A nuclear battery powered by radioactive decay rather than chemical reactions could last for decades. The most efficient design yet may bring this concept closer to reality.

Researchers have wanted to use radioactive atoms to build exceptionally long-lasting and damage-resistant batteries since the 1900s. While some prototypes have been assembled and even used in space missions, they were not very efficient. Now at Soochow University in China and his colleagues have improved the efficiency of a nuclear battery design by a factor of 8000.

They started with a small sample of the element americium, which is usually considered to be nuclear waste. It radiates energy in the form of alpha particles, which carry lots of energy but quickly lose it to their surroundings. So the researchers embedded americium into a polymer crystal that converted this energy into a sustained and stable green glow.

Then they combined the glowing americium-doped crystal with a thin photovoltaic cell, a device that converts light to electricity. Finally, they packaged the tiny nuclear battery into a millimetre-sized quartz cell.

Over 200 hours of testing, Wang says, the device produced a stable supply of electricity at a relatively high energy with unprecedented efficiency – and it only needed minimal amounts of radioactive material to function. Although americium has a half-life of 7380 years, the nuclear battery should run for several decades, because the components surrounding the sample will eventually be destroyed by the radiation.

at Morgan State University in Maryland says the new battery has “much improved overall conversion efficiencies and output power” compared to past designs. However, it still produces much less power than conventional devices. It would take 40 billion of them to power a 60-watt light bulb, for instance.

The researchers are already working on improving their design’s efficiency and power output. They also want to make it easier and safer to use, since it contains possibly dangerous radioactive materials.

“Ideally, we envision our micronuclear battery being used to power miniature sensors in remote or challenging environments where traditional power sources are impractical, like deep-sea exploration, space missions or remote monitoring stations,” says Wang.

Not long after the last world war, the historian William L. Shirer had this to say about the next world war. It “will be launched by suicidal little madmen pressing an electronic button. Such a war will not last long and none will ever follow it. There will be no conquers and no conquests, but only the charred bones of the dead on an uninhabited planet.”

As an investigative journalist, I write about war, weapons, national security and government secrets. I’ve previously written six books about US military and intelligence programmes – at the CIA, The Pentagon, Defense Advanced Research Projects Agency– all designed to prevent, or deter, nuclear world war III. In the course of my work, countless people in the upper echelons of US government have told me, proudly, that they’ve dedicated their lives to making sure the US never has a nuclear war. But what if it did?

“Every capability in the [Department of Defense] is underpinned by the fact that strategic deterrence will hold,” US Strategic Command (STRATCOM), which is responsible for nuclear deterrence, publicly. Until the autumn of 2022, this promise was pinned on STRATCOM’s public Twitter feed. But to a private audience at Sandia National Laboratories later that same year, STRATCOM’s Thomas Bussiere the existential danger inherent to deterrence. “Everything unravels itself if those things are not true.”

If deterrence fails – what exactly would that unravelling look like? To write , I put this question to scores of former nuclear command and control authorities. To the military and civilian experts who’ve built the weapon systems, been privy to the response plans and been responsible for advising the US president on nuclear counterstrike decisions should they have to be made. What I learned terrified me. Here are just a few of the shocking truths about nuclear war.

The US maintains a nuclear launch policy called Launch on Warning. This means that if a military satellite indicates the nation is under nuclear attack and a second early-warning radar confirms that information, the president launches nuclear missiles in response. Former secretary of defense William Perry told me: “Once we are warned of a nuclear attack, we prepare to launch. This is policy. We do not wait.”

The US president has sole authority to launch nuclear weapons. He asks permission of no one. Not the secretary of defense, not the chairman of the joint chief of staff, not the US Congress. “The authority is inherent in his role as commander in chief,” the Congressional Research Service confirms. The president “does not need the concurrence of either his [or her] military advisors or the US Congress to order the launch of nuclear weapons”.

When the president learns he must respond to a nuclear attack, he has just 6 minutes to do so. Six minutes is an irrational amount of time to “decide whether to release Armageddon”, President Ronald Reagan lamented in his memoirs. “Six minutes to decide how to respond to a blip on a radar scope… How could anyone apply reason at a time like that?” And yet, the president must respond. This is because it takes roughly just 30 minutes for an intercontinental ballistic missile to get from a launch pad in Russia, North Korea or China to any city in the US, and vice versa. Nuclear-armed submarines can cut that launch-to-target time to 10 minutes, or less.

Today, there are nine nuclear powers, with a combined total of more than 12,500 nuclear weapons ready to be used. The US and Russia each have some 1700 nuclear weapons deployed – weapons that can be launched in seconds or minutes after their respective president gives the command. This is what Shirer meant when he said: “Such a war will not last long and none will ever follow it.”

