A doctor goes to middle school - A physician relearns physics!

Learning lessons relearned! Or

Should weight be measured in Newtons?

A small group (n=3) of middle school kids recently asked me to work with them on some physics topics.  Why they asked me a physician who has not read physics since high school is a mystery.  I think it had something to do with them knowing my interest in education.

I am a sucker for this type of stuff and thus I agreed.  I did not even ask what topic they were struggling with; after all how difficult could middle school physics be?  The fact that they asked me while we were at a charity fund raiser probably meant I was under the influence (of good thoughts!).

Turns out they wanted to know more about simple machines, solving problems regarding mechanical advantages of levers and inclined planes and pulleys.  I had to do a crash course on the topic quickly finding some resources on the web that helped me get up to speed.  The detailed description of the session follows but if you want to cut to the chase, here are the take home points.  These were brought home to me very strikingly during the 2 X 90 minute sessions I spent with them over the next 2 days.  Looking back these are the essence of constructivism and it was great to see these validated at a personal level.

Take home points:

• Spend more time on the fundamentals even if the learner appears to have gotten them.  Don't assume they know these even if it should have been learned a while back.  If nothing else, it helps to revise.  
• The learners needs to know why they are learning something before they learn it
• Connect to practical real life examples
• You have to know what they already know and don't know
• Words are constructs and carry a much deeper meaning for each person.  Having a learner rephrase something in their own words will tell you how much they understand
• Since peers are more likely to be at the same level they innately understand the perspectives and understanding of their co-learners.  
• If you sense that one of them had an AHA moment, let them explain it to the others in their words. The thrill of a learner's AHA moment will give you goosebumps.  Savor it and leverage it.
• When only one person in a group does not appear to get it, it is not because they are less intelligent but often they are thinking about it differently or even at a deeper level.  This conflict between their prior knowledge and what is being discussed is a great opportunity to leverage further discussion to clarify the fundamentals.
• Learning occurs best when the learner is motivated to learn.

As I started my crash course on simple machines, I found myself struggling to remember the definitions and units of force and work and power and the relationship between them.  So I quickly brushed up on some basics:

• Force (Newtons) = Mass (kg) X acceleration (m/sec/sec)
• Work (Joules) = Force (Newtons) X distance (metres)
• Power (Watts) = Work (Joules)/Time (sec)

As I reviewed this material, all the memories of the joy of learning physics came rushing back.  I was ready to work with the students.  I hoped I could get them to love physics as much as I used to.  I decided to make sure they were well founded in their concepts before we got into any calculations.  Our conversations went something like this (there might be some inaccuracies here but read this in the spirit in which this conversation took place):

Me: What does a machine do?
S1: It makes work easy
Me: What does that mean?
S2: It lets you do more work than you put in
S3: But that's not possible, you cannot generate more work than you input!
S1: You mean you cannot create energy right? That the principle of conservation of energy
Me: What is the relationship between work and energy? Are they the same thing?
S2: Well their units are the same
S3: You put in energy to do work right?

We went of on a tangent here:   

 Work = force X distance = mass X acceleration X distance = Kg X m/sec/sec X m = kg m^2/sec^2

 Kinetic energy = 1/2 mv^2 = 1/2kg (m/sec)^2 = 1/2 kgm^2/sec^2

 Potential energy = mgh = kg X m/sec^2 X m = kg m^2/sec^2

 So they got the idea that the units of work and energy are the same. 

Me: So what does a machine do?  Seems you decided it cannot do more work than you put it.  What is work?
S1:  It is force X distance
Me:  So how does that apply to a lever?
S2:  In an ideal case with no friction, the work put in = work put out.  So force put in X length of effort arm = force put out X length of resistance arm
S3:  So depending on the length of the 2 arms, the lever changes the amount of force.
S1: So the amount of work stays the same, the lever can make things easier by making you put in less force to do work!


Me:  Great job!  Now lets take another question.  What does it mean when you get on your bathroom scale and it reads 98 kg?
S1: That your weight is 98 kg?
S2: punches S1 lightly
S3: I am not sure what you mean.
Me: What would happen if you used the same scale on Moon?
S1:  Oh I see what you mean.  98 kg is your weight on Earth.  It would be less on Moon
S2:  Yeah, its got less gravity of course.
Me:  What about in space?
S3: Well the scale would read zero I think? Since you are beyond Earth's gravitational force.
S1:  That's 9.8
Me:  9.8 what?
S2:  9.8 Newtons.... No...  g is 9.8 m/sec^2
Me:  So what would that be...
S3:  that 98/9.8 = 10
Me: 10 what?
S1:  98 kg / 9.8 m/sec^2 = 10 kg/m/sec^2
Me: so what is the difference between mass and weight?
S2:  Oh I get it, what you weigh on Earth is your weight and the amount of matter you contain as measured in space is your mass.
Me:  OK, so what is the unit of mass?
S3:  Kg of course.
Me:  So you just told me in space a 98 kg person would "weigh" 10 kg/m/sec^2
S1:  This is confusing.  Seems like the units are all messed up.
Me:  Seems like it doesn't it?  What happens when you stand on a scale on Earth?
S2:  Your weight pushes it down.
S3:  The gravity acts on your mass and pulls it down.
S1:  You are exerting a downwards force on the scale
Me:  How much force?
S2:  Is that your weight?  So weight is a force?  Then why is measured in kg?
S3:  Yeah the unit of force is Newton!
Me:  What is force according to Newton?
S1:  Mass X acceleration
S2:  Newton is kg X m^2
Me: So how does that convert to your weight?
S3:  I get it, its the gravity acting on your mass
S1:  Yeah it is 10 kg X 9.8 m/sec^2 = 98 kg m/sec^2
S2:  Which is 98 Newtons
S3:  So weight is a force?  Why do we measure it in kg?
Me:  Yup so weight should be measured in Newtons not kg, I think we use kg because its become ingrained in our system.
S1:  Got it "The heavier you are, the more you weigh!"
On that very profound note we took a break while S2 and S3 gave S1 very strange looks!

