Mokele

Estimting Extinction Rates A nice book chapter on the topic A good paper on comparing fossil extinctions to current ones' date=' including pitfalls and fixes[/url'] More on extrapolating, and where these numbers come from That should cover a lot of it. Some quick searches in Google scholar should give you more background on extinction in the fossil record, if you want.

If you want to get your forums to be more rational and scientific, for each idea, ask two questions: 1) What would it take to prove this idea wrong? 2) What is a circumstance/test that would yield noticeably different outcomes based on whether this idea is right or wrong? The first one is the ultimate foundation of any rational idea. If you cannot define a circumstance which disproves an idea, you cannot test it, and it's reality is unknowable, making it worthless. Just ask your posters what would the test of their idea, and the criteria for declaring it false. Then see if the real world has already provided such a test. If they cannot come up with a test and with criteria for falsification, they're either irrational or stupid, and not worth listening to either way.

There's the rub, and I'd like to point out two things: 1) The fossil record can be used to calculate extinction (and speciation) rates, with appropriate cautions about preservation bias. The problem is, even for recent sub-mass-extinctions (such as the Great American Interchange about 2 million years ago), we're limited in resolution to thousand-year chunks of time, and for more distance events, the resolution is worse - if you just compared the species alive at the dawn of human civilization to those alive now, you'd have a 10x better temporal resolution than we have for the end-Cretaceous event. It's like trying to compare the slopes of two mountains, given only the altitudes for the peak and base of mountain A and the base and 1000 feet up on mountain B. You can't calculate anything but average slope of mountain A, and you have no guarantee that the slope so far of B will continue (and you can't look to mountain A for guidance, due to poor resolution). 2) Not all extrapolations are equal. If I have two data points, I can draw a line through them. Predicting the point in the middle is a lot more certain than a point far beyond the known range, because even if the trend isn't linear, you're closer to known values. If I know average male human height in the years 1600 and 2000, I'll be more accurate in predicting human height in 1800 than in either 1000 or 3000.

Oh, look, another thread in which you make grandiose, apocalyptic claims, completely devoid of evidence. $10 says you never offer any substantiative evidence, and then move on to your next bizarre claim. Zombies this time? Atlantis? Aliens? Stop wasting our time. Mokele

For a much simpler explanation: "…imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!'" --Douglas Adams

Consider it, though: Would the potential of a cure be worth being trapped in your own body for 20 years, unable to communicate? Could you even stay sane under those conditions?

Well, a Halbach array will generate repulsive force against a steel plate, but only while moving - the lift increases with speed, but is zero at rest.

It's all going to depend upon the aerodynamics of the rotors. You need to find that out before anything else. Different rotors will have different lift and need to spin at different speeds, will have different masses (thus will be harder or easier to spin up), etc.

People have woken up from comas and other highly damaged states in which recovery had been considered highly unlikely, yes. The problem is that the brain can repair some things, can't repair others, and we still don't know enough to say with 100% certainty which patients will or won't recover, except in extreme cases (either of almost no damage or almost complete destruction). However, that's not to say that we have no idea. In the vast majority of cases, the prognosis proves accurate. In this particular case, I'd say it is, because if the brain hasn't repaired in 17 years, it's never going to. Of course, a quick scan in a fMRI machine should give a lot more info. Mokele

Yes, but how many of the tiny community of paleontologists who focus on extinctions declare this? I'm being stubborn for a very good reason - overstating your claims results in listeners just discarding the whole message, even if the overstatement is a minor part of it. Claims that this is the fastest are highly dubious. Imagine how this extinction would look if we only sampled 4 areas n the entire planet, 2 marine and 2 land. That's what we're looking at in the fossil record. Of course more species are going extinct now - 95%+ of past species left no fossil record at all, and so could disappear (or appear, or stay) without us ever knowing. I fully agree that we are in a mass extinction of our own making. I just disagree about it's current and potential future magnitude with respect to prior mass extinctions.

IIRC, we are indeed currently well above the baseline extinction rate, even accounting for biases in the fossil record, so this does qualify as a mass extinction. My point was more that comparing it to the truly catastrophic extinctions like the KT event and the End-Permian event is ridiculous, and displays a serious lack of understanding about the scale of those events.

