# Firewalking; a wonderful introduction to heat

I introduce Heat Capacity by asking the following question: How come, when you get up in the middle of the night to take a pee, and walk across both tile and carpet, the tile seems much colder than the carpet even though in reality both are at the same temperature (room temperature)?
It introduces the concept of thermal conductivity, and also acts as a reminder to why we need objective measurements in science.

This video on firewalking would make a wonderful follow-up activity, and might just make some a little wary of  ‘life-coaches’.

Thermal conductivity and Low heat capacity; Firewalking explained in terms of taking a cake out of an oven.

Would work at both Junior or Senior cycle.

So how could you design an experiment to ascertain who is right?

And then while we’re here at all, let’s look at an intertaining presentation by Michael Shermer on debunking pseudoscience.

From http://www.ted.com; part one of two. The second half is also well worth seeing.

I’m teaching Sound with both Junior Certs and Leaving Certs at the moment.It was pretty cool to have ready access to these amazing clipsSonic Boom: very useful when discussing the Doppler Effect.As usual there are loads of related clips: Lyre bird imitating a chain-saw.Not sure about the relevance, but this has to be seen (and heard) to be believed.    Finally a quick search for ‘Teaching Sound” brought up some nice ideas here:We need more of this – it’s so easy to exchange ideas. Thanks Mr Noon

# Junior Cert Science Investigations

Our third years have started their junior cert investigations. The physics version is to compare the insulating ability of different materials.

Seems very basic, in fact too simple to qualify as an investigation at this level.

Until you try it out.

I don’t have third years this year but I walked in to PO’s class to see how he was getting on . They were starting off with a control: Putting 100 ml of water into an uninsulated calorimeter and plotting a cooling curve.
But they ran into problems straight away. It took ages for the water to cool down from a starting temp of 80 degrees.  So they are wondering how they will manage when it is insulated.

One student came up with the clever idea of using a set time and noting the temperature drop for different materials.

Others suggested using a smaller volume of water to begin with. So then we had to decide which was the best idea, and more importantly how would we decide which was the best idea.

Test them by experiment – bingo.

Now we were getting into it. Conflicting ideas, not quite getting published in a peer-reviewed journal, but nevertheless good stuff. Next we will look at whether we can carry out valid comparisons, but just arguing over it introduces a personal ownership factor as opposed to just following the traditional cook-book receipe.

Then there is still the issue of making sure ‘amounts’ are equal; equal by volume or equal by mass?
And oh my goodness, what if there is no one right answer?

Their homework was to come up with their own ‘hypothesis’; not which was the best insulating material, but rather which is the best way to test this.
Then the bell went and they reminded us that we wouldn’t see them again until  January.
Oh well.

I discussed this with PO last year.
The key is for us teachers to get comfortable with this approach and try to adapt all experiments so that they can be carried out in this manner. There may just be hope for us yet.

# ‘Story with Global Warming not on the syllabus?

The nice thing about Global Warming is that it that it may very well wipe us out as a species in the next couple of hundred years.
It is the single greatest catastrophe to hit human-kind EVER.

And in the grand scheme of things we couldn’t say we didn’t deserve it, or that we haven’t been warned.

Because it’s effects are not affecting us directly at this moment in time we just choose to bury our heads in the sand.
It’s like the story of the frog in the pot:
If you throw a frog into a pot of boiling water, it will jump out instantly.
Yet, if you were to place it in a pot of cool water and slowly raise the temperature to boiling point, the frog will unsuspectingly meet its fatal demise.

Consider the following.
Junior Cert Biology:
Consider and discuss how human activity affects the environment, both positively and negatively (two examples in each case).

Junior Cert Physics:
List the advantages and disadvantages of different energy sources of energy, including nuclear sources of energy, as part of the solution to national energy needs.

Actually scratch that last one.
Apparently we only need to look at energy in terms of out national energy needs, not in terms of the fact that we are the single worst thing to ever happen this planet.
So that’s allright then.

Junior Cert Chemistry:
Faic.
Not a cracker.

So how about the Leaving Cert?
Well let’s see.
There’s nothing in Biology (hopefully somebody will prove me wrong here) and nothing in Leaving Cert Physics.
Leaving Cert Chemistry does go into it in some detail (for the small percentage of students who do it at this level):
The greenhouse effect and the influence of human activity on it,
and later;
Possible implications of the increased greenhouse effect.

Well here’s one Possible effect of the greenhouse effect for you;
Your children may very well be the last generation to live what we now regard as a ‘normal’ life, and it may very well be too late for us to do anything about it now even if we did want to.
And let’s face it; with the current demand for chelsea tractors in this country, anything we do will amount to little more than lip-service.

And we can’t even say we didn’t deserve it.

Sweet dreams!

# No evolution in Junior Cert? Say it ain’t so!

Okay, let’s get one thing straight.
The greatest single idea that mankind has ever – and I mean ever – come up with is The Theory of Evolution.
It is the greatest idea in the history of the universe, and even comes ahead of the idea of the origin of the universe itself. And I say this as a physics graduate.
It’s not on the Junior Cert Science syllabus.
see for yourself

Now I do believe there is a general outcry that not enough students are taking science subjects at Leaving Cert level, and indeed this revised syllabus was designed partly to address this.
Indeed the ‘Introduction and Rationale’ section of the syllabus states:
“Arising out of their experiences in the junior cycle, it is hoped that many students will be encouraged to study one of the subjects in the senior cycle, thus preparing themselves for further study or work in this area”.

So why would you leave out the most incredible, stupendous, unbelievable (almost!), bizarre, wonderful, horrible, exciting, humbling, uplifting, emotional and awe-inspiring idea that the students could ever possible come across in thier lives, never mind in their school experience?

And here’s the kick.
Every so often the media here grab hold of the fact that the U.S. education system is having difficultity keeping evolution in their syllabus, and we think to ourselves “oh those silly yanks”.
Meanwhile we remain in ignorant bliss that we never had it on our syllabus in the first place.
Of course, the percentage of the school-going public that take Biology at leaving cert level do come across this, but for the rest of us there is nothing.
At least not in their science education.

Interestingly, while I don’t see a mention of it in the Junior Cert Religion syllabus (now there’s another missed opportunity! Imagine being able to make religion interesting?), it does make an appearance in the Leaving Cert Religion syllabus (check it out here – it’s first mentioned on page 103 of 110 in the pdf document).
Here’s part of what it says:
“Outline Darwin’s Theory of Evolution and highlight the major areas of conflict with religion”
Now there’s one to get your teeth into.

This section also delves into the origins of the universe, along with concepts like Heisenberg’s uncertainty principle. I reckon there’ll be some serious nervous religion teachers going in to class that day.

The fact that there’s nothing about The Big Bang or Origin of the Universe in the Junior Cert or Leaving Cert physics syllabus is for another day . . .