General · Language · Media · Site

Biggest ideas in the universe – Sean Carroll chats concepts

[Communicating science series] While we’re all doing stay-at-home, theoretical physicist Sean Carroll created a chat-from-home series on his YouTube channel. Usually each informal talk (so not lecture-like organization) has a followup Q&A video. The Biggest Ideas in the Universe is a series of videos where I talk informally about some of the fundamental concepts that… Continue reading Biggest ideas in the universe – Sean Carroll chats concepts

Book · General · Language · Site

Whence the arrow of time?

[“Quantum foundations” series] A physicist walks into a bar, and asks the bartender, “What time is it?” The bartender is about to reply but then recognizes the customer. “You’re a physicist, correct? So, it’s a trick question.” So, what’s with time? A venerable philosophical question. A foundational question in physics. We have electronic devices, extremely… Continue reading Whence the arrow of time?

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Quantum reality, quantum worlds – new book explores quantum foundations

[“Quantum foundations” series] [Updated December 2019] Introduction to this topic If Murray Gell-Mann was right that Niels Bohr brainwashed a generation of physicists to accept the Copenhagen Interpretation, either his influence has waned or he didn’t do a very good job in the first place. For in an informal poll conducted at an international meeting… Continue reading Quantum reality, quantum worlds – new book explores quantum foundations

General · Language · Media

Cosmological fact and fiction

In the last few months, I’ve been struck by how many articles have been published in the popular media and science news about black holes and the Big Bang. Mainstream physics and science communications (like phys.org, quantamagazine.org, etc) lately seem to be discussing more and more “mind blowing” geometries of the universe (or multiverse, eh).… Continue reading Cosmological fact and fiction

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Celebrity and cultural phenomenon — Stephen Hawking

Stephen Hawking died last week. Lots of tributes in the media about his scientific legacy and life. Sean Carroll posted an article on his blog on March 16: “Stephen Hawking’s Scientific Legacy.” It’s particularly interesting. As a career physicist and cosmologist, Carroll met and interacted with Hawking over the decades. Early in his career Carroll turned… Continue reading Celebrity and cultural phenomenon — Stephen Hawking

Book · General · Language · Problem

Sisyphean hierarchy

In the chapter “Beyond this horizon,” Sean Carroll discusses two related problems involving properties of empty space. Before discussing the vacuum energy problem, he profiles the so-called hierarchy problem in the cosmic energy scale. It’s about the effects of virtual particles. The energy scale that characterizes the weak interactions (the Higgs field value, 246 GeV)… Continue reading Sisyphean hierarchy

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Empty dumpty

[“Models of the quantum vacuum” series] A theoretical physicist walks into a bar. The bartender says, “What can I get you?” The physicist says, “Nothing.” The bartender gives the physicist an empty glass. The physicist says, “Thanks, that’s plenty!” Physicists take emptiness quite seriously. So-called empty space is an important area of study and research.… Continue reading Empty dumpty