Answer by Greg Sunderland:
Little Jimmy: "Daddy, I heard them talking on the news about a God Particle. What's that?"
Me: "That would be the Higgs Boson."
Little Jimmy: "What's a Higgs?"
Me: "That's Mister Higgs to you. He's the guy who postulated that boson."
Jimmy: "What's a boson?"
Me: "There are two kinds of statistics that particles follow. One discovered by Mr. Fermi and one discovered by Mr. Bose. The ones that do what Mr. Fermi says they do are called fermions and the ones that do what Mr. Bose says they do are called bosons."
Jimmy: "And what do they do?"
Me: "Well, to answer that I'll have to use some big, scary words. But they're actually easy to understand."
Me: "Mr. Higgs' boson helps explain why mass-energy and space-time are not actually separate entities but two ways of perceiving the unified field."
Jimmy: "…Ok three questions. What's a mass-energy, what's a space-time, what's a unified field."
Me: "The unified field is what actually exists, and mass-energy and space-time are the two concepts a Relativity theorist splits that into to explain their perceptions."
Jimmy: "No, what IS a mass-energy?"
Me: "Mass-energy is a union of the two Newtonian ideas of mass and energy. Similarly, space-time is the union of the Newtonian ideas of space and time."
Jimmy: "What's a Newtonian?"
Me: "I'm talking about Mr. Newton. He's the guy who explained everything we perceive about the world in terms of just four concepts- space, time, mass and energy."
Jimmy: "Space is what's between two objects, and time is what's between two events, right? And my understanding is that energy is the power to change the distance between objects over time."
Me: "Yeah, I told you that yesterday."
Jimmy: "But what's mass again?"
Me: "When you push gently on a cup it moves as far as your arm extends, but when you push gently on a table it barely moves, if at all."
Jimmy: "The table's heavier than the cup."
Me: "Yeah because it has more mass. Your power is divided by the weight of the object."
Jimmy: "Oh so mass is just weight then. It just depends how much stuff is joined together."
Me: "Yeah no but mass doesn't just make it harder to move things, sometime it makes it easier. Like if you want to pull down a heavy tree branch, the mass of the Earth helps you pull it down, even after you break it off and it's not even connected to the Earth anymore."
Jimmy: "You mean gravity? How does the mass of the Earth affect things it's not connected to?"
Me: "Newton had no idea. He just wrote down what he saw. Then Mr. Einstein came along and said mass and energy are not separate phenomena, they're just two perceptions of the singular mass-energy. So everything I just said about mass also applies to energy."
Jimmy: "And why do objects have mass-energy?"
Me: "Just like Newton, Einstein didn't explain that, he just wrote down what he saw. And what he saw was that mass and energy are the same."
Jimmy: "Does that mean that everything I know about energy also applies to mass?"
Me: "Yep. In fact, you can replace any instance of mass in any equation with the energy and vice versa."
Jimmy: "Really? But you said last week that E=M*A*D, so if we can replace that with E=E*A*D then A*D must equal one."
Jimmy: "Are you saying acceleration times distance always equals one?"
Me: "Acceleration equals D/t^2, so acceleration times distance equals D^2/t^2. In other words when you say acceleration times distance, that's the same as (distance over time) squared."
Jimmy: "If (D/t)^2 equals one then distance must equal time."
Me: "Yeah, that's because space and time are also not separate concepts but two perceptions of the singular space-time, and you can replace any instance of d in any equation with t and vice versa."
Jimmy: "Ok, but what's a Higgs Boson?"
Me: "I told you, the Higgs Boson helps explain why mass-energy and space-time are separate entities only in our perception of them."
Jimmy: "And how does it do that?"
Me: "Well, Newton didn't explain why objects have mass and Einstein didn't explain why objects have mass-energy, but by showing that mass-energy and space-time are just two different perceptions of the unified field, the Higgs Boson shows that mass-energy exists because our perception breaks down the unified field into mass-energy and space-time."
Jimmy: "Ok but I'm asking how the Higgs Boson does that."
Me: "Well, the unified field, fermions, and bosons are part of a theory called quantum field theory."
Jimmy: "What's that?"
Me: "It's a theory that doesn't play nice with Mr. Einstein's theory."
Jimmy: "Why not?"
Me: "Well you know that the mass of the Earth greatly affects the motion of objects near it, but actually the mass of all objects affects the motion of every other object a little bit, even if they're not near it. In other words the effect of gravity has unlimited range but it's not a very noticeable effect unless the mass is high and the other objects are close."
Jimmy: "Yes you told me that last month."
Me: "Just reminding you, because then you can probably imagine that really, really small objects like atoms don't have to care much about gravity at all. Since they're so small they have to be really, really close for it to have any effect. Luckily, these days they almost never get that close, so gravity doesn't affect our quantum observations at all."
Jimmy: "So that would mean the equations we made to describe those observations don't have any reference to gravity in them."
Me: "Yeah, and on the other hand if you apply Einstein's theory to observations of particles you get all sorts of paradoxes."
Jimmy: "What's a parabox?"
Me: "Like when two particles interact with each other and then move to opposite sides of the Earth. If you and a friend measure many such particles you'll find that your measurements on one side of the Earth have a spooky correlation with your friend's measurements on the other side."
