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Using his AC current generator, what device did Tesla build that could take low frequencies and step them up to extremely high frequencies?

The Tesla coil

In 1891, Tesla patented a device known as the Tesla coil that took ordinary household current of sixty cycles per second and increased it to extremely high frequencies, to the hundreds of thousands cycles per second.

Tesla considered this invention to be his greatest. He used it to conduct innovative experiments in lighting, phosphorescence, x-ray generation, electrotherapy, and the transmission of electrical energy without wires.

Tesla's research brought him into the invention of wireless communication. Who is often credited with the invention of radio?

Guglielmo Marconi

Working with his newly created coils, Tesla discovered he could transmit and receive powerful radio signals when they were tuned to resonate at the same frequency.

When a coil is tuned to the signal of a particular frequency, it magnifies the incoming electrical energy through resonant action.

Tesla applied for several basic radio patents in 1897 and was granted them in 1900. At the same time an Italian experimenter, Guglielmo Marconi was also working with his own device for wireless telegraphy. When he applied for patents in the United States he was turned down repeatedly because of the priority of Tesla’s patents.

Marconi used some of Tesla’s wireless ideas and on December 12, 1901, Marconi was able to transmit and receive signals across the Atlantic Ocean. When asked about Marconi’s achievement, Tesla commented, “Let him continue. He is using 17 of my patents.”

Yet in 1904, the U.S. Patent Office suddenly reversed its decisions and granted Marconi the patent for the invention of radio.

In 1909, Marconi won the Nobel Prize for Physics in recognition of his work in the development of wireless telegraphy. Tesla was furious and sued for copyright infringement. It wasn’t until 1943 that the U.S. Supreme Court finally reversed the decision and awarded Tesla the patent for radio. Unfortunately, Tesla was no longer alive, having died a few months previously.

Successful inventors need financial backing. Tesla teamed with George Westinghouse on the hydroelectric power plant at Niagara Falls. At the end of the 19th century, another prominent New York financier agreed to lend Tesla money to build an extensive laboratory on Long Island. Who was it?

J.P. Morgan

Tesla’s lifelong obsession was the wireless transmission of energy. In 1900, J.P. Morgan invested in a new laboratory on Long Island, N.Y. called Wardenclyffe. The site, designed by the prominent architect Stanford White, was to be a small city with houses, stores, and buildings to house 2,500 workers.

The centerpiece of the lab was to be a tower that could transmit messages, news, stock reports, weather warnings, and personal messages across the ocean wirelessly. The Wardenclyffe Tower began 120 feet below ground, rose 187 feet above ground, and was to be capped with a 55 ton sphere of steel.

Tesla experimented there for only a few days before creditors began to confiscate equipment for non-payment of debts. The tower was never finished and was completely destroyed in 1917 when the US government suspected German spies might use it to relay military messages during the First World War.

This investment was considered to be one of JP Morgan’s failures and Tesla’s greatest defeat.

In 1960, The Grand Conference on Weights and Measures dedicated the term “tesla” as a unit of measure. What does a tesla measure?

Magnetic field strength

The earth itself is a magnet that can generate electricity utilizing frequencies as a transmitter. All that is needed on the other end is a receiver.

In 1888, Tesla realized that he could rotate a magnetic field if two coils at right angles are supplied with AC current 90° out of phase. This was a fundamental discovery in physics. It helped create the field of magnetic resonance imaging (MRI). MRIs are a powerful diagnostic tool in medical imaging.

Radio signals can be elicited from the atoms in soft tissue when exposed to an electromagnetic field. These signals are transmitted and used to construct a computerized image of the interior of the body. The higher the signal, the higher the quality of the image.

The strength of the magnetic field is measure in gauss (G) or tesla (T) units.
1 Tesla = 10,000 Gauss

How many Nobel Prizes did Nikola Tesla win?

He won the same amount as Thomas Edison. Zero.

Tesla thought that everything we need to understand the universe is around us at all times. He believed in harnessing the forces of nature to human needs. He was green.

He anticipated worldwide wireless communication. He was visionary.

