11/18/2010

Whale Sharks Use Geometry to Avoid Sinking.

most animals movement is crucial for survival, both for finding food and for evading predators. However, movement costs substantial amounts of energy and while this is true of land based animals it is even more complex for birds and marine animals which travel in three dimensions.
For the past four years, Adrian Gleiss and Rory Wilson, from Swansea University, worked with Brad Norman from ECOcean Inc. to lead an international team to investigate the movements of whale sharks, Rhincodon typus, at Ningaloo Reef in Western Australia. They attached animal-borne motion sensors, accelerometers, to the free-swimming whale sharks to measure their swimming activity and vertical movement, which allowed them to quantify the energetic cost of vertical movement.
The team's data revealed that whale sharks are able to glide without investing energy into movement when descending, but they had to beat their tails when they ascended. This occurs because sharks, unlike many fish, have negative buoyancy.

Why I am interested for this article?
Because they are a largest species in the ocean and it is a one of the animal who hold a surprising link about the math and the energy.
What is my contribution in the world about this article?
the majestic gliding motion of the whale shark is, scientists argue, an astonishing feat of mathematics and energy conservation. Marine scientists now reveal how these massive sharks use geometry to enhance their natural negative buoyancy and stay afloat.
Where I get this information?





11/13/2010

Dark Matter

Astronomers using NASA's Hubble Space Telescope took advantage of a giant cosmic magnifying glass to create one of the sharpest and most detailed maps of dark matter in the universe. Dark matter is an invisible and unknown substance that makes up the bulk of the universe's mass.


Astronomers are planning to study more clusters to confirm the possible influence of dark energy. A major Hubble program that will analyze dark matter in gigantic galaxy clusters is the Cluster Lensing and Supernova survey with Hubble (CLASH). In this survey, the telescope will study 25 clusters for a total of one month over the next three years. The CLASH clusters were selected because of their strong X-ray emission, indicating they contain large quantities of hot gas. This abundance of Gas means the clusters are extremely massive. By observing these clusters, astronomers will map the dark matter distributions and look for more conclusive evidence of early cluster formation, and possibly early dark energy.



Why I am interested in this article?

Because, the Observations of the large-scale structure of the universe show that matter is aggregated into very large structures that would not have time to have formed under the force of their own self-gravitation. It is generally believed that some form of missing mass is responsible for increasing the gravitational force at these scales, although this mass has not been directly observed. This is a problem; normal matter in space will heat up until it gives off light, so if this missing mass exists, it is generally assumed to be a form that is not commonly observed on universe.



What contributions I give to this article?

My contributions is how it affects the Universe's expansion with this black matter. This black energy is very dengerous because this matter could be happened a big supernova who affects the destruction of the orbit but it is very interesting because they show how does form the matter in this world and how is formed the other matter.