OPPORTUNITY has been spotted, apparently on the Jawa Black Market. It does come with a new warranty however. No it doesn't speak Batchi or the binary language of moister evaporators, unfortunately.

OPPORTUNITY has been spotted, apparently on the Jawa Black Market. It does come with a new warranty however.

Does it have a good motivator?

Guys, does anybody has the idea why HarbingerDawn stopped making streams?

SpaceSpade, busy

SpaceSpade, busy

he did just release a tutorial on YouTube about how to import ship models, so, something I guess.

Oh! Right. He made a video about spaceships. I just thought that he was dead on YouTube.

I am really into dinosaurs and paleontology in general in this last period. I mean, I just can't believe how such big reptiles could fly continuously for 8000 kms... Pterosauria have nothing in common with modern birds, who derive directly from dinosaurs (for example the family of Dromaeosauridae, who Velociraptor belongs, has a lot of features in common with modern birds of prey), but they developed very similar features like you can see the toothless beak or hollow bones.

Differently from birds they have a way longer finger who is connected to their legs by a flap of skin (especially actinofibrils), and they move on ground using they whole 4 legs. Birds, like T-Rex, just move on two legs!

How do we know that they could fly 8000 km?

I am really into dinosaurs and paleontology in general in this last period. I mean, I just can't believe how such big reptiles could fly continuously for 8000 kms...

Hey Salvo! I'm also quite interested in archosaurian paleontology and similarly find them and the old world they inhabited absolutely fascinating. I'm sure people realized this when I wrote a few lengthy posts about that topic in the Science Q&A thread. But midtskogen is correct - we don`t necessarily know if the larger members of the Azhdarchidae family (of which Quetzalcoatlus is the most well-known and shown as the largest pterosaur in your picture) could fly. Certainly the smaller species could, as well the pteranodons (the other pterosaur shown). 



Recent modeling has shown that it might have been possible for large azhdarchids to fly via explosive muscle contractions from a standing position, assuming that the lower estimate for their mass is correct (+or- 150Ibs). Since we have only found scant remains of North American large azhdarchids, we can say little on that matter. We do know that based on their bill structure that these species would have acted rather like modern storks, prowling their territories for small animals to eat, but if they could fly, then it would seem that they would have little reason to do so for 800 miles around the world, unless for mating-related migrations.

Arctic terns routinely fly 60,000 to 80,000 km every year. I don't think any bird (or any animal, for that matter) has to travel those distances every year, but some do anyway.

How do we know that they could fly 8000 km?

I believe that various different teams of paleontologists calculated the average muscle-mass and wing-power of an adult Quetzalcoatlus northropi  and extrapolated the energy density it would gain by the food-sources it ate, based on the available fossil evidence. With all of these factors in mind, it was a possibility that the gargantuan creature could soar on thermals at speeds of 80mph (129km/hr) - quite possibly for days if they had the required energy-reserves. The 8000 mile distance was an inferred guess. But these are just experimental biomechanic thought-experiments, because we know so little of large azhdarchidae behavior outside of what fossil evidence can indicate. It is however generally accepted among biologists that the large azdarchidea could fly, but would do so like herons or geese - only if they needed to and there is still great debate surrounding the exact speeds and distances they could fly.

[youtube]ALziqtuLxBQ[/youtube]

If anyone is interested, the website of Science and Futurism w. Isaac Arthur has launched a new forum. If anyone wants to hop over, signing up is free and much the same crowd populates the forum as here.

Since we first heard about the Planet 9 hypothesis to explain the clustering of the periapses of numerous long-period detached Kuiper Belt Object orbits, many new objects out there have been found. The sample of objects has approximately doubled, and consequently the constraints on the nature of Planet 9 have been refined. Basically, the proposed planet is somewhat smaller, closer to the sun, and has a less eccentric orbit than first believed.

"Planet Nine is a factor of ~2 smaller in all quantities compared to what we reported in the original paper. The new estimate of the semi-major axis is a~400-500AU (could potentially be even smaller, but only marginally so). P9’s orbital eccentricity is about e~0.15-0.3. The inclination is around i~20 deg. Last but not least, the mass is about m~5 Earth masses. Planet Nine is probably not a relative of Neptune — it’s a Super-Earth."

If there were no Planet 9, the various orbital precessions of those detached KBOs would cause them to diverge and the periapsis clustering would vanish on timescales much shorter than the age of the solar system. Some object must be shepherding the objects to keep their orbital periapses clustered.

Running a bunch of N-body simulations, injecting various test masses in hypothetical orbits, and letting it scatter a bunch of smaller objects, we can see which values for the orbit/mass of the test object in our simulation will produce the outcome we see in the detached KBO orbits. Naturally a range of parameters will produce plausible fits to what we see, but the more objects we can compare to, the better an idea what must be perturbing them is, because our picture of what that outcome must be gets clearer.

Ignoring issues with stability, 2 or more different massive objects objects would have different orbital precession rates, completely erasing the periapsis clustering we see, as the "average" periapsis of the detached KBOs we see is anti-aligned to the periapsis of the perturbing body.

If that admittedly non-Bayesian description of a rather Bayesian problem makes sense.
The Search for Planet 9

I write about these possibilities in my Origin series.

Out of curiosity, is this something you wrote? I also recall seeing a YouTube sci-fi series called Origin.

Yes, the basic outline was created first, where I defined the physics of the universe/multiverse/omniverse based on known and some theoretical physics and tried to make it as self-consistent as possible, you see little tidbits about it that I drop here and there lol.  It's about 20 chapters right now, but not developed beyond that point yet, started it back in 2010.  The written part is on Scribd.

PS- Arctic Terns experience more sunlight than any other creature on this planet!  I believe they have a sixth (magnetic) sense that helps them navigate.

The written part is on Scribd.

Cool, I'll check it out.

I believe they have a sixth (magnetic) sense that helps them navigate.

Most migratory birds do.

Since we first heard about the Planet 9 hypothesis to explain the clustering of the periapses of numerous long-period detached Kuiper Belt Object orbits, many new objects out there have been found. The sample of objects has approximately doubled, and consequently the constraints on the nature of Planet 9 have been refined. Basically, the proposed planet is somewhat smaller, closer to the sun, and has a less eccentric orbit than first believed.

Hey G, have you seen this recent interview with Konstantin Batygin (the main researcher behind this search for IX)?
[youtube]gG58idb6HuA[/youtube]