15 Hacker News comments link this video. Each one links back to its thread.
tzsNov 2020Strongly recommends
There's an episode of PBS Space Time about this, "The Speed of Light is NOT About Light" [1], which comes pretty close to making the same points you are making. It might be useful to watch this earlier episode, "Are Space and Time an Illusion?" [2], first. There is a later episode (or maybe a couple of them) that go into how interactions with the Higgs field make it so things with mass travel slowed than the speed of causality. To tie back to the warp drive news, they have an episode that would be a good place to start on warp drives, "Is The Alcubierre Warp Drive Possible?" [3]. There's also "Superluminal Time Travel + Time Warp Challenge Answer" [4], and "Will Wormholes Allow Fast Interstellar Travel?" [5]. A non-warp unknown physics drive that comes up a lot also got an episode, "The EM Drive: Fact or Fantasy?" [6]. There is at least one episode covering interstellar travel without using any unknown physics, "5 REAL Possibilities for Interstellar Travel" [7]. The scope of the series is basically anything vaguely connected to astronomy, cosmology, and quantum mechanics, and the episodes are all pretty short (5-12 minutes), so it is a great thing to watch when you've got a short wait for something. Here's the series home page [8], and their YouTube channel [9]. Also on the PBS streaming app, for those who like to get their physics on their big screen TVs. [1] ▶ this video [2] [link] [3] [link] [4] [link] [5] [link] [6] [link] [7] [link] [8] [link] [9] [link]
in “Warp Drive News” · View on HN
willis936Oct 2020Strongly recommends
PBS SpaceTime has a treatise on relativity. There are a dozen videos worth watching on this topic alone. The video about “the speed of causality” is the one that caused me to level up: ▶ this video Here is a 12 video playlist on relativity: [link] Here is a six video series on measuring space and time: [link]
in “NIST Pair of Atomic Clocks Reveal Einstein's Relativity at a Personal Scale” · View on HN
shagieAug 2022Recommends
As an aside, the PBS space time video The Speed of Light is NOT About Light : ▶ this video As an aside to the aside - as I rewatch it I quickly notice how young he looks (and then note the date is 2015 on there - one of the early ones and the production is less refined). You may also like The Geometry of Causality [link]
in ““I survived the TCP transition” (2013)” · View on HN
cthalupaOct 2020Recommends
You’re correct. The speed of light is not actually about light. ▶ this video has a great explanation from the always excellent PBS Space Time, for the curious.
in “Faster Than Light in Our Model of Physics: Some Preliminary Thoughts” · View on HN
rhinokungfuDec 2019Recommends
Some of the confusion is, I think from referring to speed of light as "speed of light". When it really is speed limit of causality between 2 points in space. And light (em waves) just happen to be able to hit that limit. Now since expansion of space is itself not going to allow one point in space to cause any effect on another, it (the expansion) can be faster than speed of causality. PBS space time has a good video on this - ▶ this video
in “If the universe is 13.8B years old, how can we see 46B light years away? (2018)” · View on HN
rhinokungfuDec 2019Recommends
Posted this to a point above, but probably more pertinent here, so reposting - Some of the confusion is, I think from referring to speed of light as "speed of light". When it really is speed limit of causality between 2 points in space. And light (em waves) just happen to be able to hit that limit. Now since expansion of space is itself not going to allow one point in space to cause any effect on another, it (the expansion) can be faster than speed of causality. PBS space time has a good video on this - ▶ this video
in “If the universe is 13.8B years old, how can we see 46B light years away? (2018)” · View on HN
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dkerstenSep 2019Recommends
@mesid asked in a now dead comment: > What does speed of causality mean? And how is light so close to that? Take a look at this video by PBS Space Time on the topic: ▶ this video You may need to go down the rabbit hole and watch the earlier videos on relativity and related topics.
in “Water found on a potentially life-friendly alien planet” · View on HN
rhinokungfuAug 2019Recommends
Speed of light is not really just speed of light, but universal speed limit of causality. Light (electromagnetic waves just happens to be one of the few things capable of hitting that limit. Even the effect of gravity is limited to speed of light. PBS Space time has a good video on this - ▶ this video . So to answer your question, no it is not possible for anything to affect us any faster than the universal speed limit of causality (that light happens to be able to hit).
