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.
To create wiser adults, add empathy to the school curriculum.
- Stories are at the heart of learning, writes Cleary Vaughan-Lee, Executive Director for the Global Oneness Project. They have always challenged us to think beyond ourselves, expanding our experience and revealing deep truths.
- Vaughan-Lee explains 6 ways that storytelling can foster empathy and deliver powerful learning experiences.
- Global Oneness Project is a free library of stories—containing short documentaries, photo essays, and essays—that each contain a companion lesson plan and learning activities for students so they can expand their experience of the world.
Numerous U.S. Presidents invoked the Insurrection Act to to quell race and labor riots.
- U.S. Presidents have invoked the Insurrection Act on numerous occasions.
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It looks like a busy hurricane season ahead. Probably.
- Before the hurricane season even started in 2020, Arthur and Bertha had already blown through, and Cristobal may be brewing right now.
- Weather forecasters see signs of a rough season ahead, with just a couple of reasons why maybe not.
- Where's an El Niño when you need one?
Welcome to Hurricane Season 2020. 2020, of course, scoffs at this calendric event much as it has everything else that's normal — meteorologists have already used up the year's A and B storm names before we even got here. And while early storms don't necessarily mean a bruising season ahead, forecasters expect an active season this year. Maybe storms will blow away the murder hornets and 13-year locusts we had planned.
NOAA expects a busy season
According to NOAA's Climate Prediction Center, an agency of the National Weather Service, there's a 60 percent chance that we're embarking upon a season with more storms than normal. There does, however, remain a 30 percent it'll be normal. Better than usual? Unlikely: Just a 10 percent chance.
Where a normal hurricane season has an average of 12 named storms, 6 of which become hurricanes and 3 of which are major hurricanes, the Climate Prediction Center reckons we're on track for 13 to 29 storms, 6 to 10 of which will become hurricanes, and 3 to 6 of these will be category 3, 4, or 5, packing winds of 111 mph or higher.
What has forecasters concerned are two factors in particular.
This year's El Niño ("Little Boy") looks to be more of a La Niña ("Little Girl"). The two conditions are part of what's called the El Niño-Southern Oscillation (ENSO) cycle, which describes temperature fluctuations between the ocean and atmosphere in the east-central Equatorial Pacific. With an El Niño, waters in the Pacific are unusually warm, whereas a La Niña means unusually cool waters. NOAA says that an El Niño can suppress hurricane formation in the Atlantic, and this year that mitigating effect is unlikely to be present.
Second, current conditions in the Atlantic and Caribbean suggest a fertile hurricane environment:
- The ocean there is warmer than usual.
- There's reduced vertical wind shear.
- Atlantic tropical trade winds are weak.
- There have been strong West African monsoons this year.
Here's NOAA's video laying out their forecast:
ArsTechnica spoke to hurricane scientist Phil Klotzbach, who agrees generally with NOAA, saying, "All in all, signs are certainly pointing towards an active season." Still, he notes a couple of signals that contradict that worrying outlook.
First off, Klotzbach notes that the surest sign of a rough hurricane season is when its earliest storms form in the deep tropics south of 25°N and east of the Lesser Antilles. "When you get storm formations here prior to June 1, it's typically a harbinger of an extremely active season." Fortunately, this year's hurricanes Arthur and Bertha, as well as the maybe-imminent Cristobal, formed outside this region. So there's that.
Second, Klotzbach notes that the correlation between early storm activity and a season's number of storms and intensities, is actually slightly negative. So while statistical connections aren't strongly predictive, there's at least some reason to think these early storms may augur an easy season ahead.
Image source: NOAA
Batten down the hatches early
If 2020's taught us anything, it's how to juggle multiple crises at once, and layering an active hurricane season on top of SARS-CoV-2 — not to mention everything else — poses a special challenge. Warns Treasury Secretary Wilbur Ross, "As Americans focus their attention on a safe and healthy reopening of our country, it remains critically important that we also remember to make the necessary preparations for the upcoming hurricane season." If, as many medical experts expect, we're forced back into quarantine by additional coronavirus waves, the oceanic waves slamming against our shores will best be met by storm preparations put in place in a less last-minute fashion than usual.
Ross adds, "Just as in years past, NOAA experts will stay ahead of developing hurricanes and tropical storms and provide the forecasts and warnings we depend on to stay safe."
Let's hope this, at least, can be counted on in this crazy year.
Philosophers like to present their works as if everything before it was wrong. Sometimes, they even say they have ended the need for more philosophy. So, what happens when somebody realizes they were mistaken?
Sometimes philosophers are wrong and admitting that you could be wrong is a big part of being a real philosopher. While most philosophers make minor adjustments to their arguments to correct for mistakes, others make large shifts in their thinking. Here, we have four philosophers who went back on what they said earlier in often radical ways.
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