Um, what are they?

Sorry, but no. Statements like this are the reason people brush the whole issue of current extinctions off as alarmism. The fact is, we could burn every drop of oil right now, releasing all of that greenhouse gas at once, and the effect would still *pale* in comparison to prior mass extinctions. In the Permian Catastrophe, 90% of life died. 90% And the fossil record is biased against rare species, so the actual total was probably much higher. Mokele

Some of it is indeed from the parent's consent/demand that their kids be educated (remember, education used to not be mandatory, and it was the parents who insisted it should be, way back when). But some of it is also from the perspective of "disrupting the learning environment". For instance, it's acceptable to dispute a teacher's claim in class, but not to drag out the argument so it takes up the entire class period, simply because in doing so, you're depriving the other students of their lesson.

Sure, that's what we're here for!

It's a bit of a split, actually. If you have a small population, and a beneficial mutation occurs, it spreads very quickly. But there's also less chance of any *particular* mutation showing up at all. Imagine birds on an island. That there are few mutations in the gene pool at any given time doesn't matter, since the birds are surviving just fine, and beneficial mutations just make them better at surviving. Over thousands of years, mutations come and go, with the best being selected for and becoming permanent, and those which are neutral or bad being eliminated. It doesn't really matter how long it takes for any particular mutation to show up, because the birds are surviving just fine, and until someone has a new beneficial trait, there's no inequality in fitness. Now dump a new predator on the island, one which the birds have no behavioral response to - they don't just need a particular mutation, they need it now, and if nobody has one, well, bye bye birdies. Unlike before, they can't just wait a few hundred generations for it to crop up, because the new predator will have eaten them all by then. Basically, small populations are vulnerable to extinction due to sudden changes, such as invasion or environmental change, which they don't have the standing stock of genetic diversity to adapt to.

Yep, that's quite good for a beginner, and in fact the only flaw I can find is that if the small bills are beneficial, then they *are* the favorable heritable trait, not just that they have the potential to be so. It also ties into the idea that for island populations, fragmented populations, large critters, inbred populations, or just about any situation where genetic diversity is low, it's harder to adapt because, well, the mutational variation you need might just not be out there.

Hey, everyone needs a hobby. Ahh, I was thinking more along the lines of having the CoG tens of meters, or maybe just ten meters, above geosynchronous altitude. Just enough to keep a little bit of tension in the line, but not enough to really have a huge effect on orbit.

Actually, the issue of "tugging on the line" is something I've considered. Remember, the tether is going to be subject to some pretty insane wind forces, which could result in unwanted motion of the satellite and stress on the whole structure. Would it be better to have the CoG above geosynchronous, to put more tension on the tether and hopefully resist disturbances?

I wouldn't bother trying to recreate a biological eye. Remember, evolution doesn't produce an optimum, but rather simply a cobbled-together organ that's merely sufficient for the animal's needs. Hell, the human retina is backwards.

Massive OT discussion of religion deleted. This is for discussing the status of the current-closed forum on the subject, NOT the subject themselves. Stray again and copious OT warnings will flow.

It's also worth noting that the Cambrian "explosion" actually took about 50 million years (almost as much time as has passed since the dinosaurs died). If you compress any events to that degree, it'll look like an 'explosion'.

They're ice crystals. In the first video, you can clearly see the crystaline structure. How can they be so big and move so fast? Because objects right in front of the camera look big and appear to move fast. More importantly, I find it ridiculous that you can call any of this "proof". Proof is when you bring me, in person, a dead alien for me to cut up, or a spaceship to disassemble. To call this 'proof' shows less about aliens and more that you want so badly to believe that you'll cling to any possible evidence without taking even a moment to critically analyze it.

Sione - you claimed there is peer-reviewed evidence. Either put up or shut up. Seriously, just about every peer reviewed journal has a website and online journal archives. If this evidence exists, link to it. We want *evidence*. No old man on youtube will *ever* be evidence.

Norman Albers is on a two week vacation due to persistently insulting members and staff.