May 2019 - Missing the Forest for the Tree: A Worldview Grounded in Science

1905: Special Relativity

Posted on May 29, 2019February 4, 2024 by Dan

Special Relativity is a theory proposed by Albert Einstein that attempts to explain the relationship between space, time and motion. Einstein outlined his proposal in a scientific paper titled “On the Electrodynamics of Moving Bodies” published on September 26th, 1905.

Approaching the Limits of Classical Physics

Einstein's famous E=mc^2 equation shows the equivalence of mass and energy — Einstein’s famous E=mc^2 equation shows the equivalence of mass and energy

Isaac Newton’s laws of motion were a wildly successful explanation of the physics of motion, and a dominate force in scientific understanding of physics for over two centuries. However, by the turn of the 20th century some critical shortcomings in the explanatory power of Newton’s famous laws were becoming evident. One of the major phenomena classical physics couldn’t explain was the behavior of light. Classical physics assumes that space and time are absolute and that the speed of light is invariant. It is simply added to or subtracted from the speed of a light source. However, experimental evidence, particularly from the Michelson-Morley experiment of 1887, which demonstrated that the speed of light in a vacuum is independent of the motion of the Earth about the Sun, suggested this is not the case. Their experiments suggested that the speed of light is constant for all observers, regardless of the speed they are traveling at.

Working out a Swiss patent office, the 26-year old Einstein solved these problems with his Theory of Special Relativity and later his Theory of General Relativity. Special relativity describes motion at a constant speed traveling in a straight line (a special case of motion, hence the name) while general relativity describes accelerating motion. Interestingly, his famous equation E=mc^2 did not actually appear in the original paper but was added essentially as an addendum a few months later.

Einstein’s Theory of Special Relativity is based on two principles:

The laws of physics are the same in all inertial frames of reference
The speed of light is the same in all inertial frames of reference (186,000 miles/second)

This implies that an observer at rest observes light traveling at a speed of 186,000 miles/second while another observer traveling at 180,000 miles/second relative to the observer at rest also observes light traveling at 186,000 miles/second. Based on these principles several interesting conclusions can be worked out. These conclusions are, or course, relative to an observer at “rest.”

Time slows as speed increases
Mass increases as speed increases.
Mass and energy are equivalent as exemplified through Einstein’s famous E=Mc^2 equation
The length of an object contracts as speed increases

Testing the Theory and Acceptance

As unlikely as these conclusions seem they have been verified repeatedly through many experiments. The conclusions seem counter-intuitive because many of these effects are only perceptible at near-light speeds. Perhaps this is why the acceptance of special relativity was not immediate and was met with harsh criticism by many scientists. The idea that measurements of time and length could change with velocity conflicted with everyday experiences. However, the aesthetic beauty of its mathematics initially attracted interest among some scientists, prompting further inquiry.

The tide of acceptance began to turn as the predictive power of special relativity was confirmed by experimentation. The most famous example was the 1919 solar eclipse experiment, led by Sir Arthur Eddington, where light was shown to bend around the mass of the sun. This experiment was more about general relativity, however the success of general relativity helped to bolster the acceptance of its counterpart, special relativity.

Experimental confirmation also came from the field of atomic physics. The most famous and direct experimental verification came through nuclear reactions in 1932, when James Chadwich discovered the neutron. Subsequent experiments in atomic physics with experiments involving nuclear fission and fusion continued to confirm the validity of E=mc^2.

Another famous experiment that validated special relativity was a time dilation experiment done in 1971 using high precision atomic clocks flown on commercial airlines. By comparing the time measured by the atomic clocks on the airplanes to those on the ground, experimenters confirmed that the clocks on the airplanes ran slightly slower than the stationary clocks on the ground, in accordance with special relativity. Further experiments using particle accelerators and high energy experiments have provided validation by demonstrating the increase in mass and the time dilation of particles moving at relativistic speeds.

By the beginning of the 21st century special relativity has been fully accepted and fully integrated into the fabric of modern physics. It plays a crucial role in the application of many technologies, including the development of GPS, particle accelerators, and nuclear energy.

Continue reading more about the exciting history of science.

Reasons to be an Atheist #1: Science Works

Posted on May 21, 2019March 18, 2024 by Dan

The reasons to be an atheist today are numerous and varied. This article will be the first in a series of articles outlining the many reasons to be an atheist. The first reason to be discussed acknowledges that we have a better system of explaining the world than a religious one. The world is big, complex, and many times confusing. This is one of the reasons people turn to religion, because they feel that religion will provide answers to some of life’s biggest questions. However there is a more accurate system of thought out there that provides these answers and unlike religion, it actually works. It’s called science.

