Starship Asterisk*

neufer wrote:

neufer wrote:

mjimih wrote:
can someone direct me to an article that explains why the Earth won't try to steal the little satelite away from the asteroid when it flies by?

The Earth pulls almost equally on QE2 and its satellite.

The L₁ Lagrangian point: is about 800 kilometers above the surface of QE2 such that the satellite would have to orbit at least that high above QE2 for the Earth to have a chance to steal it away.

neufer wrote:

geckzilla wrote:
What about just changing its orbit rather than stealing it?

• Maybe 400 km.

Upon reconsideration: the tidal effects by the Earth on the satellite are much less than I originally thought.

This is because tidal effects by the Earth are:

• 1) on average, perpendicular to the satellite velocity (and, hence, ineffective)
  2) of a fleeting duration much shorter than the L₁ satellite period (~4.5 years in this case).

Hence, any satellite of an Earth grazing asteroid must be many L₁ distances away to be affected.

mjimih wrote:Is Earth possibly intelligent because it is small enough to not be pulling these errant rocks into it "as often" as larger Earths might be able to do? Would a super Earth always be attracting large destructive rocks to it so often or regularly that intelligence would have trouble developing to the math and physics teacher level.

alter-ego wrote:
Just to establish a reference point from the radar images, I made a crude estimate for the moons orbital radius (upper bound) and orbital period. Assuming QE2 is a sphere 2.7km in diameter with a density ≈ 3g/cm³, I get an orbital radius ≈ 22km and a period ≈ 5 days.
The radar data actually describes a projected view the orbital plane wrt Earth, i.e. it is most likely inclined from our perspective. I assumed the orbital plane is not inclined, and the moon's motion was directly toward Earth. Therefore the true orbital velocity can only be larger than what I estimate, which in turn means a smaller radius and shorter period. As I said this is very rough estimate.

As suggested earlier for a moon rotation that's locked to the orbital period (Doppler data), then the orbital period ≈ 2 days. This shorter period is well in line with expectation and my estimate's uncertainty.

neufer wrote:

alter-ego wrote:
Just to establish a reference point from the radar images, I made a crude estimate for the moons orbital radius (upper bound) and orbital period. Assuming QE2 is a sphere 2.7km in diameter with a density ≈ 3g/cm³, I get an orbital radius ≈ 22km and a period ≈ 5 days.
The radar data actually describes a projected view the orbital plane wrt Earth, i.e. it is most likely inclined from our perspective. I assumed the orbital plane is not inclined, and the moon's motion was directly toward Earth. Therefore the true orbital velocity can only be larger than what I estimate, which in turn means a smaller radius and shorter period. As I said this is very rough estimate.

As suggested earlier for a moon rotation that's locked to the orbital period (Doppler data), then the orbital period ≈ 2 days. This shorter period is well in line with expectation and my estimate's uncertainty.

I concur with your calculation assuming the total duration of this sequence is ~72 minutes or ~30% of a full rotation. However, you could well have overestimated the density by a factor of ~2 or more which would reduce the orbital radius => 11km and period => 2.5 days. This seems somewhat more reasonable considering the 2-3 pixel Doppler width of the satellite.

neufer wrote: Yes...but don't forget that math and physics teachers wouldn't be here if an asteroid hadn't wiped out the dinosaurs.

Czerno 1 wrote:After some hundred mega-years, possibly dinosaurs would have spawned math and physics teachers. Including one dino called Newton, or one Einstein. Who can tell ?

rstevenson wrote:The dinosaurs lived for about 165 million years. They've been gone for about 65 million years. So "we" have had 100 million fewer years to develop, and still we managed a Newton and an Einstein. Seems to me they had their chance to see how thinking would work out, and they chose other paths.

Chris Peterson wrote:Simple observation of the world demonstrates that "thinking" isn't a particularly useful skill, and far more species have done much better without it than we have with it.

Could Dinosaurs Have Evolved Intelligence?

It's easy, from our present-day perspective, to poke fun at walnut-brained dinosaurs that lived tens of million of years ago. However, you should bear in mind that the proto-humans of 5 or 6 million years ago weren't exactly Einsteins, either--though, as stated above, they were significantly smarter than the other creatures in their ecosystems.