Nuclear war is the only scenario other than an asteroid strike that could end civilisation in a matter of hours. The soot from burning cities and forests will blot out the sun and cause nuclear winter. Agriculture will fail. Some 5 billion people will die. In the words of former Soviet leader Nikita Khrushchev, “the survivors will envy the dead”.

I wrote Nuclear War: A scenario to demonstrate – in appalling, minute-by-minute detail – just how horrifying a nuclear war would be. “Humanity is one misunderstanding, one miscalculation away from nuclear annihilation,” UN secretary-general António Guterres warned the world in 2022. “This is madness. We must reverse course.”

How true.

Ěýby Annie Jacobsen, published by Torva (ÂŁ20.00), is available now. It is the latest pick for the żěè¶ĚĘÓƵ Book Club: sign upĚýhereĚýto read along with our members

The heaviest version of oxygen ever created falls apart mysteriously quickly. This finding implies a problem with our understanding of a fundamental force of nature.

at the Tokyo Institute of Technology in Japan and his colleagues created oxygen-28 – an isotope of oxygen with eight protons and 20 neutrons – by smashing an energetic beam of fluorine atoms into liquid hydrogen.

The fluorine atoms each had 20 neutrons and nine protons. When they collided with the liquid hydrogen, they each lost a proton, turning the atoms into oxygen-28. The researchers expected these atoms to be stable. But instead, they found that they only existed for about a zeptosecond, or trillionth of a billionth of a second, and then decayed into the less heavy oxygen-24 and four neutrons.

“This is extremely surprising. It opens a very, very big fundamental question about nature’s strongest interaction, the nuclear strong force,” says at Saint Mary’s University in Canada, who was not involved with the experiment. The strong force binds quarks together to make protons and neutrons, but our understanding of how exactly it works when all those particles show up in large numbers is currently incomplete, she says.

Kondo and his team expected that oxygen-28 would hang around a lot longer because it was thought to be “doubly magic”.

Within the nucleus of every atom, protons and neutrons are grouped into shells, each of which can accommodate specific numbers of particles. When all occupied shells are fully filled, the number of particles within them is called “magic” and the nucleus that they comprise becomes extremely stable.

Subscriber-only newsletter

Sign up to Lost in Space-Time

Sign up to newsletter

If both protons and neutrons fully fill an atom’s shells, then it is called doubly magic. The oxygen that sustains life on Earth has this property, which is what allows it to be so abundant.

Through various studies of isotopes like calcium-40 and nickel-48, seven numbers are widely recognised as being magic, including the number 20 for neutrons. The new experiment challenges this idea.

Theoretical models will have to be re-made, and more experiments will need to be done in order to get a sense of what the particles inside oxygen-28 actually do if they are not in full and stable shells, says Kanungo.

Researchers have produced the lightest version of a uranium atom ever. It has only 122 neutrons compared with the 146 neutrons found in more than 99 per cent of the world’s naturally occurring uranium, which is known as uranium-238.

Isotopes of an element always have the same number of protons – in uranium’s case, 92 – but differing numbers of neutrons. Isotopes are labelled by the total number of protons and neutrons that their nuclei contain, and the new isotope has the lowest number of those particles ever at 214, making it uranium-214.

Zhiyuan Zhang at the Chinese Academy of Sciences and his colleagues produced the new isotope through a time-consuming process involving blasting samples of tungsten with powerful beams of argon and calciumĚýuntil the atoms fused together. They then picked the uranium-214 atoms out of the sample using a magnetic device called a separator.

“The production of these atoms is very difficult, because not every collision can produce what we want,” says Zhang. “About 10¹⁸ beam particles were delivered to collide with the target, but only two nuclei of uranium-214 were produced successfully and separated.”

The researchers watched those nuclei decay and determined that the half-life of uranium-214 – the length of time until half of a given sample of particles has decayed radioactively – is about 0.52 milliseconds. They performed similar experiments on two previously discovered isotopes, uranium-216 and uranium-218, and found that their half-lives are about 2.25 milliseconds and 0.65 milliseconds respectively.

They also measured how these isotopes decay and found that uranium-214 and uranium-216 undergo alpha decay, in which an atom loses two protons and two neutrons, unexpectedly easily compared withĚýother uranium isotopes. This probably means that the interactions between protons and neutrons in these atoms are more powerful than in others, they say.

“Our finding might be the first experimental evidence that the strong proton-neutron interaction can play an important role in alpha decay in [heavy nuclei],” Zhang says.