Civilizations have invented thousands of religions over the centuries in an attempt to explain the world around them. After centuries of debate the results of religion are inconclusive on most topics and it’s been a spectacular failure on the rest. As for one popular example, in the early 17th century the Catholic Church forbid Galileo Galilei from teaching the Copernican view of the Solar System that placed the Sun at the center of the system with the Earth and the other planets orbiting around it. According to the church at the time this view was in conflict with the teachings of the Bible. Clearly, the Bible got this basic fact wrong. On the other hand, there is overwhelming evidence that science works very well as a system of thought for explaining the world around us. By adapting a scientific worldview we have no reason to be religious.

Science works because of its method and its commitment to the principles of scientific objectivity. Religion relies on blind faith to reveled prophecy. The two systems of thought for attempting to understand the world couldn’t be more polar opposites. Let’s take a look at why science works by looking at the five steps of the scientific method and the five principles of scientific objectivity.

The Scientific Method

The scientific method consists of five steps.

Making an observation – this involves observing some phenomena that requires an explanation of the phenomena
Asking a question – the purpose here is to identify a specific problem and to narrow the focus of the inquiry
Formulating a hypothesis – the hypothesis is an educated guess that can be tested
Testing the prediction in an experiment – this is the investigation to see if the real world behaves as the hypothesis predicts
Analyzing the result – here is where the conclusion is drawn on whether the evidence supports or rejects the hypothesis

The Scientific Method as an Ongoing Process — The Scientific Method
(Credit: Wikimedia Commons)

Scientific Objectivity

The scientific method works because it is objective. While it is true that scientists are people, and peoples perceptions of the world are subjective, that doesn’t mean that science hasn’t figured a way around that problem to become objective in practice. Scientific objectivity also consists of five principles.

Observability – for something to be scientifically objective it must be observable. This includes things that our senses cannot observe directly but we can observe the effects through equipment such as infrared radiation.
Universality – for something to be scientifically objective it must consider and account for all relevant data.
Self-consistency – all of the observable data must fit into a self consistent pattern to produces accurate results.
Reproducibility – the data must be reproducible by other people.
Debatability – the results must be debatable. The is the error-correcting process in science since individual people make strong emotional attachments to their idea’s or sometimes make mistakes.

The Difference Between Science and Religion in Explaining how the World Works

The scientific method along with its adherence to scientific objectivity provides the strongest tools we have to answering questions about the world around us. The universe works how it works and its up to us to discover how it works. That’s what science does, it discovers how the world works through observation and experimentation. Inventing superstitious religious stories and institutionalizing them over the generations doesn’t prove they must be correct, especially when observation and experimentation say otherwise. There is an enormous wealth of observable evidence that fits into a self consistent pattern that we call the theory of evolution by natural selection and which explains how humans, and all other species, evolved on this planet. There is absolutely no observable evidence for the creation myth of Adam and Eve in the book of Genesis from the Bible.

As the body of scientific knowledge has grown over time it has replaced religious explanations with scientific explanations. Religion still thinks it can provide answers to questions that science can’t yet answer, but that doesn’t mean that science won’t ever answer them. The remarkable progress of scientific knowledge over the past few centuries is one of the strongest reasons to abandon your religion and become an atheist.

Further Reading: Science as a Candle in the Dark by Carl Sagan; The Magic of Reality by Richard Dawkins; The God Delusion by Richard Dawkins; A Devil’s Chaplain by Richard Dawkins; Letter to a Christian Nation by Sam Harris; God and the Folly of Faith: The Incompatibility of Science and Religion by Victor Stenger

1977: Voyager Program

Posted on May 21, 2019January 12, 2024 by Dan

The Voyager Program represents an ambitious undertaking in exploring the boundaries of the Solar System, and beyond. The program consists of two spacecraft, Voyager 1 and Voyager 2, launched by NASA in 1977 in order to probe the four outer planets of the Solar System as well as their moons, rings, and magnetospheres.

Background and Objectives of the Voyager Space Program

The primary objective of the Voyager space program was to complete a comprehensive study of the outer edges of our Solar System. This mission was made possible due to a bit a good luck. Known as The Grand Tour, a rare geometric alignment of the four outer planets that happens roughly once every 175 years allowed for a single mission to fly by all four planets with relative ease.

Originally, the four-planet mission was deemed too expensive and difficult, and the program was only funded to conduct studies of Jupiter and Saturn. and their moons. It was known, however, that fly-by of all four planets was possible. In preparation of the mission over 10,000 trajectories were studied before two were selected that allowed for close fly-by’s of Jupiter and Saturn. The flight trajectory for Voyager 2 also allowed for the option to continue on to Uranus and Neptune.

