is a picture

This experiment that has been running for 80 years!  Yes EIGHTY years!! Click here for details.

I thought I read somewhere that it "dripped" again recently but can't find the reference.  Ah well...

Now For the lowest viscosity?  Lets talk liquid helium!!  Now that is one cool substance.

This deserves a post on its own! But for now check this YouTube video on its properties.  This is the first of 5 segments.  But watch them all!!

You must admit UGOTTALUVPHYSICS!!

Frames of reference

Have you ever been resting in your friends parked car in a parking lot, not really paying attention, waiting for friends to come back with your coffee and you notice the car beside you move.  Your initial reaction is that you are moving.  That is a perfect example of frames of reference.  

The motion you see is based on how you look at it at or where you view the motion from.  I really can't explain it any better then how these two Professors did it back in 1960. I first saw this in high school and is excellent.

It is presented by Prof. Ivey and Prof. Hume of the University of Toronto.  

Well worth the 30 minutes it takes to watch!

Click here and enjoy!

Inertia

Inertia, more commonly known as Newton's first law.

I'll start with this picture and explain about it farther down.

Have you ever been sitting on a couch, watching your favorite show and the phone rings but the phone is in the other room and you don't feel like getting up to get it...well... that is inertia.

A very simple summary of the rule is "What ever the object tends to be doing at any given time, it wants to keep doing that."

The heavier, more massive, the object, the more inertia it has.  

Picture a piano...try to move it..pretty tough..now picture a piano moving.. it'll be pretty hard to stop.  That is an example of Inertia.

Another way of looking at it is this..

Picture yourself pushing car.. now try to push it as hard and as fast as you can.  If you push the car hard and fast enough you can actually put a dent in the trunk as you push it because the car didn't move as you were pushing it because of it's large inertia/mass...

Now picture the same thing but in a larger setting.. and thanks to Mythbusters you can actually see it.

The theme of this show..and overall a great critical thinking show at that.. was to try to have two trucks hit a car on opposites sides at the same time and crush it.  The problem was they couldn't time it right.  The trucks never hit the car at the same time.  So thanks to their success they have an almost unlimited budget and they were able to do something awfully cool. They were able to

 do this experiment with a rocket sled.  They put a car up against a brick wall and then tried to slam a rocket sled into the car to squish the car at both ends... seems logical... you push a car at one side the car gets pushed into the wall, so  both ends gets squished at the same time... well they forgot to remember Newton's First law..INERTIA.  The car is being pushed so quickly that the cars inertia is easily visible and the car refuses to move.

Here are three picturess from the above video.. you have to watch the video to truly see the effect...

Notice how the back wheel hardly moved while it was being "squished".  The cars inertia allowed it to be crushed on one side and not dented at all on the other.

Now that is cool...

In future posts I'll get more into inertia but what a great introduction to Inertia...

 and you have to admit..

Ugottaluvphysics.

Physics..the language..

Language..language.. language...

Everything has language..and language is sometimes confusing... but we need it...

A good example is in sports. Three of my favourite sports come to mind which have the same rule and each rule has a different meaning...

Rugby, hockey and soccer all have the offside rule...all have different meanings.  They needed a name to call the rule so they decided, for one reason or another to call it offside.  It could have been named other things but I'm happy to accept they used offside..confusing yes but acceptable..  To clarify my point, if you know nothing about either of the games but you know someone who does, try to get them to explain what offside means. Confusing huh!! Now try to get them to write a nice clear concise definition of it on paper... probably sounds gibberish if you don't understand the language of the game...But once you get to know the language of the sport it actually makes sense... 

Imagine reading the rules of rugby and they mention hooker, tight five, standoff, loose head, tight head, ruck, maul, up and under etc... your head would be spinning with the jargon..but once you get with the game it actually makes perfect sense... and is then more fun to both watch, play and coach...

The number of nights killed arguing the rules and decisions players made while playing any game (and having a few beverages at the same time) is great entertainment.  It makes the game more fun to watch and play.. and as a viewer you appreciate the nuances more.

Same can be said with physics (or any other science or just about any other job/skill/occupation for that matter).  It really isn't that bad once you get to know the language.  But you must be willing to learn the language.  It comes easier to some as too others but that is normal.  It is just like other things in life.  My golf game is awful but my billiard playing is a heck of a lot better, (mainly because I put a lot more time into it..My swing could just be as good if I put the time into it)  but i enjoy both just as much.

In physics you have a whole bunch of terms Inertia, Force, charge, poles, mass, momentum etc.  They sound confusing but they really aren't that bad once you get to know what they mean.  It may sound weird to some but talking about physics makes me appreciate physics that much more.  Just like talking about a good hockey game.  I have numerous friends (in and outside of teaching) who love talking physics.  The nice thing about physics is I don't need to go anywhere to see physics in action like, for example, if i want to go see a live rugby game.  For rugby I have to go to the rugby pitch to see a game Saturday afternoon.  With physics I can walk out my door anytime and see physics in action.

In the upcoming posts I'll try to take some of the mystery out of the terms.  If you also find someone or some forum or other blog that discusses physics you will learn to appreciate it that much more.  Keep an open mind....  I'm always learning about physics.  Just like about my favourite sports.  And I hope you get to learn to like the language of physics.  It will make it easier to then read about it and maybe even speak about it more often...  since you know..

Ugottaluvphysics!