in “Milky Way’s Black Hole Just Flared, Growing 75 Times as Bright for a Few Hours” · View on HN
stcredzeroFeb 2018Recommends
Something to head off likely confusion: The Speed of Light is not about the Speed of Light. ▶ this video Don't get these two things mixed up: - The speed of electromagnetic waves in the local medium - The maximum speed our reality allows for causal phenomena
in “Speed of light drops to zero at 'exceptional points'” · View on HN
neomAug 2017Recommends
These PBS Spacetime episodes should help: The Speed of Light is NOT About Light - ▶ this video Is Quantum Tunneling Faster than Light? - [link] The Quantum Experiment that Broke Reality - [link] Pilot Wave Theory and Quantum Realism - [link] The Future of Gravitational Waves - [link]
in “Rumours swell over new kind of gravitational-wave sighting” · View on HN
light_hue_1Nov 2023Cites it
I don't understand why the video needs be so negative. Why dump on other videos? And unfairly so! > Science educators love to make videos about relativity, but surprisingly few of them seem to understand what this stuff really means. The two examples the video gives of science educators that don't "know what this stuff means" are Don Lincoln and Matt O'Dowd. Both have PhDs in physics. Lincoln was on the team that discovered the Higgs boson. O'Dowd is a professor at CUNY. They know what they're talking about. Then the video gives as an example of a bad explanation the PBS Space Time on the speed of light. But that video makes pretty much the same argument. That the speed of light/causality falls out logically even if you don't postulate it. The author clearly didn't watch that video carefully ▶ this video I would have subscribed to this channel, but this tone is a bad look.
in “Getting the Lorentz transformations without requiring an invariant speed” · View on HN
willis936Feb 2023Cites it
"c" isn't "the speed of light" so much as "the speed of causality". Light just happens to be massless packets of energy that move at the speed of causality. For all intents and purposes this is happening in real time from our local frame of reference. ▶ this video
in “Mysterious object is being dragged into the black hole at the Milky Way’s center” · View on HN
irjustinAug 2020Cites it
downvoted because time traveling through a medium vs traveling through curved space are not anywhere near the same underlying principles[0]. The implication being suggested is - if I was trapped in a block of plastic or... underwater, I would experience time different compared to someone standing on land just because "c" is slower. Clearly not the case. To be specific, when "the speed of light" is discussed like this, it usually means the "speed of causality"[1] which is the underlying meaning of "c" in relativity. The speed of causality through a medium (i.e. water) is the same as a vacuum if spacetime curvature is the same. [0] [link] [1] ▶ this video
in “Do we really travel through time with the speed of light?” · View on HN
stcredzeroSep 2018Cites it
Great answer, but do you have more information on this? PBS SpaceTime. The Speed of Light is not about Light: ▶ this video
in “SETI spots dozens of new mysterious signals emanating from distant galaxy” · View on HN
stcredzeroJul 2017Cites it
humanity will eventually create a "perfect" version of ourselves, which with then exterminate us because we are inferior Human cultural evolution has already created self-proclaimed "perfect" cultures that went on to attempt exactly this. The Nazis were only the most recent notable example. There are many examples in history of groups who considered it their holy duty or moral duty to take over the world. Fortunately, for most of human history, this hasn't been feasible, but technology is changing this equation. then the AI-human race will create a perfect society and branch off to explore the universe. Physics tells us that the "speed of light" is actually the absolute speed of causality for mass-energy. ▶ this video So until consciousness can inhabit a substrate independent of mass-energy and based on space itself, and thus not subject to the light speed limit, any intelligent civilization which expands is doomed to create its own rivals. In Michael Swannick's Vacuum Flowers the Earth is taken over by a hegemonic super-intelligence, but it's forever trapped there, because when attempting to expand, the light-speed lag will cause a sub-part of it to bud off and immediately attack its greatest rival -- which is always the rest of itself. In any case, civilizations are clearly not stable on cosmic time scales. Who in their right mind would think that billions of interacting sentients with their own agendas would produce any stable organization? It's ridiculous on the face of it.
in “Evolution of Sexual Intimidation: Male Baboons Beat Up Females, Increases Mating” · View on HN