No, that idea has been discredited. The inward migration of Jovians not only does not eject terrestrial planets at habitable distances, but it causes more comets and icy asteroids to come in from the outer system and bombard them, ensuring that they'll have plenty of water and organic compounds. (Although too much water maybe isn't a good thing; ocean life probably can't thrive without mineral runoff from the land, so a planet entirely immersed in oceans wouldn't have a lot of life except maybe around thermal vents in the depths.)
And we know this from direct observation, right? No?
Of course not; nobody's directly imaged a terrestrial planet yet. We know it from computer simulations and theory, but that's the only basis we have for
Lullaby's claim either. We don't have direct observation to confirm either interpretation. But this is what our best current understanding of theory suggests. Of course it's not absolute gospel; no one who understands the first thing about science would try to claim that. We're talking about theoretical models, and the theoretical model suggesting that Jovian migration would eject terrestrial planets has been shown to be flawed. That was my point -- not that we have some magical godlike knowledge, because science isn't approached in such terms, but that the model
Lullaby was referring to has been superseded by a new model.
Obviously no one has imaged a terrestrial planet yet -- I alluded to that in the second paragraph of my post. By cutting that part out of your reply, you make me look like an idiot rather than respond to my point that it's a bit too early to be slinging words like "discredited" around based on little more than sophisticated speculation. At best, a computer model is based on the sum of what is known about a subject, and at that is a rarely-achieved ideal. Do these models account for general relativity? How have they tackled three-body mechanics? No simulation predicts the hexagonal formation in Saturn's southern hemisphere, nor even the braiding observed decades ago in that planet's rings, I think. So models
must be checked against direct observation before their assumptions are confirmed, and that simply has not happened yet regarding these hot Jupiters.
And all of that assumes such models exist, because I've never seen any references to them. Do you have a citation I could review, Christopher? Don't misunderstand and think I'm calling you a liar, I know there's a lot of idle speculation out there that gets reported as science, and it's easy to get caught up in that. It's just that I have a hard time understanding how a super Jovian can migrate in through a solar system
without doing damage to the orbits of inner worlds and haven't seen any research suggesting otherwise.
I'm not even sure all these "super jovians" we've been detecting really are gas-giants anyway. Some of them seem so outlandish that I wonder if they're artifacts of observation errors. Or maybe super-massive nickle-iron worlds. Leading back to how the observation is made: we know only that there are cyclic variations in doppler shifting or infrared emissions. Out of 150 exoplanets found, only one, I think, has actually been imaged as a planet, and that one orbits at the far reaches of its solar system far beyond where Pluto lies in ours.
EDIT:
Of course, I say all that
and then find a paper by Avi M. Mandell, Sean N. Raymond, Steinn Sigurdsson that describes behavior similar, but somewhat different than your own. I'm reading it now ... it's an amazing idea based upon two gas giants, one migrating, the other stable shepherding the inner planetary material so that it doesn't get ejected, but rather put into elliptical orbits that are then damped by protoplanetary dust. I see some problems in this idea, namely why would only one gas giant be migrating, but want to read and digest the full paper before I shove my size eleven and a half further down my ingestion orifice. I'd still like to see your sources, Christopher, if they're different, because it appears I may be a couple of years out of date on this subject.