Tesla made a great deal of money on his patents but then spent even more on his experiments. He died penniless. He was not a businessman.

Tesla had keen memory and the ability to visualize and construct complicated objects in his mind’s eye. He thought long and hard before physically assembling them. He believed he might be the hardest-working man if thought is equivalent to labor.

He was a genius.

Atoms are formed from electrons, protons, and neutrons. Which two types of particles form the atomic nucleus?

Protons and neutrons

Electrons are placed at a distance, outside the nucleus.

All elements are made up of atoms. Atoms are the smallest indivisible unit of an element. Atoms are made up of protons, electrons, and neutrons.

Protons have a positive electrical charge (+), electrons have a negative electrical charge (-), and neutrons are neutral (0) with no electrical charge.

Protons and neutrons cluster to form a densely packed core of positive charge, the nucleus of the atom.
Unlike charges (+ and -) attract each other. Like charges (+ and +, - and -) repel each other. Atoms, in their elemental form, have a balanced amount of positive protons and negative electrons.

Which particle is necessary for the formation and breakdown of chemical bonds?


An atom is mostly empty space.

The nucleus is a densely packed core of positive charge. Negatively charged electrons are in constant movement outside and around the atomic nucleus. It is the attraction of opposite charges that bind the atom together.

Electrons with the least amount of energy are closest to the nucleus and those with a greater amount of energy are further away.

Atoms can share acquire, lose, or share electrons with other atoms. This action results in chemical bonds  that hold atoms together to form molecules. Reactions generally bring reactants to a more stable state.

What do we call the flow of electrons between atoms?


When the charges are out of balance, an atom is either positively or negatively charged. The switch between one type of charge to another allows electrons to flow from atom to atom. This flow of electrons is what we call electricity.

Everything in the universe is made up of atoms.

In our body, neural signals are electrical in nature. Electrical signals within the human body are fast. They allow for nearly instantaneous response to control messages.

What do we call the type of electricity that has an imbalance of electrical charges within or on the surface of a material?

Static electricity

Some atoms hold onto their electrons more tightly than others.  Certain materials will “capture” electrons when they come into contact with other matter. When separated, a charge imbalance may occur. Electrons have built up on one surface and will remain there until they are discharged or moved.

Since the charges are identical, the electrons repel each other and try to separate.

Because this electricty does not flow through wires or conductor that transmit energy, it is called static.

When an atom gains an electron, is it more positively or negatively charged?


An electron is a subatomic particle with a negative charge. An atom acquiring an electron would increase in negative charge and decrease in positive charge.

The addition of electrons is called reduction because the negative charge has reduced the amount of positive charge.

The loss of electrons from a substance is called “oxidation” because the positive charge is increased.

When an electron moves from one molecule to another, is it considered an oxidative reaction or a reduced reaction?


When an electron moves from one molecule to another, one molecule loses an electron and other gains an electron. You cannot have one without the other. Reduction and oxidation occur simultaneously. Hence is it shorted to “redox” reaction.

Not all redox reactions involve the complete transfer of electrons. It is still considered a redox reaction when substances share electrons because positive and negative charges have shifted.

No chemical bonds are broken in redox reactions but changes take place in the molecular structure of the molecules and the molecules nearby. This shape shift enables electrons to move between molecules.

Many biological processes rely on redox reactions. The relocation of electrons releases energy stored in organic molecules. This energy is ultimately used to synthesize ATP.

How fast does an electron move in a wire?

Quite slowly

An electron, if pushed, can travel nearly the speed of light in open space like in outer space or in an accelerator.

Traveling through matter, in this case a wire, slows it down to snail’s pace. For electron to move down a wire, it interacts with many atoms along the way. They kind of drift, moving at about 1 meter per hour. 

While electrons travel slowly within a wire, their interaction propagates into a wave. The exact length of time it takes for an electromagnetic field to travel in wire depends on the type and thickness of the wire but it can travel nearly the speed of light.

Why are wires usually made of metal?

Metals are conductors

The physical and chemical behavior of an atom is determined by its outermost electrons. Metals readily lose electrons in their outermost shell.

