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...solid introduction to Charles Darwin's groundbreaking theory of evolution. The geneticist Steve Jones and the historian Fern Elsdon-Baker explain and comment on Darwin's theoretical approach, and explore how evolutionary theory is relevant to modern environmental concerns and recent developments in genetics. Fern Elsdon Baker introduces the Darwin Now project and...

...solid casting...[Diagram to demonstrate pore-free die casting (Active atmosphere casting)] Conventional high pressure die casting uses air at 10–20 MPa to fill the mould rapidly, leading to air entrapment (porosity) in the casting, with a reduction in mechanical properties, weldability, ease of heat treatment and pressure soundness. Low pressure die casting and the...

...solid model Step 4 is to create a solid CAD model of the hub. This is a complex process which involves a series of assumptions and simplifications which need to be taken into account to get a true picture of the hub's behaviour. Creating a mesh model Step 5 is to create a mesh model of the hub, with 72 000 elements. The mesh density is at its greatest in areas of...

...Sedimentary rocks Geologist Tony Lee reveals the hidden stories locked into the features of sedimentary rocks. A rock matrix Did you know rocks are far from solid? Discover how the internal matrix of rock is formed. Rock successions Fieldwork is an important and fun part of geology. Explore large-scale geological investigation with this look at rock layers and deposits....

...hot… mostly vaporised rock, with no solid or liquid surface.” (see video below). Transcript Clearly this hypothesis is a work in progress, however according to how well it accounts for the observations we currently have of the Earth-Moon system, it is likely that this hypothesis has the best chance of replacing the single giant impact hypothesis! Watch this space…...

...liquid water overlying warm, tidally-heated, rock. It is pretty clear that Europa has a global ocean below its surface ice shell, and that this shell is repeatedly cracked apart by tidal stresses, and that occasionally whole patches melt completely, exposing the underlying ocean to space. The only outer planet moon where a probe has landed is Saturn’s largest moon,...