20^th Century Science                                                 1895-2000

            The science of this time period is so expansive that it needs to be divided into two eras.  So, we will be discussing science prior to World War II and science after the war.

            The science of the early 20^th century was driven by an area of science that we haven’t discussed this year…the science of rays.  X-rays, subatomic particles and quantum theory are all important discoveries in physicals that do not pertain to any of the 7^th grade standards.  However, these discoveries do impact astronomy, geology, biology, medicine, and the building of an atomic bomb, which affects the fate of the Earth.

            The science of the late 20^th century was centered on astronomy.  Scientists wanted to know what was out there, so telescopes and radio astronomy took off.  More importantly, the goal was to get out there and try to reach the moon.  With the weapons that were developed during the war, the technology needed for rocketry was now available.  World War II served to accelerate the scientific achievements of this time. Sadly, much of this science does not pertain to the standards we cover in 7^th grade.  

            Science in the 19^th century was still the occupation of a few people.  In the 20^th century, this was going to change.  It is fair to say that more people had the role of scientist in the 20^th century than in all the other centuries combined.  Many of the advancements were made by teams of scientists working together, unlike the past where science took on more of an individual flavor.  This increase in science spread into its impact on society as well.  Science also became a team effort more than an individual pursuit.  Technology for various discoveries was expensive which caused the need for industries or groups of scientists to cover the costs.

            The science of the Renaissance and Enlightenment had an impact on the philosophical views of society, but not much on society itself.  This would change in the 20^th century as universities, corporations and industries all included scientific exploration in their realms.  Companies such as Bell Labs and the German chemical laboratories led the way in this scientific pursuit.  In fact, Germany could be considered to be the lead scientific country of the 19^th century.

            That would change when Hitler came to power in 1933.  The United States would soon become the leading scientific country, largely due to the great number of European scientists that fled Europe for the United States.  Probably the most influential of these scientists was Albert Einstein.

ALBERT EINSTEIN

            It seems fair to qualify Albert Einstein as one of the greatest scientists of the 20^th century, if not, all time.  Einstein was definitely a man shaped by the world around and the need to understand that world.  He received one of his first toys, a compass, at the age of 5.  This device intrigued him and would be the first step on his long walk of science.  By the age of 10, Einstein had dropped out of school and began a program of self-education, concentrating on science.  Einstein had violin lessons and was taught about Judaism at home.  His original desire for a career was to be an electrical engineer, but he failed the exam.  He then desired to become a teacher of mathematics and physics, a goal that was accomplished in 1901.  It was during this time he was asked to join the Swiss military, but was declared exempt because of flat feet and varicose veins.  He then met his first wife, Mileva Maric and had two children; the second was put up for adoption.   He would marry her two years later.   He then moved on to a job working in a patent office.  It was during this time at the patent office that Einstein arrived at many of his conclusions about theoretical physics.  Amazingly, he did this without the help from colleagues or literature.  One of these papers was on special relativity for which he is most famous.    To make this concept understandable, he uttered this quote, “ If you spend two hours with a beautiful woman, it seems like two minutes.  If you sit upon a hot stove for two minutes, it seems like two hours.”  Einstein would them move on to become a professor at the University of Zurich.  He would see his marriage come to an end in 1914.   All of this work would tire him out and he suffered a physical collapse in 1917.  His cousin, Elsa would nurse him back to health and he would marry her in 1919.  This year, a solar eclipse would prove his idea of General Relativity correct.  He soon recovered and starting making international visits.  In 1932, he would return to Germany but soon began feeling pressure to leave when he was identified as a Jew.  Einstein would eventually bring his family to the United States and would receive permanent residency in the United States in 1935 and citizenship in 1940.

            Einstein made many important discoveries and proposed the possibility of many others.  He claimed that light would bend due to gravity as it passed a large object in space.  He told the government of the United States about Germany possibly building an atomic bomb and encouraged the U. S. to investigate nuclear research.  The United States followed Einstein’s advice and created their own nuclear bomb.  Einstein then proclaimed that while the ability to create a nuclear bomb was significant, one should never be built or used.              Einstein died on April 18^th, 1955.  His ashes were scattered at an undisclosed location.

