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View Full Version : Is the Oort Cloud hypothetical?



parallaxicality
2014-Apr-19, 06:58 AM
I'm in a minor wiki dispute over the precise meaning of the word "hypothetical". For years, Wikipedia's article on the Oort Cloud, which I largely wrote, has described it as hypothetical. I don't really see any problem with this. You have an observation: comets are coming in from all corners of the sky. You form a hypothesis: there exists somewhere out there a spherical cloud of the things. You wait and wait until telescopes and spacecraft are powerful enough for you to confirm it. Seems pretty straightforward to me. But one user has accused me of intellectual dishonesty because my use of the word "hypothetical" makes it seem like it isn't widely believed to exist. This is odd: apparently there exists some kind of middle ground between hypothesis and fact that I wasn't aware of, a kind of "factualisation by acclamation". I dunno. Is this a case of science beaten by somantics, or am I wrong?

galacsi
2014-Apr-19, 07:08 AM
I'm in a minor wiki dispute over the precise meaning of the word "hypothetical". For years, Wikipedia's article on the Oort Cloud, which I largely wrote, has described it as hypothetical. I don't really see any problem with this. You have an observation: comets are coming in from all corners of the sky. You form a hypothesis: there exists somewhere out there a spherical cloud of the things. You wait and wait until telescopes and spacecraft are powerful enough for you to confirm it. Seems pretty straightforward to me. But one user has accused me of intellectual dishonesty because my use of the word "hypothetical" makes it seem like it isn't widely believed to exist. I dunno. Is this a case of science beaten by somantics, or am I wrong?
I agree with you,it is still an hypothesis , but from a mainstreamer point of view , like the one seen in this site , the Oort cloud is a reality , like GW or universe expansion and so on.You have no right to doubt about the cloud ,these are the rules of the game.

Shaula
2014-Apr-19, 08:57 AM
I agree with you,it is still an hypothesis , but from a mainstreamer point of view , like the one seen in this site , the Oort cloud is a reality , like GW or universe expansion and so on.You have no right to doubt about the cloud ,these are the rules of the game.
Of course you have the right to doubt, and to test. That is what science is about. All being mainstream means is that it is generally accepted. Not that it is right.

antoniseb
2014-Apr-19, 11:24 AM
I think that it is misleading to call it hypothetical. At the most doubtful level you can say its properties are only estimated. We do see very long period comets coming in from all directions and from a specific range of distances. The number of these comets detected so far in our cosmically brief period of observation gives us an estimate as to how many must be out there. So, it is tested and verified. Those comets keep coming. It is not merely a hypothesis.

That being said, I do appreciate caution when declaring that a model is real. Don't abandon that.

Romanus
2014-Apr-19, 05:45 PM
^
I'd lean more towards calling it a theory than a hypothesis, myself; there is no viable current alternative to the Oort Cloud that matches observations.

George
2014-Apr-19, 06:18 PM
The only real problem seems to be the semantics with the use of the word hypothetical. Most people here see it in the scientific sense, meaning it is part of or even the closest thing to a theory. The Hollywood version of it, and often held by the general public, is a far more fictional meaning, hence the problem.

The hypothesis (a less abused term) of the Oort Cloud is becoming more viable with the evidence of the long period comets and the verification of the Kuiper Belt, both regions are part of an overarching formation theory of the outer solar system. The orbit of Comet West, for example, seems to extend to the inner region of the outer Oort cloud.

It would not surprise me if most people think our telescopes should be able to see stuff out there, but I recall calculating at what distance Jupiter would become invisible to the HST (31 mag.) and it was something close to only about 10,000 AU. [I can recrunch it if you'd like a hard number to use.] As you know, illuminated objects diminish in brightness as to the 4th power as they become farther away. It is, surprisingly, easier to see large planets near bright stars even though the stars are much, much farther away. [IR scopes do make Oort Cloud objects more detectable, admittedly.]