De revolutionibus orbium coelestium

What Hacker News says

1. aeternumSep 2023
   Is there any evidence that arithmetic coding works at the level of concepts?

   As a thought experiment, suppose Copernicus came up with this Hutter prize idea and declared that he would provide the award to whoever could compress the text of his book on the epicycle-based movement of planets around the sun (De revolutionibus orbium coelestium).

   Today we can explain the actual motion to high accuracy with a single sentence that would have been understandable in that age: "A line drawn from the sun to any planet sweeps out equal areas in equal time"

   This however is mostly useless in attempting to win the Copernican Hutter prize. Predicting the wording of some random human's choosing (especially at length) is very far removed from ability to predict in general.

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2. cygxOct 2022
   In my opinion, that would make things even worse:

   The sentencing clearly states that the earth revolving around the sun "is a proposition absurd and false in philosophy, and formerly heretical", and by that time, Copernicus's De revolutionibus orbium coelestium had already been placed on the Index of Prohibited Books.

   Are you saying the church actually knew Galileo was right, and did this anyway?

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3. c3dJul 2012
   Nope. Our technological advancements were not of the kind that categorically violate principles of physics as we come to describe since we have started doing "science."

   Do you really state that modern science does not violate any principle of what was considered the best of physics knowledge 500 years ago? We are talking about 1512 here, the year Copernicus started writing what would turn into De revolutionibus orbium coelestium. It would take practically another 150 years for people to start thinking about explaining the motion of planets with an inverse square law.

   For the record, the classical period of witch hunt was 1480-1750, and many of the things that are part of our daily life would have sent us directly to be burnt at the stake back in 1512:

   - Creating light without fire

   - Driving vehicles that move without being drawn by an animal, in a devilish smell

   - Watching talking heads in a box

   - Speaking to people who are over a mile away

   - Resurrecting dead people (at least, "dead" as far as 1512 physicians could tell)

   The problem with your reasoning is that you filter ancient "science" according to today's knowledge, instead of considering what was considered knowledge back then. As a result, you don't see a contradiction between what we know today and what was known back then, when there really is one.

   Here is a great example. Isaac Newton today is considered as a great scientist. Yet to him, his physics work was secondary to his alchemy work. Do you think Newton was stupid not to know that alchemy was a "pseudo science"? Or does that indicate that back then, alchemy was as valid a field of research as the motion of planets? For that reason alone, I claim that our current technological advancements "categorically violate principles of physics" as they were known at the time of Newton.

   A more recent example is the theory of aether, which was considered perfectly legitimate less than 150 years ago. And let's not even talk about Heisenberg's uncertainty principle, which even Einstein had trouble digesting, or Goedel's theorem, which was the exact opposite of what leading 1900-era mathematicians like Poincarre were expecting.

   Science is a belief system. What makes it strong is that it changes over time. Unfortunately, some take science as a complete and eternal belief system, i.e. what is not scientific provable cannot be taken seriously, and what we know today constrains what we will know tomorrow. Both arguments are often used by "skeptics" as a "rationale" against God or UFOs. The truth is that science is not complete: what we cannot experiment with is not scientific. That includes, in the current state of know-how, both God and UFOs. Self-proclaimed "skeptics" should take a hard look at past "knowledgeable people" who fought Pasteur, Einstein, Galileo or other revolutionaries based on established knowledge.

   Let me finish with the fact that UFO observations do not violate known physics laws. Some people observe what appears to be devices traveling at high velocity, with very high accelerations and often without emitting (much) sound, and with an intent (if not an intelligence). Often, observations are made by a sufficiently large body of people and correlated with enough physical evidence to make it as solid as the advance of Mercury's perihelion. Occam's razor recommends that we take the simplest explanation. If it flies like an alien spaceship and quacks like an alien spaceship, then it is likely to be an alien spaceship.

   While we do not know how to build such devices, there is no theoretical impossibility that I'm aware of. Even assuming an intelligent extraterrestrial origin does not violate laws of physics. We observe that we are the third most intelligent species on this planet, but nothing dictates that we have to be even in the top 10 in the universe. At worst, faster-than-light travel violates special relativity, which is an outdated understanding of the structure of space-time by today's standards. Many serious physicists have proposed ways to travel faster than light. And even if there is no practical way to travel faster than light, there's nothing to say that extraterrestrial don't have extremely long lifespans.

   In short, deciding to dismiss UFOs out of hand is highly non-scientific. It seems to be little more than a deep-rooted fear of the unknown. There is evidence for UFOs, not just sociological, but also a few rare leftovers (e.g. radar recording, radioactivity in the soil, etc). It's not enough data to be able to build solid science yet, but then, that was the case for planetary motion data 500 years ago.

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