The Microbiome Revisited
Here’s a wonderful and instructive synopsis of current research on the microbiome and its relationship to our overall health states.
Dr. Warren Peters of Loma Linda University Medical Center speaks of current investigations into the connections between our “gut bugs” and diseases such as obesity, autism, Alzheimer’s disease, rheumatoid arthritis and multiple sclerosis.
Right and Left Handedness
Researchers at Ruhr University in Bochum, Germany, have determined that the primary reason for a developing human fetus “choosing” right or left handedness is asymmetry in spinal chord development. You can read more about it here.
For a more general discussion of what “left” means in science, society and our language, click on the video below.
One of my favorite subjects in all of physics is cosmology, the study of the evolution of the Universe, past, present and future.
One way to introduce this subject is to address a famous paradox called Olbers’ Paradox, named after the German astronomer Heinrich Olbers. The paradox is stated in the form of a question: “Why is the sky dark at night?”
The most obvious answer is that the Sun is on the other side of the Earth, but that is not the point of the question. In an infinite but homogeneous and eternal universe filled with an infinite number of stars and galaxies in any particular direction, there should be a dazzlingly bright accumulation of light along any line of sight for a nighttime sky viewer.
The first person to partially and correctly answer Mr. Olbers’ paradox was none other than the American poet and short story writer Edgar Allan Poe, who speculated that the sky is dark because the light from distant stars hasn’t got here yet.
The true and complete answer is that we don’t know if the Universe is infinite in extent or not, but either way, the Universe had a beginning and is expanding, so there are luminous parts of the Universe we haven’t seen yet or may never see. Further there is light getting here that we can’t see, because the expansion of the Universe has redshifted it into the invisible infrared range.
This second point was brilliantly illustrated by the Hubble Deep Field picture produced by the Hubble Space Telescope in late 1995, wherein a presumably empty patch of sky is completely filled with infrared images of distant, immature galaxies.
The Collatz Conjecture
The Collatz Conjecture refers to a set of numbers produced by two simple mathematical operations.
Basically, you start with any positive integer. If the integer is even, divide it by two; if it is odd, multiply it by three and add one. Initially, the results seem all over the place, but ultimately, the sequence of resultant numbers always ends with one. No one knows why, although I think the process may have some physical significance.
Enjoy the explanatory video above, courtesy of Numberphile.