Wire, being made of metal, is an excellent conductor as these electrons flow freely from particle to particle with little resistance.

Yet as electrons flow in a wire, they collide with the metal atoms and move them faster. This friction produces heat. The faster the atoms move, the hotter the wire gets.    

Your toaster is a good everyday example of electrons making heat. Metals, conductors, and electrons all help to make your morning breakfast.

If electrons pass freely through conductors, what do we call those materials that resist the flow of electrons?


The difference between conductors and insulators is how strongly the electrons are held in the chemical bonds to the atom.

Electrons move easily through metals. Non-metal elements hold their electrons more tightly in chemical bonds and resist the motion of charge through them.

Plastics make good insulators because they have few or no free electrons. Copper wires are coated with insulating material to prevent the charge from spilling out.

With enough voltage applied, however, any insulating material will break down and start to leak electrons.  This is often a dangerous short-circuit spark.

As in a wire, electrons move through our bodies generating energy. What is the name of the series of compounds through which electrons move and create chemical energy in the form of ATP?

Electron transport chain

The electron transport chain is a series of redox active compounds found on the inner membrane in mitochondria and in the thylakoid membrane in choloroplasts.

Electrons pass sequentially through the chain, meeting compounds with increasing affinities for electrons until they are finally transferred to oxygen, the ultimate oxidant.

As they pass, they electrically and chemically charge the membrane.  This charge is used to drive synthesis of ATP, stored chemical energy for cell survival and growth.

It is how plants extract energy from sunlight and animals extract energy from food.

In 1966, a seminal paper on how electrons transfer in biology was published the Biophysical Journal. Who co-authored the paper? Hint: he had very close ties to the Department.

Britton Chance

Britton Chance and Don DeVault co-authored a paper “Studies of Photosynthesis using a Pulsed Laser” in the Biophysical Journal.

In it, they describe that electrons don’t pass from molecule to molecule by collisional contact, but instead quantum mechanically “tunnel”  through the molecular space in the proteins.

Biological electron tunneling can take place even near absolute zero of temperature where nearly all molecular motion has stopped.

What is the dominant factor in determining the rate in which electrons move through biological membranes?


Different parameters affect the movement of electrons through molecules, including the molecules’ vibration and environment, but the predominant factor is distance.

Chris Moser and Les Dutton calculated the rate at which electrons tunnel through proteins based on the distance between the molecules. This calculation has become known as the “Moser Dutton Ruler”.

Nature likes a distance of 14 Angstroms or less (1 millimeter = 10,000,000 Angstroms) to maintain a working rate of electron transfer through chains of redox molecules. The closer the molecules, the faster the transfer.

Every time we breathe oxygen into our bodies, we activate electron tunneling, ultimately making biochemical energy in the form of the molecule ATP.

What is the most magnetic of all naturally occurring minerals on Earth?


Magnetite is a naturally-occurring mineral found in almost all igneous and metamorphic rocks. Known for its ability to attract small pieces of iron, it was used as an early form of magnetic compass.

Crystals of magnetite have been found in bacteria and in the brains of some animals.

Magnetic sensitivity is common in birds. Magnetite has been found to be concentrated in the birds’ beaks and, along with visual clues, thought to be responsible for their ability to migrate over thousands of miles.

What is another way that birds can sense the magnetic field?

With their eyes

The eyes of migrating birds contain a yellow flavin-containing protein called cryptochrome. When the flavin absorbs daylight, the excited flavin electron acquires a spin that is now sensitive to magnetic fields.

This changes the ability of the electron to tunnel to other centers in the protein and gives the bird a visual signal of the direction north.

The Dutton lab is designing artificial magnetic field-sensitive proteins to explore how this works.

Do pigeons migrate?

Some do, some don't

Bird migration is regular seasonal movement. Birds will search for hospitable climates and abundant resources as seasons change. There is a high cost associated with migration including mortality and predation. Animals will not make that effort without good reason to do so.  

Several species of pigeon (Band-tailed Pigeon, Mourning Dove) will migrate to warmer climates in winter to take advantage of changing food supplies.

