Gravity Doesn't Exist
Erik Verlinde is a theoretical physicist and string theorist and the Institute of Theoretical Physics at the University of Amsterdam. The "Verlinde formula," which relates to conformal field theory and topological field theory, is named after him. In a paper called "On the Origin of Gravity and the Laws of Newton," published in January, 2010, Verlinde introduced a new approach to the idea of gravity, positing that it is not a fundamental force but an "emergent phenomenon."
Verlinde's idea that gravity doesn't exist was featured in Big Think's "Month of Thinking Dangerously.
Question: Why is gravity an illusion?
Erik Verlinde: Gravity, of course, is something that have, well, many people have already thought about. It’s something that we see every day and it’s not like it’s not existent in our ordinary life. But what I mean by that it’s an illusion is that one would eventually like to know where it comes from, an explanation. Up to now we have, well, descriptions, I mean, Newton, of course, is the one famous for first writing down a theory of gravity and he described why apples fall and why the moon goes around the earth using the same basic equation for gravity, but he described it. He had to assume that gravity was there and then had to write down a law that described that when two masses are a certain distance, how they attract each other.
But he was also not very happy with the fact that we should just, well, assume that these things, these objects, attract each other and without even anything in between. So if there are two masses and empty space, there’s no, nothing that really happens between them, but still, they’re attracting each other. And he thought that was kind of mysterious and that it was something he would have liked to explain in a better way.
So later came Einstein and Einstein, with his theory of relativity, eventually realized that also gravity has to be described in a different way. And it took him quite some years, but eventually he wrote down a theory where he thought about space and time together and then his explanation of what gravity would be is that there’s masses which curve space, and time. And then motion of planets and of the earth around the moon, or the moon around the earth is then described by thinking about moving in this curved space-time and how then objects are, well, making their orbits. And the reason they go around then in circles is that space and time itself is curved, in the sense that things don’t move in straight lines anymore, they go around. So that was his explanation, but he had to write an equation for it, which again, assumed that gravity was there because he basically wrote down matter curves space-time.
So in a certain way that’s still a description or what, I should say is, well, one would like to understand again why this description sort of, well, how you can understand it from a more basic point of view. So what I’ve done in my paper is try to start from a, well, from a point of view where you don't assume gravity to be there, they would like to explain it by seeing how you can derive it from a more microscopic set of equations where gravity itself is not assumed, but then just follows from a certain logical reasoning.
Question: How should we think about the forces that exist to create the illusion of gravity?
Erik Verlinde: If you think about particles, very tiny particles, and it turns out that things like positions and velocities are not very precisely defined, you have to take into account the fact that there’s an uncertainty in when we look at something, we may influence the measurement, but I mean, also just, there’s a fundamental limit on how precise you can understand the position or the velocity of a particle. They cannot be all, not both described infinitely precise.
So taking gravity into account then gives us a bit of a problem because then we have to talk about space-time and then these quantum certainties gives us another way of looking at space-time at the short distances. So this led to problems... and string theory is another way of also looking at gravity and quantum mechanics, which I’ve been working on quite a bit. So people have studied the problem of quantum mechanics in gravity from various perspectives—from string theory, but also was thinking, for instance, about black holes, what happens with black holes. And I’ve taken some of the things we’ve learned about it and seen that there is some explanation of maybe where gravity then comes from, from those... new way of thinking about quantum mechanics and gravity together.
So if you then start trying to explain where it comes from, it has to do with the fact that this at the microscopic scale, a certain information about how you describe this, which we don’t see ourselves, we forget about that. And it turns out that if you take that into account, in some appropriate way that you can understand where gravity comes from.
Question: When other people talk about gravity, what are they describing?
Erik Verlinde: The theory that Einstein wrote down, when you apply it, for instance, to these black holes, you see that it starts resembling things that we call thermodynamics. That’s a theory that describes how gases move when you give them a temperature or when there is pressure and you... well, you can apply it in very many situations, but it’s some way in which we describe how things happen at very large, fairly large scales, in terms of not looking at the individual notion of the atoms and molecules, but by just thinking about these objects like temperature, pressure, and so on, which, are, what I call microscopic quantities. I mean, a temperature that is just an average of all of the motions or little collisions of atoms, say, for instance on my skin, if I think about what temperature I feel, it’s something about the average energy that each of the molecules in the air is carrying.
