next »

[charlienomad]

This thread may only be of interest to me (and possibly Clydey) but I thought it might be fun to have a science thread in which folk who follow such matters can post articles that catch their eye...  The intention is for discussion about specific subjects, rather than science vs religion, creation vs evolution, which are covered elsewhere.  

This paper in Nature Geoscience caught my eye:

Surprising return of deep convection to the subpolar North Atlantic Ocean in winter 2007–2008.  Våge et al, 2008

"In the process of open-ocean convection in the subpolar North Atlantic Ocean, surface water sinks to depth as a distinct water mass, the characteristics of which affect the meridional overturning circulation and oceanic heat flux. In addition, carbon is sequestered from the atmosphere in the process. In recent years, this convection has been shallow or non-existent, which could be construed as a consequence of a warmer climate. Here we document the return of deep convection to the subpolar gyre in both the Labrador and Irminger seas in the winter of 2007–2008. We use profiling float data from the Argo programme to document deep mixing. Analysis of a variety of in situ, satellite and reanalysis data shows that contrary to expectations the transition to a convective state took place abruptly, without going through a phase of preconditioning. Changes in hemispheric air temperature, storm tracks, the flux of fresh water to the Labrador Sea and the distribution of pack ice all contributed to an enhanced flux of heat from the sea to the air, making the surface water sufficiently cold and dense to initiate deep convection. Given this complexity, we conclude that it will be difficult to predict when deep mixing may occur again."

Anyone who has watched "The Day after Tomorrow" will be familiar with the idea that the slowing down of the deep thermohaline circulation in recent years has been a direct result of "global warming" (I put it in brackets as it is not a phrase I particularly like).  This article points out that a mixture of processes in the North Atlantic resulted in sufficient cooling of surface waters in the Labrador Sea (between Canada and Greenland) to kickstart it again.  It is a good example of the complexity of the climate system, and why some of the broad, sweeping assertions made in the popular press don't reflect reality very well.  Predictions about future climate changes are based on computer models, and the kind of processes described in this paper are too complex to appear in a model, and yet have clearly had a far-reaching affect...

Thoughts? Comments?  Any science issues that have caught your eyes recently?

[Sarah_]

When DavidB decides to show his face around here again he'll join in with you.

[Neil]

I would like to ask, is perpetual motion possible?

Anything's possible. But creating energy from nothing. Highly doubtful.

[charlienomad]

So do you feel certain that this alleged discovery is a hoax?

Yes - have a look at this article on the bbc [noembed]http://news.bbc.co.uk/2/hi/technology/6283374.stm#[/noembed]

[charlienomad]

Well that article suggests it's not a hoax but instead that he is truly believing something that is false. Interesting

Or says he believes it - remember he is trying to raise capital to increase the value of his company...

[charlienomad]

Quantum Teleportation Between Distant Matter Qubits: Olmschenk et al., 2009, Science

"Quantum teleportation is the faithful transfer of quantum states between systems, relying on the prior establishment of entanglement and using only classical communication during the transmission. We report teleportation of quantum information between atomic quantum memories separated by about 1 meter. A quantum bit stored in a single trapped ytterbium ion (Yb+) is teleported to a second Yb+ atom with an average fidelity of 90% over a replete set of states. The teleportation protocol is based on the heralded entanglement of the atoms through interference and detection of photons emitted from each atom and guided through optical fibers. This scheme may be used for scalable quantum computation and quantum communication. "


While this isn't much of a step towards being beamed to work from home in a nanosecond, quantum teleportation may be the next, next, next-step towards ultrafast computing in tiny packages...  The future is here

[charlienomad]

Well - I realise my "Science thread" idea has taken off like the proverbial lead balloon, but I am going to soldier on regardless because, frankly, it's better than actually doing work...

An article recently published in Earth Science Reviews, a well-respected geology journal, seeks to bring an end to a debate which has been raging in some circles about the terminology used in a particular sub-discipline of sedimentology called "sequence stratigraphy."  This attempt will no doubt fail, and if I haven't been thrown off by then for boring people to death I will post a link to the paper I suspect will be published shortly by opponents to this one...

There are a few folk on here who like to think of themselves as masters of debate and pedantry...  I suggest we all take a lesson for the debate that has taken place here, on the University of South Carolina website prior to the publication of this paper.  Masters of pedantry at work - stand back in awe!!:D

[charlienomad]

Keep at it, Charlie. Apologies for not contributing, but I haven't been in that sort of frame of mind lately.

Sign of a healthy mind, if you ask me - man cannot live on rhetoric and debate alone... It's good to have other interests