The difference between science and engineering

I’m often asked what the difference is between science and engineering. Or, put another way, why did I find working in a ‘School of Engineering’ when I’m a physicist (i.e. a scientist) so difficult sometimes? (I now work in  ‘Te Aka Matuatua – School of Science‘ at the University of Waikato.)

The two disciplines blur a bit at the edges, and there can be substantial overlap between them. But, broadly speaking, I’d say a scientist is interested in how processes work, and why they work, and what might be done with them, whereas an engineer is concerned with making them work.

Here’s an example in the news recently: nuclear fusion. This has to be the Holy Grail of energy generation. Basically, if we can get nuclear fusion happening in a controlled way on Earth, we have a near infinite supply of clean energy, without a carbon dioxide molecule in sight.  Nuclear fusion is what powers the sun and other stars – a nuclear reaction (actually, a series of reactions) turns hydrogen into helium, releasing a vast amount of energy. In concept it’s easy. Hydrogen is readily accessible on earth (as H2O, water !); all we need do is to get it hot enough and let those nuclei get close enough together to fuse, and use the heat produced to generate electricity. The tricky part is making it happen.

Large-scale power generation from nuclear fusion is said to be about 30 years away. The problem (and ongoing jibe) is that it has always been about 30 years away. In 1990, it was about 30 years away (i.e. likely to happen now). In 1960 it was about 30 years away (i.e. likely to happen in 1990). The more that we try to get this technology to work in a meaningful way, the more engineering challenges the problem throws up.

The challenges are engineering ones, not science ones. We know the processes involved – what happens and why it happens – what we don’t know is how to make it happen on a large scale. But perhaps things are now looking better than the 30-year rule suggests. The demonstration reactor ITER, (banner photo) in France, is well into its build phase. The timeline is ambitious, but it hopes to achieve a  fusing plasma in 2025 and be in operation by 2035, a mere 15 years away. If that goes to plan, we will have reached the point where we can produce a continuous supply of energy (in ITER’s case about 500 megawatts) from fusion. The next part would be to capture that energy (more engineering!) and supply it as electricity, and a that point energy generation by nuclear fusion  can be said to be a reality.

Maybe in 30 years, then?


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