catdynamics

QRT

catdynamics — Sat, 14 Oct 2017 12:43:53 +0000

QRT

scienceblogs.com is shutting down

moving back to ye olde blog: catdynamics

out

catdynamics Sat, 10/14/2017 - 08:43

A missing piece of the puzzle

catdynamics — Sun, 22 Jan 2017 21:15:37 +0000

A missing piece of the puzzle

I've been puzzling over the rationale for some recent events...

Exxon has a large contract to develop oil and natural gas resources in the Russia.
This can only go forward if sanctions on Russia are lifted, which seems likely to happen in the near future.

But, there is too much oil and capacity to surge produce more oil and gas on the market. If nothing else, the US has well developed capacity which is idling.
The problem, as it has been for the last few decades, is that Saudi Arabia can squeeze new producers out of the market, by increasing production and sharply dropping prices, for a while, which forces higher costs producers off the market.
Then the Saudis cut back.
Oil prices go up.
Profit.

So... for the Exxon deal to be really worth while, in the medium term, the Saudi capacity would have to be curtailed.
Or some other major producer removed from the market.

That, could of course be arranged, given the national security resources of a major power or two.

But that'd be totally evil.

catdynamics Sun, 01/22/2017 - 16:15

Glöggt er gests augað

catdynamics — Sun, 22 Jan 2017 20:48:25 +0000

Glöggt er gests augað

The Aspen Art Museum is doing a series of interdisciplinary lectures, titled "Another Look"

Another Look Lecture: Gabriel Orozco & Cosmology - so this is a thing.

I did one of the lectures. The first one, I gather.
It was quite an interesting experience, for me at least.
Good fun, riffing on the perspective from physics on Orozco's work, which is partially inspired by astronomy and thoughts on cosmology.

MoMA was very helpful in providing a perspective on Orozco's work over the years.
The actual exhibition was very interesting. The central floor display piece was quite startling in person and gave me a new perspective.

Detail from central exhibit piece of Gabriel Orozco's exhibit at the Aspen Art Museum

The second talk was on Friday:
Another Look: Obituaries & Adam McEwen with Bruce Weber
Wish I could have been there.
No, I really wish I could have been there... :-)

There will be more "Another Look" lectures, I gather.

From From Unsafe Art

catdynamics Sun, 01/22/2017 - 15:48

Jólasveinar og Jólakettir

catdynamics — Sat, 24 Dec 2016 04:10:55 +0000

Jólasveinar og Jólakettir

The origins and history of the Yule Lads with bonus Christmas Cat...

Even I did not know that peak Yule Lads was 82!
Criminy!

catdynamics Fri, 12/23/2016 - 23:10

Last minute stocking stuffers for nörds

catdynamics — Sat, 24 Dec 2016 00:43:47 +0000

Last minute stocking stuffers for nörds

Ok, I confess, I was supposed to get these reviewed before the Holidays, but a Sequence of Unfortunate Events Intervened and I am only part way through these.

Anywho, if you need a last second pressie for random acquaintances so disposed, there are a couple of interesting science books out there:

A Fortunate Universe: Life in a Finely Tunes Cosmos by Geraint Lewis and Luke Barnes, is a nice up to date book for the general (educated) public on modern physics and cosmology.
If covers modern cosmology and some of the Big Questions of our times, in particular the issue of anthropomorphism how "fine tuned" our Universe is.
Welshman finds QSO
Modern Prometheus: Editing the Human Genome with Crispr-Cas9 by James Kozubek is a personal history of the discovery of the CRISPR-CAS9 genes and their use, and a discussion of the implications and potential of the technology.
It is not an easy book, it does not flow, the discussion is technical given the intended audience and the narrative digresses frequently with often convoluted discussion.
But the topic is interesting and the coverage is comprehensive.
Mapping the Heavens: The Radical Scientific Ideas That Reveal the Cosmos by Priyamvada Natarajan.
Ok, I haven't read this one, don't have a copy.
But, I've heard very good things about it.
A big picture of current research in cosmology, aimed at the educated general reader, covering a range of topics but focusing on the search for dark matter, if what I am told is true.
I'd like to read it, so I'm sure you ought to also.

catdynamics Fri, 12/23/2016 - 19:43

All Roads Lead to Rome

catdynamics — Fri, 23 Dec 2016 23:43:20 +0000

All Roads Lead to Rome

Roads to Rome

All roads really read to Rome

moovel lab makes funky maps,
go play

catdynamics Fri, 12/23/2016 - 18:43

Vikings, Santa & Jól

catdynamics — Mon, 12 Dec 2016 12:38:43 +0000

Vikings, Santa & Jól

Grímfrost in Sweden give their take on the Meaning of the Season

- the Goat of Þór is serious business though...

catdynamics Mon, 12/12/2016 - 07:38

Stekkjastaur – the Elfs are Coming - Pt 1 Revisited

catdynamics — Mon, 12 Dec 2016 08:45:28 +0000

Stekkjastaur – the Elfs are Coming - Pt 1 Revisited

Today is the 12th of december, and there are 13 days until christmas.
This means, of course, that the first of the yule elves came to town this morning.