The familiar type of pigeon we see in urban areas is the Rock Dove. It does not migrate because there is no reason for it. Resources are plentiful in cities. Cities provide shelter, warmth, and discarded human food.

Still, like migrating birds, these pigeons can orient themselves easily. They have outstanding homing capabilities and can travel long distances to return to their nesting areas.

What is the difference between pigeons and doves?

Not much

There is no strict division between pigeons and doves. They both have small rounded heads, slim bills, plump bodies with dense soft feathers, tapered wings, scaley legs, and make cooing calls.

Pigeons and doves constitute the bird clade Columbidae, which includes about 310 species. Generally speaking, the word “dove” is used for the smaller species and “pigeon” for the larger. Usually the terms are used interchangeably.

What species of pigeon went from being one of the most abundant birds in the world during the 19th century to extinction at the beginning of the 20th century?

The passenger pigeon

Estimates range from 3 to 5 billion passenger pigeons living in North America when the Europeans first arrived. It is believed that this species constituted 25% to 40% of the total bird population in the United States.

The passenger pigeon resembles a larger, more brightly colored Mourning Dove.

It was a gregarious animal that lived in large numbers to ensure successful breeding. The immense groups they formed were almost beyond comprehension. A single flock could contain hundreds of millions of birds.

Passenger pigeons filled forests eating tree nuts and insects. They would migrate in the spring and fall. They had a propensity for eating everything and then taking over the sky.

In 1813, John James Audubon described a flock moving 60 miles an hour, a mile in width, obliterating the noonday sun, and taking three days to pass over.

What was responsible for the demise of several billion passenger pigeons?

a) Disease
b) Human predation
c) Dwindling resources

b) Human predation

Passenger pigeons tasted good and were easy to kill. In the days before refrigeration, they were like a living convenience store.

Initially, the killing of passenger pigeons did not make much of a dent in the enormous population. As society grew more modern, the location of nesting birds could be telegraphed. Professional hunters chased them around the country all year long.

In 1878, the refrigerated rail car was introduced and tens of thousand passenger pigeons could be crammed into cars and transported to large cities hundreds of miles away. Restaurants could offer wild game on their menu.

At the same time there was an explosion in logging which destroyed their habitat.

In its lifetime, little was known about passenger pigeons besides how to catch, kill, and cook them.

When did the last passenger pigeon die?


Many view the story of the passenger pigeon as a cautionary tale. It is a complicated history of industry and economics versus nature and conservation.

The passenger pigeon lived in collaboration on a giant scale but may have died because of it. When massed together, they were easily slaughtered. The surviving birds could not exist in smaller flocks.

In the 1880s and 1890s, when it was clear the passenger pigeon was doomed, several ineffective laws protecting the pigeon were passed. By then, the number of remaining birds was too few to successfully reestablish the species.

In 1900, a boy in Ohio killed what was thought to be the last wild passenger pigeon. A small captive population remained at the Cincinnati Zoo including a pair named George and Martha. By 1910, only Martha remained.

On September 1, 1914, Martha died. She was 29 years old. She is now known as a symbol for the threat of extinction.

The public interest in the demise of the passenger pigeon helped to strengthen conservation laws. These laws have helped save many other migratory species.

What is the name of the controversial program that would like to resurrect extinct species?


De-extinction is the process of creating an organism which is a member of an extinct species. The most popular methods are cloning and selective breeding.

The sentimental attachment to the passenger pigeon and its extinction has led a team of scientists to try to bring it back to life. Reconstructing the passenger pigeon genome is the first step in its de-extinction. Genes for key passenger pigeon traits like its long tail or orange-colored breast need to be identified and then spliced into the genome of its closest living relative. This doctored DNA could be injected into the eggs of band-tailed pigeon, and successive generations would be bred and selected for passenger pigeon traits.

This idea is not without controversy. If successful, any resurrected species would not be returning to its original habitat. It is unclear how its reappearance would fit into the current ecosystem.

Critics argue that time is better spent serving existing species.

What slang expression was invented to describe a bird that was used to lure other birds into a trap?

