Pleistocene Indonesian bathymetry

With the recent announcement of another quite old, non-human hominoid in SE Asia, once again people are asking questions about how such humanoids got there, as if these non-human animals were stupid, or incompetent, or ... whatever reason.
So, I did a bit of bathymetry work, since I've got tools to hand. I'm sure I'll use these again.
The common estimate for the decrease in sea level (compared to today) at the height of the last ice age, is 100m, so I've adjusted the rainbow colour scale to cover the 90-110m range ; anything deeper than that is marked in blue ; anything shallower is white ; present day exposed land is given an altitude palette.

Is Luzon isolated from the mainland by deep water? 

On this first plot, there is an obvious wide gap to the north. It actually goes down to several km depth, but since you normally drown in the top few metres of water, that doesn't really matter. The minimum sea passage is several hundred kilometres. That's quite a challenge.

 Moving to the southern approach, the question is more complex. At a 100m lower sea level, there is no "dry" route to Luzon, but several of the channels are down in the few-tens of km width. These would certainly be easier for people to have crossed, regardless of their species. Whether that is how the Luzon hominids got in ... is at the moment a judgement call. But if I were looking for places to search for bone-bearing deposits, that's where I'd start. 

This next picture I just anticipate I'll need at some point. Constructed from the same data (GMRT) and with the same shading to differentiate 100m+ versus 100m- water depths, it shows the context of the Homo Floresiensis discovery site (Liang bua cave, my typo). You will note that at least one water crossing of about 30km or larger is needed to get from mainland Asia to Liang bua.
The sea to the north of the two Nusa islands is known as the Flores Sea, for which the species was named.

Plots done using GeoMapApp, www.geomapapp.org and the GMRT dataset they pick up.

Fake dinosaur footprint.

Very quick post.

Geology class
A faked dinosaur footprint. A4 clipboard for scale.
On a field trip to Arran.
In 1985
We don't know who carved this fake dinosaur footprint, but the carver didn't notice that he (she?) cut across several sediment beds (NNE to SSW lineation in this view), marking it as an evident fake.

Photo has suffered from fungus and bad storage for years before being scanned. The carving is pretty unrealistic too.
Prompted by the footprints recently reported from Skye.

"BrexitExit" and the costs of Hubris

In the aftermath of the disastrous (for the Tory Government) 2017 general election (for clarity - the one in June ; I remember 1974 and the two general elections that year, and I'm not going to rule out a second one this year), the question of how badly the UK Government's team at the upcoming "Brexit" negotiation will be weakened is obviously of importance. On one side will be a team from the UK's DUP-CUP Coalition of Chaos, constantly looking over their shoulders to see if they're getting the sack this afternoon, and on the other side a team of professional negotiators with homes to go to and careers that won't be badly affected one way or the other by the result. It's not going to go the way that the Government  or their Brexit supporters want. And the deal that will be aimed at by the professional EU negotiators will be one that is so bad for Britain that it becomes an unavoidable question whether or not it is worth carrying on.
 The UK Government is going to have to try to exit from Brexit. Hence the tag "#BrexitExit".

At that point, one would expect - "require", even, since part of the charge of the EU government is to extend and enhance the EU - the EU negotiators to extract some political payment. If membership of a club is considered an attractive thing, then defectors must be punished, and punished publicly. 

I think one of the high probabilities of a demand for suspending Article 50 and ceasing Britain's efforts to leave the EU will be Britain signing up for the Euro.

The fact that this would be utterly repugnant to many of the political engineers of the whole Brexit debacle would, of course, be one of the motives for making this demand. There are swords which have not been fallen upon, and that is not an acceptable end point of the process. 

I'm also trying to remember an aphorism to the effect that "Those who the Gods wish to destroy [for their sin of hubris], they will first drive insane." [See footnote-2]

Boy, was PM Theresa May suffering a severe attack of hubris when she called the election, and now it's either Furies or Harpies that are keeping her awake at night.

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Links : (submitted as comment/ idea to a journalist on NZZ, Neue Zürich Zeitung) Back-link?

Footnote 1 : "DUP-CUP" Democratic Unionist Party is well known ; the official name of the Tories has always (well my political lifetime, at least) been the "Conservative and Unionist Party" ; normally Tories refer to themelves as "Conservatives", but when first toadying to the DUP, May started using the full name, and telegraphing what was coming by that wording.

Footnote 2 :  That phrasing actually seems to be from the 1870s by Longfellow, but the concept has been traced back via multiple re-uses to Sophocles' Antigone lines 622-624

that a man can reason the bad
into good, when a god
seduces his wit.

 That's the common (in 5th century BCE Athens) condemnation of Sophists.

Musings on Climate Change and it's Mitigation.

What to do about global climate change?

Lots of BLAH but several things are clear :
- Climates are complex. Certainly more complex than we DO understand;  possibly more complex than we CAN understand (without using machines) ;
- People are in deep - ostrich mode (obvious from coverage) ;
- by combination, the two above mean that nothing will be done, until too late. (It may already be too late.)
Hence, the increasing interest in "geoengineering". But which of the many possible schemes to follow? Surely a more difficult, and important, question.

The first point is important. Many proposed schemes interfere with complex systems in complex ways. It is perfectly hard to predict the consequences. Another concern is the time LAG between action and effect and (not unreasonable ) concerns of overshooting the desired end point. Another reasonable concern is the plausible disproportionate effect of controls on people less responsible for the problem.
SO . . .  I see the simplest solution as
(1) change insolation, not the atmosphere. The atmosphere is just too complex.
(2) change the insolation in space
(3) add components  (and so effect) in small but simply additive increments.

