Atomic Heroes and Radioactivity

The year is 1911. Harriet and Milton, dressed in protective hazmat suits, are peering through the window of the door of Marie Sklowdowska-Curie's laboratory in Paris. Harriet had warned Milton before leaving the time machine that the dangers of radioactivity weren't well understood when it was first discovered. Marie and the other scientists are handling their sample with bare hands, which people now know never to do.

Milton raises his paw to knock but Harriet holds him back.

"Wait, Milton. Before we go in to the danger zone to meet one of my heroes, I think we need to get up to speed with the story of atomic science – that's the study of the smallest things."

Milton wants to get on with the adventure. There are interesting noises and smells coming from inside the laboratory. "Really, Harriet? I've travelled from Ancient Greece to Paris in 1911, visiting nearly all the most famous scientists on the way: what else do I need to know?" He is scratching at the door and mewing like he does when he wants his bowl of cat food. If Harriet doesn't hurry with her story, someone will hear and let them in before they're ready to understand what is going on inside.

"We mustn't get ahead of ourselves ..."

"I thought that was what we were always doing in the time machine!"

She laughs. "True – you have a point. But there's so much to tell in the modern story of science because it rapidly gets more complicated and specialized." Thinking quickly, Harriet realizes how to attract Milton's attention. "In the case of atomic science, though, it starts with plum pudding."

Milton stops scratching. "Oh! This sounds very hopeful." He sits down expectantly, his mouth watering.

"Here: have a look at this."

"That's very curious," says Milton. "You know my master, Schrödinger, works on atoms?" Harriet nods. Milton has the good fortune to belong to one of the twentieth century's cleverest men. "Well, what I've always wondered when I've heard him talking is this: if most of an atom is empty, why does anything appear solid?" He raps on the wooden door to prove his point.

"That is an excellent question, Milton," agrees Harriet. "The answer is that the pictures we are talking about – plum puddings and solar systems – can mislead us to taking them too literally. Natural laws seem to act differently at the quantum, or very smallest, level, so it is easy for us to go wrong."

"So the space isn't really empty?" Milton wrinkles his whiskers in thought.

"Only when we are imagining an atom as if it's unmoving, like a diagram of the solar system; but electrons in an atom dance around the nucleus all the time super-fast. Another image that might help is to picture an atom like a swarm of bees. The bees, or electrons, are moving around so fast that the swarm makes a shape that is the sum total of all the little insects."

"I wouldn't touch a swarm ..."

"I should hope not!"

"But what makes an atom solid, then?"

"Our bee-like electrons are full of energy. When we touch them they push back, making what we touch feel 'solid'. Again this is a picture, but it's not a bad one to describe how the forces inside an atom work."

"I think I'd better look into this some more," says Milton. "It's fascinating stuff."

"You are turning into a real scientific explorer, Milton." Harriet is so proud of him. "I have to admit I've told you all I know. When we get back to quantum physics later on our quest, maybe you can tell me what you found out?"

Milton puffs out his chest, pleased with the responsibility. "I will!"

The door opens and a lady in a long dress looks down at them.

"I was right: I thought I heard knocking. Who are you two?"

Fortunately, the time travellers are hidden by their hazmat suits. They both stand on their back legs to look as human as possible.

"Visitors," says Harriet.

"Very small ones," adds Milton. He tucks his tail out of sight. "On a school trip."

"We've heard exciting things about your work so we've come to see what you are doing," continues Harriet.

Marie Sklodowska-Curie opens the door wider. "Then you'd better come in, children. Why are you dressed like that?"

"Um ..." says Harriet.

"It's the fashion where we come from," replies Milton quickly.

"How odd." The scientist guides them into her workroom. "But let me show you what we're doing. Today we are extracting radioactive uranium from pitchblende. That's the black material on the workbench. Miners digging up uranium in places like Cornwall in England sometimes find seams of it underground and send it to me as they know I find it very useful. It is full of fascinating elements."

"What does radioactive mean, madame?" asks Milton. He doesn't fancy getting too close to the pitchblende.

"Please, call me Marie." She picks up the rock, quite unafraid to handle it. "Radioactivity is a new idea – I'm not surprised you don't know. The first hint we got about radioactivity was when a talented German scientist, Wilhelm Röntgen, discovered X-rays by mistake. He was doing another experiment and saw that some photographic paper across the laboratory had changed colour."

"That must've seemed odd," says Harriet.

"Indeed," agrees Marie. "Another scientist might've ignored it, or put it down to accident, but Röntgen decided to ask more questions. He realized the new rays coming from his experiment could pass through things without being reflected or bent and had reached the paper. He began to test out his idea and even took an image of his wife's hand with the new rays. You can see the bones and her wedding ring, but no skin or flesh."

"Ooh, spooky!" says Milton.