Stool pigeon

One quick method for capturing passenger pigeons was to use a single bird as a decoy. A bird was tied to a stool (or a block of wood) that would rise up and down when pulled by a cord. A group of wild birds would be fooled into thinking that it was quietly feeding. When they joined him, they were netted.

The original definition of stool pigeon was a bird decoy (early 1800s) but evolved into anything that betrays its own group.
As years went on, the definition broadened into a police informer (late 1800s).

One of the most famous birds alive today is a Red Knot who has migrated 350,000 miles in his lifetime. Scientists call him “B95”. What is he also known as?


Red Knots are medium-sized shore birds, about the size of a starling, that breed in the high Arctic. They have one of the longest migrations of any bird – 9,000 miles – from the Arctic to the southern tip of South America.

In February 1995, researchers banded a 2-year-old Red Knot with the number “B95” and have tracked him to this day. He is the oldest living Red Knot on record.

Being 20 years old, he has logged at least 350,000 miles in his lifetime. Having flown the distance from the Earth to the moon and halfway back, he has been dubbed “Moonbird”.

During spring migration Red Knots, including Moonbird, stop to refuel on their way back to the Arctic. Where do they stop to rest, relax, and eat horseshoe crab eggs? (Hint: it’s local)

Delaware Bay

Being shore birds, Red Knots migrate to coastal areas. During their hemispheric migrations they make a local crucial stopover. They arrive in the spring at the Delaware Bay just as horseshoe crabs are spawning. They stay for about 2 weeks, doubling their weight by gorging on eggs before moving on to complete their journey north.

It is estimated that 90% of the entire population of the Red Knot subspecies C. c. rufa can be present in the Delaware Bay in a single day.

B95 (a.k.a. Moonbird) was spotted there this past May. His long life and stamina has endeared him to researchers. This 4-ounce bird has become a mascot for shorebird conservation efforts. Most shorebirds are in decline. Red Knots are the most imperiled due to the overharvesting of horseshoe crab eggs but as resources rebound, so do the Red Knots. Numbers are increasing and through it all, there has been Moonbird.

Which bird has eyes that are larger than its brain?

The ostrich

The ostrich is the world’s largest bird and is native to Africa. Ostriches are strong runners and can sprint up to 43 miles per hour. Their wings, useless in flight, help them change direction while running.

Ostrich eyes are the largest of any land vertebrate: axial length = 38 mm and of globose shape with an anterior focal length of 21.8 mm.* Ostriches’ eyes take up approximately two-thirds of their heads so there is little room left for brains. They do, however, have exceptionally good sight both near and far.

Their eyes weigh ~60 grams and their brains ~40 grams.

Despite their extraordinary speed and vision, ostriches are not very good at eluding predators. Without a lot of brain power, they tend to run in circles.

*Martin, Ashash, and Katzir (2001) Ostrich Ocular Optics. Brain, Behavior, and Evolution 58(2):115–120.

This week's answer:

Which bird has the largest brain in proportion to its size and is known for its incredible memory?

The hummingbird

Hummingbirds are very small, weighing less than a nickel. Their metabolism is extremely high so they are in constant search of food. These tiny birds must consume more than their weight every day or starve to death.

90% of their diet is nectar. Nectar is a mixture of glucose, fructose, and sucrose, and is a poor source of nutrients. Hummingbirds supplement their diet with insects and spiders.

Hummingbird brains weigh ~4.2% of its body size, the largest proportion in the bird kingdom. That part of the brain related to learning and memory is particularly large, up to five times larger than those found in seabirds, songbirds, and woodpeckers. This excessive brain power has made them skilled and efficient foragers.

They have excellent memories. They visit hundreds of flowers each day and remember where each one is located and how long it takes a flower to refill with nectar once it has been drained.

Next week's question:

In 1782, the American Bald Eagle was depicted in the Presidential Seal of the United States. Benjamin Franklin was disappointed. What bird did Ben prefer to be our national symbol?



Past questions and answers are in the trivia archives: 2012 / 2013

Questions? Comments? Corrections? Contact Mary Leonard,

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