We covered many other questions.
Why are screws and wedges like an inclined plane?
How does the concept of distance apply to inclined planes and to pulleys?
How does a movable pulley generate mechanical advantage when a fixed one does not?

The conversations went on for a long time.  Their eyes were shining, there were numerous "AHA" moments.  They were excited.  They were teaching each other.  I had the most fun I had in a long time.

The only problem...
They want me to do physics sessions with them throughout the summer vacation!

I wonder where all the retired folks go... this would be an amazing win -win situation.  They could work with school kids to help ignite their passion for the sciences or other subjects while keeping their own brains and hearts young.

Google Drive and Kindle - connect them automatically!

I have written a lot about reading articles on the tablet - referring mostly to an Android tablet.
For those who have a Kindle or a Kindle Fire, with the advent of Google Drive and Wappwolf, there is now an automated way for getting your articles sent to the Kindle.

Google Drive is the new incarnation of Google Docs.  This works a bit like Dropbox but has 5GB storage.
Kindle is Amazon's eBook reader
Wappwolf is a great app that works with Google Drive (and also Dropbox).  When you save a file in a specific folder in Google Drive, it will complete a set of predefined tasks for you.  Thus whenever you see an article that  you may want to read on your Kindle, just save it to a specific folder (e.g. "Send to Kindle") in the Google Drive.  This will automatically show up on your carousel or book shelf on your Kindle.

Wappwolf has a number of other automations that it can perform e.g. photographs saved in a specific folder could be uploaded to Facebook or Google+.

The Wappwolf website indicates that SkyDrive and Box functionality will be coming soon.

This is a great advantage of cloud storage and cloud apps.  They can automate your repetitive tasks and improve efficiency.  I am waiting for the app that when I save an article to "Send to my cortex" folder will upload it to my brain while I sleep!

Is Academic Medicine Reaching a Twitter Tipping Point?

The last 3 days have been exciting and invigorating - meeting old friends and making new ones at the SGIM Annual Meeting in Orlando.  There have been some amazing presentations and workshops.

Looking back over the last few days, it seems that SGIM members are beginning to adopt social media.

• The SGIM education technology group decided to use Twitter instead of a listserv to stay in touch between the annual meetings.  The plan is to use a #SGIMedTech hashtag for the group
• There was a great tweetup of SGIM tweeps 

• A Social Media Interest Group was created with #SGIMSoMe hashtag
• There is now a growing list of SGIM members using Twitter
• The group decided to do a project to study the effect of SoMe to help other interest groups improve communication between meetings.  

Does this mean academic medicine is reaching a tipping point?  There is still a lot of reluctance to adopt Social Media but the walls might be coming down.  I expect in 1 or 2 years, I will look back at this post and remember how this all started with a tweetup on one Thursday evening in Orlando!

Challenges in doing Social Media Workshops for Medical Educators

In the last 2 weeks, I have had the privilege to be invited to do presentations on use of Social Media in Medical Education at 3 different places.  It is exciting to see the growing interest levels in social media in medical academia.  There is a buzz in the air at these events which is quite refreshing.

Each of these was a large group presentation to an unfamiliar audience.

Sitting at the airport waiting for a flight back home from the last one of these, here are some reflections:

• Presenting when you don't know your audience's level of expertise with the topic is always challenging.
• Use Google Moderator if possible to get some idea of what the audience would like to see.  This is a great tool do a needs assessment and also weave a social activity into the hidden curriculum.
• Find out as early as possible about Internet access at the site.  Will the audience have Internet access?  Is it a public WiFi or is a password or some other security measure required?
• If you require your audience to go online project a slide with appropriate instructions before your presentation.  
• If you need the audience to download an app or create an account, ideally you want to send these instructions out by e-mail well ahead of time.  Thus if you want to do a demo of a Twitter chat you may want them to create a Twitter account ahead of time and remind them to remember the password.  
• Expect a significant portion of the audience not to have followed up on those instructions. There could be many good reasons for this, e.g. did not want to create a Twitter account due to privacy concerns. Or they are in a different stage in Kolb's learning cycle (more on this below).  Say something to prevent chaos (e.g. "how do I get connected?" or "I never got the instructions!" or "I am worried about creating a public profile").  Say something like, "How many have created a Twitter account? That's great, we have enough participants for a good demo.  Those who have not, will be able to watch the exercise as we will project it on the screen.  Those who did, please follow the instructions in your handout (or on the screen) to get started. 
• One of the best ways to think about the audience participation is to review Kolb's learning cycle.  According to Kolb, when people learn new things, they either want to watch and think OR feel and do.  This is a bit of a simplification and you can read more about this here.  Kolb has a learning style inventory that people can fill out and share with you so you can know ahead of time what their learning style is.  But that is a long questionnaire and is not free.
  I wonder if one could pair up an Assimilator (watch-think) person with an Accomodator (feel-do) person and have them work together through the exercises?  
• Somehow we also have to account for the participants' digital competence.  Ideally you could create small groups which include at least one computer expert and one Accomodator.  
• The auditorium/room where you are presenting might preclude working in small groups.  
• All you can do is cross your fingers and toes and hope for the best!  Just try and light the fire and leave them with resources to go back to.  I tell the audience to find a social media mentor at their local institutions who can get them started.