Jimmy: "You mean like the particles were communicating with each other?"
Me: "Yeah, except the correlation is instantaneous- there's not enough time for any signal to get from one side of the Earth to the other."
Jimmy: "So it's like gravity then, in that one object can affect another object without touching it?"
Me: "That possibility is called non-locality. But Einstein said that if non-locality is true then you can go back in time and kill me before you are born, thus preventing you from preventing your birth, all within the same consistent timeline."
Jimmy: "Killing isn't right. And that logic is not only not right, it's not even wrong. It's just nonsense."
Me: "Yeah, so non-locality is impossible. But Mr. Bell said there's another possibility- that none of the particles we're perceiving are actually real."
Me: "Check it out online if you don't believe me- most physicists don't believe in realism anymore. Specifically, they don't believe in counter-factual definiteness."
Jimmy: "Why are there so many long words for these things?"
Me: "You know a lot more words in total than you learned today. You're just noticing that these words are all new. That's because everything you thought you knew is all just perceptions and now you have to re-learn about what actually exists."
Jimmy: "Ok so what's a counter-factual?"
Me: "It's the result of a measurement that nobody made."
Jimmy: "Does that actually exist?"
Me: "Of course not. A result is the consequence of an action, and actions which are not done don't have results. But as great a man as Einstein believed in counter-factuals."
Me: "Because if counter-factuals don't exist then nothing is real until we perceive it, and Einstein said he liked to think the moon was still there even when nobody is looking at it."
Jimmy: "So what's a Higgs Boson?"
Me: "The Higgs Boson explains why some particles have mass. The problem of where mass comes from is complicated because mass is strongly connected to gravity, and no theory of gravity plays nice with the currently popular model of particle physics. Gravity doesn't appear in quantum equations, so it can't explain the motion of big objects for which gravity is important; and the non-realism of quantum theory doesn't appear in Einstein's theory so he can't explain the motion of small objects for which non-realism is important."
Jimmy: "So what's to be done?"
Me: "Well, we know that everything can be explained by space-time and mass-energy, but we want to know where mass-energy comes from, so we can either say it comes from space-time, or that both space-time and mass-energy are just two perceptions of a more fundamental unified field. In that case, we can say that mass-energy comes from the unified field when and only when someone perceives it to be two things instead of one."
Jimmy: "So mass-energy is generated via perception. And what's a Higgs Boson?"
Me: "It's a particle. And like all particles, it's not real."
Jimmy: "But on the news they said some scientists at a large hatcher collider or whatever saw it when they smashed some protons together."
Me: "It exists subjectively when you measure it. And it exists abstractly when we simulate it in a computer. But when you don't do either it's not there waiting to be measured. Unmeasured results don't exist."
Jimmy: "So what does exist?"
Me: "The unified field."
Jimmy: "How do you know?"
Me: "The string theorists told me."
Jimmy: "But didn't Einstein say mass-energy and space-time are real?"
Me: "The string theorists say he was just perceiving their unified field in two subjective ways."
Jimmy: "Just like Einstein said Newton was perceiving his space-time in two subjective ways. Likewise for his mass-energy."
Me: "Similar to how you might think that brightness, temperature, or electric charge are fundamental quantities, until you got schooled by Newton and shown how you're just perceiving his mass, energy, space, and time in a multitude of different ways.
Jimmy: "Wait, if mass-energy and space-time depend on my brain, what is my brain made of?"
Me: "Space-time and mass-energy."
Jimmy: "What? That's just going round in circles."
Me: "No, because there's objective reality, and then there's your perceptions of it. The unified field is objective, and represents the entire physical world."
Jimmy: "Including my brain?"
Me: "Yeah well no you see you don't objectively have a brain."
Jimmy: "…Mum says I do."
Me: "That's just her perception. She's breaking down the unified field into all those subjective parts, until she perceives you and me and herself to exist. I presume if she cut your head open she would perceive a brain to be there too."
Jimmy: "Let's just say we did that one."
Me: "Yeah so subjectively you have a brain and I have a brain but objectively there's just the unified field."
Jimmy: "So how can something that doesn't objectively exist break down the unified field which does actually exist?"
Me: "Objectively the unified field does not consist of space-time and mass-energy, those are both just in your head. Objectively it has no parts. But it seems to have a multitude of parts (including thinking parts) to those thinking parts."
Jimmy: "Mind f*ck."
Jimmy: "So what's a Higgs Boson?"
Me: "It's a particle that can be observed in a particle collider, and those observations allow scientists to formulate equations for a Higgs field, which explains why the Higgs boson and some other particles have mass."
Jimmy: "And how does it do that?"
Me: "Before Mr. Higgs came along, all our equations for particles were symmetrical, so the mass value on one side of the equation was always canceled by the value on the other side. The Higgs field induces a spontaneous symmetry breaking, which leaves mass on one side of the equation and not the other."
Jimmy: "But that's all just maths, isn't it? How does it really work?"
Me: "No, remember I said the Higgs boson exists subjectively when you measure it, and it exists abstractly when we do maths with it. But when you don't do either it's not there waiting to be measured. Unmeasured results don't exist."
Jimmy: "So it's all in my head?"
Me: "Yeah but your head's all in your head too."
Jimmy: "The news is hard."
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