Physics Introduction Lesson 1 by Owen Borville 11.13.2025
Physics is the study of the nature, properties, and interaction of energy, matter, space, time, and mechanisms of phenomena both qualitatively and quantitatively. Physics involves the qualitative and quantitative description of the mechanics of motion, forces, heat, light, radiation, sound, electricity, magnetism, and the structure of atoms.
The steps of the scientific method are to (1) Observe and ask a question, (2) Conduct research, (3) Formulate a hypothesis, (4) Test the hypothesis with an experiment, (5) Analyze the data, and finally (6) Communicate the results and (7) Draw a conclusion. Scientists may revisit or adjust steps.
Quantitative properties are properties that can be measured. Measured quantities must include units, a standard for expressing and comparing measurements. The English system of units is a traditional system that uses feet, gallons, pounds, etc. The metric system of measurement uses values that are a factor of 10 and includes units such as the meter, liter, kilogram, etc.
The International System of Units (SI Units) was designed as a universal system for all scientists in the world. The seven SI base units are: Length (meter, m), Mass (kilogram, kg), Time (second, s), Electric Current (ampere, A), Temperature (kelvin, K), Amount of Substance (mole, mol), Luminous Intensity (candela, cd).
The Magnitude of Units and their Prefixes:
Tera= T (1x10^12= 12 zeros) (1,000,000,000,000)
Giga= G (1x10^9= 9 zeros) (1,000,000,000)
Mega= M (1x10^6= 6 zeros) (1,000,000)
Kilo= k (1x10^3= 3 zeros) (1,000)
Deci= d (1x10^-1= 1 decimal space) (0.1)
Centi= c (1x10^-2= 2 decimal spaces)(0.01)
Milli= m (1x10^-3)= 3 decimal spaces)(0.001)
Micro= µ (1x10^-6)=6 decimal spaces)(0.000001)
Nano= n (1x10^-9)=9 decimal spaces)(0.000000001)
Pico= p (1x10^-12)=12 decimal spaces)(0.000000000001)
Order of magnitude refers to the size of a quantity as it relates to a power of 10.
Mass is a measure of the amount of matter in an object or sample. The weight of an object can change depending on the location on Earth, but the mass does not change and mass always stays the same. Mass is measured in kilograms or grams in the SI system. 1 kg = 1000 g.
Atomic Mass Unit is used to express the masses of atoms and other similar sized objects. One atomic mass unit = 1 amu = 1.66o5378 x 10^24 grams
Temperature Scales Used in Physics:
The Celsius scale (degrees Celsius) (°C) = the freezing point of pure water = 0°C, boiling point of pure water = 100 °C
The Kelvin scale (K) = the absolute scale and the lowest possible temperature = 0 K (absolute zero)
Conversion equation from Kelvin to Celsius scale = K = °C + 273.15
Fahrenheit scale (degrees Fahrenheit) (°F) = the freezing point of pure water = 32 °F, boiling point of pure water = 212 °F
Celsius to Fahrenheit conversion equations:
(°F) = (°C) x (9/5) + 32
(°C) = (°F - 32) x (5/9)
Therefore, a temperature of 80 (°F) = 26.67 (°C). A temperature of 10 (°C) = 50 (°F)
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Derived Units are units of measurement that are not included in the base SI units but can be calculated using algebraic combinations of the fundamental units. The derived SI unit for volume is the meter cubed or cubic meter (m^3). Another unit for volume is the liter (L).
One decimeter cubed equals one liter. 1 dm ^3 = 1 L
One centimeter cubed equals one milliliter. 1 cm^3 = 1 mL
Density: The density of a substance is equal to the mass of the substance divided by the volume.
density = (mass)/(volume) = d= m/v
Units of density for solids = g/cm^3 (grans per cubic centimeter)
Units of density for liquids = g/mL (grams per milliliter)
Units of density for gases = g/L (grams per liter)
A conversion factor is a ratio of measuring the amount of one unit that is equal to another unit. Conversion factors can be used to change between different unit systems from around the world, including the SI system and the traditional English units. To convert a certain unit value to another, the units are multiplied by a fraction of equal units.
