Velikovsky's work surfaces from time to time in certain circles, but the fundamental problems with it are seldom mentioned by his supporters. They like to argue about this or that particular aspect of his theories, but they completely ignore the real reasons why the scientific establishment considers his a complete quack.
Velikovsky frequently advanced extravagant theories about cataclysmic events without the faintest hint of how they could have happened. His work is long on poetic description and mythological references, and very short on calculations, numbers, and testable predictions. To mention just a few very serious objections:
1a) Where exactly did we find a large mass of solid rock in Jupiter, anyway? Anything that was ripped off of a gas giant should be made up almost exclusively of hydrogen, with a seasoning of other gasses.
2) He then has Venus careening about the inner system in a manner completely inconsistent with the Newtonian laws of motion. It magically sheds vast amounts of energy at just the right moment to allow it to settle into a nearly-circular orbit.
3) During its trip, Venus manages to have two close encounters with Earth. The first one stops the Earth's rotation, while the second one starts it going again. Need I point out that such an event would produce mountains of unmistakable evidence?
3a) This supposedly happened only a few thousand years ago, so as to account for the Biblical account of the sun standing still in the sky for a day. Need I point out that all macroscopic life on Earth would have been rendered extinct by such an event?
3b) Oh, and somehow, Earth got re-started with exactly the same period of rotation as before.
3c) And somehow both Earth and Mars retained their nearly-circular orbits.
Now, all of this comes from just a couple of chapters of one book. So far as I can tell, the bogon flux remains at a similarly high level through the rest of Velikovsky's work. Is anyone really surprised that it is thoroughly discredited?
A few comments on the material that was originally quoted:
> With surface pressure 90 times and mass 75 times Earth's, the atmosphere
> Venus has thermal properties comparable to an ocean 3,000 feet deep.
> Penetration of solar energy is nowhere near sufficient to produce
> appreciable heating to any depth.
Sounds impressive, but what it really means is that the author doesn't know anything about atmospheric science. What these numbers really show is that it takes a long time for any change in solar energy output to have an effect on the planet's surface temperature. That doesn't tell us anything at all about what surface temperature to expect.
> Carbon dioxide, the major constituent of the
Why are we talking about 'candidates'? Anyone with a telescope can
> atmosphere, is incapable of producing the postulated runaway
> on its own. It would require an additional component to "close" the
> critical 25 % transparency window that permits reradiation back into space
> at thermal wavelengths. Water vapor, the primary candidate, is
> conspicuously absent.
Why are we talking about 'candidates'? Anyone with a telescope cansee that Venus' atmosphere is in fact opaque to visible light. The last I heard, the composition of Venus' atmosphere had been measured to a pretty high degree of accuracy. Plug those numbers into a greenhouse simulation, and you get a good agreement with the observed surface temperature value. So what problem are we trying to explain?
> Probably the most damning for the
> greenhouse theory is the data from all of the US and Russian probes
> showing that the thermal gradient of the atmosphere is from base to
> cloud tops, i.e. the heat source is at the bottom, not outside.
Apparently, the author doesn't realize that this is exactly the result that the greenhouse model predicts.
> According to the probe data, the emitted surface infrared flux is 40 times
> more than enters as sunlight.
Again, that's exactly what the greenhouse model would predict.
> Rigorous mathematical modeling by the thermodynamicist George R.
The kinds of energies Velikovsky throws around would be enough to melt the
surface of Venus to a depth of several hundred miles (we'll ignore the fact
that if it was ripped out of Jupiter's core it would have been completely
molten to start with). Bleeding that much heat off into space would take
several tens of millions of years, even without a thick atmosphere in the
way. The surface now should be thousands of degrees, not hundreds.
> Talbott showed that given an incandescent state 3,500 years ago as the
> recent-origin theory proposes, the cooling curve over that period yields a
> temperature today exactly as observed.
The kinds of energies Velikovsky throws around would be enough to melt the surface of Venus to a depth of several hundred miles (we'll ignore the fact that if it was ripped out of Jupiter's core it would have been completely molten to start with). Bleeding that much heat off into space would take several tens of millions of years, even without a thick atmosphere in the way. The surface now should be thousands of degrees, not hundreds.
The rest of it is equally vacuous - it is the sort of thing that someone who doesn't really grasp the underlying science would come up with. If anyone wants more info on a specific point, let me know. On the whole, I think the entire topic is not worth the time it takes to argue about it.
Billy Brown, MCSE+I