Tag Archives: science explained

Viruses and What is Life

Viruses are generally considered not to be alive (they must use a host cell of something else to reproduce). However, defining exactly what life is, is not as easy as you might think.

The debate about what counts as a living thing is fuelled today by the discovery of the first virus that is able to fall “ill” by being infected with another virus.

the discovery of a giant virus that itself falls ill through infection by another virus seems to suggest they too are alive, highlighting how there is no watertight definition of what exactly scientists mean when they refer to something as “living”.

“There’s no doubt, this is a living organism,” the journal Nature is told by Prof Jean-Michel Claverie, director of the Mediterranean Institute of Microbiology in Marseilles, part of France’s basic-research agency CNRS. “The fact that it can get sick makes it more alive.”

Related: People Have More Bacterial Cells than Human CellsBacteria Feed on Earth’s Ocean-Bottom CrustRetrovirusesBacteriophages: The Most Common Life-Like Form on Earth

Why ‘Licking Your Wounds’ Works

Why ‘Licking Your Wounds’ Actually Works

scientists found that histatin, a small protein in saliva previously only believed to kill bacteria was responsible for the healing.

To come to this conclusion, the researchers used epithelial cells that line the inner cheek, and cultured in dishes until the surfaces were completely covered with cells. Then they made an artificial wound in the cell layer in each dish, by scratching a small piece of the cells away.

In one dish, cells were bathed in an isotonic fluid without any additions. In the other dish, cells were bathed in human saliva. After 16 hours the scientists noticed that the saliva treated “wound” was almost completely closed. In the dish with the untreated “wound,” a substantial part of the “wound” was still open. This proved that human saliva contains a factor which accelerates wound closure of oral cells.

Because saliva is a complex liquid with many components, the next step was to identify which component was responsible for wound healing. Using various techniques the researchers split the saliva into its individual components, tested each in their wound model, and finally determined that histatin was responsible.

Bees, Hornets and Wasps

Photo of a bee by Justin Hunter

Bee vs. Hornet vs. Wasp

A bee can generally only sting you once, while hornets and wasps can sting multiple times.

Bees are fuzzy pollen collectors that almost always die shortly after stinging people (because the stinger becomes embedded in the skin, which prevents multiple stings). Bees don’t die each time they sting, though; the primary purpose of the stinger is to sting other bees, which doesn’t result in the loss of the stinger.

Wasps are members of the family Vespidae, which includes yellow jackets and hornets. Wasps generally have two pairs of wings and are definitely not fuzzy. Only the females have stingers, but they can sting people repeatedly.

Hornets are a small subset of wasps not native to North America (the yellow jacket is not truly a hornet). Somewhat fatter around the middle than your average wasp, the European hornet is now widespread on the East Coast of the U.S. Like other wasps, hornets can sting over and over again and can be extremely aggressive.

Photo by Justin Hunter

Related: Bye Bye British BeesWasps Used to Detect ExplosivesColony Collapse Disorder ContinuesBye Bye BeesVanishing Giant Nests of Yellow-jackets

Cause of Super Heated Ground

Unexplained ground heat burns boy’s feet

There was no fire, but the ground was hot enough in a Colorado Springs park to burn through an eight year old boy’s shoes and cause at least second degree burns on his feet.

After the boy was treated and sent to the hospital firefighters took surface readings that showed hard to believe temperatures. According to Chief Matthews, “The highest temperature we got at the surface of the soil with the sun shining on it was 800 degrees, which is pretty darn significant. Radiant heat from the sun will get it up around 150, 160 degrees, but not to that level.”

Firefighters have taped off the area and are monitoring it until they can figure out what’s causing the ground to get so hot. Tests by hazmat team members show there are no dangerous gases. Crews have cut a fire-line around the area to prevent the heat from potentially starting a wildfire.