Anthropology

            In 1895, Eugene Dubois brought to Europe fossils of what he called Java Man.  These fossils were the first examples of Homo erectus that man had ever seen.  In fact, these were the first fossils of human ancestors that could not be categorized as Homo sapiens.   Dubios’ discovery was met with considerable resistance by society, so much that Dubois eventually hid the fossils beneath the floorboards in his house.   Then in the early 20^th century, more fossils of Homo erectus were found in China and Africa, confirming the new species.  Another scientist named Raymond Dart would meet with the same skepticism when he discovered the head of child, which represented a new species called Australopithecus, a relative of the human.  Again, it would take many other discoveries of Australopithecus to prove Dart correct.  These discoveries would soon be followed in 1902 by the construction of Neanderthal Man.  Pierre Boule was able to put together a complete Neanderthal skeleton.  In 1927, the first fossilized teeth of what would come to be known as Peking Man were found and in 1932, Ramapithecus remains were found.  Ramapithecus was originally believed to be a human ancestor, but later classified as an ancestor of orangutans.  In the past, cave paintings were found in various parts of the world.  These paintings were met with the same skepticism as the fossils were.  But as with all new discoveries, when more samples are found, the previous discoveries gain credibility.  In 1940, four teenage boys in the Lascaux caves found some of the most advanced cave paintings ever discovered.  The paintings were dated as being 17,000 years old. 

After the War

            The discovery of ancient hominids fueled the study of anthropology.  Scientists discovered that the split between humans and apes took place only a few million years ago.  Prior to this era, scientists thought that the earliest relative to humans was a 30 million year old ape.  Two of the most famous anthropologists would have to be Louis Leakey and his wife Mary.  They spent a great deal of their lifetimes looking for the origins of human life in Africa.  Louis Leakey found what would become to be known as A. bosei that was 1.75 million years old.  Two years later, in 1961, Leakey found the first example of a Homo habilis.  This would be followed by the discovery of “Lucy” in 1974.  Don Johansen and Maurice Taleb (or Tom Gray) found 40% of a female Australopithecus afarensis believed to be 3 million years old.  Why the name “Lucy” at the time of the celebration of the discovery, the Beatles song “Lucy in the Sky with Diamonds” was playing and the name stuck. Lucy is believed to be an adult (wisdom teeth were erupted) who was 3 and ½ feet tall and weighed 60-65 pounds. Ten years later, Andrew Hill found a hominid fossil that was 5 million years old.  Currently, the oldest fossils that seem to be related to humans date back 7 million years.

            The dating of fossils became more accurate with the concept of Carbon-14.  By discovering the decay rates of elements, scientists were able to more accurately determine the age of fossils.  Willard Libby made this discovery in 1946.  This technology was put to use in 1954 when Barghoorn and Tyler discovered fossils of monerans or bacteria.  These fossils were dated as being 2 billion years old, the oldest fossils on record. In 1964, rocks dated to be 2.5-2.9 (       ) were found to contain chlorophyll, which would become a building block for plants.  Finally, in 1986 a miner found a fossilized frog in amber that was dated as being 35million years old.

            Sadly, not all the anthropological discoveries of this era were positive.  The Piltdown man which was discovered in __________ to be a hoax in 1953.  It seems the scientists that “discovered” this jaw filed down some parts and broke off others that would identify it as an orangutan jaw.  Why do this?  There are many theories.  The most common is that the English scientists felt left out.  Germany and France had given us Neanderthal and Cro-Magnon, respectively.

Anthropology Fun Fact

1922- Howard Carter finds the tomb of Tutankhamen.

1963- The cave paintings at Lascaux were closed the public due to humidity from people

breathing was damaging the artwork.

1984- Lindow Man is found in a peat bog.  The chemicals in peat preserve him very well.

Astronomy

            What is out there?  How far away is it?  Can we go there?  These questions had driven astronomers in their studies for centuries.  Finally, some of the answers to these questions would be realized.  The solar system, finally determined to be heliocentric, would be studied and explored to its outer reaches.  Closer to home, the moon would become an objective that would cross the scientific border and enter into the realms of society and politics.

