10/15/14

Earth’s magnetic field could flip within a human lifetime


An intriguing possibility was reported on Science Daily this morning:

Earth’s last magnetic reversal took place 786,000 years ago and happened very quickly, in less than 100 years — roughly a human lifetime. The rapid flip, much faster than the thousands of years most geologists thought, comes as new measurements show the planet’s magnetic field is weakening 10 times faster than normal and could drop to zero in a few thousand years.

Why would this matter? The article continues:

And since Earth’s magnetic field protects life from energetic particles from the sun and cosmic rays, both of which can cause genetic mutations, a weakening or temporary loss of the field before a permanent reversal could increase cancer rates. The danger to life would be even greater if flips were preceded by long periods of unstable magnetic behavior.

When will this happen? That’s the big question behind the headline. Soon, warn geologists. But their “soon” in geological time doesn’t mean the same as “your breakfast will arrive soon” in a restaurant. It seems overdue for a flip, but no one is sure when that might happen. A 2002 story in The Guardian warned that it was imminent – in geological terms:

“Some experts have stuck their necks out to predict that we can expect the next reversal some time in the next 2,000 years.”

I think we can have that cup of tea while we wait. It may not happen in our lifetimes. But, the article has that shock effect nonetheless:

The Earth could be about to turn upside down. The planet’s magnetic field is showing signs of wanting to make a gigantic somersault, so that magnetic north heads towards Antarctica, and magnetic south goes north. Compasses will point the wrong way, and migrating birds, fish and turtles are going to be very confused.
Just when this will happen, how long it will take and what the consequences will be, is difficult to fathom. What is not in doubt, though, is that it will happen. About every half a million years or so, the Earth’s magnetic field flips upside down.

And that’s the worry: every half-a-million years is a lot less time than the 786,000 years since the last flip-over. This summer, Scientific American warned it could happen sooner rather than later:

Earth’s magnetic field, which protects the planet from huge blasts of deadly solar radiation, has been weakening over the past six months, according to data collected by a European Space Agency (ESA) satellite array called Swarm.
The biggest weak spots in the magnetic field — which extends 370,000 miles (600,000 kilometers) above the planet’s surface — have sprung up over the Western Hemisphere, while the field has strengthened over areas like the southern Indian Ocean, according to the magnetometers onboard the Swarm satellites — three separate satellites floating in tandem.
The scientists who conducted the study are still unsure why the magnetic field is weakening, but one likely reason is that Earth’s magnetic poles are getting ready to flip, said Rune Floberghagen, the ESA’s Swarm mission manager. In fact, the data suggest magnetic north is moving toward Siberia.

So we wait, unable to do anything about it. Have another cuppa, if you must. Yes, you have time.

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09/26/14

The Utility Animal


In the July/August edition of Pets Magazine (the Cat Care issue) there are two articles that caused me concern. One is “The Loyalty and Bravery of a Cat” (p.28), the other is “Quick-Thinking Cat Saves the Day.” (p.26). The latter is a pet profile from the Purina Hall of Fame that honours pets for “extraordinary actions.” The former is about a YouTube video showing a family cat attacking a dog that had itself attacked the family’s four-year-old son.

The acts themselves and the cats involved are extraordinary and deserving of praise as individual animals. But the idea that cats in general need to be propped up as utility animals, that in order to have intrinsic value they need to perform some service for humans, bothers me deeply.

It also annoys me that cat lovers feel the need to be defensive about cats and find ways to make them seem more like dogs. They are separate species with very different social (pack) cultures and cannot be expected to behave like one another.

All animals evolved to fulfill their own purpose. Some have become domesticated through their interactions with humans; a few are even companion animals we call pets. Dogs and cats top that small list. And a small percentage of those perform acts that are of use or beneficial to humans.

Valuing an animal on the basis of its utility is to devalue the life of that animal. Animals do not exist to serve human needs. Yes, they can be trained to perform tasks, but that isn’t their purpose.

Cats have value simply by being cats. All life has its own inherent value and we cannot measure that value against its usefulness to our lives. Not should not – cannot. There is no appropriate measuring stick.

Any attempt only promotes subjective value judgments over other species. It’s akin to measuring the distance to a neighbouring planet by the number of bicycle lengths between us. Irrelevant.

Value your pet, value all life, for what it is. Not what use, not what advantage and not what profit you can gain from it. And I am happy to share my home with my pets for the sake of their companionship alone.

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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