Early assessments show the problem area is coal dust. Neighbors say the area has appeared blackened as long as they can remember. What has to be determined is if it was dumped here years ago or if there’s something happening underground. Crews from the state geological are on the way to figure out an explanation.

So can you figure it out? I was happy I could (if not I didn’t I would just leave off this sentence).

Cause of super-heated ground found

What they found has a relatively simple solution according to Kurt Schroeder with Colorado Springs Parks, “What the state representatives indicated to us is that the coal spoil that’s been on top of the ground for years and years reacts with the sun, heat of the sun and it spontaneously combusts.”

Because it’s coal refuse likely dumped at this spot years ago, the recommendation from geologists is capping it. Crews will dump two feet of fill over the spot to keep the sun causing the coal remnants from igniting again.

Good old scientific thinking leads to understanding what happens in the world around us. See more posts with scientific explanations for what we experience.

New Iron Based Superconductors

Research Suggests Novel Superconductor Is in a Powerful Class All its Own

discovered surprising magnetic properties in the new superconductors that suggest they may have very powerful applications — from improved MRI machines and research magnets, to a new generation of superconducting electric motors, generators and power transmission lines. The research also adds to the long list of mysteries surrounding superconductivity, providing evidence that the new materials, which scientists are calling “doped rare earth iron oxyarsenides,” develop superconductivity in quite a new way

Early this year, Japanese scientists who had been developing iron-based superconducting compounds for several years, finally tweaked the recipe just right with a pinch of arsenic. The result: a superconductor, also featuring oxygen and the rare earth element lanthanum, performing at a promising -413 degrees F (26 K). The presence of iron in the material was another scientific stunner: Because it’s ferromagnetic, iron stays magnetized after exposure to a magnetic field, and any current generates such a field. As a rule, magnetism’s effect on superconductivity is not to enhance it, but to kill it.

Iron based superconductors might resist magnetic fields over 100 Tesla

The new superconductors seem like they will be able to make improved MRI machines and research magnets, a new generation of superconducting electric motors, generators and power transmission lines. Tesla is a unit of magnetic field strength; the Earth’s magnetic field is one twenty thousandth of a tesla.

Related: Superconducting SurpriseMystery of High-Temperature SuperconductivitySuperconductivity and Superfluidity

Cosmology Questions Answered

A great list of Cosmology Questions Answered, including: Why do we think that the expansion of the Universe is accelerating? What is quintessence? What is the Universe expanding into?

Everything that we measure is within the Universe, and we see no edge or boundary or center of expansion. Thus the Universe is not expanding into anything that we can see, and this is not a profitable thing to think about. Just as Dali’s Corpus Hypercubicus is just a 2-D picture of a 3-D object that represents the surface of a 4-D cube, remember that the balloon analogy is just a 2-D picture of a 3-D situation that is supposed to help you think about a curved 3-D space, but it does not mean that there is really a 4-D space that the Universe is expanding into.

Explaining the Missing Antimatter

Flipping particle could explain missing antimatter

It is one the biggest mysteries in physics – where did all the antimatter go? Now a team of physicists claims to have found the first ever hint of an answer in experimental data. The findings could signal a major crack in the standard model, the theoretical edifice that describes nature’s fundamental particles and forces.

In its early days, the cosmos was a cauldron of radiation and equal amounts of matter and antimatter. As it cooled, all the antimatter annihilated in collisions with matter – but for some reason the proportions ended up lopsided, leaving some of the matter intact.

Physicists think the explanation for this lies with the weak nuclear force, which differs from the other fundamental forces in that it does not act equally on matter and antimatter. This asymmetry, called CP violation, could have allowed the matter to survive to form the elements, stars and galaxies we see today.

“It is tantalisingly interesting at the moment,” says Val Gibson, an expert on B meson physics at the University of Cambridge. “If it is true, it is earth-shattering.” Jacobo Konigsberg, who leads the CDF collaboration, says that Tevatron researchers are “cautiously excited” about the analysis. He points out that more data needs to be analysed to rule out a statistical fluke, which has happened several times before in particle physics.

