08/22/14

Gut instincts


Ars TechnicaA story on Science Daily says research suggests our so-called “free will” may be less free than we ever imagined. We may, instead, be meat puppets ruled by the desires and cravings of the smallest symbiotes we carry: our gut bacteria.

The story opens:

It sounds like science fiction, but it seems that bacteria within us — which outnumber our own cells about 100-fold — may very well be affecting both our cravings and moods to get us to eat what they want, and often are driving us toward obesity… researchers from UC San Francisco, Arizona State University and University of New Mexico concluded from a review of the recent scientific literature that microbes influence human eating behavior and dietary choices to favor consumption of the particular nutrients they grow best on, rather than simply passively living off whatever nutrients we choose to send their way… the authors believe this diverse community of microbes, collectively known as the gut microbiome, may influence our decisions by releasing signaling molecules into our gut. Because the gut is linked to the immune system, the endocrine system and the nervous system, those signals could influence our physiologic and behavioral responses.

Actually this is not really surprising. It has long been known that human evolution has been affected by both viral and bacterial presence, as well as having our own DNA encoded with bits from them. And recently it was discovered bacteria can encode DNA from other animals – even dead ones – into their own.

The discovery of the recombinant DNA process should have alerted everyone to the wider possibility that there may be biological analogues already. After all, it only makes sense that in any symbiotic relationship, there must be some way for all parties to communicate with each other for mutual survival. The gut is a competitive environment with numerous species, so they also need a mechanism for cooperation and communication in ways that also help keep the host alive.

Most life on the planet has some form of symbiotic relationship and many are mutually beneficial like that with our gut flora, although there are also parasitic relationships as well.

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08/16/14

The First Dark Age


End of the Bronze AgeThe causes of the first “Dark Age” have long been the topic of debate among historians and archeologists. Many ideas and theories have been put forward; none have found universal agreement. It’s commonly referred to in scholarly circles as “The Catastrophe.

Earthquakes, drought, migrations (or the more popular single-people migration theory), volcanoes, barbarian raiders, climate change and systemic collapse have all been blamed for the sudden collapse of civilizations in the eastern Mediterranean over a short period of time.

While any one of these may account for particular cities, or even a small geographical region, it is difficult to apply those theories collectively to the collapse over such a wide area. There is simply no evidence to connect the incidents of collapse.

Nor do they explain why the empire of Egypt and Assyria, both on the periphery of the larger area affected, seem to have escaped relatively intact from the collapse – although Egypt’s might and influence came out of the period severely diminished.

Whatever the cause, over a period spanning roughly 50 years of the late 13th and early 12th centuries BCE, many civilizations in the Aegean basin and southeast Asia underwent a violent collapse. Dozens of cities and settlements were destroyed or abandoned. Archeologists have uncovered evidence of fire and destruction in many of the remains of the great ancient centres. There are signs of “instant cities” – settlements that sprang up suddenly in previously unsettled areas, suggesting they developed from a mass of escapees bonding together for safety after fleeing a disaster.

It would be centuries before most of this area rose again to similar prominence. It was a Dark Age for the eastern Mediterranean.

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08/14/14

Testing a Homeplug-Powerline Network


DlinkI’ve had some wireless issues for quite some time now. There are dead spots in the house – a central wall has metal ducts and a gas fireplace, which are beside the laundry room with its metal-enclosed washer and dryer. About 5-6m of metal interfere with the wireless signal. The modem is attached to the cable, which comes through the north side of the house, and there are no other active cable outlets in other rooms (there are outlets for cable, but they’ve never been properly connected).

Plus the ducts and pies in the basement and the metal front door interfere with the signal out of doors, making it difficult to get good reception in a large portion of the yard – including our favourite summer sitting location; the newly rebuilt front deck.

 

And just to confound matters, my Acer Aspire laptop has the annoying habit of losing its internet connection – while all my other wireless devices are fine – although it can see other networks nearby and even connect to my modem. Just not the net.

