Skip to main content

Why do objects with the same charge repel each other?

This is a great question, and there's at least two ways of answering it: an explanation of what we know about the physics underlying electromagnetic interactions, and a philosophical answer. 


As far as the philosophical answer, i.e. "why does anything do X," the answer is that this is the way our universe works. It's entirely possible that, in other "universes" at other times or under other conditions in our own universe, this would change. Without...

This is a great question, and there's at least two ways of answering it: an explanation of what we know about the physics underlying electromagnetic interactions, and a philosophical answer. 


As far as the philosophical answer, i.e. "why does anything do X," the answer is that this is the way our universe works. It's entirely possible that, in other "universes" at other times or under other conditions in our own universe, this would change. Without a deeper understanding of why the physical rules of our universe have the values they have, we can only speculate why anything is the way it is. It's frustrating but also interesting, at least to me, because you end up asking more questions and discovering more information you didn't know. 


The more technical answer has to do with quantum mechanics. Interactions between objects are typically mediated by particles called force carriers. For the electromagnetic force (i.e. charges), the force carrier is a photon. Photons also have a property called spin, which is one aspect of the way we describe the photon's existence as a "blip" in the electromagnetic field. Because the photon has a spin value of 1, like charges repel; for force carriers with spins of 0 and 2, like charges actually attract.


Why does spin 1 mean that like charges will repel? Getting into this level of detail would require a tutorial on relativity. To simplify, you can think of a charge as being a distortion in a field, either up or down (it's not literally up or down, but we can still make a point). The field wants to be flat. When opposite charges, i.e. opposite distortions, come in contact, they "flatten out," whereas similar distortions would add even more stress to the system. For systems where the spin of the force carrier is 0 or 2, you can think of it as NOT wanting to be neutral—it wants to stack up as many of those charges as it can. This is why gravity involves "like charges" (mass) attracting each other; because gravity can be thought of as having a spin 2 force carrier.

Popular posts from this blog

In chapter one of The Great Gatsby, what advice does Nick's father give him? How does this make him a good person to tell this story?

Nick says that his father advised him that, before "criticizing anyone," he "remember that all the people in this world haven't had the same advantages" as Nick.  As a result, Nick claims that he is "inclined to reserve all judgments," presenting himself to the reader as a fair and dispassionate arbiter of character, and thus, a reliable narrator.   The problem is that Nick immediately reveals himself as anything but reliable, as he then launches... Nick says that his father advised him that, before "criticizing anyone," he "remember that all the people in this world haven't had the same advantages" as Nick.  As a result, Nick claims that he is "inclined to reserve all judgments," presenting himself to the reader as a fair and dispassionate arbiter of character, and thus, a reliable narrator.   The problem is that Nick immediately reveals himself as anything but reliable, as he then launches into a discussion of how pe...
Post a Comment
Read more

How did the United States become an imperial power?

"Imperial power" is a bit of a vague label. It tends to mean several things at once, so let's unpack it. In the sense of "this country was built on conquest by force," the "imperial power" part of America actually predates the United States proper. The territories that would become the United States were imperial colonies, established by the great European empires of the 17th and 18th centuries. Much of the US Constitution and American governance generally goes back to England, history's largest and most successful imperial power, but vital aspects of American culture come from other imperial powers, such as France and Spain. Much of American culture comes from sources other than the old empires, but they were key influences on what the United States became. In the sense of "this country treats conquest by force as a fundamental component of its culture, economy and politics," the United States has always been an imperial power. Even earl...
Post a Comment
Read more

How and why does James Gatz become Jay Gatsby? Describe the young Gatsby/Gatz.

James Gatz, a poor Midwestern boy of probable Jewish lineage, becomes Jay Gatsby, a presumed WASP and wealthy socialite, when he moves to New York City and acquires his fortune. It is wealth that has allowed Gatz to transform himself into Gatsby. However, those who know his background (e.g., Daisy and Tom Buchanan) never allow him to forget that he is nouveau riche -- that is, an upstart who has just recently made his fortune,... James Gatz, a poor Midwestern boy of probable Jewish lineage, becomes Jay Gatsby, a presumed WASP and wealthy socialite, when he moves to New York City and acquires his fortune. It is wealth that has allowed Gatz to transform himself into Gatsby. However, those who know his background (e.g., Daisy and Tom Buchanan) never allow him to forget that he is nouveau riche -- that is, an upstart who has just recently made his fortune, whereas they arose from well-to-do families. Gatz became Gatsby through determination and discipline. At the end of the novel, the narr...
Post a Comment
Read more