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What is that called? Occam's Blindfold? We don't know it's a rock. We don't really know what it is, other than it's the first thing we've picked up from an i

What is that called? Occam's Blindfold? We don't know it's a rock. We don't really know what it is, other than it's the first thing we've picked up from an interstellar trajectory, is bizarrely shaped, didn't reflect the pull from the sun, swung by the Earth and then accelerated away.

monkeydreams 4y ago
It's Occam's Razor. In order for it to be an interstellar rock, you require no other assumption because there is little evidence to suggest it isn't. If you believe it is a probe you must assume an alien civilisation. Occam's Razor suggests fewest assumptions win.
- twawaaay 4y ago
  Except the whole discussion is still here exactly because there is evidence to suggest it isn't a rock. Supposedly it accelerated a bit, inconsistent with what we know about how rocks move through space.
- david927 4y ago
  I made a “play on words” to convey the notion of discarding data in the insistence on coming to a conclusion rather than simply holding ambiguity. No decision needs to be made. We don’t know if it’s a rock or anything else and that’s ok.
- DennisP 4y ago
  You don't have to believe it's an alien probe to accept the substantial evidence that it's not a simple rock.
  - vecter 4y ago
    There is no such "substantial" evidence. If there really was scientifically agreed upon "substantial" evidence, then it would be world-shattering news.
    - DennisP 4y ago
      Why? It's some weird object that's not a simple rock. Most people don't see that as earth-shattering, just weird. The basic weirdness is this: it didn't move like a rock, and anything normal that outgassed from it would have been visible, but it wasn't. There have been a couple hypotheses for weird things it could have been made of, but those ideas look unlikely for their own reasons. One for example was that it was frozen hydrogen, but that would have evaporated in interstellar space. The earth has not shattered because most people assume there's a reasonable explanation that nobody's figured out yet.
threatofrain 4y ago
A better reframing of the same concept is scientific parsimony, which suggests a heuristic for economical empiricism. Occam’s Razor suggests to people that probability is somehow being calculated.
lamontcg 4y ago
The delta-V from non gravitational forces was only 17 m/s or 38 mph. By comparison it has a hyperbolic excess velocity of 26.33 km/s and its maximum speed was 87.71 km/s. Its "maneuvering acceleration" amounted to 0.02% of its maximum velocity. That is all consistent with some combination of radiation pressure, solar wind and offgassing. Its closest approach to Earth was 0.1618 AU which is not terribly remarkable, it isn't like it did a close flyby in between the Earth and Moon or something. We also now know that planetary systems are incredibly common, it is almost certain that Oort clouds are incredibly common. And while stars rarely collide, they do commonly come close enough to gravitationally interaction, and it is likely that material would be flung into interstellar space by that. Our imagination of interstellar space being just gas and dust and otherwise empty is likely very incorrect.
- david927 4y ago
  Thank you. I stand corrected. And yet... you have to admit it’s intriguing...
  - lamontcg 4y ago
    It is intriguing because it may have been ejected after a star went red giant and stripped most of its volatiles from it, a billion years ago and wandered across the galaxy very slowly until it first encountered our solar system. It would have been incredible to be able to put together a lander mission, but the direct delta-V to rendezvous would be ludicrous.
    - actionfromafar 4y ago
      A fast fly-by would not have been though, if it had launched as soon as we saw it.
      - haimez 4y ago
        A “direct intercept” like you’re suggesting gives you very little time to take any measurements even if we had a vehicle standing by. For now it’s not the kind of mission NASA has chosen to fund just in case they got the opportunity to scramble a one time fly-by mission to collect a few seconds of data on an object that happened to streak past us this millennia.

monkeydreams 4y ago

It's Occam's Razor. In order for it to be an interstellar rock, you require no other assumption because there is little evidence to suggest it isn't. If you believe it is a probe you must assume an alien civilisation. Occam's Razor suggests fewest assumptions win.

twawaaay 4y ago
Except the whole discussion is still here exactly because there is evidence to suggest it isn't a rock. Supposedly it accelerated a bit, inconsistent with what we know about how rocks move through space.
david927 4y ago
I made a “play on words” to convey the notion of discarding data in the insistence on coming to a conclusion rather than simply holding ambiguity. No decision needs to be made. We don’t know if it’s a rock or anything else and that’s ok.
DennisP 4y ago
You don't have to believe it's an alien probe to accept the substantial evidence that it's not a simple rock.
- vecter 4y ago
  There is no such "substantial" evidence. If there really was scientifically agreed upon "substantial" evidence, then it would be world-shattering news.
  - DennisP 4y ago
    Why? It's some weird object that's not a simple rock. Most people don't see that as earth-shattering, just weird. The basic weirdness is this: it didn't move like a rock, and anything normal that outgassed from it would have been visible, but it wasn't. There have been a couple hypotheses for weird things it could have been made of, but those ideas look unlikely for their own reasons. One for example was that it was frozen hydrogen, but that would have evaporated in interstellar space. The earth has not shattered because most people assume there's a reasonable explanation that nobody's figured out yet.

threatofrain 4y ago

A better reframing of the same concept is scientific parsimony, which suggests a heuristic for economical empiricism. Occam’s Razor suggests to people that probability is somehow being calculated.

lamontcg 4y ago

The delta-V from non gravitational forces was only 17 m/s or 38 mph. By comparison it has a hyperbolic excess velocity of 26.33 km/s and its maximum speed was 87.71 km/s. Its "maneuvering acceleration" amounted to 0.02% of its maximum velocity. That is all consistent with some combination of radiation pressure, solar wind and offgassing. Its closest approach to Earth was 0.1618 AU which is not terribly remarkable, it isn't like it did a close flyby in between the Earth and Moon or something. We also now know that planetary systems are incredibly common, it is almost certain that Oort clouds are incredibly common. And while stars rarely collide, they do commonly come close enough to gravitationally interaction, and it is likely that material would be flung into interstellar space by that. Our imagination of interstellar space being just gas and dust and otherwise empty is likely very incorrect.

david927 4y ago
Thank you. I stand corrected. And yet... you have to admit it’s intriguing...
- lamontcg 4y ago
  It is intriguing because it may have been ejected after a star went red giant and stripped most of its volatiles from it, a billion years ago and wandered across the galaxy very slowly until it first encountered our solar system. It would have been incredible to be able to put together a lander mission, but the direct delta-V to rendezvous would be ludicrous.
  - actionfromafar 4y ago
    A fast fly-by would not have been though, if it had launched as soon as we saw it.
    - haimez 4y ago
      A “direct intercept” like you’re suggesting gives you very little time to take any measurements even if we had a vehicle standing by. For now it’s not the kind of mission NASA has chosen to fund just in case they got the opportunity to scramble a one time fly-by mission to collect a few seconds of data on an object that happened to streak past us this millennia.