Marie smiles. "Not so much spooky as spectacular! That led us to realize that these new X-rays would be very useful for doctors. You can see inside the body."

"What happened next?" asks Harriet.

"The story then comes here to Paris. Henri Becquerel was studying the light, or fluorescence, that comes off uranium. He realized that it was different from X-rays. My husband, Pierre, and I became fascinated by this and carried on working on the mystery. Pierre died in an accident a few years ago and I've had to carry on my research without him since then. I was the one who coined the term 'radioactive' to describe what is happening to the uranium. It seems to be catching on in scientific circles."

"So what is happening to the uranium?" asks Milton.

"Ah, that's the most curious thing." Marie shows them her samples set out on the laboratory desk. "It's like the dreams of the alchemists so many centuries ago. They wanted to change one element into another in their search for gold. Here we have uranium, which is slowly losing particles and turning into lead. We didn't know this was possible until now and it is changing how we thinking about elements."

"How exciting!" exclaims Milton.

"I've also discovered two other new elements – thorium and polonium. That last one I named after the country where I was born, Poland," she adds proudly.

"And she goes on to be the first woman to get a Nobel Prize, and the first person to be awarded two Nobel Prizes, for her scientific work," Harriet whispers to Milton.

Fortunately, Marie doesn't hear the whispers. "I think radioactive substances will prove very useful to doctors as they can cross physical barriers. Perhaps they will even help cure cancer ...?"

Looking around her workplace, Milton is worried that Marie isn't taking enough care of herself. "Might they not also be very dangerous?"

Harriet steps on his tail. "You mustn't interfere with the timeline!" she hisses. "Even when we want to."

"I suppose they might," says Marie. "We'll need to test this in the laboratory." The scientist looks at her watch. "I'm afraid I'll have to cut this short. I have to get back to my children for dinner time."

"Thank you for your time. It was a pleasure meeting you," says Harriet.

The time travellers hurry back into the time machine.

"Marie might be the first working-mother scientist," says Harriet with a sigh as they watch her leave the laboratory for the day.

"She is a very impressive lady," agrees Milton.

"Her daughter, Irène, follows her into science and you are right about the health hazards. Tragically both Marie and Irène die young of blood cancer brought on by the unsafe working conditions. The dangers of handling radioactive materials were not understood until much later."

"I suppose a good lesson to learn is to always obey safety instructions in the school laboratory," muses Milton.

"That's right. Things that look harmless can turn out to be deadly."

Milton tries to lift the mood as the machine whirrs into life. "I've heard that lots of natural objects are radioactive."

"Oh yes – like what?" Harriet isn't really paying attention.

"Bananas."

That stops her in her tracks. "Bananas?"

"It's true. That's because they have a special form of the element potassium in them – and that's a little radioactive."

"I didn't know that," admits Harriet. "Are they safe?" She's quite fond of the fruit.

"Guess how many you would have to eat to get a fatal dose of radioactive poisoning?" asks Milton as Harriet sets the next coordinates for the time machine. "I've looked it up."

Harriet thinks about it a little more. Animals have been eating bananas for millions of years and she's never heard of any deaths. "Thousands?"

"No, ten million – in one go." Milton grins.

"I think my tummy would explode first if I tried that!" says Harriet.

"Exactly. So it is safe to go on eating bananas. It is not possible to eat enough to do any harm from radiation."

"Now we've settled the slippery question of radioactive bananas, are you ready for the next stage in the atomic age?" asks Harriet.

"Yes!" Milton rummages in the food cupboard for a banana for Harriet and a sardine for himself. All this talk of them has made him hungry. It would be a good idea to have a snack to carry them over until dinner time.

"It involves a very big question to do with right and wrong," she adds.

Milton emerges triumphant from the cupboard, waving a banana. He feels fairly confident his experience on the Curiosity Quest has prepared him for everything. "OK, let's go. I'm ready for anything."

Atomic bombs and the Manhattan Project

The time machine lands in July 1945 in New Mexico, USA. Milton begins to take off his hazmat suit because it looks very hot outside. The sun beats down on the desert and a heat haze shimmers on the horizon.

"Leave the suit on," cautions Harriet.

They exit the machine and find themselves among a group of observers watching the desert.

"What's going on?" whispers Milton. What could they all be doing looking so expectantly into the distance? "Camel racing?"

"We're in America, Milton! No camel racing. We're here for the first ever test of a nuclear weapon."

Milton is getting fidgety. He doesn't mind laboratories but military experiments sound a different thing altogether. "Harriet, I thought this was the Curious Science Quest ...?" "And sometimes science is used to help fight wars. Remember Archimedes in our Greek adventure?"

"That didn't end well for him!"

