- Professor Bloomfield, you are well-known as a communicator of physics and a person who teaches it to non-scientists. At the same time for quite a long time you have been practicing a specific approach: you try to explain physics in plain accessible language, and you use simple examples from everyday life that anyone could understand. This is quite different from typical ways of teaching science and typical problems that students solve at high school or college, such as calculating the travelling time of a vehicle having a certain mass and moving from point A to point B with the speed of C and so on. Based on your experience, can you tell us whether this approach really makes physics easier to understand, and generally how a subject as seemingly difficult as physics is explainable to people who are not really familiar with natural sciences?

I call the standard course that you have described ‘physics for physicists’. It’s a conventional course and it’s taught to everyone whether they’re physicists, or pre-healthcare medics, or engineers, or people studying languages or social sciences. And it usually focuses on calculations. This course goes principle by principle through physics, and students have to solve problems related to those principles. And only occasionally the course applies those problems or formulas to the real world. It’s what physicists are used to teaching, and it’s often how they themselves learn physics at school. But this approach has very little to do with how physics came to being and how all these laws and principles were discovered. Unfortunately, very few people come out of this course really understanding what happens. And the conceptual aspects of science are the ones that get compromised the most.

I remember myself coming out of a university course and being a really good undergraduate physics student but really not understanding a lot of the important concepts. I could do the calculations well, but I really didn’t know what was happening in some parts, and I could explain very little of that. So what I do now is just throw out all that and decide that I will teach physics in the context of real objects, things people are familiar with, that they have some intuition in, and just find the physics in those. Because that’s how physics was learned in the first place: people were trying to figure out how this or that happened. And I don’t do many calculations during my course, because I think it’s a huge distraction. Although the concept part of physics is actually often harder to understand than the mathematical part, that’s where all the physics is: it’s not in calculations and formulas, but in the concepts and ideas. And that’s the part that I am trying to convey to ordinary people. I just start at the beginning, trying to understand what it is like not to understand any physics at all, and only after that I move on to more complex things, and try to tell the story, to build a narrative, because any science can be told as an exciting, fascinating story.

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- Famous American author Kurt Vonnegut once wrote: “Any scientist who can’t explain to an eight-year old what he is doing is a charlatan”. Do you agree with this quote?

I do. It’s a little too strong, but it’s not that far off. A lot of physicists will say that they can’t explain their work to ordinary people, but I think that’s because they don’t want to try. Most people have heard someone say something like «Oh, that’s a quantum physics thing, you wouldn’t understand». Well, what can I say? That’s just lazy. There’s no reason not to explain any concept: black holes, Higgs bosons, anything. The secret is to respect and appreciate your audience and understand that it’s about them, not about you or other physicists.

- What age is the best age to start learning physics?

Quite a young age, I think, seven or eight. This is not to expect the children to become junior Stephen Hawkings but to give them some introduction to science, to how nature works. And the teachers should not just show them magic tricks but make them understand what is behind those things, why it all works that way. And just keep doing that until they’re old enough to make use of it.

- Can you tell me about some examples that you use when illustrating certain laws of physics?

Sure, here’s one. At the first class with a group of new students, many of whom had taken a so-called ‘physics for physicists’ course in their high school years, I asked them this question: «Can a rotary lawnmower, with a blade that spins really fast, cut grass if the grass is not attached to the ground with its roots but is just lying (or standing) on the surface?» And the students said: «No, the lawnmower can’t cut the grass that isn’t attached.» Which, of course, isn’t true. And it’s all about inertia here. The grass stays still until someone pushes against it to make it move. And the cutting blade is very sharp so it doesn’t do that, it just cuts right through the grass instantly. And I demonstrate that to my students step by step. And when it’s all done they understand that the principle by which the lawnmower works is a certain physical property known as inertia. And it applies not only to cutting grass but to kitchen machines such as coffee grinders, food processors, blenders, meat mincers, vegetable cutters. All of them work because of inertia.

- There is a lot of feedback about your classes from your students on the Internet. And I must say that they are of a very high opinion of your teaching, but also a few of them note a specific feature: when they come to your class they think that everything is very clear and easy to understand and very exciting to learn. But at the same time afterwards they say they have some difficulties taking physics exams, because they have to do some extra work for that. Why do you think this happens?

