Ted Streshinsky/CORBIS/Corbis via Getty Images
Mike Follows
Sutton Coldfield, West Midlands, UK
Only a few are truly essential to biology and modern technology. Life itself depends on a core group of about a dozen elements – such as carbon, hydrogen, oxygen and nitrogen – along with others like phosphorus, sulphur, calcium and iron that support essential biological processes. Without these, life as we know it wouldn’t exist.
Industrialised civilisation relies on a further set of elements that underpin commerce and technology. Silicon is central to electronics; copper and iron are crucial for infrastructure and machinery; and elements such as lithium and cobalt are important for batteries. Rare earth elements also play key roles in many high-tech devices, ranging from smartphones to wind turbines. Losing this group wouldn’t eliminate life, but it would dramatically reshape society.
A particularly important case is uranium, one of the few elements capable of sustaining controlled nuclear fission. It has played a major role in nuclear power generation and in nuclear weapons. However, we could develop nuclear power that produces minimal waste, cannot undergo meltdown and makes diversion of material for weapons impossible.
“
There are only a few elements on the periodic table that are truly essential to biology and modern technology
“
For this, we would need thorium, used in liquid fluoride thorium reactors – a technology whose development was mothballed after the second world war. Such reactors could provide abundant energy without contributing to the greenhouse effect.
Hillary Shaw
Newport, Shropshire, UK
It depends on what society you envisage. We use all 118 elements, even if just to advance knowledge of nuclear physics. Many higher radioactive elements are useful in medicine or for peaceful nuclear power. However, if you envisage a hunter-gatherer society with no money (no gold or silver) and no simple technology (like mercury thermometers), you could delete well over half the periodic table. All column 18 noble gases, from helium upwards, could go, as could elements 43 to 48, technetium to palladium, and everything from 55 (caesium) upwards. Beryllium, scandium, tellurium and yttrium could probably also go.
Though, if you are going to eliminate these from Earth, please replace them with an equivalent mass of lower elements. Even a small reduction in the mass of our planet might slightly accelerate the loss of hydrogen, hastening the day when Earth becomes a waterless desert.
Eric Kvaalen
Les Essarts-le-Roi, France
Almost all the elements are used for something, so if we didn’t have them, we would be worse off to the extent that the element is useful. Some have very short lives, so aren’t really useful, other than for writing scientific papers. And then there’s polonium, which can be used for shortening human lives.
Nick Canning
Coleraine, Londonderry, UK
Because the elements are built through a process of nuclear fusion from hydrogen on up, the natural abundance of the elements generally decreases with increasing atomic number. Evolution has mostly employed the most abundant elements in forming biochemical systems, so, life. Thus we couldn’t delete the first 36 elements (period 1 to 4 of the table).
Even the noble gas helium, which is chemically inert and not part of any biochemical process, is necessary, as it is essential in the nuclear reactions that lead to the formation of carbon, which is so central to life. We could probably delete all elements above uranium, at 92, with little effect.
To answer this question – or ask a new one – email lastword@newscientist.com.
Questions should be scientific enquiries about everyday phenomena, and both questions and answers should be concise. We reserve the right to edit items for clarity and style. Please include a postal address, daytime telephone number and email address.
New Scientist Ltd retains total editorial control over the published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.