This raises the question: what if at least some dinosaur species had survived the K/T extinction 65 million years ago? Dale Russell, the curator of vertebrate fossils at the National Museum of Canada, has caused a stir with his speculation that Troodon--a human-sized theropod dinosaur about as smart as an opossum--might eventually have evolved a human-sized brain if it had been left to evolve for another few million years.

This is just amusing speculation, of course; for one thing, the whole question of brain size also depends crucially on metabolism. If the dinosaurs were indeed cold-blooded, there's no question that they would have had to evolve a warm-blooded metabolism to proceed on the march to intelligence--and even if they were already warm-blooded, their low EQs meant they had a lot of catching up to do.

rstevenson wrote:
I'm an odd combination of cynic and optimist. I'm cynical about the short-term behaviour of small groups of humans, but optimistic about our long-term prospects as a race. And for those long-term prospects, thinking is not only useful, it's vital. We're just not as good at it, yet, as we need to be. (Note that I'm talking about long-term prospects. Getting there will require surviving some risky times, for sure, and there's no guarantee we'll manage it.)

Rob

Chris Peterson wrote:

rstevenson wrote:
The dinosaurs lived for about 165 million years. They've been gone for about 65 million years. So "we" have had 100 million fewer years to develop, and still we managed a Newton and an Einstein. Seems to me they had their chance to see how thinking would work out, and they chose other paths.

Simple observation of the world demonstrates that "thinking" isn't a particularly useful skill, and far more species have done much better without it than we have with it.

rstevenson wrote:

Czerno 1 wrote:After some hundred mega-years, possibly dinosaurs would have spawned math and physics teachers. Including one dino called Newton, or one Einstein. Who can tell ?

The dinosaurs lived for about 165 million years. They've been gone for about 65 million years. So "we" have had 100 million fewer years to develop, and still we managed a Newton and an Einstein. Seems to me they had their chance to see how thinking would work out, and they chose other paths.

However, I've often wondered if they did in fact travel some way along the path towards thinking, and were just knocked down at the wrong moment by whatever killed them. They could have come all the way to early forms of agriculture without leaving any evidence that would survive for 65 million years.

Rob

geckzilla wrote:But communication doesn't necessarily involve thinking. If thinking helped us successfully procreate, then I guess we'd see more and more Einsteins. Instead, the opposite seems to happen.

stephen63 wrote:

junk.jpg

bystander wrote:

stephen63 wrote:

junk.jpg

Well, I don't know who the person is on the right, but I don't know all the people on the left, either. Who is top right next to Carl Sagan?

geckzilla wrote:An atheist site would have included a nice, big photo of Dawkins. And Darwin was firmly agnostic iirc.

geckzilla wrote:
We drop all the bad Asteriskians at QE2 and make them run laps around it until they feel sorry.

Then we let them back. It's probably hard to run around the moon without jumping off it.

neufer wrote:

alter-ego wrote:
Just to establish a reference point from the radar images, I made a crude estimate for the moons orbital radius (upper bound) and orbital period. Assuming QE2 is a sphere 2.7km in diameter with a density ≈ 3g/cm³, I get an orbital radius ≈ 22km and a period ≈ 5 days.
The radar data actually describes a projected view the orbital plane wrt Earth, i.e. it is most likely inclined from our perspective. I assumed the orbital plane is not inclined, and the moon's motion was directly toward Earth. Therefore the true orbital velocity can only be larger than what I estimate, which in turn means a smaller radius and shorter period. As I said this is very rough estimate.

As suggested earlier for a moon rotation that's locked to the orbital period (Doppler data), then the orbital period ≈ 2 days. This shorter period is well in line with expectation and my estimate's uncertainty.

I concur with your calculation assuming the total duration of this sequence is ~72 minutes or ~30% of a full rotation. However, you could well have overestimated the density by a factor of ~2 or more which would reduce the orbital radius => 11km and period => 2.5 days. This seems somewhat more reasonable considering the 2-3 pixel Doppler width of the satellite.