My proposition: combine magnetic force propulsion with solar sail technology and the properties of the L1 Lagrange point.
- Orbital objects near L1 stay there with little station-keeping effort.
- This is an area around 1Gm (a million km) from Earth, on the Sun-Earth line.
- The Sun (and Earth) has a non-trivial magnetic field in the region of L1
- At L1 the area covered by the Sun is AROUND 10000 km across. Area ~750000 sq.km.
- We have TRIED  (failed, not for relevant reasons) to launch a solar sail of around 100m diameter. 0.03sq.km
- To reduce insolation by 1%, 7500sq.km of blocking solar sail would be needed. That is a lot of launches, but not immense. Incremental improvements will increase effectiveness of each vessel and launch.

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Update : Does the Earth's magnetic field extend out to a million km (L1)?

Eta Carinae - (yet) Another Hypothesis

Was the nineteenth century giant eruption of Eta Carinae a merger event in a triple system?

2015 paper referring to the 1838 to 1860-ish Eta Carinae outburst
S.F. Portegies Zwart and E.P.J. van den Heuvel

They propose that before 1838 (in Earth's reference frame) Eta Carinae was a triple massive star system. The 1843 outburst was the result of a merger in 1838 (which formed the ~90 MSol main star of the present system), followed by the 1843 impact of the third (non-merging) body of the initial trio with the expanded envelope of the merged star.

Interesting idea. Stimulates the obvious question of what is the prognosis?

Ohhh, I hope they passed it through a native-English speaker (or translator) before publishing things like "Also if our model would finally not be the one that explains all the characteristics of Eta Car, still and evolution as discribed and modelled here is expected to happen not rarely in nature."

So, what is the lookout for the future of Eta Car? Apart from "uncertain"?

Issues with Oolite

Contradictory messages in Stellar Serpents.OXP(z)

Someone got to it first.

New Year 2015-2016.

New Years pretty sky things.

 London skyline from Primrose Hill. A huge pall of smoke from the fireworks drifts east  from the Eye (site of the firework display) ; the Post Office Tower shines somewhat excessively in the foreground. And the Moon and Jupiter look down on the whole lot, unconcerned.
The park's ground has been trashed. And rubbished severely too. Both Oksana and I got hit by flying (falling) champagne corks in the last minutes of the nominal old year.

 More traditional firework photos.




New Year's Eve weird things. The sheep in the back row has 3 horns.

Seriously. I suspect a developmental problem. But this being the Land of the Inbred Yokels (Cotswolds), it could be someone's idea of a joke.

Close up :

Quite how someone could attach a third horn to a sheep is one question ("Why" is another), while I could envision developmental issues where a horn could be duplicated. Then there's always the "parasitic twin" explanation.

Methusalah's star

I'm composing a mail for His CeilingCatness at WEIT, but it needs work.

So far : 

A common attack tactic for creationists is general assault on science - which they frequently support by deliberate mis-reading of reports, and/ or mixing of data from different eras. As you well know.

A popular target is that in the mid-late 1970s some stars had their ages estimated up in the 10+Ga (giga-annum, billion years ago) age range, while measurements from the ground put the cosmic microwave background at around 6 to 7 billion years. Obvious fodder for the god-squaddies. "Science can't be right, therefore God!"

This factoid sometimes gets described as the "Methuselah Star" and variations thereof.

One of the particular stars involved, and the most extreme example is in the Henry Draper star catalogue https://en.wikipedia.org/wiki/Henry_Draper_Catalogue, number HD 140283 (catalogue data and references at http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+140283&submit=SIMBAD+search). This is a spectroscopic catalogue that was published 1918-1924. 19-teens era spectroscopy required relatively bright stars, and it should be no surprise that "Methusalah's Star" is quite close (parallax 16.1140+/-0.0720 milliarcseconds (from SIMBAD, link above) - translating to 62+/-0.1 parsecs, 202.4+/-0.3 light years. That's about the total thickness of the Milky Way's "disc" ; the Milky Way has a shape similar to a CD or DVD disc. Really quite close! Corollary : in the rest of the galaxy, there are probably a lot of equally old, if not older, stars.

Multiple measurements since the 70s have improved our estimate of the age of the universe (BOOMerang https://en.wikipedia.org/wiki/BOOMERanG_experiment, WMAP https://en.wikipedia.org/wiki/WMAP Planck, https://en.wikipedia.org/wiki/Planck_Surveyor), and converged on 13.772±0.040 Ga as the age of the CMB - which is about 370,000 years after the big bang ( 0.00037 Ga - compare with the uncertainty cited above). Obviously that no longer conflicts with the age estimate for "Methusalah's Star".

Having updated the age of the universe, and the distance to the "Methusalah Star", what about it's age? Well that has been updated too. (Arxiv link below) Unfortunately, stars don't come with "Best Before" dates, or even interesting sets of isotopes (which we can read at many trillions of km range), so estimating their ages is rather difficult. But that has improved even more since the 1970s then the age estimates for the CMB.

What initially attracted attention to HD 140283 - why indeed, the astronomers producing the catalogue considered it worth taking note of - is that it's spectrum contained very few, weak absorption lines for what the astrophysicists call "metals" (their jape is that anything which is not hydrogen or helium is a "metal" ; hilarious!). In the 19-teens that was just a datum. As the characterisation goes, astrophysics at that time was more "stamp collecting" than "science". However when Hoyle (and others) developed a theory of powering stars by nucleosynthesis in the 1930s and 40s, this both justified the value of "stamp collecting science" and provided a tool for understanding the ages of stars.

[explain stellar age modelling]

Need to keep the emphasis on nucleosynthesis and core heat production, not get side-lined into primordial elements.