We are star-stuff: teaching about the elements

We had fun with these resources yesterday so I thought I would share them.

First up, where did all the stuff that makes up you and me come from?

Hold up your hand: You are looking at stardust made flesh. The iron in your blood, the calcium in your bones, the oxygen that fills your lungs each time you take a breath – all were baked in the fiery ovens deep within stars and blown into space when those stars grew old and perished. Each one of us was quite literally made in heaven. Modern science has shown us that we are more intimately connected to the stars than anyone dared to guess.”

The author of this magical piece, as far as I establish, is Marcus Chown, but if anyobdy can confirm or correct I would appreciate it.

I have this taped to the outside of my lab door, and was delighted to see a first-year take it down into her notebook recently (not sure the senior years ever stop to even notice it, but maybe that says more about our education than anything else).

It turns out that pretty much all the hydrogen in and around us is here from the time of the Big Bang over 13 billion years ago, and most of the helium is also that old (although helium is still being created all around us in the form of nuclear radiation). These are the first two elements in the periodic table. These eventually formed stars and in the process (nuclear fusion) formed the next 24 elements (up to iron). But even the energies involved in the sun’s day-to-day activites aren’t great enough to produce elements heavier than iron. So where did all the other 90 elements come from? (and remember that all these elements are what you and I are made from today).

Eventually the fuel (and energy) to produce fusion runs out and thus begings the final steps of a star’s incredible journey. But even in death they have a sting. Most ‘dead’ stars don’t just sit there, no sirree bob. The phrase ” it’s better to burn out than fade away” cannot be more apt than when applied to the death knell of one of these incredible stellar objects. If the star has enough mass then after collapsing in on itself it ‘rebounds’ and sends out the mother of all shock waves, one which is so strong that it actually tears the sun itself apart – it has become a ‘supernova’. A supernova explosion can be as bright as 4 billion (yes billion) suns. Not surprisingly it can become the brightest thing in the night sky for days (the last documented one within out own galaxy seeems to have been in 1604, but the Chinese also had written about one a thousand years before that).  Not that the 1604 explosion actually happened in 1604; it actually happened 13,000 years previously – it just took that long for the light to get from there to here (‘there’ and ‘here’ also being relative terms). But I digress.

When the star explodes the energy it contains is now sufficient to create all the heavier elements above iron, from copper upwards.

So there you have it: we are stardust.

The Amerian physicist Neil de Grasse Tyson sums it up rather nicely:

The gentleman you saw briefly in the background is Carl Sagan

Sagan was like Richard Dawkins without the arrogance, indeed he was a much more successful communicator  because he delibertately chose to preach not just to the converted, but to all. He would not have been impressed with Dawkins:

People are not stupid. They believe things for reasons. The last way for skeptics to get the attention of bright, curious, intelligent people is to belittle or condescend or to show arrogance toward their beliefs.

Here is Sagan taking us on a whirlwind tour of the history of our planetary and biological evolution.

But of course there’s no chance that any of the good stuff here will ever appear on a syllabus near you.
It’s also pretty unlikely that, with the exception of Humphrey Jones over at the frogblog, many other science teachers get animated by this. It seems to be the humanities teachers who are more likely to tackle the mystery and wonder of science. I guess those teachers who are fascinated by the wonder in Science are happy enough to enthuse their own students and leave it at that.
For another day perhaps.

And now for something completely different:

Science really does seem to be coming back into fashion – no longer is it just for the nerds. Or maybe it still is for nerds, but nerds are now cool. Thank you Stephen Fry.
Here’s Daniel Radcliff’s version:

Finally, for something a little more light. And for bonus points, for what sitcom do this band have an even more catchy tune?


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