Science

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.

Ten Great Ideas

Been thinking about my previous posting.

What are the ten great ideas in Science that we don’t emphasise?

The average student remembers bugger-all about science, but if we were told there were ten things that a student had to remember, what would they be?

1. Kinetic Theory – Everything is made up of atoms and vibrate at temperatures above -273 degrees Celsius.

2. Evolution

 3. Global Warming

4. Each atom is 99.9999% empty, and so therefore all objects which appear solid are almost completely empty space.

5. Deep Time: The age of the universe, the age of the Earth, the age of first life, and the age of humans

6. Science does not offer Absolute Proof

7. Fundamental Attribution Theory: Humans are genetically hard-wired to apportion blame for our own mistakes to others while wishing to take the credit for achievements which are outside our control.

8. Quantum Theory

9. What Science doesn’t know

10. Mass Extinctions

Where does the ‘stuff’ in trees come from?

learner.org is an interesting site which “uses media and telecommunications to advance excellent teaching in American schools.”

One of the issues they address is the area of misconceptions in Science.
This is a wonderful video which asks where does the material that makes up trees come from.

College graduates from Harvard and MIT were asked and not one of them gave the correct answer. In fact their answers were very similar to those given by six year olds.

It makes us question what other serious misconceptions we are responsible for, and leads us to question what and why we are teaching.

If we put together the ten most important ideas in science, how many of them are emphasised in our science courses?

College students answering these questions kicks in at about the 8-minute mark.

A primary school kid gets a look at solid air (dry ice) at 53:20. The look on his face is worth waiting for.

The video is 1:21 long. Access it here

Some nice Modern Physics resources

I think my first post here was on teachers.tv. They have just released some new gems on particles, presented by Brian Cox.
They include The Forces of Nature, The Building Blocks of Matter and The Hunt for the Higgs.

Some of these include interviews with Murray Gell-Mann. Follow this up with an entertaining presentation from the Nobel Laureate himself at Ted.com

In Search of Giants

Gell-Mann on TED.com

Magnets are so cool

Magnets are possibly the coolest thing on this planet. Einstein was fascinated by them, as is every kid who comes across them. Not only in Junior Cert but also in Leaving Cert. We just don’t do enough with them.

I have to admit to being just a tad obsessed with them myself.
There is a Junior Cert activity where you hang a bar magnet so that it aligns itself North-South. I never bothered with this because hanging the magnet from a retort stand meant that the magnet became attracted to the metal in the stand. Hanging it anywhere in the lab would have resulted in it being attracted to nearby metal (or so I thought) and getting a saddle for the  magnet to sit in was also a pain.
Then there is the issue of the magnets losing strength and becoming less effective.

 Discussing it with my Chemistry colleague Peter O Boyle, he showed me a simple way to hang the magnet, so I tried it with a recently purchased bar magnet, and just let it hang form my hand. And to my great amazement it worked a treat!

I know plotting compasses do this anyway, but there is something very weird about holding a piece of metal on a string, and no matter what way you turn around, the metal continues to stay still (or nearly so). Something very weird indeed. And it’s a feeling you don’t experience with a textbook

Apologies to everyone I have ever taught for not trying this before

‘Course nowadays there is a new generation of magnets of  which Neodymium seem to be the easiest to get hold of. There must be a bucket load of cool things to do with these.

 They certainly make the demonstrations in ElectroMagnetic Induction work a lot more smoothly.

One impressive application is ‘The World’s Simplest Motor’. Nobody should be allowed teach magnets again without getting the students to make these (there are even easier alternatives – do a search for ‘homopolar motors’ on youtube).

The Physics of Christmas

Related Links, courtesy of the PTNC forum

Is Santa Real?
A scientific debate which looks at both sides

Star of Bethlemen
What are the possible explanations? (in swf format)

Noradsanta
Ian Robertson has provided the following nugget:
At xmas every year for some 24 hours by far the busiest website in the world far is Norad Santa . Here the men and women of the North American Aerospace Defense Command behind the strongest doors in the world protecting their command centre under Cheyenne mountain use a range of surveillance technology to track Santa’s sleigh.
Kicks off in December.
Santa 2025
An uptodate activity (you need to register):
Santa is planning ahead for when humans colonise the rest of the Solar System – he may decide to move to another planet! In this fun activity pupils analyse planetary data to find which planet best satisfies Santa’s future requirements.

They then e-mail Santa to advise him of their decision, and – if you wish – design a Christmas card to show why this planet is such a great place to spend Christmas.

Science and Religion

Today Mr Dungan’s Leaving Cert Religion class joined our Applied Maths class for a discussion on Religion and Science. It started off very slowly but got a little heated before too long and the feedback was fairly positive with most students hoping we would repeat the exercise later in the year, but possibly in a more structured format.

