Science Cheerleader

Very exciting day here spurred by an article about Science Cheerleader’s efforts to increase adult science literacy in the Chronicle of Higher Education and today’s FOX News “headline news story” about our Brain Makeover! The traffic brought this site to its knees. Might still be slow at times.  Thanks for your patience and persistence. We should have it all fixed soon.
And, welcome, to all of our new subscribers!

Cheers,
Darlene

18. All life is connected.

Ecosystem is a term that refers to all of the living things in a specific area, together with the material surroundings. Plants and animals within as ecosystem often depend on each other in complex ways, so that it is not usually possible to change one part of the system without changing other parts as well. Study of the records of past ecosystems shows that both the kinds of plants and animals associated with it and the kinds of relationships between them change over time, so we should not think of ecosystems as rigid and unchanging, nor assume that any change in an ecosystem must be for the worst.

Lesson #13 of 18 in the Brain Makeover collaboration with Professor James Trefil/GMU, the 76ers Cheerleaders and the Science Cheerleader. See Brain Makeover Series.

The surface of the earth is constantly changing.

The Earth can be thought of as being separated into three layers. The core, at the center, consists of heavy materials like iron and nickel. At the very center the core is solid, but farther out it is liquid. The next layer is the mantle, composed of heavy minerals, and the outermost layer is the crust. The surface of the Earth is separated into tectonic plates, some 30-50 miles thick. These plates move around in response to convection in the Earth’s mantle. The continent are the uppermost layer of the tectonic plates. The constant motion of the plates causes a constant change in the surface features of the planet. Only the Earth among  planets in the solar system has this kind of variability in its surface.

Where plates are moving away from each other, hot magma from the mantle comes to the surface to form mountain chains and deep sea vents. Where plates are moving together, one plate will slip beneath the other, forming mountain chains or deep ocean trenches, depending on whether or not there is a continent on the plate. If plates slide by each, as they do in the San Andreas Fault, their motion will cause frequent earthquakes.

All matter is made from quarks and leptons

The primary parts of the nucleus of the atom are the positively charged proton and the electrically neutral neutron. During the twentieth century it was discovered that there are literally hundreds of other particles—all unstable—that take part in various interaction at the atomic level. These can be divided into two major classes: there are hadrons that exist inside the nucleus and participate in the strong interaction, and leptons that do not. Protons and neutrons are both hadrons, while the electron is an example of a lepton. One way of thinking about atoms, then, is to say that their nuclei are made of hadrons, while leptons (electrons) in orbit complete the structure.

More recently, it was realized that all of the hundreds of hadrons can be understood as different combination of particles more fundamental still—particles called quarks. In this scheme, then, the quarks make up the hadrons that constitute the nucleus, while the leptons in orbit complete the atoms that make up all matter.