23 Jan 2019

Nanogirl: 'The whole goal of science is to prove yourself wrong every day'

From Afternoons, 1:10 pm on 23 January 2019
Michelle Dickinson AKA Nanogirl

Michelle Dickinson AKA Nanogirl Photo: RNZ

Even the best and brightest are wrong sometimes – but people seem more resistant than ever to question their own beliefs.

Nanotechnologist and science educator Dr Michelle Dickinson, AKA Nanogirl, is passionate about debunking commonly-held myths, but she recently discovered that one of her own long-held beliefs was false. Artificial sweeteners, which she had thought were cancer-causing, are in fact... not.

Dickinson's false belief shows how easy it is for myths to become entrenched in our minds as facts, she tells Jesse Mulligan.

“I had a belief that artificial sweeteners caused cancer. I can’t tell you where that came from, it was probably from my mum who read it in a magazine or on the internet.

“And I believed that that was true and so I avoided artificial sweeteners … I’m a nanotechnologist, I haven’t got a specialisation in artificial sweeteners and I never questioned it, I just accepted that somebody told me once that it caused cancer and therefore I was going to avoid them."

While researching for her NZ Herald column, Dr Dickinson came across a study that analysed 13,000 peer-reviewed papers on artificial sweeteners.

“I realised that this 'artificial sweeteners cause cancer' belief actually came from one study in the ‘70s that was done on rats.”

That study was the one that attracted all the media attention, she says.

“The media story was the one that got through to my brain [although it] was not backed up scientific evidence when you look at the bigger picture. And so I was totally wrong.”

These kinds of falsehoods have a habit of sticking around, Dr Dickinson says.

“I always thought that bulls went for the colour red because that’s how it works in the bull ring? Bulls are colourblind, and we only realised that relatively recently. It’s not the red colour [they're attracted to], it’s the fact they’re having something waved in their face."

French matador Sebastien Castella reacts during a bullfight at the Canaveralejo bullring in Cali, Colombia, on December 30, 2018.

French matador Sebastien Castella reacts during a bullfight at the Canaveralejo bullring in Cali, Colombia, on December 30, 2018. Photo: James Arias / AFP

“I was told at school we tasted on different parts of our tongue, so the five tastes that we have are located on different parts of the tongue – they’re not.”

Proving something to be wrong is the cornerstone of good science, she says.

“As a scientist we will come up with a hypothesis, something that we think is true, and the whole goal of science is to prove yourself wrong every day because your hypothesis should be able to stand up to all of the attacks against it.

“So as a scientist you will design experiments that try and prove your theory wrong all the time,” Dr Dickinson says.

The principle of peer review underpins this, she says.

“Other people will look at your research and say 'you may have had a bias here, you were doing an experiment to prove yourself right'.”