As you know, Bob, there are thirteen of the Yule Lads, or jólasveinar, as we call them.
And they are not really elves, since their mother is a troll.
The childstealing, cannibal Grýla, of legend.

Stekkjastaur

They come to town, one each day until christmas eve, and then leave in order, starting christmas day and finishing on the 6th of January.
They leave small treats or presents in the shoes of good children, if the kids know to leave their shoe out by the door or window. Strangely, our neighbour kids do not seem to have caught on to this, yet.
If you are naughty, you get a potato, or an onion.

Their arrival is critical, since any child who is so naughty as to not get a single piece of clothing, candle or a game before Christmas Eve, will be eaten by Jólakötturinn (the "Christmas Cat" – big as a house it is, silent, deadly).

Jólaköttur - feline solsticus

The lads are pranskters, and quite mean ones, none of your Ho, Ho Ho! Coke swilling softies. Stekkjastaur sneaks up on the ewes and sucks the milk out of their udders, though this is hard going as he is stilt-legged.

On the other hand, the munchkins find it very convenient to be in a multicultural family, especially since the Better Half is fond of the Feast of St Nicholas; my extended family feels presents should be given on christmas eve after dinner; while the in-laws go with the anglo-style stocking and christmas morning thing.

And the one time the Big Kid got a potato, she laughed so hard she fell over, and then came into the kitchen with a big grin and asked that we cook it for her… (it got donated to local wildlife as a compromise).

We are of course not talking superstition.
I mean, I don’t “believe” in elves.
I just know not to mess with them.
You leave their houses alone, leave a seat (1st class, natch) on the occasional flight for them, and maybe put out the occasional bowl of milk… elves don’t need your belief, and trolls of course don’t care, they just eat you.
I should note that Iceland’s one Nobel laureate treated the issue of elves in Icelandic culture extensively, so there.

Just remember, you must have an evergreen for the solstice festival, and you better burn it when you are done, after 12 days, of course.
If you do not, winter may never end!

Next one up, any hour now, is Giljagaur. Sneaky one.

repost from '08

catdynamics Mon, 12/12/2016 - 03:45

A Pale Red Dot: The Closest Exoplanet

catdynamics — Wed, 24 Aug 2016 11:00:56 +0000

A Pale Red Dot: The Closest Exoplanet

The Pale Red Dot project has found a planet.

It is a terrestrial planet, orbiting in the formal habitable zone of Proxima Centauri, the nearest star to the Solar System.

This wide-field image shows the Milky Way stretching across the southern sky. The beautiful Carina Nebula (NGC 3372) is seen at the right of the image glowing in red. It is within this spiral arm of our Milky Way that the bright star cluster NGC 3603 resides. At the centre of the image is the constellation of Crux (The Southern Cross). The bright yellow/white star at the left of the image is Alpha Centauri, in fact a system of three stars, at a distance of about 4.4 light-years from Earth. The star Alpha Centauri C, Proxima Centauri, is the closest star to the Solar System.

Proxima Centauri is a low mass red dwarf, and is part of a triple system, the other two stars being α Centauri A and B, which are solar like stars in a close orbit around each other.

3D map of all known stellar systems in the solar neighbourhood within a radius of 12.5 light-years. The Sun is at the centre. The colour is indicative of the temperature and the spectral class — white stars are (main-sequence) A and F dwarfs; yellow stars like the Sun are G dwarfs; orange stars are K dwarfs; and red stars are M dwarfs, by far the most common type of star in the solar neighbourhood. The blue axes are oriented along the galactic coordinate system, and the radii of the rings are 5, 10, and 15 light-years, respectively.

The whole system is a little over 4 light years away, the nearest stars to the Sun, and Proxima is the closest of the three stars.

This image of the sky around the bright star Alpha Centauri AB also shows the much fainter red dwarf star, Proxima Centauri, the closest star to the Solar System. The picture was created from pictures forming part of the Digitized Sky Survey 2. The blue halo around Alpha Centauri AB is an artifact of the photographic process, the star is really pale yellow in colour like the Sun.

α Centauri B was thought to have a planet, but the evidence for that particular planet is looking shaky.

This picture combines a view of the southern skies over the ESO 3.6-metre telescope at the La Silla Observatory in Chile with images of the stars Proxima Centauri (lower-right) and the double star Alpha Centauri AB (lower-left) from the NASA/ESA Hubble Space Telescope. Proxima Centauri is the closest star to the Solar System and is orbited by the planet Proxima b, which was discovered using the HARPS instrument on the ESO 3.6-metre telescope.

It may have been noise. α Cen A and B were in conjunction, making them hard to observe, but are now separating, and observing campaigns to look for planets around those star are continuing.

