Get ready for the quettabyte: new prefixes for really big numbers

Hello Nature readers,
Today we discover that the Great Depression shaped people’s DNA, explore a new era of behavioural climate research and learn how many yottabytes are in a quettabyte.

The Great Depression shaped people’s DNA

The cells of people who were conceived during the Great Depression show signs of ageing faster than they should. The changes were measured in the cells’ epigenome, the chemical tags attached to DNA that determine how and when genes are expressed. Researchers say that the patterns they have uncovered could be tied to higher rates of disease and death.

Extreme numbers get new names

By the 2030s, the world will generate around a yottabyte of data per year — that’s 10²⁴ bytes, or the amount that would fit on DVDs stacked all the way to Mars. The data boom has prompted the governors of the metric system to agree on new prefixes to describe the outrageously big and small. The prefixes ronna and quetta represent 10²⁷ and 10³⁰, and ronto and quecto signify 10⁻²⁷ and 10⁻³⁰. Earth weighs around one ronnagram, and an electron’s mass is about one quectogram. Ronna and quetta might sound strange now, but so did giga and tera once, says metrologist Olivier Pellegrino. This is the first update to the prefix system since 1991, when zetta (10²¹), zepto (10⁻²¹), yotta (10²⁴) and yocto (10⁻²⁴) were added.

Theranos founder sentenced to 11 years

Elizabeth Holmes has been sentenced to 11 years and 1 month in prison after being found guilty of fraud against investors in her blood-testing company, Theranos. Theranos claimed it could run more than 200 health tests on just a few drops of blood taken from a finger prick — but the claims were exaggerated. “She pushed the envelope a little too far,” says legal scholar Anat Alon-Beck. “You fake it ’til you make it, but it was too much ‘fake’.”

Online groups support women in STEM

Giving women fair access to careers in science, technology, engineering and mathematics (STEM) requires mentorship and a professional network — so-called social capital. “I can’t underscore how important this community is for girls and non-binary people,” says Tarika Barrett, an education reformer and chief executive of the non-profit organization Girls Who Code. “When they’re feeling as though they can’t persist in the field, they have that community to lean on, coupled with their computer-science expertise.” Four leaders of groups dedicated to women in technology share their stories and tips for better allyship.

‘A new era of behavioural climate research’

Climate change is rooted in human behaviour, and behavioural change will be key to achieving solutions. A joint special from Nature Human Behaviour and Nature Climate Change focuses on how to better incorporate behavioural science into tangible improvements in climate policy. “We are at the beginning of a new era of behavioural climate research,” says the accompanying editorial.

When your book gets a backlash

Neuroscientist Gina Rippon describes shoddy science reporting and the misuse of brain research as “neurotrash”. One example is the way brain images are “hijacked by self-help gurus, relationship counsellors and even those espousing single-sex education”, she says. Neurotrash contributed to the furore over her book, in which she argues that our brains are not fixed as male or female at birth, but are instead highly plastic, changing constantly throughout our lives and influenced by the gendered world in which we live. Rippon shares what it was like to write and promote her first popular-science book and how she dealt with the backlash.

Podcast: A radical plan for vaccine equity

Countries in the global south who found themselves at the end of the queue for COVID-19 vaccines have banded together to create a radical plan to produce mRNA vaccines locally. If successful, they could end a dangerous dependency on wealthy nations and help to stop pandemics before they start.