For example, one inch equals 2.54 centimeters. Therefore, to convert a numerical value of inches to centimeters, multiply the number by (2.54 cm/1 inch). The same units cancel out from the numerator to the denominator, so that the final answer in the desired units, centimeters. For example, 10 inches is how many centimeters? 10 inches (2.54 cm/1 inch) Inch units cancel out and the final answer is 25.4 centimeters.
The conversion factor can also be used within a unit system, such as converting 2,000 meters to kilometers. Therefore, 2,000 meters is multiplied by the conversion factor (1 km/1000 meters), so meters cancel out and the final answer is 2 kilometers.
Significant figures are the meaningful digits in a reported number of measurement. Measurements by any method other than counting whole numbers must be rounded to the nearest significant figures. The last digit in a measurement is the uncertain digit. The rules for counting significant figures in a measurement are:
(1) Any nonzero digit is significant. Ex. 125.3 = 4 significant figures
(2) Zeros between nonzero digits are significant. Ex. 208 = 3 significant figures; 7007.05 = 6 significant figures
(3) Zeros to the left of the first nonzero digit are not significant. Ex. 0.0012 = 2 significant figures; 0.0005 = 1 significant figure
(4) Zeros to the right of the last nonzero digit are significant if a decimal is present. Ex. 9.3000 = 5 significant figures
(5) Zeros to the right of the last nonzero digit in a number that does not contain a decimal point may or may not be significant. To avoid confusion, use scientific notation in this case. Ex. 200 = 2 x 10^2 = 1 significant figure; 2.0 x 10^2 = 2 significant figures; Ex. 7.00 x 10^-5 = 0.0000700 = 3 significant figures.
When adding or subtracting numbers, the answer cannot have more digits to the right of the decimal point than any of the original numbers. If adding a number with two digits right of the decimal point to a number with three digits right of the the decimal point, the answer must be rounded to two digits after the decimal point.
When multiplying or dividing numbers, the number of significant digits in the final answer should be the original number of the smallest number of significant figures. In other words, when multiplying a number with two significant digits with a number with four significant digits, the final answer can only have two significant digits and must be rounded accordingly.
When calculating two numbers, one of which is a counted whole number and the other a decimal, the counted whole number does not limit the significant figures of the final answer. Ex. 5 x 3.5 = 17.5.
In calculations with multiple steps, round at the end of the calculation to reduce any rounding errors. Ex. 4.29 x 8.76 = 37.5804. Final step. 37.5804 x 5.42 = 204.
Accuracy and Precision in Measurement: Accuracy is how close a measurement is to the true value. Precision is how close a series of multiple measurements are to each other. Therefore if a series of measurements are not close to the true value, but each measurement is close to each other, the measurements are precise but not accurate. The measurements can be accurate but not precise if all of the measurements are near the true value but are scattered in different positions or values. Accurate and precise measurements will all be near the true value and all near the same position or value. Neither accurate or precise measurements will not be near the true value and each measurement will be in different positions or measured values.
Uncertainty is a quantitative measure of how much your measured values deviate from the standard or expected value. Percent uncertainty is the ratio of uncertainty of a measurement to the measured value, expressed as a percentage. The method of adding percent of the precent uncertainty in a quantity calculated by multiplication or division is the sum of the percent uncertainties in the items used to make the calculation. An approximation is an estimated value based on prior experience and reasoning.
A conversion factor is a fraction in the same quantity is expressed one way in the numerator and another way in the denominator. Ex. If one meter is equal to 3.3 feet, then the conversion factor can be either (1 m/3.3 ft) or (3.3 ft/1 m). This conversion factor can be used to convert measurements from feet to meters or vice-versa.
Using dimensional analysis or the factor-label method, the units of original value must be in the denominator of the conversion factor in order to cancel out units. Ex. To convert 6.0 feet to meters, use the conversion factor where meters is in the denominator in order to cancel out units. Therefore, 6.0 ft multiplied by (1 m/3.3 ft), the feet cancel out and 6.0 is divided by 3.3 ft to obtain the answer = 1.8288=1.8 meters (round to 2 significant figures).
