Phenomena Ideas

The largest tree in the world is a giant sequoia (Sequoiadendron giganteum) in California's Sequoia National Park. Called General Sherman, the tree is about 52,500 cubic feet (1,487 cubic meters) in volume. That's the equivalent of more than half the volume of an Olympic-size swimming pool, commonly considered to be 88,500 cubic feet (2,506 cubic meters). General Sherman is also tall, standing 274.9 feet (83.8 meters) high. Incredibly, this enormous tree started as a small seed, merely 4–5 mm (0.16–0.20 in) long and 1 mm (0.04 in) wide. This begs the question, where did General Sherman gets its mass?

• General Sherman Tree Facts

• Incredible View Of General Sherman Tree, Sequoia National Park (video)

• Trees Come 'From Out Of The Air,' Said Nobel Laureate Richard Feynman

A teen cuts his finger on his helmet at practice. The open wound becomes a source of food for the bacteria which thrives in the nutrient rich host. The bacteria invades cells and uses toxins to hijack the protein producing organelles of the cells. This leads to the production of an amino acid that is recognized by other bacteria causing more hijacking in neighboring cells. Consequently cells and neighboring blood vessels eventually burst causing tissue to die. Simultaneously, as the bacteria infects cells, the body's immune response reacts by producing antibodies and white blood cells that are directed to the infected location in the body. Since the bacteria infection has caused cells and blood vessels around the infected area to burst this complicates the body's immune response from reaching the infected area. Additionally treatment of the area is not possible by the prescription of oral antibiotics that normally reach the infected area through the blood stream, leaving only surgery and the manual application of antibiotics to the infected area as a possible treatment at later stages of infection. 

• Necrotizing Fasciitis (Flesh-Eating Bacteria)

• Immune responses to bacteria

The location of Aspen forests and the behavior of rivers changed in Yellowstone National Park after wolves were reintroduced. Wolves are predators at the top of the food chain; however, their impact on ecosystems extends well beyond the simple predator/prey relationships they have with animals like elk and deer. Wolves provide balance to ecosystems through this idea of a “trophic cascade”, which means that what happens at the top of the food chain effects what happens at all other tropic levels. The reintroduction of wolves into Yellowstone National Park in 1995 has dramatically changed the park, in terms of population dynamics, organism behavior, the regeneration of vegetation, and even the behavior of rivers and streams.

• Wolf Reintroduction Changes Ecosystem

• Wolves of Yellowstone (National Geographic)

The 1988 forest fires in Yellowstone impacted the plants, animals, and soils of the forest ecosystem. The fires burned live plants and trees as well as debris on the ground releasing nutrients into the soil. Climate impacted the amount of moisture in the ecosystem. Nutrients and moisture in the soil are used by seeds to re-establish vegetation in the burnt forest. Before the fires, the tree community was made up of lodge pole pine trees and quaking aspen. These trees left behind seeds and root structures buried in the soil. The first plants to re-establish after a fire were grasses and wildflowers. The lodge pole pine and quaking aspen are adapted to fire and are able to slowly re-establish themselves years after a fire. Fire also creates new habitats for animals and insects. If an ecosystem has soil before a disturbance it goes through secondary succession after the disturbance. If an ecosystem does not have soil and soil forms the ecosystem goes through primary succession.

• 1988 Fires (NPS)

• The Story Behind the Yellowstone Fires of 1988 (NYT)

• Ecological Consequences of Fire (NPS)

• Succession: Biological Progression

Walking in deciduous forests in early spring, you may notice a strange phenomenon. Around the base of tree trunks are perfectly circular "thaw circles." The reason for these circles is heat - as the spring sun warms the forest, the dark tree trunks absorb more heat than the highly reflective snow around them. As this heat radiates out, it uniformly melts the nearby snow in a ring around the tree. Some small plants seem to use this phenomenon to get a jump on the spring growing season and grow close to tree trunks. Scientists are currently testing this hypothesis and estimate that these plants may get as much of a 20% increase in their growing season by sprouting in these thaw circles.

• The Strange Magic of Forest Thaw Circles

• Thaw circles around tree trunks provide spring ephemeral plants with a big head start on the growing season (Nature)

• Why does the snow melt in circles around trees?

