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Old 02-14-2013, 07:39 PM   #111
orangeatheist
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Quote:
Originally Posted by mhgaffney View Post
Why is Venus so hot?

This is the proper question to kick start the discussion of Venus. The entire planet is volcanic -- with surface temperatures at the poles equal to those at the equator. This is very very strange. Indeed, it's unique in the solar system.
Uniqueness does not equal "strange." And, there's already an explanation for the uniform temperature of Venus. It's actually very simple:

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...Venus has a much thicker atmosphere. If you could stand on the surface of Venus, you would experience 93 times the atmospheric pressure we experience here on Earth; you’d have to dive down 1 km beneath the surface of the ocean to experience that kind of pressure. Furthermore, that atmosphere is made up almost entirely of carbon dioxide. As you’ve probably heard, carbon dioxide makes an excellent greenhouse gas, trapping heat from the Sun. The atmosphere of Venus allows the light from the Sun to pass through the clouds and down to the surface of the planet, which warms the rocks. But then the infrared heat from the warmed rocks is prevented from escaping by the clouds, and so the planet warmed up.

It’s believed that plate tectonics on Venus stopped billions of years ago. And without plate tectonics burying carbon deep inside the planet, it was able to build up in the atmosphere. The carbon dioxide built up to the point that any oceans on Venus boiled away. And then the Sun’s solar wind carried the hydrogen atoms away from Venus, making it impossible to ever make liquid water again. The concentration of carbon dioxide just kept increasing until it was all in the atmosphere. (http://www.universetoday.com/47905/why-is-venus-so-hot/)
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Venus is so hot because it is surrounded by a very thick atmosphere which is about 100 times more massive than our atmosphere here on Earth. As sunlight passes through the atmosphere it heats up the surface of Venus. Most of this heat cannot escape back into space because it is blocked by the very thick atmosphere of Venus. The heat becomes trapped and builds up to extremely high temperatures. This trapping of heat by the atmosphere is called the greenhouse effect because it is similar to how the glass in a greenhouse traps heat. (http://coolcosmos.ipac.caltech.edu/c...nus_heat.shtml)
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Venus' thick, toxic atmosphere traps heat in a runaway "greenhouse effect." (http://solarsystem.nasa.gov/planets/...m?Object=Venus)
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Venus' atmosphere consists mainly of carbon dioxide, with clouds of sulfuric acid droplets. Only trace amounts of water have been detected in the atmosphere. The thick atmosphere traps the sun's heat, resulting in surface temperatures higher than 880 degrees Fahrenheit (471 degrees Celsius). Probes that have landed on Venus survived only a few hours before being destroyed by the incredible temperatures. Sulfur compounds are abundant in Venus' clouds. The corrosive chemistry and dense, moving atmosphere cause significant surface weathering and erosion. (http://solarsystem.nasa.gov/planets/...y=OverviewLong)
Don't see any controversy Venus's temperature is causing. Seems pretty simple to me. But it's a conspiracy of brilliant idiots, stupid Americans, clowns and paid off Tier One Scientists, right?

Quote:
Originally Posted by mhgaffney View Post
Venus also rotates in the opposite direction of the other planets. Another major anomaly. Nor has this ever been explained. It certainly points to a different origin.
So many unsupported assertions packed into such a tiny quote.

Venus does not rotate in the opposite direction of the other planets. Uranus has an axial tilt which is very near to 90, and can be considered to be rotating in a retrograde.

Venus's retrograde rotation has explanations:

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"The standard answer to this question and things like Neptune's tilt is that there was a large collision early in the planetary formation process. The models of planetary and solar system formation have the angular momentums of the planets and their orbits in the same direction as the initial angular momentum of the gas cloud. You need something like a collision to get anything else." - Eric Christian

"Of the nine planets, a bare majority (Earth, Mars, Jupiter, Saturn, and Neptune) rotate in a way we consider 'normal'. Mercury and Venus are slow, Venus, Uranus, and Pluto are retrograde, Uranus and Pluto are highly inclined. Mars' inclination varies chaotically over long (billion-year) time scales, so it is not always 'normal' either. It is only parochialism that makes us point and laugh at the zany antics of the other planets.

"How a planet rotates is related to how it was formed from the accretion of planetesimals. If more impacts occur on one side than the other, then it will tend to rotate accordingly. But the impacts are largely random. Tidal effects can also change the rotation." -David Palmer (http://imagine.gsfc.nasa.gov/docs/as...s/981026a.html)
Granted, no one is absolutely certain of the cause:

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....scientists are still puzzled by Venus's retrograde, or backward, rotation. Now a team of scientists from the French research institute Astronomie et Systemes Dynamiques have proposed a new explanation, published in this week's issue of Nature.