Classification of Matter:
A substance is a form of matter that has a definite composition and distinct properties. Substances can be a compound or a single chemical element. Substances are distinguished from each other by composition and may have unique appearance, smell, taste, or other properties. Ex. gold, silver, oxygen, iron, water (H2O), carbon dioxide (CO2), silica or silicon dioxide (SiO2), hydrogen (H2), carbon monoxide (CO).
A mixture is a physical combination of two or more substances. A homogeneous mixture is uniform throughout the mixture (also called a solution). Ex. saltwater, air, vinegar, steel, bronze, coffee. A heterogeneous mixture is not uniform throughout the mixture and the different parts are visible, while the composition of each sample will vary. Ex. oil and water, cereal in milk, sand and water, soil, concrete.
Solid forms of matter contain particles that are held tightly in an ordered pattern. Solid matter does not conform to the shape of its container. Liquid forms of matter are made of particles that are close together but are not held tightly in position. Liquid particles also conform to the shape of their container. Gas forms of matter have particles that have have large separation between each particle and the particles move freely to fit its container. Gas particles conform to both the shape and volume of its container.
All substances can exist as a solid, liquid, or a gas state. The state of the substance can be converted or changed without changing the identity of the substance.
A mixture can be separated by physical means into its components without changing the identities of the components.
Quantitative properties of matter can be measured and expressed with a number. Qualitative properties do not require measurement and are usually based on observation.
A physical property is one that can be observed and measured without changing the identity of the substance. Ex. color, odor, density, melting point, boiling point, electrical conductivity, hardness, solubility, and the state of matter of solid, liquid, or gas.
A physical change is one in which the state of matter changes, but the identity of the matter does not change, such as during changes of state of matter. (Ex. melting, freezing, boiling, condensation). In addition, cutting or crushing a substance, or dissolving a substance in water are physical changes. When mixtures are separated, the identity of the matter does not change.
A chemical property is a property of a substance when it interacts with another substance. Ex. flammability, toxicity, corrosiveness (rust), reactivity, and radioactivity.
A chemical change is one that results in a change in composition of a substance and the original substances no longer exist. Ex. oxidation, burning a substance, rusting or corrosion of iron, apple browning, cooking eggs, milk souring, and food digestion in the body.
Extensive properties of matter depend on the amount of matter, such as mass and volume. Intensive properties of matter do not depend on the amount of matter, such as temperature and density.
A constant in science is a quantity that does not change under specific conditions, such a universal physical constants on Earth or control variables in experiments.
A theory is an explanation of a pattern or phenomenon in nature that is supported by scientific evidence and verified multiple times by a variety of credentialled scientists. A law in physics and science is a qualitative or quantitative description or pattern in nature that is supported by very much scientific evidence and experimentation. A model is a representation of an idea in physics or science qualitatively or quantitatively that is too difficult to show directly.
Physics is related to many other scientific fields and has many applications. Physics and chemistry are both concerned with the interactions of atoms and molecules, atomic and molecular structure. Engineering deals with applied concepts of the physics of materials used to make life more convenient for mankind, such as mechanical machines and electronics. Architecture deals with structural stability of buildings, along with the acoustics, heating, cooling, and lighting of the buildings. Geology, geoscience, and environmental science also use the concepts of physics to study radioactivity in rocks, pollution and water resources, earthquake movements, landslides on the Earth's surface, and heat transfer inside the Earth. Geologists and geophysicists use the concepts of physics to search for economic resources inside the Earth. Atmospheric scientists use the concepts of physics to study weather patterns and to predict future weather patterns that affect mankind. Biology and medicine uses physics to study the structure and physiology of cells, tissues, and body organs and systems. Physics is also used in creating new technology to study the body of humans, animals, and living things through x-rays, MRI, and ultrasound along with radiotherapy.
The field of physics fulfills the Biblical Creation Mandate to use the resources of the Earth to benefit mankind, in addition to being good stewards of the Earth (Book of Genesis 1:28, 9:1-20).
Classical physics was physics that developed from ancient times by natural philosophers until the end of the 19th century that focused on classical mechanics and forces of objects on Earth and our Solar System. Modern physics began in the 20th century and is focused on the study of atomic and subatomic particle theory, quantum mechanics (of the invisible), and relativity (objects approaching the speed of light or a strong gravitational field).
