Not even 100 years ago computers could do a few operations per second, today you can put a 100,000,000,000,000 operations per seconds computer in you pocket.
I agree though that Alcubierre drive is probably a dud, no one with serious physics education takes that as a real possibility, there are always some crackpots but seeing the math and looking at the standard model it’s very unlikely such a thing exists. Close to speed of light travel is probably good enough though, people are hung up on the idea humans will take to the stars but that’s just very unlikely. AI on the other hand seems almost plausible with our current technological basis already.
> Not even 100 years ago computers could do a few operations per second, today you can put a 100,000,000,000,000 operations per seconds computer in you pocket.
These computers still obey the same fundamentals though, in fact we’ll reach the Moore limit soon and it’ll take a breakthrough to advance further. Steady progress inside what’s possible is different than the argument of OP about the physics of WD being fundamentally flawed.
Theory of low-dimensional semiconductors and many other theories underlying modern computers were largely incomplete or non-existent 100 years ago, general relativity isn’t that old either and there are substantial gaps in the extremes (e.g. huge masses/curvatures on the quantum scale), there’s definitely stuff lurking there waiting to be discovered. Just because we kno a lot doesn’t mean we know everything, there are ridiculous gaps in our understanding e.g. mass-energy density of the universe, I expect our understanding of the world to fundamentally change again this century, maybe more than once.
Just expanding on a peer comment in a different direction, but no - modern computers are fundamentally different.
Earlier computers used relatively simple vacuum tubes for switches. Imagining billions of these fitting in your pocket, let alone being able to be powered by a tiny battery, would have seemed completely nonsensical. Modern computing required the development of entirely new technology that people had no real reason to think would ever exist. The Golden Age sci-fi got so much right, yet basically nobody predicted miniaturization on anything like the scale we achieved. Because they wanted to remain within the domain hard sci-fi, and not what would have been perceived as fantasy at the time.
I disagree with this definition of "fundamentally different", because nothing in physics stops you from building a computer out of a billion vacuum tubes.
That's very different than requiring negative energy or something never observed.
Interesting question, actually I think building a computer out of vacuum tubes that would rival say an iPhone 15 seems impossible, the waste energy alone would be prohibitive. The Eniac used around 100 W per vacuum tube, for 10^13 tubes that’s 10^15 W, and that’s two orders larger than the global electricity output, and keep in mind you need to deliver that on a small cubic area of your computer and you need to dissipate that heat somehow (a 1 megaton nuke dissipates around 1 MWh of energy, so this computer would have to dissipate the energy equivalent of one billion megaton nukes per hour). Setting off a billion megaton nukes every hour in a small area seems almost as ridiculous to me as converting the entire mass of Saturn into energy. Also signal runtimes and crosstalk would likely make this infeasible as well. So no, you would never be able to scale vacuum tube technology to the current level of semiconductor physics, not even remotely. If you told the Eniac engineers you know how to put 20 billion vacuum tubes in the area the size of a coin and make each of them switch a few billion times per second they would have been quite skeptical I think and relegated you to the realm of science fiction, because the theory of semiconductors and the “exoticly” engineered electron bandgap materials patterned on the scale of a few angstrom you need for them would’ve been largely incomprehensible to them.
You're shifting the goal posts there. We're talking about a device that fits in your pocket, powered by a tiny battery. And, by the knowledge of computing at the time. The amount of energy required to power such a device, let alone the space, would have made the concepts plainly impossible, by the limits of what was known at the time.
That's all true, but fundamentally compute has worked the same way for decades, maybe even 100 years at this point. The scales are orders of magnitude different, but the fundamentals haven't changed much. I believe that's all they were pointing out.
I agree though that Alcubierre drive is probably a dud, no one with serious physics education takes that as a real possibility, there are always some crackpots but seeing the math and looking at the standard model it’s very unlikely such a thing exists. Close to speed of light travel is probably good enough though, people are hung up on the idea humans will take to the stars but that’s just very unlikely. AI on the other hand seems almost plausible with our current technological basis already.