The Curious Cat Science and Engineering blog explores: innovation, technology, research, education, economics, gadgets, health care and scientific inquiry.
The video by Richard Hartel, professor of food engineering at the University of Wisconsin-Madison, demonstrates how the molten liquid candy cools to form what from a technical standpoint actually is a glass. Unlike window glass made of silica, this tasty glass is made of sugar.
Viscosity describes a fluid’s internal resistance to flow and may be thought of as a measure of fluid friction. Water has very little viscosity (unless it is frozen). Thick honey has higher viscosity (especially if it is cooler – I keep my honey in the fridge and it does not flow very quickly).
Interesting discussion on the bacteria living inside our cells. For example, many plants have bacteria that get inside the root system and then help fix nitrogen for the plant. Some sea slugs take the chloroplasts from algae they eat and incorporate it themselves, allowing them to get energy from light (photosynthesis): they become photosynthetic slugs.
They Might be Giants once again provide an enjoyable view into the wonders of science. Previously they published the video, The Sun is a Mass of Incandescent Gas. They published an updated video, a couple years ago, which captures the best current understanding based on the scientific inquiry process: Why Does the Sun Really Shine? (The Sun is a Miasma of Incandescent Plasma).
I really do love, They Might be Giants. Even before their focus on science I enjoyed their music. But they have done wonders with all their recent work. Go Giants. Get their DVD: Here Comes Science.
Jellyfish is a common name for gelatinous water dwelling animals. The diversity of these invertebrates is amazing. And what actually counts as a jellyfish is not easy to determine. Watch this great video to learn about Cnidarians, Urochordata, Polychaetes and Ctenophores.
Mexican free-tailed bats in the Central Valley, California: the voracious insect-eating species protects the local crops from pests. Bats really are wonderful animals and very beneficial to people. They eat many insects and some also help pollinate some plants. The Mexican free-tailed bats seem to even benefit from human activity (taking advantage of bridge underpasses as homes, for example), but many other bat species are in trouble.
One of the enduring puzzles in biology and the social sciences is the origin and persistence of altruism, whereby a behavior benefiting another individual incurs a direct cost for the individual performing the altruistic action. This apparent paradox was resolved by Hamilton’s theory, known as kin selection, which states that individuals can transmit copies of their own genes not only directly through their own reproduction but also indirectly by favoring the reproduction of kin, such as siblings or cousins. While many studies have provided qualitative support for kin selection theory, quantitative tests have not yet been possible due to the difficulty of quantifying the costs and benefits of helping acts. In this study, we conduct simulations with the help of a simulated system of foraging robots to manipulate the costs and benefits of altruism and determine the conditions under which altruism evolves.
By conducting experimental evolution over hundreds of generations of selection in populations with different costs and benefits of altruistic behavior, we show that kin selection theory always accurately predicts the minimum relatedness necessary for altruism to evolve. This high accuracy is remarkable given the presence of pleiotropic and epistatic effects, as well as mutations with strong effects on behavior and fitness. In addition to providing a quantitative test of kin selection theory in a system with a complex mapping between genotype and phenotype, this study reveals that a fundamental principle of natural selection also applies to synthetic organisms when these have heritable properties.
Great discussion and illustration of the state of our understanding of physics, matter, dark matter and the rest of the stuff our universe has from PhD comics. What is the universe made of? 5% of it is normal matter (the stardust we are made of), 20% dark matter and the other 75% – we have no idea!
Dark Cosmos is a nice book on some of these ideas. It is 5 years old so missing some of the latest discoveries.
The Plasmodium parasite responsible for malaria is transmitted by the bite of infected mosquitoes, and is thought to kill almost 1 million people worldwide each year.
Jake Baum at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia, and colleagues used transmission electron microscopy and 3D immuno-fluorescence microscopy to record a series of still images during the 30-second-long invasion, and combined them into a movie.
Get ready to re-think your ideas of reality. Join UCSD physicist Kim Griest as he takes you on a fascinating excursion, addressing some of the massive efforts and tantalizing bits of evidence which suggest that what goes on in empty space determines the properties of the three-dimensional existence we know and love, and discusses how that reality may be but the wiggling of strings from other dimensions.
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