So temperature is not really a microscopic thing I can define. And so gravity is somewhat like that in the sense that the thing, the equations that we currently use to describe gravity are basically obtained from averaging, or at least describing things at a much tinier scale and then forgetting about certain details. So temperature, for instance, also forgets about how all of the individual molecules are moving, we don’t have to keep track of that, but still, we can describe quite well how gases move when we just talk about pressure and temperature and even differences in pressure. For instance, then if you have one room with one pressure and another room with lower pressure, you simply know that the gas will flow from one to the other. And these kind of differences, they’re necessary to get things moving.
Question: Does your research have any implications for our daily lives?
Erik Verlinde: It’s fun to think about things like gravity and even, well, what I had in my paper, things like even the laws of Newton, because they do play a role in one’s every day life. But it’s surprising that when I go and walk out the door or something like that, it’s not like I immediately sort of think about these things in a different way. For me, I think it’s more importantly eventually, what will be the implications for understanding, not just gravity, but also what’s happening in the universe. I mean, the gravity equations of Einstein are also used in describing the expansion of the universe, the Big Bang Theory are all based on these same equations.
What I hope is that the ideas that we are now starting to develop for gravity can eventually sort of lead to possibly somewhat better or even more refined way of thinking about the early Universe. And I think that will influence a little bit more my thinking than... I think as human beings we like to know where we come from and how the universe all sort of developed into what it’s now and there I think eventually this will have some impact.
Recorded on August 6, 2010
Interviewed by David Hirschman
The theoretical physicist believes that gravity is an emergent phenomenon, not the elemental "force" that Newton and Einstein theorized it to be. He thinks it is the result of patterns of complex, microscopic phenomena.
Sure, Epicureans focused on seeking pleasure – but they also did so much more.
'The pursuit of Happiness' is a famous phrase in a famous document, the United States Declaration of Independence (1776). But few know that its author was inspired by an ancient Greek philosopher, Epicurus. Thomas Jefferson considered himself an Epicurean. He probably found the phrase in John Locke, who, like Thomas Hobbes, David Hume and Adam Smith, had also been influenced by Epicurus.
Nowadays, educated English-speaking urbanites might call you an epicure if you complain to a waiter about over-salted soup, and stoical if you don't. In the popular mind, an epicure fine-tunes pleasure, consuming beautifully, while a stoic lives a life of virtue, pleasure sublimated for good. But this doesn't do justice to Epicurus, who came closest of all the ancient philosophers to understanding the challenges of modern secular life.
Epicureanism competed with Stoicism to dominate Greek and Roman culture. Born in 341 BCE, only six years after Plato's death, Epicurus came of age at a good time to achieve influence. He was 18 when Alexander the Great died at the tail end of classical Greece – identified through its collection of independent city-states – and the emergence of the dynastic rule that spread across the Persian Empire. Zeno, who founded Stoicism in Cyprus and later taught it in Athens, lived during the same period. Later, the Roman Stoic Seneca both critiqued Epicurus and quoted him favourably.
Today, these two great contesting philosophies of ancient times have been reduced to attitudes about comfort and pleasure – will you send back the soup or not? That very misunderstanding tells me that Epicurean ideas won, hands down, though bowdlerised, without the full logic of the philosophy. Epicureans were concerned with how people felt. The Stoics focused on a hierarchy of value. If the Stoics had won, stoical would now mean noble and an epicure would be trivial.
Epicureans did focus on seeking pleasure – but they did so much more. They talked as much about reducing pain – and even more about being rational. They were interested in intelligent living, an idea that has evolved in our day to mean knowledgeable consumption. But equating knowing what will make you happiest with knowing the best wine means Epicurus is misunderstood.