Alexandria is a teenage girl in St. Louis, Missouri, who is living with sickle cell anemia. She is one of approximately 72,000 Americans currently living with the disease that can cause, among other symptoms, anemia, episodes of pain, delayed growth, and frequent infections. Sickle cell anemia was caused by a substitution mutation in the DNA of a child living thousands of years ago in Africa and has been passed down ever since. This mutation had altered the child’s hemoglobin, the molecule in red blood cells that carries oxygen through the body. It was not harmful; there are two copies of every gene, and the child’s other hemoglobin gene was normal. The child survived, had a family and passed down the mutation to future generations. Some dependents of that child, like Alexandria, received two copies of the mutated gene which causes them to have sickle cell disease. This leads to the question: Why has this disease been passed down through thousands of generations even though it can have such deleterious effects?

• How One Child’s Sickle Cell Mutation Helped Protect the World From Malaria (NYT)

• Sickle-cell disease (Wikipedia)

• Human Genetics: Concepts and Application (PBS)

Lucy and Maria are twins of a mixed race couple. Their mother is half black and half white, where their father Vince is white. Maria has caramel complexion and thick curly black hair with brown eyes and no freckles, where Lucy has pale white complexion, straight ginger hair, blue eyes and freckles. Many would presume that both twins would exhibit the same phenotypes, however due to the dizygotic nature of their inception, more variability is possible. With dizygotic twins, there are two eggs fertilized by different sperm. During the process of meiosis, sex cells are synthesized with one set of chromosomes (23), which meet during the process of fertilization to generate a zygote with half of the genetic material from the mother and half from the father. Half of the genetic makeup of Lucy and Maria is from their father Vince and half is from their mother Donna. During meiosis, regions of the chromosome can swap creating new genetic combinations and diversity. With this variability opportunity, the likelihood of having the identical genotypes as a sibling is highly unlikely due to random and independent assortment of genes in a chromosome. While unlikely, there is still a chance to have similar attributes present in fraternal twins, as the gene pool of traits between their two parents is only so vast. Most people perceive twins to have the same genetic and physical expression, however this is only the case with identical twins because they are derived from one egg and sperm fertilization event where the zygote divides into two. 

• Twin Teens, One Black, One White, Celebrate Their Differences

• 11 Facts About Fraternal Twins

Peter and Rosemary Grant have been studying the finches on Daphne Major in the Galapagos Islands since 1973. During that time, they found concrete evidence of natural selection, the driving force of evolution. In 1977, a severe drought killed off many of Daphne’s finches, setting the stage for the Grants’ first major discovery. During the dry spell, large seeds became more plentiful than small ones. Birds with bigger beaks were more successful at cracking the large seeds. As a result, large finches and their offspring triumphed during the drought, triggering a lasting increase in the birds’ average size. The Grants had observed evolution in action.

• Evolution of Darwin's finches and their beaks

• The Origin of Species: The Beak of the Finch (HHMI)

• Galapagos finches caught in act of becoming new species (BBC)

The lampsilis mussel lives in the Missouri River. The mantle flesh that spills out of the females' shells is not only shaped like a fish, but moves like one, every so often twitching with a flip of its “tail.” When a predatory fish like a bass attacks the lure, the mussel fires its larvae in the fish's gills. Here the parasitic young attach and drain nutrition from their host before ejecting and settling on the riverbed. Typically lampsilis species mimic the small fish prey of the largemouth bass. The lures are incredibly lifelike and even sport eyespots for extra trickery. A large amount of variation exists among the population of mussels with varieties mimicking different types of fish. When a bass falls for the lure, the mussel releases a cloud of larvae, some of which attach to the gills of the bass where they stay until they are ready to drop off and complete their life cycles. Amazingly, the mussels have developed these life-like lures even though they themselves have no eyes and have never seen the fish they are mimicking.

• Absurd creature of the week: This mussel does an incredible impression of a fish

• How Mussels Fool Fish Into Carrying Their Parasitic Babies

Cities around the world experience variation in weather, intensity of sunlight, and hours of daylight on any given day of the year. In this unit, students will investigate why three cities around the world (one in the northern hemisphere, one in the southern hemisphere, and one equatorial city) experience completely different seasonal conditions on the same date. On December 25th, the northern hemisphere experiences their winter season, marked by colder temperatures and shorter periods of daylight. On the same date, locations in the southern hemisphere are in their summer season, marked by warmer temperatures, more intense sunlight, and longer periods of daylight. However, locations along the equator experience nearly the same temperatures, intensity of sunlight, and hours of daylight on December 25th as they would at any other time of the year.

• Why Earth has 4 seasons

• Why Do We Have Different Seasons?