The Different Instruments of the Voyager Spacecraft
(Credit: Nasa.gov)

The two Voyager spacecraft are identical, each equipped with several instruments used to conduct a variety of experiments. These include television cameras, infrared and ultraviolet sensors, magnetometers, plasma detectors, among other instruments.

In addition to all of its instruments, each Voyager spacecraft carried on it an addition interesting item called the Golden Record. The Golden Record is a 12-inch gold-plated copper disk designed to be playable on a standard phonograph turntable. It was designed to be kind of time capsule, intended to communicate the story of humanity to any extraterrestrial civilization that might come across it. The Golden Record contains a variety of sounds and images intended to portray the diversity of culture on Earth. This includes:

greetings in 55 languages, including both common and lesser-known languages.
a collection of music from different cultures and eras including Bach, Beethoven, Peruvian panpipes and drums, Australian aborigine songs, and more
a variety of natural sounds such as birds, wind, thunder, water waves, and human made sounds such as laughter, a baby’s cry and more.
various images such as human anatomy and DNA, plant and animal landscapes, the Solar System with its planets and more
a “Sounds of Earth” Interstellar Message, featuring a message from President Jimmy Carter and a spoken introduction by Carl Sagan

The Golden Record from the Voyager Space Mission

A committee chaired by the astronomer Carl Sagan was responsible for selecting the content put on the record. The value of the Golden Record is, in Sagan’s own words:

“Billions of years from now our sun, then a distended red giant star, will have reduced Earth to a charred cinder. But the Voyager record will still be largely intact, in some other remote region of the Milky Way galaxy, preserving a murmur of an ancient civilization that once flourished — perhaps before moving on to greater deeds and other worlds — on the distant planet Earth.”
Carl Sagan

The Launch, Voyage and Discoveries

Voyager 2 was launched on August 20,1977 from the NASA Kennedy Space Center at Cape Canaveral, Florida, sixteen days earlier than Voyager 1. The year 1977 provided a rare opportunity where Jupiter, Saturn, Uranus, and Neptune were all in alignment allowing Voyager 2 to fly by each of the four planets. Voyager 1 was on a slightly different trajectory and only flew by Jupiter, Saturn, and Saturn’s largest moon Titan.

Voyager 2’s fly-by of Jupiter and Saturn produced some important discoveries. It provided detailed and close up images of both planets and its moons. While much was learned about each planet, its useful to note one important discovery of Jupiter and Saturn. On its fly-by of Jupiter, Voyager 2 revealed information on its giant red spot such as its size and structure (a complex storm with a diameter greater than the Earth!), dynamics, and its interaction with the surrounding atmosphere. On it’s fly-by of Saturn, Voyager 2 revealed information on its rings such as its structure (close up images revealed the rings are made up of countless, individual particles), dynamics, and various features.

After the success of the Jupiter and Saturn fly-by’s, NASA increased funding for Voyager 2 to fly by Uranus and finally Neptune. Currently both spacecraft are leaving the Solar System as they continue to transmit data back to Earth.

Continue reading more about the exciting history of science!

Richard Dawkins

Posted on May 16, 2019January 23, 2024 by Dan

Richard Dawkins (1941 – present) is an evolutionary biologist known for emphasizing the role of the gene in biological evolution. His 1976 book The Selfish Gene popularized this gene-centered view of evolution.

Richard Dawkins was born in Kenya to two parents very much interested in the natural sciences who cultivated his curiosity in the natural world. At the age of eight his family moved to England where he attended public school before enrolling at Balliol College, Oxford – a constituent college of Oxford University. He was raised in a traditional Anglican upbringing, but by this point in his life he had abandoned Christianity in favor of the scientific worldview.

After a brief teaching job at UC Berkley in the USA, Dawkins returned to the UK in 1970 to be a lecturer at the University of Oxford. In 1976 he published his book The Selfish Gene, a wildly popular book that was effective at both explaining the gene-centered view of evolution to laypeople as well as persuasively convincing other scientists the validity of the idea. Not since Charles Darwin’s revolutionary book On The Origin of Species has a scientific literature been so successful at achieving both of those important ends. Interestingly, Dawkins coined the now famous term meme in this book, a term that has become an icon of internet culture.

Dawkins has gone on to author countless other best-selling science books while working as a professor at the University of Oxford. Since 1970 he has been a fellow of New College, Oxford. In 1995 he was appointed as chair to The Simonyi Professorship for the Public Understanding of Science, a position endowed by Charles Simonyi with the instructions that Richard Dawkins be the first to hold the position. In 2006 he founded the Richard Dawkins Foundation for Reason and Science – a nonprofit science education organization.

