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Comment Re: Fake News (Score 1) 270

1. That was just an old theory, and not a widely accepted one.

2. Given what we've just seen, it demonstrably isn't.

That doesn't mean that there aren't compounds formed at great pressure that can remain stable at moderate pressures and represent very dense energy sources - there surely are. Metastability is a very real thing. But apparently not in the case of metallic hydrogen at ~STP.

Assuming that this actually even was metallic hydrogen; even that is somewhat in dispute.

Comment Re:Doubt it (Score 2) 63

Alphabet's just upset that they've been messing around with self-driving cars for the better part of a decade and it still doesn't look any closer to a product, and Uber has stolen a march on them by actually _using_ them. If you can't make your product succeed, tearing down the competition is almost as good.

Uber aren't using them, they are talking about using them, but all their "tests" are just PR at this point since we are still a couple of generations of self-driving cars away from them being able to do last mile point-to-point driving.

Comment Re:Maybe (Score 1) 204

Indeed, on both counts. And in particular I like the word "rogue planet". Again you have an adjective imparting additional information about another object ("Rogue X"), "rogue" can be readily quantified ("Not in a stable orbit around any particular star or cluster of stars"), and it's a very evocative term. And rogue planets are absolutely expected according to our current models. They'll be incredibly difficult to find, but they're out there.

We're also coming to the realization that there's a lot of objects, potentially including large ones, that are only tenuously bound to our solar system. And it's likely that we readily exchange this mass with other nearby stars over cosmologic timescales; parts of our solar system (primarily distant ones) likely formed by other stars, and things that condensed during the formation of our star system are likely now orbiting other stars.

Comment Re:Conversations before Appointment (Score 1) 895

I don't see that happening in the Senate long-term.

IMO, Democrats will be running the House sooner rather than latter, for the simple reason that it's where seats are allocated proportionally to the populace - so large Democratic majorities in dense areas like the coasts do translate directly into seats there. But for Dems to take the Senate, in the age where party affiliation is the single most important question deciding whether the politician gets a vote or not, would require there to be more blue states than red states. Which, right now, means more urbanized states than rural states. And I don't think that's happening anytime soon.

Comment Re:What field are these abused H1B visa workers in (Score 1) 271

You have described everything precisely. The only thing that I would add is that for the two different "castes" within the H1B system that you have identified, there's one other difference.

People who are working for Apple, Microsoft, Intel etc are using H1B as a gateway to a green card, and ultimately to citizenship - which they can do, because H1B is explicitly "dual intent", so you can apply for a green card without getting kicked out of the country; and because there's a specific process whereby employer sponsors the employee for a green card. This isn't to say that every single H1B working for these companies will do that - but the majority will. The companies in question are generally interested in retaining employees long-term, so they do sponsor any employee who asks for green card (in fact, they will proactively push you to apply if you don't do so yourself), and will provide lawyers to handle the application for you, pay various fees etc.

People who are working for Tata, Infosys etc are not there for citizenship. It's not that they wouldn't want to - it's that those companies will generally not sponsor them. So it's really just a gig to come work in US and earn a lot of money (comparatively to what they could earn at home), and then come back rich, and with a US job on your resume.

Comment Re:Fix the abuse, keep the program (Score 1) 271

Kill H-1B, and replace it with a proper skilled immigration track. Look at Canada for inspiration:

http://www.canadavisa.com/cana...

https://www.canadavisa.com/com...

I am a former H-1B (now with a green card), who previously acquired Canadian permanent residency via skilled immigration program, so I had a chance to compare both. Canadian system wins hands down, and not just because it was easier for me personally. It just makes more sense in general, especially the overall points system, where the immigrants know what kinds of skills and traits maximize their chances, and citizens know that those getting visas and citizenship are actually screened to maximize benefits for their country.

Comment Re:"equalize the marketplace" (Score 1) 271

H1Bs create both supply and demand. They create supply in the industry in which they work, but they create demand in numerous other industries - services, housing etc. For that matter, they also create demand in their own industry - they're still using those products (and higher wages mean that they can use more of them, being able to afford better devices, faster Internet connectivity etc).