Recent studies have shown that at the isotopic level, the Earth and Moon are remarkably similar. While they may have relatively different amount of elements such as iron, they share the same isotopic signatures in a number of elements. What does this finding mean in terms of the origins of the two celestial bodies? Scientists have hypothesized a number of possible hypotheses to account for the formation of our moon. Perhaps the Earth captured a wayward planet that became trapped in our gravitational pull. Or maybe the early Earth spun so fast it lost the material that formed into the Moon. Or perhaps the early Earth was struck by another planet, expelling the materials that formed our moon. The answer to this question impacts our understanding of the formation of the entire solar system.

• The Genetics of the Earth and Moon (Nautilus)

• When and How Did the Moon Form?

• How Was the Moon Formed?

The severity of 2017 hurricanes has been influenced by two main factors: The absence of an El Nino system, which creates a high wind shear and disrupts storms. Wind shear is the difference in wind speed over a distance in the atmosphere (in our case, we are concerned with vertical wind shear). High wind shear disperses the heat and moisture needed for the hurricane to form. Additionally, the difference in wind speed distorts the shape of the storm, making it more difficult for it to condense into a hurricane formation. El Nino weather systems result in increased wind shear, as well as cooler than normal water surface temperatures off the coast of Africa, where most hurricanes form. The cooler water contributes less heat energy, making it difficult for storms to form. Because 2017 did not have the wind shear and water cooling effects of El Nino, more frequent and intense storms were able to form. A second factor contributing to the intensity of the 2017 hurricane season was unusually high temperatures in the Atlantic ocean, which intensify storms by allowing them to absorb more heat energy. Climate change offers an explanation for the rise in temperatures, as oceans act as reservoirs that absorb the increased atmospheric heat, creating warmer water and further fueling the hurricanes.

• 2017 Atlantic Hurricane Season Fast Facts

• Was the Extreme 2017 Hurricane Season Driven by Climate Change?

Spread over 16,000 square miles in eastern Washington are hundreds of monuments to a very different past environment. In an area that gets less than eight inches of rain a year stands an ancient waterfall that was three miles wide and 400 feet high, ten times the size of Niagara Falls. Dry Fall is only one of the hundreds of geologic features that tell of an ancient past of massive erosional forces. These include mounds of gravel as tall as skyscrapers, deep holes in the bedrock that would swallow entire city blocks, rolling hills that look from above like the ripples at the edge of a lake, and countless oddly placed boulders. The first farmers of the area named this the 'scablands'. Today, geologists see these features as an enigma: What could have caused this landscape?

• Formed by Megafloods, This Place Fooled Scientists for Decades (NatGeo)

• The Channeled Scablands of Eastern Washington (USGS)

• Explore the Scablands (PBS Nova)

Conifers in the Western U.S. are dying at high numbers due to infestations of bark beetles. When temperatures are lower and precipitation is higher, the trees and the cold weather limits the number of beetles. With climate change, winters are less severe meaning higher temperatures. More intense droughts are also happening more often. With these changes in climate, beetles are not dying as often, reproducing faster, and trees are less able to defend themselves. In fact, bark beetles populations have exploded to 10x the baseline rate. Since 2000, bark beetles have killed enough trees to cover the entire state of Colorado.

• Bark Beetles Are Decimating Our Forests. That Might Actually Be a Good Thing.

• Bark beetles at work (video)

• Assessment and Response to Bark Beetle Outbreaks in the Rocky Mountain Area

Polar bears require sea ice and glaciers to hunt their prey. Due to rising global temperatures caused largely by human contributions to increased amounts of greenhouse gases in the Earth's atmosphere, the amount of sea ice has decreased significantly. As a consequence of shrinking sea ice habitat, polar bears contact with Arctic coastal communities increases. As the ice recedes and bears can't find food, hungry bears are more likely to come into contact with communities in their search for food. This is dangerous for people and bears. Dangerous interactions with people and loss of normal sources of food from sea ice hunting are among the factors that threaten polar bears.

• Polar Bears Really Are Starving Because of Global Warming, Study Shows

In 1947, after WWII, there was an excess of pure metallic sodium. The sodium was commonly being used to make synthetic rubber as a substitute for natural rubber supplies. There were 10 tons of this highly reactive solid sodium. The transportation of these sodium barrels were considered to be a high risk, so there were no carriers willing to transport them in order to sell. The solution was to dump these sodium barrels into a lake in Washington. They did not want to cause harm, so they chose Lake Lenore since it is an alkaline lake that contained no fish. Once the sodium was dumped in the lake, there were large explosions and the pH level drastically changed, making the lake much more basic due to the sodium hydroxide formed. The explanation of this disposal in 1947 can be explained through the properties of sodium and chemical reactions.