These observations that you’re quoting are very familiar: I have heard them from my students multiple times. They tell me that they walk out of the classroom being absolutely certain that they’ve understood everything, but after a while it just falls apart. There are two issues here, in my opinion. The first one is: students don’t always understand that you can’t learn physics passively; it’s important to think everything over by yourself, to come to some conclusions on your own. So when they come out of the class they’ve heard me think about certain principles of physics, and now their task is to think about them themselves. Now they have to relearn it and teach what they just heard to themselves. Maybe they also need to talk about it to their friends, and maybe talk to me again, ask me some more questions. So, to completely understand it, they have to go through the same thought process, the same issues, and possibly multiple times. And the other problem of such difficulties becomes obvious when I ask them to use the ideas I talk about in class applied to a completely new problem. For example, if I talked about how a lawnmower cuts grass, and then I switch and ask about how a food processor cuts food, for some students that sounds like a completely different story, and they have no idea what I’m talking about. They say to me: «We never talked about food processors in class! How can you ask us a question about that?” And I’m asking them that because I want to teach them to think logically and solve problems, including ones they’ve never heard before, using the things that they have already learned. But generally that’s okay, of course. Not all of the students will be able to handle those things right away. Some of them just haven’t adapted their minds to understanding physics yet, but they still can do it if they try hard enough.

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- Do you think that people who are not going to become physicists need to learn physics anyway?

Explaining how things work, teaching to non-scientists how things work has become a mission in my life. And I do that because physics doesn’t just live in a laboratory, physics is all around us, even inside our homes. And it’s very good to understand how the water is delivered to your house, and why the water pressure is high or low, or how your stove works, or why the pot gets hot, and what’s the difference between cooking by baking or by broiling. All these things are physics, and if you don’t understand them, they will remain a mystery to you, and you will have to follow recipes to cook food or hire repair people to come fix even the smallest problems with plumbing our electrical sockets. Because some people don’t understand even the simplest things.

If past experience is anything to go by, you can’t even make simple political decisions without knowing physics. For instance, here in the US we have walked away from climate change and global warming as a country. And it’s a serious mistake, in my opinion, because it’s not that hard to explain why climate change is occurring. But a lot of people don’t understand this, and don’t believe that climate change is actually happening. And they’re condemning if not themselves, then certainly their children and grandchildren, for a very difficult world.

- So, could we say that physics then is a science that helps us survive? Because all the basic safety regulations are based on physics, right?

I think that’s right. But if you understand that you can’t put your fingers inside an electrical socket, it’s one thing. And if you understand why, it’s completely different. Many people rely on their intuition, and it sometimes does help, but sometimes it misleads you. For instance, people think that you have to push a vehicle or constantly accelerate to keep it moving. But actually you have to push something to change its motion, not to keep it moving. You don’t have to do anything to keep your vehicle moving, it will move due to inertia. And this is where bad decisions come from, such as drivers slamming on their brakes when they come to what they think is a dangerous curve on ice. And that’s one of the worst things you can do in such a situation. Of course, modern cars try to compensate for your mistakes but not entirely: they still can go out of control if you break improperly on ice.

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- What personal qualities do you think a physicist or just generally a physics-savvy person is supposed to have?

Logic and problem solving. When I teach my students (non-scientists), I teach them some physics for sure, but I think that the more important thing I teach is logic and problem solving. As for physicists, these two skills are something that physicists need just to survive in the world of physics. A lot of physics graduates stop doing physics after a while, because there aren’t so many jobs in the physics field. But they go and find jobs in organizations that need people who can think logically and solve complex problems of any kind.

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- Is doing physics today different from what it used to be back in the 1980s when you started out?

I think that science has become harder to do, because everyone wants to do something that’s new, that no one has ever done before. And after a while you understand that most of the easy new things have already been done. And it’s getting harder and harder to find something that’s new. And even of you can find some unoccupied niche, experiments, especially in physics, have become more expensive, today they require more people and more technology, so the money that universities have to spend to get young faculty members started is skyrocketing! You can’t imagine how extraordinarily expensive it is these days to start someone doing science. At least experimental and applied science. You can certainly do theoretical physics for much less money, but the experimental work is becoming insanely expensive.

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- What do you enjoy more: scientific research or teaching and educational activities? In other words, what is more interesting: discovering new things by yourself or telling someone about physics?

When I first came to the university many years ago, I came out of Bell Laboratories, the famous scientific think tank. And back then I thought I would focus on research and teaching would be a nuisance, something that I would have to do just to justify my job. But I ended up really enjoying teaching, and I think that my teaching and educational work has been more valuable than my research. And that is despite the fact that the research I did for 20 or 30 years was quite well-recognized by the physics community. But this research didn’t change the world, it didn’t make it a better place. So I think my teaching was in the end more important. And especially since I really like teaching now, I enjoy explaining physics to ordinary people. And lately I’ve returned to doing research as well, and this research is very different from what I did before. My current science work is much more practical, and I’m doing it myself in a laboratory, so I’m not managing people to do research but I’m doing it all myself. And it’s lots of fun, I am enjoying it even though things that I do sometimes take years to accomplish.