Physics grew from ancient natural philosophy into a rigorous experimental and mathematical science, passing key milestones such as Newtonian mechanics, Maxwell’s electromagnetism, and the 20th‑century revolutions of relativity and quantum theory.
Antiquity and Classical: Greek to Medieval Early physics began as natural philosophy: thinkers like Thales, Democritus, Aristotle, and Archimedes framed questions about matter, motion, and forces, and produced the first systematic accounts of nature. Observational astronomy and geometric models (Ptolemaic astronomy) guided practical and theoretical work through antiquity and into the medieval period, where Islamic and later European scholars preserved, critiqued, and extended classical ideas.
16th-17th Century Scientific Revolution: Mechanics of Motion and Gravitation From the 16th to 17th centuries the field transformed. Copernicus’ heliocentrism, Galileo’s experiments on motion, Kepler’s planetary laws, and Newton’s 1687 Principia—which formulated the laws of motion and universal gravitation—created a predictive, mathematical framework for mechanics and celestial motion that dominated for two centuries.
19th Century: Thermodynamics and Electromagnetism The 1800s saw major unifications and new laws: the laws of thermodynamics formalized energy and heat; Dalton’s atomic theory revived atomism; and Maxwell’s equations unified electricity and magnetism into classical electromagnetism, predicting light as an electromagnetic wave. Experimental advances (Faraday, Coulomb, Young, Fresnel) and the industrial context accelerated both theory and application.
20th Century and Modern Physics The 20th century produced two paradigm shifts: Einstein’s special (1905) and general relativity (1915) reworked space, time, and gravity, while quantum theory (Planck, Bohr, Heisenberg, Schrödinger) replaced classical ideas at atomic scales. These developments led to quantum field theory, the Standard Model of particle physics, and modern cosmology (Big Bang framework), and opened active frontiers such as quantum gravity, dark matter, and dark energy.
Physics today is a diverse, experimental and theoretical enterprise spanning scales from subatomic particles to the cosmos, and from applied condensed‑matter research to foundational questions about spacetime and information.
Physics is the study of the nature, properties, and interaction of energy, matter, space, time, and mechanisms of phenomena both qualitatively and quantitatively. Physics involves the qualitative and quantitative description of the mechanics of motion, forces, heat, light, radiation, sound, electricity, magnetism, and the structure of atoms.
The steps of the scientific method are to (1) Observe and ask a question, (2) Conduct research, (3) Formulate a hypothesis, (4) Test the hypothesis with an experiment, (5) Analyze the data, and finally (6) Communicate the results and (7) Draw a conclusion. Scientists may revisit or adjust steps.
Quantitative properties are properties that can be measured. Measured quantities must include units, a standard for expressing and comparing measurements. The English system of units is a traditional system that uses feet, gallons, pounds, etc. The metric system of measurement uses values that are a factor of 10 and includes units such as the meter, liter, kilogram, etc.
The International System of Units (SI Units) was designed as a universal system for all scientists in the world. The seven SI base units are: Length (meter, m), Mass (kilogram, kg), Time (second, s), Electric Current (ampere, A), Temperature (kelvin, K), Amount of Substance (mole, mol), Luminous Intensity (candela, cd).
The Magnitude of Units and their Prefixes:
Tera= T (1x10^12= 12 zeros) (1,000,000,000,000)
Giga= G (1x10^9= 9 zeros) (1,000,000,000)
Mega= M (1x10^6= 6 zeros) (1,000,000)
Kilo= k (1x10^3= 3 zeros) (1,000)
Deci= d (1x10^-1= 1 decimal space) (0.1)
Centi= c (1x10^-2= 2 decimal spaces)(0.01)
Milli= m (1x10^-3)= 3 decimal spaces)(0.001)
Micro= µ (1x10^-6)=6 decimal spaces)(0.000001)
Nano= n (1x10^-9)=9 decimal spaces)(0.000000001)
Pico= p (1x10^-12)=12 decimal spaces)(0.000000000001)
Order of magnitude refers to the size of a quantity as it relates to a power of 10.