ESO researchers, using the radial velocity variability technique, have detected a quite robust signature of a planet with a mass of 1.3 Earth masses, or more, in a 11 day orbit around Proxima Centauri.

This plot shows how the motion of Proxima Centauri towards and away from Earth is changing with time over the first half of 2016. Sometimes Proxima Centauri is approaching Earth at about 5 kilometres per hour — normal human walking pace — and at times receding at the same speed. This regular pattern of changing radial velocities repeats with a period of 11.2 days. Careful analysis of the resulting tiny Doppler shifts showed that they indicated the presence of a planet with a mass at least 1.3 times that of the Earth, orbiting about 7 million kilometres from Proxima Centauri — only 5% of the Earth-Sun distance.

Since the Proxima Centauri is almost 1,000 times fainter than the Sun, this puts the putative planet well within the habitable zone of the star, near the inner edge of the zone, but formally inside it.

This infographic compares the orbit of the planet around Proxima Centauri (Proxima b) with the same region of the Solar System. Proxima Centauri is smaller and cooler than the Sun and the planet orbits much closer to its star than Mercury. As a result it lies well within the habitable zone, where liquid water can exist on the planet’s surface.

The planet would most likely be tidally locked to the star, and might either have one face locked to the star (like the Moon to the Earth), or, conceivable, be in a 2:3 tidal lock, like Mercury is with the Sun.
In either case, it is conceivable for this planet to have liquid water on its surface, IF it is has reasonable thickness atmosphere of nice enough composition.

This artist’s impression shows the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image between the planet and Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.

This is the nearest star to the Sun.

The relative sizes of a number of objects, including the three (known) members of Alpha Centauri triple system and some other stars for which the angular sizes have also been measured with the Very Large Telescope Interferometer (VLTI) at the ESO Paranal Observatory. The Sun and planet Jupiter are also shown for comparison.

It has an Earth like planet orbiting in a nice orbit.
It will be about as easy to characterise as any exoplanet ever.
There really are a lot of exoplanets everywhere, and a lot of them are Earth mass, and a lot of those are in nice orbits.

What a nice Universe.

Next, a nice intense workshop on how to find lots of low mass planets in the habitable zones of lots of stars in the near future.
Should be a fun workshop.

ESO press release - with bonus videos and extra graphics and links.

"A terrestrial planet candidate in a temperate orbit around Proxima Centauri" Anglada-Escude et al. Nature, 25 August, 2016

Two new papers on the topic:

"Proxima Centauri as a Benchmark for Stellar Activity Indicators in the Near Infrared" Paul Robertson et al., ApJ submitted - stellar photometric activity may mimic low amplitude radial velocity variability, and cause false positive signals for candidate planets. This paper looks at multi-band photometry over a long timeline for Proxima Centauri to characterize time scales on which the star varies.
tl;dr there is very little variability on 5-15 day time scales, which makes it very unlikely the planet candidate is a false positive due to stellar variability.

"Effects of Proxima Centauri on Planet Formation in Alpha Centauri" Worth & Sigurdsson, ApJ in press - theory paper by Rachel Worth, my PhD student, on planet formation models for the α Centauri system, taking its putative dynamical history into account.
tl;dr - theoretically there can be planets in the system, few, low mass in close orbits, including around Proxima Centauri. Details could elucidate past history and formation of system.

catdynamics Wed, 08/24/2016 - 07:00

Iceland Football Demographics

catdynamics — Mon, 27 Jun 2016 12:54:54 +0000

Iceland Football Demographics

In case anyone hasn't noticed, Iceland is playing England in the Euro 2016 Cup today, round of 16.

This is the first time Iceland has been in a major football tournament, the first time, obviously, they have progressed to the second stage, and as I write this they are unbeaten in tournament play.

Iceland has a population of just over 330,000.
It is about half the size of Wyoming, both in area and population.

For perspective, the mens' football team is drawn approximately from the 21-37 year old demographic, which has about 65,000 people in it. Or about 33,000 males.
The football squad has about 20 players, so the chance of someone in Iceland being on the national football team at any given time is about 1/1,500.
Your prior odds of making the national team growing up are order 0.1%, given turnover in the squad etc.

Now think about the fact that there are multiple national squads in different sports and activities and Iceland tries to represent fully at the international level...

A typical male in their early 20s tends to have a social network of about 1-200 people. These are relatives, friends, classmates and teammates.
There will be some overlap among the national team members, but as a good approximation, 10% of the population of Iceland are part of the national teams social network.
That is 1/10th of the country are the friends, relatives, lovers or co-workers of the football team.

Not coincidentally, about a 1/10th of the population of Iceland has gone to France for the Euros, a significant fraction of them are in the stands at any given time.
Enough were there that it significantly reduced the turnout for the Presidential Election this week when Iceland advanced out of the groups to the elimination rounds!

Icelands is unbeaten, England has never lost to Iceland.

Maybe it will come to penalties...

Game On.

PS: well, that was a jolly Good Game.

catdynamics Mon, 06/27/2016 - 08:54