• Ten Tons of Sodium, Disposed Of in Lake, Erupt in a Display Like a 'Baby Bikini' (NYT archives)

On May 6, 1937, the Hindenburg arrived hours behind schedule at the Lakehurst Naval Air Station in New Jersey due to inclement weather with wind, rain, and possible lightning. The landing of the Hindenburg with these types of conditions was against regulations, but by the time the Hindenburg began its landing the weather was clearing up. The Hindenburg seems to have been traveling at a fairly fast speed for its landing and for some reason, the Captain attempted a high landing from a height of about 200 feet. Soon after the mooring lines were set, some eyewitnesses reported a blue glow on top of the Hindenburg followed by a flame towards the tail section of the craft. The flame was almost simultaneously succeeded by an explosion that quickly engulfed the craft causing it to crash into the ground killing 36 people. Spectators watched in horror as passengers and crew were burned alive or jumped to their deaths. As Herb Morrison announced for the radio, "It's burst into flames.... Get out of the way, please, oh my, this is terrible...Oh, the humanity and all the passengers.” In 37 seconds the great Hindenburg had completely burned. Of the 91 people on board, 36 had died.

• Hindenburg Disaster: Real Zeppelin Explosion Footage (1937)

• Hindenburg disaster (Wikipedia)

At first, chemicals used during rocket liftoff are in a less-reactive (stable) state, as can be seen in gases flowing out without any noticeable reaction. These chemicals (the fuel), like all matter, inherently have energy related to forces of protons and electrons of neighboring atoms. The bond energy between atoms is one type of energy. In some cases, matter can change without any added energy other than that taken from the surrounding environment—for example, the chemical reaction of baking soda with vinegar. In other cases, additional energy is required to destabilize the reactants and allow them to change. Just before rocket liftoff, sparks are applied to the fuel to provide this energy (the “activation” energy).

In a reaction that releases energy, the difference between the energy of the products (H2O) and the energy of the reactants (H2 and O2) results in excess energy being released into the environment [exothermic reaction]. At the particle level, it takes less energy to break the bonds in H2 and O2 molecules than that released when the new bonds in H2O molecules form. This energy is released into the environment as heat, light, and sound. Once the reaction starts, the sparks can be removed because some of the released energy causes more hydrogen and oxygen atoms to rearrange into water (similarly, once a fire starts, you don’t have to continue adding outside energy [heat] to keep the flame going).

To make the rocket launch, the chemical reaction takes place in a reaction chamber outside the fuel tank, where the gases are released at a controlled rate (not too fast or too slow). The released energy in this exothermic combustion reaction causes the gases to move faster, raising pressure, which causes the primary product (H2O vapor) to expand and exit from the downward-facing nozzle. The gas flowing out of the nozzle has mass and its downward movement creates a force (Newton’s Second law, F=ma). When something moves in one direction, there is an opposing force in the opposite direction (Newton’s third law). This creates the force that pushes the rocket upward and into space.

• Types of chemical rocket engines

• Newton's Laws of Motion

To learn more about the threats of nuclear testing to human health, during the 1950's the Committee for Nuclear Information conducted a baby tooth survey. This survey emerged out of concern that nuclear testing in the atmosphere, as part of nuclear weapons development, could cause long-term health risks. As part of the survey, parents were asked to mail in their children's baby teeth for testing. As a result of a study of more than 30,000 baby teeth, mostly from children from St. Louis, Missouri, it was determined that a spike in radioactive Strontium-90, a chemical element that resembles the important nutritional element Calcium, was found in the teeth examined in the study. This was concerning because Strontium-90 was released in the atmosphere as a bi-product of the nuclear testing and was incorporated along with (and in place of) Calcium into the bones and teeth of developing unborn babies and continued even after birth. Because Strontium-90 has a half-life of 28 years, it was believed that these nuclear tests had unnecessarily resulted in what amounted to unnecessary and potentially harmful (e.g., potentially cancer causing) exposure to radioactivity over the life of these children. 

• Experiments explained: Baby Tooth Survey

• St. Louis Baby Tooth Survey, 1959-1970

An empty tanker car was steam-cleaned, sealed, and left overnight. Overnight, the outside temperature decreased. At a certain point, the massive, sturdy tanker car imploded in on itself in an instant. What forces could have caused the tanker car to implode? How can changes at the molecular level lead to such incredible forces on the scale of a railroad tanker car?

