The sinking bubbles in Guinness and stouts in general have intrigued drinkers and scientists alike.  Research into this phenomena has been highlighted before on this blog (post linked here).  The latest research published in arxiv (academic paper linked here) demonstrates the importance of the shape of the glass in generating the fluid circulation necessary for the creation of the sinking bubbles.  Numerical simulations and experimentation show that the standard pint glass which has a narrower base cause the falling bubble effect whereas a glass that has a larger base does not i.e. results in rising bubbles.  Essentially the small (nitrogen, as opposed to carbon dioxide used in most beers) bubbles are being carried along by the local fluid motion in the glass and the shape of the glass influences the circulation of the beer as it is poured determining a sinking or rising bubble effect.  More explanation is provided in a BBC news article here.

What are climate models?  The UK Met. Office explains:

Here is our wonderful planet (or the northern hemisphere part at least!). Images taken from the Russian Elcctro-L satellite every 30 minutes are stitched together to make this video.

The geostationary weather satellite takes the highest resolution images of our planet, they are single shot photos. The images consist of visible and near-infrared wavelengths (e.g. vegetation is red not as the human eye sees it).

More details are provided here.

Here is another beautiful movie showing ocean fluid patterns (previous post here).  This time we have a numerical simulation of the discharge of fresh water from the Amazon River entering the saltwater of the Atlantic Ocean.  The ocean model (Mercator Ocean) simulates sea surface temperatures over a 3 year period.

HT FYFluidDynamics

A few weeks ago I posted on a stunning video capturing computer simulated ocean current patterns.  Today I’m posting on surface wind flow patterns over the contiguous United States.  Both show the visual beauty of these large-scale fluid flow patterns.  You have to follow this link to view live moving imagery which is based on near-term surface wind forecasts.  Do check out the moving fields, but shown below are some snap shots showing some of the patterns that get generated.

Apparently my Royal Society article of last year was the journals (Proceeding A) most cited paper of 2011 and the 8th most downloaded.  The illustrious top-ten are listed here: Anyway the prize for this accomplishment is that the complete article is freely available online through 2012 (i.e. no journal pay-wall).  So please go ahead and have a look – download and cite the paper some more!

A numerical study of hydrologically driven glacier dynamics and subglacial flooding  by Sam Pimentel and Gwenn E. Flowers


“When the apostles returned, they told Jesus everything they had done. Then he took them with him and they withdrew privately to a town called Bethsaida.” Luke 9:10 (NET Bible)

The small fishing village of Bethsaida, mentioned on several occasions in the New Testament, literally means “house of fishing”.  However, Bethsaida lies almost three kilometers from Lake Galilee’s waters edge!  How can this be?  The solution to this conundrum provides a classic example of how Earth Science and Archeology can interact with Biblical scholarship to shed light on Biblical interpretation.

The most likely location of Bethsaida is the present day location of Et-Tell, which as I say lies some distance from the waters edge.  In order to understand how this could be we must appreciate that landscapes change and evolve over time.  In this particular instance an understanding of plate tectonics, landslides, lake level variations, and delta formation are needed in order to appreciate how these processes have shaped the landscape.

The Jordan Valley lies along a major fault line.  The friction between the sliding African and Arabian plates has given rise to many earthquakes (about one every hundred years) several of which are recorded in the Bible.  Tectonic rifting has caused significant uplift at et-Tell; furthermore sediment layers at the site have revealed a history of major landslide events.  One such debris layer, carbon-14 dated to a period just subsequent to New Testament events, measures 50 by 200 by 25 metres.  Such a large debris flow would have damed up the Jordan River, eventually causing a catastrophic outburst flood  (as is evidenced by boulders scattered up to 40 meters from the present river course).  In addition silt from the Jordan river has built up over time gradually filling the northern section of the lake, hence the Jordan delta has been extended by extensive sedimentation.  Water levels of the Sea of Galilee have themselves fluctuated in response to climate and have declined drastically due to land irrigation (see for example our discussions on this blog highlighting the historical changes to the Sea of Galilee and the Dead Sea).  When carefully piecing this evidence together a picture emerges that  suggests this site was located either at the shoreline or easily accessible to the lake via an estuary during New Testament times.  There is also textual evidence (e.g. from Josephus) as well as archeological evidence.   Further and more detailed information on the evidence for this deduction are well described is an article at The Bible and Interpretation entitled Why the fishing town Bethsaida is not found along the shore of the Sea of Galilee.  The wikipedia entry for Bethsaida also provides some good information.

“Immediately Jesus made his disciples get into the boat and go on ahead to the other side, to Bethsaida, while he dispersed the crowd.” Mark 6:45 (NET Bible)

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