- And what scientific projects are you engaged in now?

My scientific work has been developing a material that’s a shape memory silicone. Normal silicone or any rubber immediately snaps back to its original shape after you push it out of shape and let go. But my material learns the new shape, stays in it for a while after you let go, and starts returning to its original shape only after that. This is a very useful property. For instance, we are now making ear plugs out of this material. They have a sort of a bulb shape, and you can push them out of shape with your fingers, make them long and thin to fit in your ears. And after you insert them in your ears they will gradually try to return to their bulb shape. But as soon as this silicone material presses up against your ear canal, it stops changing and seals. This material is very soft and it doesn’t care very much about returning to its original shape, so it just stays in your ears providing reliable ear protection. It’s also quite comfortable for your ears, because it replicates the shape of your ear canal. It should be about the best ear protection that’s possible, I think – for sound, for noise, for water. And now we are trying to market this product for the first time. We have almost collected the amount that is necessary for that through a Kickstarter crowdfunding campaign.

It’s also quite clear that, due to its properties, this material can be widely used in various industries such as the footwear industry. So we are working on other possible uses for this material. There is quite a lot of work here, so I understand quite clearly what I’m going to do in the next few years.

- Could you please tell us about your book «How Everything Works. The Physics of Everyday Life». What aims were you trying to achieve when you wrote it and do you think you have achieved them?

This book grew out of the course I developed in 1991. It was then that I started teaching non-scientists about how things worked, and I really wanted to support this course with a book, and my task was to actually explain laws and concepts of real physics in there, not just pretty pictures or stories about the history of science. No, only real science! But I eventually created a book for ordinary readers, not just students, to show how the world around us works in terms of physics. And I tried to explain as many physical concepts as I had time for. And I learned a lot myself while working on the book! Because physicists only think they know a lot. Actually they don’t! Some subtleties related, for instance, to how aircrafts fly are much more complicated than the way most physicists understand them - I most certainly didn’t back when I took on writing this book. So I had to read books on aerodynamics written by engineers who really do know how these things work down to the last detail. And the same goes for many other topics. And then, after learning all these things, I used my usual style to explain them, always starting as simple as I think was needed for ordinary people.  

© Corpus Books

© Louis Bloomfield

- You also have an Internet also called «How Everything Works». Do you update it by yourself?

I do, but I haven’t worked on it for quite a long time. It was very useful in the 1990s and maybe early 2000s; back then it was visited by a lot of people because there were very few resources like it or even similar to it on the web. So if you wanted to understand how a microwave oven worked you would go to my site because almost no one else was doing it. And today there are so many resources like this on the Internet that it’s hard to compete with them anymore. You can find out about how a microwave oven works from a thousand of websites now. So these days it isn’t such a good use of my time now to work on that website.

- Still, the archives of that website have about 2000 different questions that people sent you. What were some of the most frequently asked questions?

Probably the one about microwave ovens, that was a big favorite. The thing is, microwave ovens are so mysterious for most people. They have no idea how they work. And a lot of people were asking if these ovens are dangerous, if the food that you prepare in them is dangerous and what you can do wrong in a microwave oven. I answered hundreds of questions like that, always trying to convince these users that microwave ovens are no more dangerous than any other electrical appliances and that they do not poison the food in any way.

- What about the really  unusual and extraordinary questions? The ones that you weren’t even sure how to answer?

Some of my favorites were probably not even questions but just people telling me stories that confirmed something that I had observed. For example, I used to teach how old television sets worked – the ones that came before flatscreens and that had cathode ray tubes in them. And I always talked about how these TV sets developed high voltages, because they operate by throwing a large amount of electrons against the screen with very high energy. And I remember one of my readers emailing me confirming that the voltages in cathode ray tube TV sets are indeed very high! He wrote that, when showing such a television set to a friend, he opened it up and pointed a place in it that you shouldn’t touch with your hand. But he still touched it with a pencil. As you know, pencils have graphite in them that conducts electricity, so the poor guy got a tremendous shock – the current went into his body through the pencil and came out of his lip: he had literal sparks coming out of his lip! Fortunately, he dropped the pencil immediately and the incident ended with no serious consequences. And I used to receive this kind of stories all the time.

© Eris Qian

- To conclude our conversation, could you please give some advice to people who are not so familiar with physics yet but who have suddenly understood that they need physics in their lives? What should they start with?

There are certainly lots of books about science for ordinary people. But probably the best way would be to start with something you really care about. For example, if you are into music you could read some of the introductory books about the physics of music or science of music, properties of musical sounds, acoustics, etc. Because if you are already passionate about something then you’ll be sure to pick up the physics aspects of it as well! Not to mention that in the age of Internet you shouldn’t have a problem finding the materials for that.