Solar System

            Much of the astronomy of this time dealt with trying to understand the solar system.  Scientists were find themselves looking through telescopes at the beginning of this era and actually land on another celestial body by the end of this era.

            Telescopes and our observations through them would remain the primary focus of the 20^th century.  Eight planets had been discovered and in 1905, Percival Lowell would predict that a 9^th one would be found.  Twenty-five years later, Clyde Tambaugh did discover the 9^th planet, which would come to be called Pluto.  However, discussion on Pluto centered on whether or not it was a planet or a moon of Neptune.  Scientists were already aware of moons of Saturn and Jupiter.  Could Pluto with its relatively small size be just another moon?  Since Pluto has its own orbit and does not orbit around another planet, many scientists would argue that Pluto is, indeed, another planet.

            In 1895, James Keeler would turn his telescope toward Saturn.  Saturn had always been a fun planet to study, due to its spectacular rings.  It was the rings that intrigued Keeler.  He noticed that they did not rotate as an entire unit.  This led him to the conclusion that Saturn’s rings were not solid, but instead made of particle.  This would later be proven true.  It is believed that Saturn’s rings are actually billions of snowballs.  In 1899, William Pickering would discover the 9^th moon of Saturn, only to be followed by other astronomers discovering the sixth and seventh moons of Jupiter.

            Twenty years later, the idea of our solar system being extremely small in comparison to the universe took hold.  In 1919, it became realized that the Earth was on the outer edge of a spiral galaxy called the Milky Way.  Ever wonders how the Milky Way got its name?  The Milky Way can be seen as a white, cloudy mist in space.  The Greeks claimed this was the milk from Hera’s breast-feeding her “children” or constellations in the sky.  With the realization that the Sun is just one of 400 billion stars in the Milky Way, and that the Milky Way is just one of billions of other galaxies in the universe, scientists understood how small, and insignificant, and rare, and precious humans are.  This also made us wonder how big the Universe actually was. Herbert Doust from Muskegon, Michigan calculated the distance to the Andromeda Galaxy as being 700,000 light years from the Earth.  He also realized that the distance to other galaxies was much greater.  Using Newton’s ideas, especially those dealing with gravity, Carl Ludvig Charlier predicted that our universe would eventually collapse, but he figured that it wasn’t collapsing at the moment.  In 1917, it was predicted that the universe was actually expanding, later to be proven by Edwin Hubble, in 1929.  In 1927, George Lemaitre would take the ideas of an expanding universe (reversed the process), and one that may eventually collapse and arrived at the idea of the Big Bang.  Lemaitre claimed that the Universe could have begun as some sort of cosmic egg, eventually hatching, living out its life and possibly returning to egg form.  The ultimate size of the universe is still up for discussion, but it is believed to be 14.6 billion years old, an age derived at by studying the farthest stars.

            So how did the Earth get here?  Much speculation has been presented on this idea, but in 1944, Carl Weizsacker came up with the idea of planetesimals.  He claimed that small pieces of space debris were surrounding the Sun, collected by the Sun’s gravity.  These pieces, he called planetesimals, would smash into one other and in some instances, stick together.  This would create a slightly larger planetesimal with slightly more gravity.  This would continue to happen over and over, eventually forming planets.

Space Flight

            Once we realized what was out there, the question became how could we go there?  This concept had been discussed since the time of Galileo.  Most of the discussions centered on rocketry, but slingshots, cannons and various other flying machines were possibilities as well.  In 1895, Konstantin Tsiolkovsky would write one of the first scientific papers on space flight.  He proposed using a liquid fuel rocket to propel man to the moon.  It was this paper that would earn him the Russian distinction of being the father of space flight.  In 1919, Robert H. Goddard would agree with Tsiolkovsky and propose that a rocket could carry a vehicle to the moon.  He was highly criticized and shrunk from the public eye.  His idea did not die, however.  Hermann Oberth took this idea and expanded upon it.  How fast would you need to go in order to escape the Earth’s gravitational pull?  This value was crucial to determining if space travel was even possible.  In 1926, Goddard would emerge once again as he launched a liquid fueled rocket 184 ft (56m), which traveled at a speed of 60mph.  The Germans took this as a hint that they would need to start their own rocket project.  In 1927, the Germans formed the Society for Space Travel.  One of its founding members would be Wernher Von Braun.  Goddard continued his pursuit and launched a rocket with a camera, barometer and thermometer into the sky.  Five years later, it was Von Braun’s turn.  He launched a liquid fueled rocket 1.5 miles into the air.  Four years later, in 1938, Von Braun launched another rocket that went 11 miles into the sky.  Sadly, Hitler decided that these rockets could better serve his purpose if they were to be used as weapons.  In 1944, the Germans built the first rocket-powered plane.  Controlling this rocket plane was not an easy thing to do and the plane had a nasty habit of exploding.  Needless to say, the plan for a rocket plane quickly disappeared.