Comment Re:Maybe (Score 1) 204

The short of it, Jupiter moves things around; it's very good at scattering other bodies, even large ones. First it dragged outer populations into the inner solar system, then scattered inner solar system material out, and then on its retreat pulled outer solar system material back in. It's actually a very big deal that it did that, as it brought ice into the inner solar system.

Comment Re:Maybe (Score 2) 204

1. "Adjective nouns" need to have similarity to "noun" but aren't necessarily a subset. Gummy bears aren't a subset of bears either.

Gummy bears are not a scientific term. Besides, the IAU itself already uses the word dwarf in this manner. Dwarf stars, dwarf galaxies... but carved out an inexplicable exception for dwarf planets.

I'd like to see a citation on this. I highly doubt that you can simulate the formation of a solar system where multiple Mars analogues can coexist in the same orbit

False equivalency. There's a difference between "two Mars sized planets existing in the same orbit" and "Mars' orbit having been cleared". And more to the point, the biggest problem with the concept of Mars clearing its orbit is that its orbit was already largely cleared when it formed. According to our best models, Jupiter reached all the way in to around where Mars' orbit is today, and had cleared almost everything to around 1 AU. Earth and Venus accreted from planetesimals between each other. Mars accreted from planetary embryos ejected to the space in-between Earth and Jupiter. Without Jupiter's migration, simulations produce an Earth-sized Mars and several planetary embryos in the asteroid belt on eccentric / high inclination orbits, something akin to the situation between Neptune and Pluto - except with the embryos nearly Mars-sized.

3. In a geological sense yes. But the current definition of planets is based on orbital mechanics, after which Earth is a lot closer to Jupiter than to Ceres/Pluto.

Huh? By what aspect of orbital mechanics? By semimajor axis and velocity, Earth is much closer to Ceres than Jupiter. Are you talking inclination and eccentricity? Then we should boot Mars in favour of low inclination / eccentricity asteroids.

4. Hydro-static equilibrium as a dividing line is way worse. There are roughly 100 TNOs where we don't really know whether they are elliptical.

Hydrostatic equilibrium can be very easily estimated based on mass, which can be approximately deduced within a range of feasible albedos and densities, and very accurately deduced if the body has a moon. By contrast, it's almost impossible to estimate neighborhood clearing to any distance beyond Neptune, or at all in the case of extrasolar planets. Which, to reiterate, the IAU definition says aren't planets, even though they have an extrasolar planet working group.

We'd have to visit each and every one of them with a probe just to put them in the proper category.

This is utter nonsense.

Meanwhile, it's completely clear which bodies qualify for the "clearing its orbit" rule.

No, it's not. We have virtually no clue what lies in the outer reach of our solar system. As we speak there's a search for a new planet that could be as big as an ice giant. It's a huge open question as to whether it would have cleared its neighborhood, and it will be very difficult to ascertain.

All currently qualifying planets have roughly 99% or more of the mass in their orbit in themselves. Ceres has 30%.

You seem to have some weird concept going on that "semimajor axis = orbit". Ceres has nothing of significance in its orbit. The asteroids are not all in the same orbit. They're certainly more likely to cross each others orbits, but that's not the same thing.

And again, since you apparently missed it: the reason that the inner solar system is largely cleared except for the asteroid belt (and the reason that the latter exists) is Jupiter. Mars did not clear its own neighborhood.

5. The definition should be mutable. Why should a planet that gets ejected keep counting as a planet?

You seriously have to ask why something that hasn't changed but is in a different location shouldn't suddenly be declared to be something entirely different? If you take a rabbit to Canada does it suddenly become a dwarf rabbit?

6. I highly doubt life could form in a non-cleared orbit.

Once again, you're stuck on this misconception that the only orbital parameter that exists is the semimajor axis. And also apparently a notion that stable orbital resonances don't exist.

Orbits can come in a wide range of forms. If you want to see how crazy they get, check out Epimetheus and Janus ;)

As for a life bearing celestial in orbit around another (gas giant) planet: I don't think anybody feels bad about calling that one a moon? As in "Yavin 4".