Mass is a measure of the amount of matter in an object or sample. The weight of an object can change depending on the location on Earth, but the mass does not change and mass always stays the same. Mass is measured in kilograms or grams in the SI system. 1 kg = 1000 g.
Atomic Mass Unit is used to express the masses of atoms and other similar sized objects. One atomic mass unit = 1 amu = 1.66o5378 x 10^24 grams
Temperature Scales Used in Physics:
The Celsius scale (degrees Celsius) (°C) = the freezing point of pure water = 0°C, boiling point of pure water = 100 °C
The Kelvin scale (K) = the absolute scale and the lowest possible temperature = 0 K (absolute zero)
Conversion equation from Kelvin to Celsius scale = K = °C + 273.15
Fahrenheit scale (degrees Fahrenheit) (°F) = the freezing point of pure water = 32 °F, boiling point of pure water = 212 °F
Celsius to Fahrenheit conversion equations:
(°F) = (°C) x (9/5) + 32
(°C) = (°F - 32) x (5/9)
Therefore, a temperature of 80 (°F) = 26.67 (°C). A temperature of 10 (°C) = 50 (°F)
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Derived Units are units of measurement that are not included in the base SI units but can be calculated using algebraic combinations of the fundamental units. The derived SI unit for volume is the meter cubed or cubic meter (m^3). Another unit for volume is the liter (L).
One decimeter cubed equals one liter. 1 dm ^3 = 1 L
One centimeter cubed equals one milliliter. 1 cm^3 = 1 mL
Density: The density of a substance is equal to the mass of the substance divided by the volume.
density = (mass)/(volume) = d= m/v
Units of density for solids = g/cm^3 (grans per cubic centimeter)
Units of density for liquids = g/mL (grams per milliliter)
Units of density for gases = g/L (grams per liter)
A conversion factor is a ratio of measuring the amount of one unit that is equal to another unit. Conversion factors can be used to change between different unit systems from around the world, including the SI system and the traditional English units. To convert a certain unit value to another, the units are multiplied by a fraction of equal units.
For example, one inch equals 2.54 centimeters. Therefore, to convert a numerical value of inches to centimeters, multiply the number by (2.54 cm/1 inch). The same units cancel out from the numerator to the denominator, so that the final answer in the desired units, centimeters. For example, 10 inches is how many centimeters? 10 inches (2.54 cm/1 inch) Inch units cancel out and the final answer is 25.4 centimeters.
The conversion factor can also be used within a unit system, such as converting 2,000 meters to kilometers. Therefore, 2,000 meters is multiplied by the conversion factor (1 km/1000 meters), so meters cancel out and the final answer is 2 kilometers.
Significant figures are the meaningful digits in a reported number of measurement. Measurements by any method other than counting whole numbers must be rounded to the nearest significant figures. The last digit in a measurement is the uncertain digit. The rules for counting significant figures in a measurement are:
(1) Any nonzero digit is significant. Ex. 125.3 = 4 significant figures
(2) Zeros between nonzero digits are significant. Ex. 208 = 3 significant figures; 7007.05 = 6 significant figures
(3) Zeros to the left of the first nonzero digit are not significant. Ex. 0.0012 = 2 significant figures; 0.0005 = 1 significant figure
(4) Zeros to the right of the last nonzero digit are significant if a decimal is present. Ex. 9.3000 = 5 significant figures
(5) Zeros to the right of the last nonzero digit in a number that does not contain a decimal point may or may not be significant. To avoid confusion, use scientific notation in this case. Ex. 200 = 2 x 10^2 = 1 significant figure; 2.0 x 10^2 = 2 significant figures; Ex. 7.00 x 10^-5 = 0.0000700 = 3 significant figures.
When adding or subtracting numbers, the answer cannot have more digits to the right of the decimal point than any of the original numbers. If adding a number with two digits right of the decimal point to a number with three digits right of the the decimal point, the answer must be rounded to two digits after the decimal point.
When multiplying or dividing numbers, the number of significant digits in the final answer should be the original number of the smallest number of significant figures. In other words, when multiplying a number with two significant digits with a number with four significant digits, the final answer can only have two significant digits and must be rounded accordingly.