"Science is part of our world, not cocooned from real events. Military commanders often make use of new developments in weapons and machines, as well as pay for research. What scientists decide to do with their discoveries influences everyone's lives. That's why ordinary people need to know what is going on and help scientists decide right from wrong."

Milton agrees with that, so sits back to listen. "OK, how did we get from Marie's laboratory to the desert?"

"Remember how Niels Bohr discovered the tightly packed nucleus of the atom?"

Milton nods. "You tricked me about the plum pudding though. Just as well we had bananas and sardines in the cupboard."

Harriet pats his back in apology. "Scientists realized that the nucleus was full of energy. Radioactive elements have a densely packed and unstable nucleus – a little like a balloon that can be popped. If you bombard the nucleus with particles, two results are possible. You can split the atom, releasing energy. This is called fission and is the kind of process used for electricity generation in most nuclear power plants. Aside from the damage of the bomb blast, one of the big effects is that it produces radioactive fallout that lasts for a very long time. People can get very ill and die from radioactivity long after the first explosion.

"The second way is when your particle is absorbed by the nucleus and turns the atom into a new element. This is called fusion because the atom and particle fuse together. It is the kind of reaction that goes on in the sun, where hydrogen fuses to form helium, releasing lots of energy. Without that, there would be no life on earth."

"Cool!" exclaims Milton.

"Yes, the world would be very cool indeed without fusion energy! Potentially the radioactive fallout is much less in this process – next to nothing in a perfect system – but it is very hard to achieve because you are trying to put a star like the sun in a box. Scientists are still working on how to do it as it would be a great source of energy and help us battle climate change. They know the theory but the engineering of the box is a real challenge!"

A countdown begins over a loudspeaker.

"Ladies and gentlemen, please put on your sunglasses," says the announcer.

Deep in the desert, the first nuclear bomb is ticking down to explosion.

"These people aren't making power for the electricity grid, are they?" whispers Milton. "They're using it to make bombs for fighting a war."

Harriet looks at him sadly. "And a terrible war it is too. I remember it well. Hitler, the leader of Germany, took over much of Europe and, with his ally, Japan, was threatening the world. Many European scientists of Jewish descent fled and ended up working with other scientists in what was called the Manhattan Project. Then they were faced with a terrible choice: they knew that Hitler's researchers were also working on nuclear weapons, so should they also? It was a race to get there first because they knew he'd use them for evil purposes. With that prospect to spur them on, they succeeded. This is the big question I told you about. If you have a terrible weapon like a bomb and know that your enemy might get it soon if the war carries on, do you use it to bring the battle to an end?"

"Um ..." Milton isn't sure. He's also heard awful things about what happened in World War II.

The countdown reaches its conclusion: "Three ... two ... one!"

Out in the desert, a huge mushroom cloud rises up, with shockwaves rippling out from the centre of the explosion.

Harriet shakes her head sadly. "Or is the weapon so terrible that it should never be used under any circumstances? Hitler had been defeated by 1945 without it, but Japan was fighting on. Hundreds of thousands of people died at Hiroshima and Nagasaki when American planes dropped two bombs on Japan soon after this test. That did produce a quick end to the war but the human cost was huge. Most of the people who died weren't soldiers but ordinary men, women, and children."

"I don't know," says Milton. "That seems wrong but the Americans were in a bad situation fighting a desperate war. Did they have to drop it on people? Wouldn't proving they had it be enough?"

Harriet sighs. "I don't know, Milton. The scientists weren't the ones who decided where and how to drop it; that was the decision of the military and the political leaders. But I think it does show that scientific curiosity leads us into very difficult places, not just wonderful ones."

"So how do we know what we should do?"

"We mustn't forget that morality, or values of right and wrong, isn't going to be found in a test tube. You have to look beyond the laboratory for that in other kinds of knowledge."

"Where then?"

"I'd start in values built over the ages from philosophy and religion. Love for your neighbour, the duty to look after nature, and other teachings like that. Society – that means everyone – must always think of the rights and wrongs of how science is used. We now have weapons of mass destruction and these need to be in the very safest hands – or even better, removed by international agreement."

Milton is feeling very glum. "Harriet, these modern flights of scientific discovery are very upsetting. Can't we go on a happier adventure?"

Harriet shivers. "I agree. I've thought of something that you'll like. What would you say to a visit to Albert Einstein?"

"Oh yes!" Milton hurries back to the time machine. "I'm going to comb my fur in honour." Milton wriggles out of the hazmat suit and fluffs up his coat so he looks like a puff ball, rather like Einstein's hair in the famous photos of him.

Harriet chuckles, knowing Milton is doing this on purpose to cheer her up. "Right, then. Let's go back in time again to Bern in Switzerland in 1905."

"To a university?" Milton settles down to watch time and space fly by.

"No, to a street outside an office. The greatest scientist of the twentieth century started his celebrated career while doing an ordinary job as a clerk."