In a somewhat whimsical podcast episode, Sean Carroll explores the physics and "rules" of time travel. Probably the first two thirds explore the physics. Carroll notes that if time travel under general relativity is at all possible, it would more likely involve a spaceship attempting to navigate some kind of closed timelike curve than stepping … Continue reading The rules of time travel?
I'm just about finished reading Sean Carroll's Something Deeply Hidden. I was going to wait to post this until I'd completely finished, but all I've got left is the appendix, I perceive that I've gotten through the main points, and discussion on the previous post is veering in this direction. As widely reported, Carroll is … Continue reading Sean Carroll’s Something Deeply Hidden
Sean Carroll's latest episode of his podcast, Mindscape, features an interview with neuroscientist Malcom MacIver, one that is well worth checking out for anyone interested in consciousness. Consciousness has many aspects, from experience to wakefulness to self-awareness. One aspect is imagination: our minds can conjure up multiple hypothetical futures to help us decide which choices … Continue reading Malcolm MacIver on imagination and consciousness
Over the weekend, Sean Carroll put up a blog post to address common misconceptions about cosmology. I understood most of his points, but was confused when I saw this one: Dark energy is not a new force; it’s a new substance. The force causing the universe to accelerate is gravity. Carroll was referring to the accelerating … Continue reading Dark energy and repulsive gravity
Related to the post last week on quantum mechanics, here is a talk that got mentioned in the discussion thread. Warning: Carroll is a passionate advocate for the Many Worlds Interpretation, so don't expect a fair and balanced discussion. The video is about an hour long. http://www.youtube.com/watch?v=iXRLDatmbgA A couple of points. Carroll notes that we … Continue reading Sean Carroll on the Many Worlds Interpretation of quantum mechanics
The Edge question for this year was, "What do you think about machines that think?" There are a lot of good responses, and some predictably inane ones. Daniel Dennett gives a good write up on why the Singularity is overblown, and points out something that I've said myself, that the real danger isn't artificial intelligence, but … Continue reading What do you think about machines that think?
http://www.youtube.com/watch?v=azTMPl0Qb6o I have to admit to wondering the same thing Nick talks about here. Do any of these subatomic particles actually exist? At least in the way we conventionally define "exist"? We're talking about entities that are sometimes a wave, sometimes a point particle and, as far as we can observe, behave randomly within certain … Continue reading Does the Higgs boson actually exist?
Sean Carroll has posted a passionate defense of the Many-world interpretation to quantum mechanics. I have often talked about the Many-Worlds or Everett approach to quantum mechanics — here’s an explanatory video, an excerpt from From Eternity to Here, and slides from a talk. But I don’t think I’ve ever explained as persuasively as possible why I think it’s the right approach. So that’s what … Continue reading Sean Carroll makes the case for the Many-worlds interpretation of quantum mechanics
Sean Carroll, theoretical physicist, has a post up on his blog telling his fellow physicists to "stop saying silly things about philosophy". The last few years have seen a number of prominent scientists step up to microphones and belittle the value of philosophy. Stephen Hawking, Lawrence Krauss, and Neil deGrasse Tyson are well-known examples. To redress the balance a … Continue reading Sean Carroll defends philosophy
THE multiverse is dead, long live the multiverse. A radical new way of looking at quantum mechanics suggests that even the multiverse will come to an end. A popular view of the multiverse says that our universe is just one of an ever-inflating multitude of discrete "bubble" universes. These bubbles are eternally budding off new … Continue reading Quantum twist could kill off the multiverse, and Boltzmann brains