I’ve looked at all sorts of solutions, from wireless extenders and bridge routers, to rewiring a large portion of the house to accommodate moving the cabling to allow the modem to be placed closer to the laptop. I’ve moved the modem a few times, but the reception has only improved indoors – out of doors it remains unstable.

There is often a 10-metre ethernet cable running across the floor between laptop and modem when I want to be sure my access isn’t interrupted. Susan hates it. It’s a trip hazard and looks hokey.

This week I decided to try a different approach (a suggestion from Neville on Facebook): a powerline (aka homeplug) network extender. It’s a whole area I knew nothing about before this week, except for the vague understanding that the network connects via the AC power lines in your home.

Basically you plug one adapter into a wall socket and attach it to your modem via a (shorter) ethernet cable. They you plug in a second adapter somewhere else in your house, preferably close to your computer, do whatever the device needs to establish a connection (in my case, push a button). When they connect, you plug another (shorter) cable into the adapter and your computer.

But which one? Which type, which standard, which brand, which feature set? That’s what I spent most of my past few days studying. Reading reviews, technical papers, speed tests, manufacturers’ claims. Prices range from $40 to almost $150 for the minimal two adapters. Why the difference and would it really matter to me?

In the end I went low-end rather than cutting-edge. I bought a D-Link “PowerLine AV 500 Network Starter Kit (DHP-309AV) from the local Staples store. Took all of two minutes to set it up, another minute to connect cables and my laptop was connected to the internet.

And if it proves itself in the upcoming months, I may look at the new models due out this fall to upgrade to the new AV2 standard, and get some extra ethernet ports strung around the house.

08/11/14

Chasing storms on Saturn


There’s a beautiful video about the Cassini mission and its images of the storms on Saturn at the New York Times website. It’s amazing to see what images and information science has given us about a planet 886 billion miles (1.4 billion kms) away and its odd collection of rings and 60 moons.

Saturn’s storms

Saturn takes 30 years to orbit the Sun and in January, 2014, began its first spring in 15 years. Until then, the northern hemisphere was shrouded in darkness and the rings tilted away from us. Now the north pole is in sunlight and the magnificent, monstrously large, hexagonal storm at its centre is clearly visible. The video makes it quite an entertaining and awe-inspiring sight.

The hexagonal shape, while unusual, is natural and has been replicated in the laboratory. It is not, as some wingnut conspiracy theorists suggest, a supernatural event, anything to do with aliens or the gates of hell (nor, as uber wingnut David Icke has suggested, is Saturn a giant, artificial broadcasting device… ).

Cassini will be travelling right over the north pole in 2016 in its final – and perhaps most spectacular – mission, for a close-up view of the storm. You can read more about the weird hexagonal storm on the JPL website. The eye of the storm alone in 1,240 miles across (2,000 kms) and the dorm itself is estimated at 60 miles (100kms) deep.

Cassini took seven years to reach Saturn, but that’s a short time compared to New Horizons, which will reach Pluto next July, after a voyage of nine years.

In related news, the spacecraft Rosetta arrived at the comet 67P/Churyumov-Gerasimenko last week, the first spacecraft to rendezvous with a comet. The images sent back so far have been breathtaking. Rosetta is in orbit 62 miles (100 kms) from the comet, but will soon lower to 31 miles (50kms) to prepare for a landing. Rosetta took ten years to reach its target.

All of this is truly exciting, inspirational stuff, isn’t it? Science never ceases to amaze and astound me.

08/1/14

Neolithic site dig uncovers sophisticated structures


Orkney dig site
A Neolithic site in the Orkney Islands shows our ancestors had sophisticated building skills more than 5,000 years ago. According to a story in The Scotsman,

A groundbreaking excavation of a 5,000-year-old temple complex in Orkney has uncovered evidence to suggest that prehistoric people were a great deal more sophisticated than previously thought.
The archaeological dig at the Ness of Brodgar, which is still in its early stages, has already thrown up discoveries that archaeologists say will force us to re-evaluate our understanding of how our ancestors lived.
The picture that has emerged so far points to a complex and capable society that displayed impeccable workmanship and created an integrated landscape.