After the War

            The astronomy after the war was centered on sending probes and eventually humans into outer space.  Also, the idea of the Big Bang became common talk amongst astronomers and the general public.  Telescopes were limited on how far and how well they could see by our atmosphere and its refraction of light.  Sending probes to other planets helped end this problem, but the induction of the Hubble Space Telescope to the realm of astronomy set the scientific world on fire.

            In 1946, a new method of exploring space began.  Astronomer E.G. Bowen began using a radio telescope in Australia to examine space.  Every star in the universe emits radio waves.  By using a radio telescope, we can identify stars based on their signals.  More recently, scientists have been using radio telescopes to “listen” for messages that may be coming from another life form.  Listening to these radio waves also allowed scientist to formulate the idea of the Big Bang.  Three astronomers named Gamon, Alpher and Herman created this theory in 1948.  The idea of a radio telescope allowed us to examine space without the limits of sight, but what if we could improve our sight?  An idea that approached this concept was provided in 1947.  An astronomer named Spitzer proposed that if we were to place a telescope outside of the earth’s atmosphere, we would not have to deal with the refraction caused as light passed through the atmosphere.  Sadly, this idea would not be realized until 1990 with the invention of the Hubble Space Telescope.  Once Hubble was up and running, it did not take long to realize the importance of this invention.  Finally, with all the new discoveries and information provided by better telescopes, a new way to catalog the data was needed.  In 1951, Dirk Brouwer used computers to calculate the orbits of various celestial bodies.  His data is was able to calculate orbits until 2060.  In comparison, the astronomy program on my computer can show the position of stars, planets and galaxies until the year 32,000 or 30,000 years from now.

Exploring the Solar System

            Astronomers would use telescopes to see what was in our solar system, but what if we wanted to go there?  Human travel was too risky and expensive, but space probes could be sent.  The discoveries made by probes and those that continued to be made by telescopes made our solar system seem much smaller.  In 1974-75, Charles Kowal discovered the 13^th and 14^th moons of Jupiter.  Why do you think that Jupiter would have so many moons?  In 1976, Pluto was discovered to have a thin atmosphere consisting of methane or natural gas and two years later, its moon (Charon) was discovered by James Christy.  Two space probes that provided valuable information were named Voyager I and Voyager II.  They discovered a ring around Jupiter, studied the moons and rings of Saturn and searched the surfaces and atmospheres of Uranus, Neptune and Pluto.  Voyager I would also have a small role in the first Star Trek movie.

The Great Space Race

            Once the idea of rocketry became common, the race was on to reach the moon.  The two competitors in this race were the United States and the Soviet Union.  The Soviets won almost every race except reaching the moon first.  The United States landed Apollo 11 on the moon on July 20^th.  Neil Armstrong was the first man to walk on the moon, followed by Buzz Aldrin.  Michael Collins was also part of this mission, but he stayed in the command module that orbited the moon.  Here is a timeline to show the events that led up to this achievement.

Astronomy Fun Facts

--While most telescopes were reflecting telescopes, the largest refracting telescope was

     built in 1897 and is at the Yerkes Observatory in Wisconsin.

--In 1911, a meteorite the size of a basketball hit and killed a dog in Egypt.  This is the

only mammal ever to be killed by a meteorite.

--In 1981, the United States would launch its first Space Shuttle, called Columbia.  This

was the first reusable spacecraft.

