What makes us alive? Moreover, what makes us dead?

When it comes to death, science is part of the problem as well as part of the solution. Deepening our understanding of the body’s processes and learning how to keep them going longer has complicated and obfuscated the end of life.

There’s a claustrophobic moment in the new film of Stephen Hawking’s life when he describes his wife being given the option to let him die. It was 1985 and A Brief History of Time was a still-unpublished manuscript. Hawking had been hospitalised with pneumonia. He was placed on a life-support machine and put into a drug-induced coma. The doctors asked Jane Hawking if she wanted them to turn off the machine.
 
We can all be glad she said no, otherwise the planet would have been much the poorer for the past 28 years. Nonetheless, the shadow of death hangs over the whole film. One day – and it may not be many years away – Hawking will be no more. His declaration in September that assisted suicide should be possible without fear of prosecution suggests he might be squaring up to the idea.
 
Death seems to be the one thing that sets human beings apart: we are aware, unlike most (if not all) other animals, of our impending demise. Worse – as Jane Hawking knows too well – in this technological age, we have to make fine decisions about death. And here the advance of science seems to offer more hindrance than help.
 
Death is not what it was. Until half a century ago if you couldn’t breathe, you would soon be officially dead. Then someone invented the ventilator. Is a body that needs a machine to operate its lungs still alive? For sure, we now say.
 
It’s no longer the case that the heart has any jurisdiction over whether you’re dead. Remember the Bolton Wanderers footballer Fabrice Muamba? His heart stopped for 78 minutes but then defibrillation got it started again. It’s a testimony to our scientific resourcefulness that we have learned how to choreograph the pulses of electrical current that will kick-start a long-immobile heart. Nonetheless, this, too, has complicated the notion of being “alive”.
 
Even what has been termed “brain death” is not enough. A lack of electrical activity inside your skull is not a sign that your brain cells are all dead. It takes up to eight hours to start dying and you can lose a lot of them before significant damage ensues. What’s more, damage to some cells makes permanent loss of consciousness inevitable. But damage to some others isn’t much of a problem.
 
Perhaps the most extreme technological management of death is among those who have paid to have their bodies frozen. Their hope is that future technologies will be able to defrost them and repair the damage that freezing cells full of water inevitably causes. This is not the last refuge of the frightened fool: plenty of our finest minds, including the MIT professor of artificial intelligence Marvin Minsky, have signed up to be cryo-preserved.
 
So, when it comes to death, science is part of the problem as well as part of the solution. Deepening our understanding of the body’s processes and learning how to keep them going longer has complicated and obfuscated the end of life. That’s why a few researchers have suggested that doctors are no longer qualified to make life-and-death decisions. Robert Veatch, a medical ethicist at Georgetown University, goes further: he thinks you should be allowed to come up with your own definition of death and inscribe it in a living will for others to respect.
 
It would certainly be nice to have a say – especially when you can see it coming. Long live Stephen Hawking. As long as he wants, that is.
Science has complicated death. Image: Getty

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 30 September 2013 issue of the New Statesman, The Tory Game of Thrones

Yu Ji/University of Cambridge NanoPhotonics
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Nanoengine evolution: researchers have built the world’s smallest machine

The engine could form the basis of futuristic tiny robots with real-world applications.

Richard P Feynman, winner of the Nobel Prize in Physics in 1965, once remarked in a now-seminal lecture that a time would come where we would “swallow the doctor”. What he meant, of course, was the actualisation of a science-fiction dream – not one in which a universal cure-all prescriptive drug would be available, but one in which society would flourish through the uses of tiny devices, or more specifically, nanotechnology. 

First, a quick primer on the field is necessary. Nanoscience involves the study and application of technologies at an extremely tiny scale. How tiny, you ask? Given that one nanometre is a billionth of a metre, the scale of work taking place in the field is atomic in nature, far beyond the observational powers of the naked human eye.

Techno-optimists have long promoted potential uses of nano-sized objects, promising increases in efficiency and capabilities of processes across the board as a result. The quintessential “swallow the doctor” example is one which suggests that the fully-realised potential of nanotechnology could be applied to medicine. The idea is that nanobots could circulate our bodily systems in order to reverse-engineer the vast array of health problems that threaten us.

It’s natural to be sceptical of such wild aspirations from a relatively young field of study (nanoscience unofficially began in 1959 following Feynman’s lecture “There’s Plenty of Room at the Bottom”), but associated research seems to be gaining widespread endorsement among prominent scientists and enthusiasts. Ray Kurzweil, Director of Engineering at Google, thinks a booming nanotechnology industry is crucial in the creation of a technological singularity, while futurist and viral video philosopher Jason Silva believes the technology will help us cure ageing.

The high-profile intrigue surrounding nanotechnology means that word of any significant developments is certain to stimulate heightened interest – which is why researchers’ achievement in building the world’s tiniest engine this month is so significant.

Reporting their results in the journal Proceedings of the National Academy of Sciences, the University of Cambridge researchers explained how the nanoengine was formed and why it represented a key step forward in the transition of the technology from theory to practice.

The prototype nanoengine is essentially composed of charged particles of gold, bound by polymers responsive to temperature in the form of a gel. The engine is then exposed to a laser which beams and heats the device, causing it to expel all water from the polymeric gel. The consequence of this is a collapsing of the gold particles into an amalgamated, tightened cluster. Following a period of cooling, the polymer then begins to reabsorb the water molecules it lost in the heating process, resulting in a spring-like expansion that pushes apart the gold particles from their clustered state.

"It's like an explosion," said Dr Tao Ding from Cambridge's Cavendish Laboratory. "We have hundreds of gold balls flying apart in a millionth of a second when water molecules inflate the polymers around them."

The process involved takes advantage of the phenomenon of Van der Waals forces – the attraction between atoms and molecules. The energy from these forces is converted into elastic energy, which in turn is rapidly released from the polymer. "The whole process is like a nano-spring," said Professor Jeremy Baumberg, who led the research.

Scientists have been tirelessly working towards the creation of a functional nanomachine – one which can effortlessly swim through water, gauge its surroundings and communicate. Prior to the research, there was a difficulty in generating powerful forces at a nanometre scale. These newly devised engines, however, generate forces far larger than any previously produced.

They have been named “ANTs”, or actuating nano-transducers. "Like real ants, they produce large forces for their weight. The challenge we now face is how to control that force for nano-machinery applications," said Baumberg.

In an email exchange with New Statesman about the short-term and long-term goals in bringing this engine closer to a practical reality, Baumberg said: “It allows us for the first time, the prospect of making nano-machines and nanobots. The earliest stage applications we can see are to make pumps and valves in microfluidic systems. Microfluidic chips are really interesting for synthesising pharmaceuticals, biomedical sensing and separation, as well as many other biochemical processes.

“But all pumps and valves currently need to be made with hydraulics, so you need a pipe onto the chip for each one, limiting strongly the complexity of anything you do with them. We believe we can now make pumps and valves from the ANTs which are each controlled by a beam of light, and we can have thousands on a single chip. Beyond this, we are looking at making tiny nanomachines that can walk around, controlled by beams of light.”

The embedding of nanobots into all facets of culture is still a long way off, and researchers will need to find a way of harnessing the energy of nanoengines. However, the prospect of one day seeing the fruition of nanorobotics is worth all the patience you can get. The tiniest robot revolution has just begun.