Current theory holds that Venus initially spun in the same direction as most other planets and, in a way, still does: it simply flipped its axis 180 degrees at some point. In other words, it spins in the same direction it always has, just upside down, so that looking at it from other planets makes the spin seem backward. Scientists have argued that the sun's gravitational pull on the planet's very dense atmosphere could have caused strong atmospheric tides. Such tides, combined with friction between Venus's mantle and core, could have caused the flip in the first place.

Now Alexandre Correira and Jacques Laskar suggest that Venus may not have flipped at all. They propose instead that its rotation slowed to a standstill and then reversed direction. Taking into account the factors mentioned above, as well as tidal effects from other planets, the team concluded that Venus's axis could have shifted to a variety of positions throughout the planet's evolution. Regardless of whether it flipped or not, it is bound to settle into one of four stable rotation states¿two in either direction. The researchers add that Venus would be more stable in one of the two retrograde rotational states. So in essence, it was just a question of time before Venus started spinning the wrong way. (http://www.scientificamerican.com/ar...pins-the-wrong)
Oooo! But lookie there! Ideas published in Nature and Scientific American! More than we can say for ol' McCanney's self-published work on his website, eh?

Quote:
Originally Posted by mhgaffney View Post
W*gs now says that earth's sister planet is hot because the nuclear fuels created at the origin of the solar system never cooled down. But he gives no explanation why or how this might be so. Indeed -- without a plausible explanation his claim is nonsense.
I don't recall W*GS saying that. My memory is that he attributed the temperatures on Venus to the runaway greenhouse affect as noted above. But it doesn't matter what W*GS says, just as it doesn't matter what you say. It only matters what consensus the experts in the appropriate field(s) reach based upon their research.

Quote:
Originally Posted by mhgaffney View Post
Earth has long since cooled. Mars has also cooled. Yet Venus gives every appearance of being a very young planet. Might this be because Venus truly is young...
Why do you say Venus has "every appearance of being a very young planet." What does that mean? That's not a conclusion anyone else has drawn. Venus is hot, and we already know why. There's absolutely no controversy about that.

Quote:
Originally Posted by mhgaffney View Post
Back around 1950 an Israeli psychiatrist Immanuel Velikovsky caused shock waves with his book Worlds in Collision, in which he argued that Biblical events like the parting of the Red sea by Moses lined up with actual events in the solar system.
Yes, another crackpot theory which actually took as fact the fictional story of Moses and the Red Sea.

Quote:
Originally Posted by mhgaffney View Post
Velikovsky argued that the planet Venus was originally a comet -- and caused catastrophes to earth and Mars while rampaging through the inner solar system -- but eventually was captured by the sun and became a planet.
Crackpot.

Quote:
Originally Posted by mhgaffney View Post
Velikovsky's book ignited one of the greatest controversies in the history of science.
Hyperbole much? The only controversy was why anyone would believe these crackpot ideas. No reputable scientist did.

Quote:
Originally Posted by mhgaffney View Post
It is said that Velikovsky's friend Albert Einstein was reading his book when he died in 1956. The two men evidently had long discussions about the book.
More conspiracy. Oh, Einstein was reading Velikovsky's book; means they were friends; probably means Einstein agreed with Velikovsky but he died before giving his old pal a full endorsement. Boy, howdy, if he had! Man, the modern scientific black-ops community would be on its head!

Quote:
Originally Posted by mhgaffney View Post
However, another astronomer, Carl Sagan,
Yeah. Just another astronomer like ol' Velikovski, eh?

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[Sagan received] a bachelor of science in physics in 1955, and a master of science in physics in 1956 before earning a PhD in astronomy and astrophysics in 1960.[11][12][13] During his time as an honors program undergraduate, Sagan worked in the laboratory of the geneticist H. J. Muller and wrote a thesis on the origins of life with physical chemist H. C. Urey. He used the summer months of his graduate studies to work with planetary scientist Gerard Kuiper (thesis advisor), physicist George Gamow, and chemist Melvin Calvin. From 1960 to 1962 Sagan was a Miller Fellow at the University of California, Berkeley. From 1962 to 1968, he worked at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts. At the same time, he worked with geneticist Joshua Lederberg.

Sagan lectured and did research at Harvard University until 1968, when he moved to Cornell University in Ithaca, New York after being denied tenure at Harvard. He became a full Professor at Cornell in 1971, and he directed the Laboratory for Planetary Studies there. From 1972 to 1981, Sagan was the Associate Director of the Center for Radio Physics and Space Research at Cornell.