When calculating two numbers, one of which is a counted whole number and the other a decimal, the counted whole number does not limit the significant figures of the final answer. Ex. 5 x 3.5 = 17.5.
In calculations with multiple steps, round at the end of the calculation to reduce any rounding errors. Ex. 4.29 x 8.76 = 37.5804. Final step. 37.5804 x 5.42 = 204.
Accuracy and Precision in Measurement: Accuracy is how close a measurement is to the true value. Precision is how close a series of multiple measurements are to each other. Therefore if a series of measurements are not close to the true value, but each measurement is close to each other, the measurements are precise but not accurate. The measurements can be accurate but not precise if all of the measurements are near the true value but are scattered in different positions or values. Accurate and precise measurements will all be near the true value and all near the same position or value. Neither accurate or precise measurements will not be near the true value and each measurement will be in different positions or measured values.
Uncertainty is a quantitative measure of how much your measured values deviate from the standard or expected value. Percent uncertainty is the ratio of uncertainty of a measurement to the measured value, expressed as a percentage. The method of adding percent of the precent uncertainty in a quantity calculated by multiplication or division is the sum of the percent uncertainties in the items used to make the calculation. An approximation is an estimated value based on prior experience and reasoning.
A conversion factor is a fraction in the same quantity is expressed one way in the numerator and another way in the denominator. Ex. If one meter is equal to 3.3 feet, then the conversion factor can be either (1 m/3.3 ft) or (3.3 ft/1 m). This conversion factor can be used to convert measurements from feet to meters or vice-versa.
Using dimensional analysis or the factor-label method, the units of original value must be in the denominator of the conversion factor in order to cancel out units. Ex. To convert 6.0 feet to meters, use the conversion factor where meters is in the denominator in order to cancel out units. Therefore, 6.0 ft multiplied by (1 m/3.3 ft), the feet cancel out and 6.0 is divided by 3.3 ft to obtain the answer = 1.8288=1.8 meters (round to 2 significant figures).
Classification of Matter:
A substance is a form of matter that has a definite composition and distinct properties. Substances can be a compound or a single chemical element. Substances are distinguished from each other by composition and may have unique appearance, smell, taste, or other properties. Ex. gold, silver, oxygen, iron, water (H2O), carbon dioxide (CO2), silica or silicon dioxide (SiO2), hydrogen (H2), carbon monoxide (CO).
A mixture is a physical combination of two or more substances. A homogeneous mixture is uniform throughout the mixture (also called a solution). Ex. saltwater, air, vinegar, steel, bronze, coffee. A heterogeneous mixture is not uniform throughout the mixture and the different parts are visible, while the composition of each sample will vary. Ex. oil and water, cereal in milk, sand and water, soil, concrete.
Solid forms of matter contain particles that are held tightly in an ordered pattern. Solid matter does not conform to the shape of its container. Liquid forms of matter are made of particles that are close together but are not held tightly in position. Liquid particles also conform to the shape of their container. Gas forms of matter have particles that have have large separation between each particle and the particles move freely to fit its container. Gas particles conform to both the shape and volume of its container.
All substances can exist as a solid, liquid, or a gas state. The state of the substance can be converted or changed without changing the identity of the substance.
A mixture can be separated by physical means into its components without changing the identities of the components.
Quantitative properties of matter can be measured and expressed with a number. Qualitative properties do not require measurement and are usually based on observation.
A physical property is one that can be observed and measured without changing the identity of the substance. Ex. color, odor, density, melting point, boiling point, electrical conductivity, hardness, solubility, and the state of matter of solid, liquid, or gas.
A physical change is one in which the state of matter changes, but the identity of the matter does not change, such as during changes of state of matter. (Ex. melting, freezing, boiling, condensation). In addition, cutting or crushing a substance, or dissolving a substance in water are physical changes. When mixtures are separated, the identity of the matter does not change.
A chemical property is a property of a substance when it interacts with another substance. Ex. flammability, toxicity, corrosiveness (rust), reactivity, and radioactivity.
A chemical change is one that results in a change in composition of a substance and the original substances no longer exist. Ex. oxidation, burning a substance, rusting or corrosion of iron, apple browning, cooking eggs, milk souring, and food digestion in the body.