The rationality he wedded to democracy relied on science. We now know Epicurus mainly through a poem, De rerum natura, or 'On the Nature of Things', a 7,400 line exposition by the Roman philosopher Lucretius, who lived c250 years after Epicurus. The poem was circulated only among a small number of people of letters until it was said to be rediscovered in the 15th century, when it radically challenged Christianity.
Its principles read as astonishingly modern, down to the physics. In six books, Lucretius states that everything is made of invisible particles, space and time are infinite, nature is an endless experiment, human society began as a battle to survive, there is no afterlife, religions are cruel delusions, and the universe has no clear purpose. The world is material – with a smidgen of free will. How should we live? Rationally, by dropping illusion. False ideas largely make us unhappy. If we minimise the pain they cause, we maximise our pleasure.
Secular moderns are so Epicurean that we might not hear this thunderclap. He didn't stress perfectionism or fine discriminations in pleasure – sending back the soup. He understood what the Buddhists call samsara, the suffering of endless craving. Pleasures are poisoned when we require that they do not end. So, for example, it is natural to enjoy sex, but sex will make you unhappy if you hope to possess your lover for all time.
Epicurus also seems uncannily modern in his attitude to parenting. Children are likely to bring at least as much pain as pleasure, he noted, so you might want to skip it. Modern couples who choose to be 'child-free' fit within the largely Epicurean culture we have today. Does it make sense to tell people to pursue their happiness and then expect them to take on decades of responsibility for other humans? Well, maybe, if you seek meaning. Our idea of meaning is something like the virtue embraced by the Stoics, who claimed it would bring you happiness.
Both the Stoics and the Epicureans understood that some good things are better than others. Thus you necessarily run into choices, and the need to forgo one good to protect or gain another. When you make those choices wisely, you'll be happier. But the Stoics think you'll be acting in line with a grand plan by a just grand designer, and the Epicureans don't.
As secular moderns, we pursue short-term happiness and achieve deeper pleasure in work well done. We seek the esteem of peers. It all makes sense in the light of science, which has documented that happiness for most of us arises from social ties – not the perfect rose garden or a closet of haute couture. Epicurus would not only appreciate the science, but was a big fan of friendship.
The Stoics and Epicureans diverge when it comes to politics. Epicurus thought politics brought only frustration. The Stoics believed that you should engage in politics as virtuously as you can. Here in the US where I live, half the country refrains from voting in non-presidential years, which seems Epicurean at heart.
Yet Epicurus was a democrat. In a garden on the outskirts of Athens, he set up a school scandalously open to women and slaves – a practice that his contemporaries saw as proof of his depravity. When Jefferson advocated education for American slaves, he might have had Epicurus in mind.
I imagine Epicurus would see far more consumption than necessary in my own American life and too little self-discipline. Above all, he wanted us to take responsibility for our choices. Here he is in his Letter to Menoeceus:
For it is not drinking bouts and continuous partying and enjoying boys and women, or consuming fish and the other dainties of an extravagant table, which produce the pleasant life, but sober calculation which searches out the reasons for every choice and avoidance and drives out the opinions which are the source of the greatest turmoil for men's souls.
Do you see the 'pursuit of happiness' as a tough research project and kick yourself when you're glum? You're Epicurean. We think of the Stoics as tougher, but they provided the comfort of faith. Accept your fate, they said. Epicurus said: It's a mess. Be smarter than the rest of them. How modern can you get?
Here's why you might eat greenhouse gases in the future.
- The company's protein powder, "Solein," is similar in form and taste to wheat flour.
- Based on a concept developed by NASA, the product has wide potential as a carbon-neutral source of protein.
- The man-made "meat" industry just got even more interesting.
When it comes to sniffing out whether a source is credible or not, even journalists can sometimes take the wrong approach.
- We all think that we're competent consumers of news media, but the research shows that even journalists struggle with identifying fact from fiction.
- When judging whether a piece of media is true or not, most of us focus too much on the source itself. Knowledge has a context, and it's important to look at that context when trying to validate a source.
- The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.