The funny point with your example being, that whenever you illustrate a large round (hydrostatic equilibrium) moon in sci-fi - Star Wars, Star Trek, Avatar, whatever - people invariably keep calling it a planet and having to correct themselves. We inherently recognize "large, round object with relevant gravity = planet", and have to shoehorn our minds into not using that term.

7. "Within each other's periapsis and apoapsis" seems like a reasonable enough definition that neither Ceres nor Pluto qualify for.

Once again, you ignore most orbital elements (seriously, stop right now and go read the Wikipedia article on orbital elements). We don't live in a 2D solar system. And your notion is oversimplified even for 2D.

All of this, let alone other aspects such as mass ratios, resonance, metastability, etc. And it gets even more complicated when you view the solar system not as a 2-body problem but a multi-body problem. Then things like horseshoe orbits, Lagrangian points, etc come into play.

8. Yes that's silly but that'll probably be changed easily enough and has no effect on Pluto.

1) It's over a decade later. Where's the fix?
2) It's just a symptom of how horribly hasty and ill-thought-out their action was.

9. How are you planning to ascertain hydro-static equilibrium for an exoplanet if we can't even do it for Varuna.

What are you talking about? Varuna is the size of Ceres. The fact that it hasn't been declared a dwarf planet by the IAU is again a symptom of the IAU's dysfunction on this issue. See #18. By contrast, we'd have no snowball's chance in hell of identifying all potential orbit crossers for it.

The fact that you bring up Varuna makes me think that you feel it shouldn't be a planet because it's an oblate spheroid. If so, that just reveals yet another problem with your understanding: you need to go look up the definition of hydrostatic equilibrium. Hint: if Varuna wasn't an oblate spheroid, then it wouldn't be in hydrostatic equilibrium.

Comment Re:TL;DR something you claim is cogent...? (Score 5, Informative) 204

The IAU spend months in total hashing out this issue and three days talking in meetings before the vote

That's just the issue: that's not what happened. The IAU discussion was a disaster. Here's the timeline:

2005: The IAU appoints a committee to investigate the issue and generate a proposal. The committee investigated the issue for a year.

The IAU meeting is scheduled from 14-25 August 2006.

16 August: The committee recommends a definition based on hydrostatic equilibrium. No "cleared the neighborhood" nonsense. They publish their draft proposal.

18 August: The IAU division of planetary sciences (aka, the people who actually deal with planets) endorses the proposal.

Also 18 August: A subgroup of the IAU formed which opposed the proposal. An astronomer in the group (aka, someone who studies stars, not planets) - Julio Ángel Fernández - made up his own "cleared the neighborhood" definition. While most of the membership starts to trickle away over the next week, they remain determined to change the definition.

22 August: The original, hydrostatic equilibrium draft continued to be the basis for discussion. There were some tweaks made (some name changes and adjusting the double-planet definition), but it remained largely the same.

Late on 22 August: Fernández's group manages to get to just over half of the attendance at the (open) drafting meeting, leading to a very "heated" debate between the two sides.

22 to 24 August: The drafting group begins to meet and negotiate in secret. The last that the general attendance of the conference knew, they'll either end up with a vote on a purely hydrostatic definition, or (more likely) no vote at all due to the chaos. Attendence continues to dwindle, particularly among those who are okay with either a hydrostatic definition or none at all.

24 August: The current "cleared the neighborhood" definition is suddenly proposed and voted on on the same day. Only 10% of the conference attendance (4-5% of the IAU membership) is still present, mainly those who had been hanging on trying to get their definition through. They pass the new definition.

It's not generally laypeople who are upset about how it went down, it's IAU members. Many have complained bitterly about it to the press. The IAU's own committee of experts was ignored, in favour of a definition written in secret meetings and voted on by a small, very much nonrandom fraction of people, the vast majority of whom do not study planets.

If there's one thing I hate, it's people who pretend that anyone who opposes the IAU definition does so because they're ignorant morons overcome by some emotional attachment to Pluto, when in reality it's been planetary scientists themselves who have been the definition's harshest critics, because it's an internally self-inconsistent, linguistically flawed, false-premise-based definition that leads to all sorts of absurd results and contradicts terminology that was already in widespread use in the scientific literature.

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