Well, it’s very premature to identify it as a “temple complex.” As for any structure being a “temple” or the whole site being a “temple complex” – that’s just a guess.

The article’s headline is hyperbolic: “Orkney dig dispels caveman image of ancestors.” This is followed by the equally fatuous opening:

THE image of our Neolithic ancestors as simple souls carving out a primitive existence has been dispelled.

I suppose that misrepresentation may have been dispelled from the writer’s rather confused mind, but few others are likely to be that daft.

Orkney dig

The media are ever wont to sensationalize things in this manner. I can’t imagine anyone with at least an elementary school education believes people living 5,000 years ago were “cavemen.” This time is contemporary with the development of early (“proto”) writing in many cultures, and actually later than some finds from 7th millennium BCE China (the Jiahu symbols from Henan, 6600 BCE). It was the time when the first towns were formed.

We’ve known about Neolithic building from the many megaliths and gravesites uncovered, as well as the communities already unearthed. The most famous of which is, of course, Stonehenge, built roughly in the same period as the Orkney site. You can see an imagined reconstruction on the National Geographic site. It’s impressive, but hardly spectacular in the way Stonehenge, Macchu Picu, Angkor Wat or the Pyramids are.

Cavemen, as they are inappropriately called, refers to people living in the Paleolithic period, which Wikipedia reminds us extended,

…from the earliest known use of stone tools, probably by hominins such as australopithecines, 2.6 million years ago, to the end of the Pleistocene around 10,000 BP.

The Neolithic is when human communities first start developing beyond the tribal stage; when architecture and agriculture, music, language and religion all developed. While archeologists and anthropologists bicker over the exact time span, in general it ran from about 10,000 BCE to about 4,500 BCE, although some place it as recent as 2,000 BCE for some groups.
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07/25/14

Gangs of Feathered T-Rex


Packs of tyrannosaurs
Imagine, if you will, an early morning scene in the late Cretaceous. The air is quiet as the day warms. At the edge of a large forest a plain of ferns ripples in the light breeze (grass would not evolve for another 20 or so million years). Under the canopy of the ancient beeches and maples, there is movement. Nothing fast, just a hint. A flash of mottled colour against the background. A glint of light off an eye. A soft snuffling. A feather falls silently to the forest floor.

Among the nearby ferns, a pack of ceratopsians grazes, adults watching the woods carefully, nervously, herding the young towards the safety of the pack’s centre with prods of their heads, honking to get the young ones’ attention. They eat the flowers that dot the plain among the ferns and cycads, chew the horsetails that grow at the edge of the ponds and streams. A youngster sees a tasty patch of moss and, unnoticed, slips out between the elders to get it.

Suddenly the forest explodes. Leaves scatter and branches snap as the muscular forms crash through the cover and converge on the young triceratops, separated from the horned protection of the pack. Two large adults, a teenager and two younger tyrannosaurs running a well-coordinated hunt as they have done many times int he past. Their speed makes them a blur against the trees.

The ceratopsians bellow in fear and rage, and quickly form a circle, heads out, protecting the oldest and youngest within the centre. The pack of tyrannosaurs’ charge sounds like thunder, and they screech in anticipation as they race to surround the doomed youngster. They circle rapidly, darting to avoid the feeble attempts at defence from the surrounded dinosaur.

The herd can’t save it, and they move away, quickly, the outer ring still shuffling backwards to keep their ferocious, horned heads facing the danger. The tyrannosaur pack ignores the herd as it feeds, tearing off chunks of the living flesh as the youngster’s screams get fainter.

Their hunger slaked for the moment, the pack would soon retire to the forest to look for another easy target that might venture close by.

Triceratops vs tyrannosaur

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