Related: First Evidence of New Physics in b <--> s Transitions (research paper)posts tagged physicsMatter to Anti-Matter 3 Trillion Times a SecondQuantum Mechanics Made Relatively Simple Podcasts

Flint and Steel: What Causes the Sparks?

Flint and Steel: What Causes the Sparks?

What many people do not realize is that iron is a pyrophoric material; in the presence of oxygen, iron catches on fire automatically! It just starts burning. “But how can this be?” you may ask. “I can hold a chunk of iron in my hand and it does not burn me”.

The answer lays in the fact that the portion of the iron object in contact with the air and your skin is not pure iron. Rather it has developed a thin coating of iron oxide, or rust, immediately upon contact with the oxygen in the air. This serves to seal off the iron inside from exposure to the air and reduces the rate of further rusting.

Iron, whether man-made objects or naturally occurring in rocks, will rust upon exposure to oxygen in the air. The act of rusting is actually an exothermic reaction called “oxidation”, which is a fancy way of saying when iron touches the oxygen in the air a reaction occurs; the iron rusts (turns into iron oxide) and gives off heat. In other words, it burns. The simplified chemical reaction can be expressed as:

Fe2 + O2 = Fe2O3 + heat

Or in English:

Iron + Oxygen = Rust + Heat

Related: Science Explains Flame ColorWhy do We Sleep?Cu2C03(OH)2

Clouds Alive With Bacteria

Clouds above the Mesa Trail by John Hunter

Earth’s Clouds Alive With Bacteria

Clouds are alive with tiny bacteria that grab up water vapor in the atmosphere to make cloud droplets, especially at warmer temperatures, a new study shows.

The water droplets and ice crystals that make up clouds don’t usually form spontaneously in the atmosphere – they need a solid or liquid surface to collect on. Tiny particles of dust, soot and airplane exhaust – and even bacteria – are known to provide these surfaces, becoming what atmospheric scientists call cloud condensation nuclei (CCN).

These microbes could be carried into the atmosphere from an infected plant by winds, strong updrafts or the dust clouds that follow tractors harvesting a field. Christner and others suspect that becoming cloud nuclei is a strategy for the pathogen to get from plant to plant, since it can be carried for long distances in the atmosphere and come down with a cloud’s rain.

The next step in determining how big a role biological particles play in cloud droplet formation is to directly sample the clouds themselves, Christner says.

Related: What’s Up With the Weather?20 Things You Didn’t Know About SnowRare “Rainbow” Over IdahoBacteria Living in Glacier – photo by John Hunter, on the Mesa Trail, Colorado

Pynchonverse Science

Mind-Bending Science in Thomas Pynchon’s Mind-Bending Novel Against The Day: Part I

Pynchon takes the science of this period and incorporates it deeply into the language and structure of Against the Day, more so perhaps than in any of his other novels. Against the Day is suffused with meditations on light, space, and time, and often plays with the tension between different perspectives in math and physics – classical physics versus relativity, Maxwell’s laws of electromagnetism described with the imaginary numbers of quaternions versus the real numbers of vector analysis. This material is not just filler – it’s critical to the core of Against the Day, a fact which has been underappreciated in early reviews of the novel.

One reviewer claimed that a new generation of writers has a “grasp of the systems that fascinate Pynchon — science, capitalism, religion, politics, technology — [that] is surer, more nuanced, more adult and inevitably yields more insight into how those systems work than Pynchon offers here.” When it comes to science at least, this claim is not true – Pynchon’s achievement in Against the Day proves that he is peerless as a poet who can mine science for gems of insight and set them into the context of the humanity that is the ultimate concern of his novels.

This great post offers a detailed explanation of some of the science related to Pynchon’s writing.

Related: Books by Thomas Pynchon (with online resource links)New Yorker Review of Against the Day