Biology

            The biology of this century would find itself beginning not with discoveries of the future, but instead a rediscovery of the past.  In 1900, three scientists rediscovered the papers and works of Gregor Mendel.  Mendel had learned a great deal about heredity, inherited traits and genetics with the work he did as an Austrian monk.  It was his work that would lead to the discovery of genes, and DNA.  Part of this was the idea that each parent contributed to the traits of the offspring.  However, in 1899, a scientist conducted an experiment with sea urchins.  By changing the stimuli to a sea urchin he was able to get them to reproduce without mating.  This process was called parthenogenesis.  The mother gave birth to all daughters.  Why do you think this was?  This experiment would be replicated in 1910, when a scientist would witness parthenogenesis in frogs.  Again, the mother gave birth to all daughters.  Before World War II, scientists would also discover that chromosomes carried the information for mutations.   Another discovery was that males had different chromosomes than females and these chromosomes would come to be known as XX for females and XY for males.

After the War

            Biology during this time was focused on DNA and its structure and function. James Watson and Francis Crick did the discovery of DNA’s structure in 1953.  They described DNA as a twisted ladder, which is known as a double helix.  Although Watson and Crick get credit for this discovery, they could not have made this discovery with out the discoveries made by Rosalind Franklin.  This female scientist spent a great deal of time looking at the x-rays that were bounced off DNA.  This work was later used by Watson and Crick to announce their discovery.

Biology Fun Facts

1912—Johann Regan used a telephone to transmit cricket chirps.  Female crickets are

attracted to the chirping and move toward the phone.

1925—Kansas science teacher John Scopes is jailed and sent to court for teaching the

Theory of Evolution in class, which went against Kansas state law.  In the end, the

validity of evolution was not put on trial, but rather if Scopes had taught

something that was against the law.  Scopes was found guilty and fined $100.

1936—Alexander Oparin suggests the idea of “Primordial Soup” from which all life

arose.

1953—A coelacanth was found in the Comoro Islands by James Smith.  The Coelacanth

is a fish with fleshy fins that was believed to be extinct.

1958—A lizard species is found that only exists as females.  This is the first vertebrate

found to exhibit this trait.

1981—The Chinese become the first to clone a fish.  They clone a carp.

1984—Wilson and Higuchi clone a QUAGGA.  This is the first extinct animal to be

cloned.

Geology and Earth Science

            Without a doubt, the most important idea concerning the geology of this era was Alfred Wegener’s idea of Continental Drift.  However, when Wegener first proposed this idea, it was not viewed as being valid, nor important.  This recognition would come later.  Instead, most of the geology of this era dealt with the internal construction of the earth.  Much of this was determined by examining the motion of earthquake waves as they passed through the Earth.

Earthquakes

            As mentioned prior, the study of earthquakes would lead much of geological pursuits.  The first type of seismograph that is used today was invented in 1899.  These seismographs measure the strength of earthquake waves.  In 1909, Andrija Mohorovicic would use this seismograph to determine that earthquake waves went through a change approximately 18 miles under the surface of the Earth.  This data was used to determine that the crust of the Earth should be 18 miles.  After that, waves reached the mantle, which was “liquid rock” and different from the solid crust.  In 1914, Beno Guttenberg would use the same test to determine that the earthquake waves went through another change about 1860 miles.  It was believed that this is when the waves went from a liquid mantle to a solid core.  In 1935, the Richter Scale would be invented to attach a number to the strength of earthquakes.  The Richter Scale ranges from 1-10 with 10 being the highest and when all rock breaks apart.  We have never had an earthquake of 10. 

Volcanoes

            The study of volcanoes would also gain prominence during this era.  Much of this fascination with volcanoes arose due to the fact that many humans started being killed by the destruction volcanoes could bring.  One major eruption took place in 1902.  Mount Pelee erupted and killed 38,000 people.  Only one man survived.  He was a prisoner in the stone jail and the lava never got to him. In 1943, a volcano that would come to be known as Paracutin grew to a height of 2 kilometers in 1952.  This volcano is known as a cinder cone volcano as it is made of small particles of ash and lava.  Paracutin started in a cornfield and was obviously shocking to the local inhabitants in Mexico.

