Profile cover photo
Profile photo
David Strumfels
358 followers -
Science / computing gourmet
Science / computing gourmet

358 followers
About
Communities and Collections
View all
Posts

Post has attachment
Ethnobiology is the scientific study of the way living things are treated or used by different human cultures. It studies the dynamic relationships between people, biota, and environments, from the distant past to the immediate present.
Add a comment...

Post has attachment
The Holocene extinction, otherwise referred to as the sixth extinction or Anthropocene extinction, is the ongoing extinction event of species during the present Holocene epoch, mainly due to human activity. The large number of extinctions spans numerous families of plants and animals, including mammals, birds, amphibians, reptiles and arthropods. With widespread degradation of highly biodiverse habitats such as coral reefs and rainforest, as well as other areas, the vast majority of these extinctions is thought to be undocumented. The current rate of extinction of species is estimated at 100 to 1,000 times higher than natural background rates.
Add a comment...

Post has attachment
Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals. Coral reefs are built by colonies of tiny animals found in marine water that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps belong to a group of animals known as Cnidaria, which also includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons which support and protect the coral polyps. Most reefs grow best in warm, shallow, clear, sunny and agitated water.
Add a comment...

Post has attachment
We hear all the time form the climate science community that even if we stop burning fossil fuels (FF) today the CO2 we have already produced will still be in the atmosphere for centuries to come. We have already lit a long slow burning fuse that will lead us to climate Armageddon. How much of this is actually true?
Add a comment...

Post has attachment

Half-life (symbol t1⁄2) is the time required for a quantity to reduce to half its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo, or how long stable atoms survive, radioactive decay. The term is also used more generally to characterize any type of exponential or non-exponential decay. For example, the medical sciences refer to the biological half-life of drugs and other chemicals in the human body. The converse of half-life is doubling time.
The original term, half-life period, dating to Ernest Rutherford's discovery of the principle in 1907, was shortened to half-life in the early 1950s.[1] Rutherford applied the principle of a radioactive element's half-life to studies of age determination of rocks by measuring the decay period of radium to lead-206.
Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristic unit for the exponential decay equation. The accompanying table shows the reduction of a quantity as a function of the number of half-lives elapsed.
Add a comment...

Post has attachment
The bandwagon effect is a phenomenon whereby the rate of uptake of beliefs, ideas, fads and trends increases the more that they have already been adopted by others. In other words, the bandwagon effect is characterized by the probability of individual adoption increasing with respect to the proportion who have already done so.[1] As more people come to believe in something, others also "hop on the bandwagon" regardless of the underlying evidence.
Add a comment...

Post has attachment
In modern physics, antimatter is defined as a material composed of the antiparticle (or "partners") to the corresponding particles of ordinary matter.

In theory, a particle and its anti-particle have the same mass as one another, but opposite electric charge, and other differences in quantum numbers. For example, a proton has positive charge while an antiproton has negative charge. A collision between any particle and its anti-particle partner is known to lead to their mutual annihilation, giving rise to various proportions of intense photons (gamma rays), neutrinos, and sometimes less-massive particle–antiparticle pairs.
Add a comment...

Post has attachment
The 1918 flu pandemic (January 1918 – December 1920) was an unusually deadly influenza pandemic, the first of the two pandemics Involving H1N1 influenza virus.[1] It infected 500 million people around the world,[2] including remote Pacific islands and the Arctic, and resulted in the deaths of 50 to 100 million (three to five percent of the world's population[3]), making it one of the deadliest natural disasters in human history.[4][5][6] Disease had already greatly limited life expectancy in the early 20th century. A considerable spike occurred at the time of the pandemic, specifically the year 1918. Life expectancy in the United States alone dropped by about 12 years.
Add a comment...

Post has attachment
An ideal gas is a theoretical gas composed of many randomly moving point particles whose only interactions are perfectly elastic collisions. The ideal gas concept is useful because it obeys the ideal gas law, a simplified equation of state, and is amenable to analysis under statistical mechanics.
Add a comment...

Post has attachment
The tidal force is a force that is the secondary effect of the force of gravity; it is responsible for the phenomenon of tides. It arises because the gravitational force exerted by one body on another is not constant across it: the nearest side is attracted more strongly than the farthest side. Thus, the tidal force is differential. Consider the gravitational attraction of the Moon on the oceans nearest to the Moon, the solid Earth and the oceans farthest from the Moon. There is a mutual attraction between the Moon and the solid Earth, which can be considered to act on its centre of mass. However, the near oceans are more strongly attracted and, especially since they are fluid, they approach the Moon slightly, causing a high tide. The far oceans are attracted less. The attraction on the far-side oceans could be expected to cause a low tide, but since the solid Earth is attracted (accelerated) more strongly towards the moon, there is a relative acceleration of those waters in the outwards direction. Viewing the Earth as a whole, we see that all its mass experiences a mutual attraction with that of the Moon, but the near oceans more so than the far oceans, leading to a separation of the two.
Add a comment...
Wait while more posts are being loaded