• Myth Busters Impossible Tank Car Implosion

• Make Your Own Tanker Implosion with a Soda Can

Voyager 2, was launched by NASA in the summer of 1977 from Cape Canaveral, Florida. It, along with Voyager 1, were to conduct closeup studies of Jupiter and Saturn, Saturn's rings, and the larger moons of the two planets. However, because of a once in a 175 year alignment of the planets, Voyager 2 was able to "swing from one planet to the next without need for an onboard propulsion system", to not only visit Jupiter and Saturn as originally planed when launched, but to also visit Uranus and Neptune. This spacecraft's flight path bent and increased its velocity enough to reach each subsequent planet using a "gravity assist" technique. Voyager 2 is the only spacecraft to have visited Uranus and Neptune. On Aug. 25, 2012 (35 years after leaving Cape Canaveral), Voyager 1 left our Solar System and entered interstellar space. Voyager 2 will soon join Voyager 1 as the first human made objects to enter interstellar space.

• Voyager: A Once in a Life-time Alignment

• NASA Spacecraft Embarks on Historic Journey Into Interstellar Space

• The Farthest Voyager in Space

A wireless charger first needs to have an AC current moving though a coil of wire. This current will create a changing magnetic field and then this changing magnetic field will produce a voltage in another coil of wire that is near it. The amount of voltage that is created is based on the number of turns of the coil and the strength of the magnetic field.

• How Does Wireless Charging Work?

One of the most familiar images of Yosemite National Park is Half Dome, the park’s tallest granite peak at nearly 5,000 feet. While thousands may have made the trek with nothing but sore leg muscles to show for it, clear warnings are posted that a climb here could be deadly, because Half Dome is a gigantic natural lightning rod. On July 27th, 1985, five men set out to climb Half Dome. When a storm hit, they sought shelter. The summit took a direct hit. Millions of volts of electricity arced over the wet stone surface—into the rock enclosure. The lightning strike killed two of the hikers and two others suffered massive internal injuries along with third degree burns. The fifth hiker was in motion when the lightning struck. Because little of his body was in contact with the rock, he did not ground the lightning’s electrical charge, and he escaped with minor injuries.

• Lightning Peril on Yosemite's Half Dome (NatGeo)

• Shattered Air: A True Account of Catastrophe and Courage on Yosemite's Half Dome (Book)

Temperatures can reach up to 122°F in Phoenix, Arizona, during the summer months. The interiors of parked cars left out in the heat can reach temperatures that are far higher. In fact, if you place a baking tray full of cookie dough on the car's dashboard, they will cook! This occurs because of several different ways heat can transfer and be trapped.

• Baking cookies in a car (video)

• For Science! A car gets so hot inside, we baked cookies!

Sound waves are initially created by some sort of vibration. Based on the basic properties of waves, (frequency, amplitude, wavelength, velocity, etc.) we know that the creation of sound waves has certain implications about energy. Being a mechanical wave, sound waves behave predictably when colliding with other waves. When a sound wave is created, it moves with a velocity that depends on the medium through which it is traveling and the general temperature. This causes an inherent kinetic energy. This energy is transferred to the particles in the glass when the wave comes into contact with them. When particles inside of materials have kinetic energy, they gain vibrational motion. This vibrational motion is enough to crack and eventually break the glass once the incoming waves have enough energy and are large enough (amplitude). In addition, the frequency of the incoming waves should be the same as the natural resonant frequency of the glass. If the particles vibrate at their resonant frequency, they will have more energy as a result. Breaking a glass with one's voice is not an easy feat to accomplish, but it is possible. In order to do it, the singer must find the resonant frequency of the glass. This can be done by tapping the glass with a fork, or wetting a finger and running it along the rim of the glass. Once this frequency is known, the problem becomes singing the note with enough volume. So, if the singer uses the correct frequency (pitch) and volume, then the sound waves produced will carry enough energy to crack the glass. 

• Fact or Fiction?: An Opera Singer's Piercing Voice Can Shatter Glass

• The Mythbusters questioned: Can a human voice really shatter glass?

Boats or Vessels pose a significant threat to whales.  If a whale is struck by a vessel going over 10 knots, it will like lead to a lethal encounter for the whale. For those whales, like the right whale that is critically endangered, these lethal encounters with individual whales have even bigger consequences. To address this issue, researchers have developed buoys that can detect whale calls. These detected whale calls are mapped to whale calls on record, specifically those of more endangered species of whales. When detected an alert can be sent to vessels within the vicinity of the detected whale(s), where the vessel can be slowed to avert these lethal encounters. 

• A Robot Buoy That Saves Whales From Boat Strikes

• North Atlantic Right Whales - The Threat from Vessel Strikes