            Amazingly, there was also a link between volcanoes and astronomy during this era.  Scientists had been studying the very large crater in Arizona.  Much speculation surrounded this crater as scientists tried to determine the age of this ancient volcano.  What they would later discover is that this crater was not the result of a volcano at all.  Instead, this crater was the result of a meteor striking the Earth.  This result led to the search for other such craters.

Wegener and Continental Drift

            In 1912, Alfred Wegener proposed that the Earth was able to shift and that the continents were able to move about on the surface of the Earth.  He said that these shifts would take place over long periods of time.  He also claimed that the continents could have been part of a large “super continent” which was called PANGAEA.  This continent eventually split into the continents we have now.  Since continental drift is not readily observable, Wegener’s theory was not widely accepted when he proposed it.  In 1915, Wegener believed that he had found certain “lines in the sand” which showed were continental drift could have taken place.  In 1921, Wegener’ idea would gain even more support when the Germans, who were testing out their new submarines discovered the Mid-Atlantic Ridge.  It would later be determined that this ridge is where two tectonic plates meet and actually separate from one another.  New lava then fills the gap.  Harry Hess made this discovery after the war.  He called this the Theory of Sea Floor Spreading.

We have already discussed the importance of certain fossils that were found during the Anthropology section.  Please review this section.

After the War

            The geology after the war was greatly influenced by the idea of plate tectonics and continental drift.  These two ideas helped explain the science behind earthquakes and volcanoes.  Geologists also noticed more evidence of catastrophes to explain the extinctions of various organisms.

            Volcanoes seemed to be a major area of study during this time.  For the most part, scientists knew where they were and could start to predict when they would erupt.  There were some surprises, however.  A farmer was working in his field one day when he saw smoke rising from his crops in Mexico.  Then ash began to spew from the ground.  It did not take long after this for Mt. Paracutin to reach a height of 2km.  What was not a surprise is when Mt. St. Helens erupted in Washington State.  Scientists had predicted its eruption on May 18^th, 1980 with plenty of warning.  However, some long time residents chose to stay and 61 people were killed when the north side of the mountain exploded.  Present day volcanoes also became linked to past devastation.  The history of a volcano named Santorini was studied and was given credit for the “destruction” of Atlantis.  Scientists do not believe that Atlantis existed, but it is a fact that Santorini was erupting during the time Atlantis would have disappeared.  What is likely is that the eruption of Santorini was written into the legend of Atlantis.

Geology Fun Facts

1907—Bertram Boltwood uses the decay of uranium to lead to determine the age of rocks

1926—Roy Chapman Andrews would discover fossilized dinosaur eggs.  Andrews would

later be the inspiration for the Indian Jones character.

General Fun Facts

1903—December 17, Orville Wright flies the first plane for 59 seconds.

1905—Einstein proves atoms exist and the first submarine is built.

1906—Orville Wright flies for an hour.

1906—AM Radio

1911—National Biscuit Company (NABISCO) makes Oreos

1912—Cracker Jack starts putting prizes in their boxes.

1912—The Titanic sinks.

1914—WWI starts

1928—Minnesota Mining and Manufacturing (3M) makes Scotch tape.

1928—Joseph Shick makes the first electric razor.

1930—Sliced bread is sold for the first time.

1939—Einstein writes to FDR telling him to research nuclear energy.

1942—January 18, Stephen Hawking is born 300 years after Galileo died and Newton

was born.

1943—Jacques Cousteau invents the Aqualung or Self-Contained Underwater Breathing

            Apparatus (SCUBA)

1948—George deMestral walks his dog and notices all the burrs stuck to his dogs fur. 

            After examining the burrs under a microscope, he invents Velcro.

1954—The US Supreme Court votes against segregated schools.

1954—A Japanese fisherman is killed from the fallout of a nuclear bomb test.

1971—Texas Instruments makes the first pocket calculator.  It weighs 2.5 pounds and

costs $150.

1973—In an attempt to curb pollution and help wildlife, push tops are used on soda and

beer cans.

1982—CD players are introduced.

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