I said I would post up relevant links, so here they are. The first two are the ones I showed on the day:

Richard Feynman on Religion & Mysticism

Uncertainty about the Big Bang
(I paused the clip when the scientists started going into detail on String Theory)

John Polkinghorne discusses Science and Religion here
Steven Weinberg discusses Science and Religion here

I think if we’re running this again two issues we might look at are
1.   free will
2. Creationism and Evolution (just enter “Ceationism and evolution” in a youtube search) but be wary, there are lots.

Uncertainty in Science

Possibly one of the most important concepts that should come out of a Science Education course is that Science does not provide certainty – it simply can’t. It’s all about probability.

The experiment we do in school to ‘prove’ that solids expand when heated, does nothing of the sort. We take one metal ball and show that it passes through a ring when cold but not when hot. Now explaining why this is not a proof is a nice excercise in itself. Initially students are slow to come up with any reason. To be honest they just don’t know what I’m on about. but then you give them a couple of examples: it’s only one metal, it’s only being heated over a rather narrow temperature range etc, and they quickly get the idea and can apply it to other experiments.

Why is this important?
To take one example, the whole notion of theory versus fact versus hypothesis is very ambiguous, but yet these words often get thrown around when knocking the theory of evolution. The implication is that because it is a ‘theory’ it is not well accepted in the scientific community; the word has a different meaning in common parlance than it has in the science world.

Secondly, scientists are often pilloried because they won’t state categorically that powerlines / mobile phones / radiated foods are safe. the implication is that if these were safe then science could prove it and say so. the reality is that you can never prove anything to be absolutely safe (life is carcinogenic) and we need to bear this in mind when weighing up the evidence.

The American physicist Richard Feynman talks about uncertainty in science – albeit in relation to his views on religion – in this clip from youtube.

So you would think this concept of uncertainty in science would get mentioned somewhere in the syllabus – at Junior or Senior Level.

But not a dickie

What’s the story with poor pay for science-related jobs?

Last Friday’s Irish Times (9/11/07) did a special supplement on “Jobs in Science”. They included the results of a survey carried out last month of salaries in the pharmaceutical and medical devices market. The results were (to my mind at least) surprising.

They listed thirteen categories and looked at the lower, mid and top entry level.

The average mid-entry level was about 29K and the average top level salary was about 45.5K. It was a little unclear because many of the top salaries were listed as 50,000+ and the + wasn’t specified.

I’ve been teaching full-time for ten years so presumably am at the lower end of mid-entry and my basic salary is about 52K.

There is no  secret here (why are people slow to say how much they get paid?) – all union journals list the salary scales for teachers. Almost all teachers with the same experience are on the same pay, although there are extra payments if you teach in a gaeltacht area, or in a school for the blind etc.

There are of course are all sorts of extras available, from correcting exam papers, to supervising exams to giving grinds.
Supervision and Substitution is another chore most teachers sign up to, covering absent teachers for a couple of periods a week for (I think) about 1500 to 2000 euro.

Starting salary for a secondary teacher (full-time) is about 37K, although the hard part is getting that coveted full-time position.

The holidays aren’t bad either.

And anyway, how are people paying big mortgages on these science-job salaries? Something seems decidely odd.
I know I wouldn’t be rushing to sign up to a science course in college based on this report.

Secondary level teacher salary scale here

It’s Science Week again! wa bloody hay

Science Week (or should that be Leo Enright Week?) tends to bring out the cynic in me.
For a full week we get bombarded with media-bytes about how great Science is, how much fun it is, and how the drop in the number of students taking up Science is nothing short of a national tragedy.
It fact let’s call a spade a spade here; students who are capable of doing Science but who instead choose a more glamorous career (in business!) are just downright selfish and unpatriotic.

But Science IS boring, – at least the way it’s presented in textbooks. And it is bloody hard. And no amount of exploding-custard tricks is going to change that.
I’ve no doubt students are delighted to be going to all these demonstration lectures – I would be too if it was going to get me off double Irish followed by Maths and Religion.

But has there been any research which shows that these lectures are actually leading to the desired outcome – and what is the desired outcome? Who gets to check? Who gets to decide whether too much (or too little) money is being spend on this?

And is it fair to portray only the fun side of Science when all around us are examples of Science gone wrong? We emphasise that it is Science which gives us our high standard of living, but when it comes to the negative applications of Science (military arms, etc.) we simply wash our hands of this and declare that this isn’t Science – it’s Technology.

And we hope nobody asks any awkward questions in these shows; why would they – it’s not like any of these more important issues get covered in their Science Classes in school – is it?

Science Week Ireland 11 to 18 November. Coming soon to a college near you.