Sagan was associated with the U.S. space program from its inception. From the 1950s onward, he worked as an advisor to NASA, where one of his duties included briefing the Apollo astronauts before their flights to the Moon. Sagan contributed to many of the robotic spacecraft missions that explored the solar system, arranging experiments on many of the expeditions. He conceived the idea of adding an unalterable and universal message on spacecraft destined to leave the solar system that could potentially be understood by any extraterrestrial intelligence that might find it. Sagan assembled the first physical message that was sent into space: a gold- anodized plaque, attached to the space probe Pioneer 10, launched in 1972. Pioneer 11, also carrying another copy of the plaque, was launched the following year. He continued to refine his designs; the most elaborate message he helped to develop and assemble was the Voyager Golden Record that was sent out with the Voyager space probes in 1977. Sagan often challenged the decisions to fund the Space Shuttle and Space Station at the expense of further robotic missions.[14]

Sagan taught a course on critical thinking at Cornell University until he died in 1996 from pneumonia, a few months after finding that he was in remission of myelodysplastic syndrome. (http://en.wikipedia.org/wiki/Carl_Sa...entific_career)
But, yeah...just another astronomer, was Sagan.

Quote:
Originally Posted by mhgaffney View Post
[Just another astonomer, Sagan,] set out to discredit Velikovsky's ideas -- and by about 1975 he had succeeded in ruining Velikovsky's reputation. Sagan claimed that his campaign against Velikovsky was a fight against superstitious nonsense -- but at times it resembled a witch hunt.
When pseudo-scientific ideas threaten the real work science does to illuminate our world and advance human understanding of it, by all means hunt it out. If Velikovski's ideas were indeed more robust than anything Sagan or the rest of the scientific community could offer, they would have won out. Pseudo-science, however, can never win. Its popular only with the truly gullible.

Quote:
Originally Posted by mhgaffney View Post
Sagan succeeded so well that Velikovsky died a broken disillusioned man. The very name Velikovsky has come to be associated with pseudo science.
Deservedly so. As do the names Ron Wyatt, Von Däniken and Henry Morris.

Quote:
Originally Posted by mhgaffney View Post
The question that needs to be considered, however, is whether Velikovsky was unfairly stigmatized.
Think the court's adjourned on that question, Mark.

Quote:
Originally Posted by mhgaffney View Post
I fully agree that most of Velikovsky's ideas about the Bible correlating with events in the heavens were wrong. Indeed, Velikovsky was wrong about just about everything. Nonetheless, he might have been right that Venus was a comet.
You're correct that even if a person is wrong about everything else they assert, they could still be right about one thing. Blind squirrel, broken clock and all that. But he wasn't right about Venus being a comet. That's just another thing he got wrong.

Quote:
Originally Posted by mhgaffney View Post
At the time - Velikovsky was unable to explain how the sun might have captured a comet the size of Venus. Celestial mechanics cannot account for such a capture. Celestial mechanics is based strictly on gravitational forces. It is assumed that electomagnetism plays no role in events at this scale.

But is this assumption valid?

This is why James McCanney's plasma discharge comet model- first proposed around 1982
1979-81. Over 30 years ago. Read your own link.

Quote:
Originally Posted by mhgaffney View Post
-- is important. His model proposes a mechanism that could explain how a large comet could be captured by the sun. According to McCanney -- under certain circumstances -- electromagnetism does play an important role in celestial events.
Peer-review, please? Maybe he could get Hawking to read it; you know, as a "friend." And then Hawking will die before being able to make comment and you can begin to draw conclusions.

Quote:
Originally Posted by mhgaffney View Post
Such a young planet would be extremely hot.
So would an old one with an extremely thick, carbon dioxide atmosphere which traps in the sun's heat. First, prove the age of Venus.

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Originally Posted by mhgaffney View Post
Measurements of Comet Ikeya-Seki by scientists at Cal Tech showed that its surface temperature was 1200 degrees at its nearest approach to the sun --which was about 20 million miles.
Yes. And dropping to 700° F. at 45 million miles. But for some odd reason no scientist has decided those readings refute the current model regarding comets. Venus is 67 million miles from the sun.

Quote:
Originally Posted by mhgaffney View Post
This calls for discussion.
Among peer-review, sure.

Quote:
Originally Posted by mhgaffney View Post
However, first, Orangeatheist and the rest must do some homework. They must take the time to read McCanney's comet paper.

http://www.tmgnow.com/repository/cometary/ori1.html

This is prerequisite.
No. It needs peer-review. I'm not a peer.

Quote:
Originally Posted by mhgaffney View Post
In order to discuss a scientific theory -- one must first understand it.
Which neither you nor I do. That's why I want peer-review. Hop to it!

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Originally Posted by mhgaffney View Post
If Orange and the rest refuse -- this shows they are not serious.
If Mark refuses to post peer-review articles discussing McCanny's and Velikovski's "models," this shows he is not serious OR that there are no peer-reviewed articles about these "models" because they're pseudo-science.

Quote:
Originally Posted by mhgaffney View Post
At that point , this becomes a failed thread
It's a failed thread because you can't find any peer-review for McCanny's assertions.

Quote:
Originally Posted by mhgaffney View Post
-- and I will no longer waste my time here.
So you admit you are wasting time. That's the FIRST thing we can agree on.
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