Extensive properties of matter depend on the amount of matter, such as mass and volume. Intensive properties of matter do not depend on the amount of matter, such as temperature and density.
A constant in science is a quantity that does not change under specific conditions, such a universal physical constants on Earth or control variables in experiments.
A theory is an explanation of a pattern or phenomenon in nature that is supported by scientific evidence and verified multiple times by a variety of credentialled scientists. A law in physics and science is a qualitative or quantitative description or pattern in nature that is supported by very much scientific evidence and experimentation. A model is a representation of an idea in physics or science qualitatively or quantitatively that is too difficult to show directly.
Physics is related to many other scientific fields and has many applications. Physics and chemistry are both concerned with the interactions of atoms and molecules, atomic and molecular structure. Engineering deals with applied concepts of the physics of materials used to make life more convenient for mankind, such as mechanical machines and electronics. Architecture deals with structural stability of buildings, along with the acoustics, heating, cooling, and lighting of the buildings. Geology, geoscience, and environmental science also use the concepts of physics to study radioactivity in rocks, pollution and water resources, earthquake movements, landslides on the Earth's surface, and heat transfer inside the Earth. Geologists and geophysicists use the concepts of physics to search for economic resources inside the Earth. Atmospheric scientists use the concepts of physics to study weather patterns and to predict future weather patterns that affect mankind. Biology and medicine uses physics to study the structure and physiology of cells, tissues, and body organs and systems. Physics is also used in creating new technology to study the body of humans, animals, and living things through x-rays, MRI, and ultrasound along with radiotherapy.
The field of physics fulfills the Biblical Creation Mandate to use the resources of the Earth to benefit mankind, in addition to being good stewards of the Earth (Book of Genesis 1:28, 9:1-20).
Classical physics was physics that developed from ancient times by natural philosophers until the end of the 19th century that focused on classical mechanics and forces of objects on Earth and our Solar System. Modern physics began in the 20th century and is focused on the study of atomic and subatomic particle theory, quantum mechanics (of the invisible), and relativity (objects approaching the speed of light or a strong gravitational field).
Physics grew from ancient natural philosophy into a rigorous experimental and mathematical science, passing key milestones such as Newtonian mechanics, Maxwell’s electromagnetism, and the 20th‑century revolutions of relativity and quantum theory.
Antiquity and Classical: Greek to Medieval Early physics began as natural philosophy: thinkers like Thales, Democritus, Aristotle, and Archimedes framed questions about matter, motion, and forces, and produced the first systematic accounts of nature. Observational astronomy and geometric models (Ptolemaic astronomy) guided practical and theoretical work through antiquity and into the medieval period, where Islamic and later European scholars preserved, critiqued, and extended classical ideas.
16th-17th Century Scientific Revolution: Mechanics of Motion and Gravitation From the 16th to 17th centuries the field transformed. Copernicus’ heliocentrism, Galileo’s experiments on motion, Kepler’s planetary laws, and Newton’s 1687 Principia—which formulated the laws of motion and universal gravitation—created a predictive, mathematical framework for mechanics and celestial motion that dominated for two centuries.
19th Century: Thermodynamics and Electromagnetism The 1800s saw major unifications and new laws: the laws of thermodynamics formalized energy and heat; Dalton’s atomic theory revived atomism; and Maxwell’s equations unified electricity and magnetism into classical electromagnetism, predicting light as an electromagnetic wave. Experimental advances (Faraday, Coulomb, Young, Fresnel) and the industrial context accelerated both theory and application.
20th Century and Modern Physics The 20th century produced two paradigm shifts: Einstein’s special (1905) and general relativity (1915) reworked space, time, and gravity, while quantum theory (Planck, Bohr, Heisenberg, Schrödinger) replaced classical ideas at atomic scales. These developments led to quantum field theory, the Standard Model of particle physics, and modern cosmology (Big Bang framework), and opened active frontiers such as quantum gravity, dark matter, and dark energy.
Physics today is a diverse, experimental and theoretical enterprise spanning scales from subatomic particles to the cosmos, and from applied condensed‑matter research to foundational questions about spacetime and information.