More recently, Dawkins has become an outspoken critic of religion, especially of creationism. In 2006 he published his most popular book The God Delusion where he debunks the notion of an intervening God in our universe and where he masterfully illustrates religious faith as a delusion. The book has proven to be provocative to some, yet it has sold over 1 million copies while becoming an international best seller. In public he has been a leading figure in promoting the virtues of atheism while lambasting vices of religion. As of May 2019 Dawkins is currently authoring another book titled Outgrowing God: A Beginner’s Guide to Atheism. It is expected out in September 2019.

1953: The Structure of DNA

Posted on May 8, 2019January 10, 2024 by Dan

In April 1953, Francis Crick and James Watson published a paper in Nature which established the structure of DNA. Their paper was of the most significant discoveries in all of biology, giving rise to the field of molecular biology, while answering the question of how life reproduces itself.

The Hunt for the Hereditary Material

DNA double helix and its nitrogenous bases

In the middle of the 19th century, the Austrian monk Gregor Mendel conducted a series of experiments with pea plants where he established some fundamental principles of hereditary. His pioneering work laid the groundwork for the field of genetics. However, the physical basis for the hereditary material of life remained a mystery for the time being.

In the early 20th century, the search for the hereditary material intensified. The American geneticists Thomas Hunt Morgan conducted important research at Columbia University with the fruit fly Drosophila that advanced our understanding of the role of chromosomes in heredity. Chromosomes were discovered in 1888, four years after the rediscovery of Mendel’s work on pea plants, and it was suspected that they were involved in the passing of hereditary traits. It was observed that patterns of trait transmission corresponded with the movement of chromosomes, an idea became known as the Chromosomal Theory of Inheritance. But in the early 20th century it wasn’t clear how to prove this.

Morgan and his team conducted a breeding and crossbreeding program involving millions of fruit flies, and through this program was able to work out correlations between particular traits and individual chromosomes that showed chromosomes were involved in the passing of genetic material. More specifically, Morgan was able to establish that one of the mutations he found in his fruit flies, a change in eye color, only occurred in males. This could only be explained if the mutation occurred on the male Y chromosome, which Morgan was also able to establish.

Chromosomes are made up mostly of proteins, with a bit of nucleic acid. The search was on the discover the molecule on the that transmitted hereditary material, and the early assumption was that it was a protein. By the 1940s various biological techniques were devised to break down the different biological materials – proteins, lipids, carbohydrates, and nucleic acids – and only when nucleic acids were broken down was the hereditary material not transmitted. However, there was a bias towards assuming that proteins were the hereditary material and more evidence was needed to convince the scientific community.

This evidence came from the experiments of Alfred Hershey and Martha Chase in the early 1950s. They designed an elegant set of experiments using radioactive tracers in viruses. This was accomplished by growing viruses in a solution with different radioactive isotopes, one with radioactive sulfur (a main component of proteins but not found in DNA) to label the protein and one with radioactive phosphorous (a main component of DNA but not found in proteins) to label the DNA. They allowed the labeled viruses to infect a culture of E. coli bacteria and initiate reproduction and then were able to trace which material was responsible for hereditary transmission by a process called centrifugation. The results of this experiment produced strong and convincing evidence that DNA, and not proteins, carried the hereditary material.

This laid the groundwork for the quest of understanding deoxyribonucleic acid or DNA which was now shown as the physical material responsible for carrying hereditary information.

Unraveling the Structure of DNA

By this point in the middle of the 20th century, it was realized by most biologists that a detailed knowledge of the three-dimensional structure of DNA was critical to understanding how the molecule works. This is the classic biological principle that form follows function. Many people were racing towards this inevitable discovery, and indeed Crick and Watson’s work was dependent on the work of others, most notably Rosalind Franklin and her X-ray crystallography. Franklin took a purified DNA crystal and produced the clearest X-ray crystal image to date. On a visit to London, James Watson was able to view this image and working with Crick they were able to deduce some important structural elements from it. First, they learned that the molecule had to form some type of helix. Second, they were able to figure out the width of this helix, which was about two nanometers, or about the size of one nucleotide.

The was one other piece of information was important to determining the structure of DNA. It was observed through experiments that there was a consistent ratio between the nitrogenous bases of the DNA. The amount of adenine always equaled the amount of cytosine, and the amount of guanine always equaled the amount of thymine.

Working with this information, Watson and Crick began building literal models of DNA strands. Through a series of trial and error, they eventually were able to build a model that fit with all of the data. Their model is the famous double helix.

The double helix model that Crick and Watson established contained a few major features. The outside consists of two sugar-phosphate backbones held together by hydrogen bonds, with nitrogenous bases on the inside. There are four types of bases – adenine (A), cytosine (C), guanine (G), thymine (T), with pairing always occurring with A & T and C & G. The copying mechanism works with the helix “unzipping” into two separate strands that act as templates for a new molecule due to the pairing mechanism.

Continue reading more about the exciting history of science!