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72-597: John Francis Clauser ( / ˈ k l aʊ z ər / ; born December 1, 1942) is an American theoretical and experimental physicist known for contributions to the foundations of quantum mechanics , in particular the Clauser–Horne–Shimony–Holt inequality . Clauser was awarded the 2022 Nobel Prize in Physics , jointly with Alain Aspect and Anton Zeilinger "for experiments with entangled photons, establishing

144-435: A mathematical theory , in the sense that the word "theory" has a different meaning in mathematical terms. R i c = k g {\displaystyle \mathrm {Ric} =kg} The equations for an Einstein manifold , used in general relativity to describe the curvature of spacetime A physical theory involves one or more relationships between various measurable quantities. Archimedes realized that

216-560: A working hypothesis . Carbon dioxide emissions Greenhouse gas ( GHG ) emissions from human activities intensify the greenhouse effect . This contributes to climate change . Carbon dioxide (CO 2 ), from burning fossil fuels such as coal , oil , and natural gas , is one of the most important factors in causing climate change. The largest emitters are China followed by the United States. The United States has higher emissions per capita . The main producers fueling

288-404: A certain economy and elegance (compare to mathematical beauty ), a notion sometimes called " Occam's razor " after the 13th-century English philosopher William of Occam (or Ockham), in which the simpler of two theories that describe the same matter just as adequately is preferred (but conceptual simplicity may mean mathematical complexity). They are also more likely to be accepted if they connect

360-570: A decade or so, and nitrous oxides last about 100 years. The graph gives some indication of which regions have contributed most to human-induced climate change. When these numbers are calculated per capita cumulative emissions based on then-current population the situation is shown even more clearly. The ratio in per capita emissions between industrialized countries and developing countries was estimated at more than 10 to 1. Non- OECD countries accounted for 42% of cumulative energy-related CO 2 emissions between 1890 and 2007. Over this time period,

432-500: A form of protoscience and others are a form of pseudoscience . The falsification of the original theory sometimes leads to reformulation of the theory. "Thought" experiments are situations created in one's mind, asking a question akin to "suppose you are in this situation, assuming such is true, what would follow?". They are usually created to investigate phenomena that are not readily experienced in every-day situations. Famous examples of such thought experiments are Schrödinger's cat ,

504-634: A generalization of Bell's Theorem provides severe constraints for all local realistic theories of nature (a.k.a. objective local theories). That work introduced the Clauser–Horne (CH) inequality as the first fully general experimental requirement set by local realism. It also introduced the "CH no-enhancement assumption", whereupon the CH inequality reduces to the CHSH inequality, and whereupon associated experimental tests also constrain local realism. Also in 1974 he made

576-766: A good example. For instance: " phenomenologists " might employ ( semi- ) empirical formulas and heuristics to agree with experimental results, often without deep physical understanding . "Modelers" (also called "model-builders") often appear much like phenomenologists, but try to model speculative theories that have certain desirable features (rather than on experimental data), or apply the techniques of mathematical modeling to physics problems. Some attempt to create approximate theories, called effective theories , because fully developed theories may be regarded as unsolvable or too complicated . Other theorists may try to unify , formalise, reinterpret or generalise extant theories, or create completely new ones altogether. Sometimes

648-517: A lack of comparability, which is problematic when monitoring progress towards targets. There are arguments for the adoption of a common measurement tool, or at least the development of communication between different tools. Emissions may be tracked over long time periods, known as historical or cumulative emissions measurements. Cumulative emissions provide some indicators of what is responsible for greenhouse gas atmospheric concentration build-up. The national accounts balance tracks emissions based on

720-498: A new branch of mathematics: infinite, orthogonal series . Modern theoretical physics attempts to unify theories and explain phenomena in further attempts to understand the Universe , from the cosmological to the elementary particle scale. Where experimentation cannot be done, theoretical physics still tries to advance through the use of mathematical models. Mainstream theories (sometimes referred to as central theories ) are

792-862: A particular base year. Choosing between base years of 1750, 1900, 1950, and 1990 has a significant effect for most countries. Within the G8 group of countries, it is most significant for the UK, France and Germany. These countries have a long history of CO 2 emissions (see the section on Cumulative and historical emissions ). The Global Carbon Project continuously releases data about CO 2 emissions, budget and concentration. and industry (excluding cement carbonation) Gt C change Gt C Gt C Gt CO 2 (projection) Distribution of global greenhouse gas emissions based on type of greenhouse gas, without land-use change, using 100 year global warming potential (data from 2020). Total: 49.8 GtCO 2 e Carbon dioxide (CO 2 )

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864-527: A postdoctoral researcher at the University of California, Berkeley and Lawrence Berkeley National Laboratory . In 1972, working with Berkeley graduate student Stuart Freedman , he carried out the first experimental test of the CHSH- Bell's theorem predictions. This was the first experimental observation of a violation of a Bell inequality. In 1974, working with Michael Horne , he first showed that

936-498: A ship floats by displacing its mass of water, Pythagoras understood the relation between the length of a vibrating string and the musical tone it produces. Other examples include entropy as a measure of the uncertainty regarding the positions and motions of unseen particles and the quantum mechanical idea that ( action and) energy are not continuously variable. Theoretical physics consists of several different approaches. In this regard, theoretical particle physics forms

1008-483: A significant contributor to warming. Although CFCs are greenhouse gases, they are regulated by the Montreal Protocol which was motivated by CFCs' contribution to ozone depletion rather than by their contribution to global warming. Ozone depletion has only a minor role in greenhouse warming, though the two processes are sometimes confused in the media. In 2016, negotiators from over 170 nations meeting at

1080-461: A significant margin, Asia's and the world's largest emitter: it emits nearly 10 billion tonnes each year, more than one-quarter of global emissions. Other countries with fast growing emissions are South Korea , Iran, and Australia (which apart from the oil rich Persian Gulf states, now has the highest per capita emission rate in the world). On the other hand, annual per capita emissions of the EU-15 and

1152-469: A wide range of phenomena. Testing the consequences of a theory is part of the scientific method . Physical theories can be grouped into three categories: mainstream theories , proposed theories and fringe theories . Theoretical physics began at least 2,300 years ago, under the Pre-socratic philosophy , and continued by Plato and Aristotle , whose views held sway for a millennium. During

1224-450: Is a framework of methods to measure and track how much greenhouse gas an organization emits. Cumulative anthropogenic (i.e., human-emitted) emissions of CO 2 from fossil fuel use are a major cause of global warming , and give some indication of which countries have contributed most to human-induced climate change. In particular, CO 2 stays in the atmosphere for at least 150 years and up to 1000 years, whilst methane disappears within

1296-497: Is a model of physical events. It is judged by the extent to which its predictions agree with empirical observations. The quality of a physical theory is also judged on its ability to make new predictions which can be verified by new observations. A physical theory differs from a mathematical theorem in that while both are based on some form of axioms , judgment of mathematical applicability is not based on agreement with any experimental results. A physical theory similarly differs from

1368-642: Is contradicted by the overwhelming scientific consensus on climate change . Observational evidence shows the overall current cloud feedback amplifies global warming and does not have a cooling effect. Clauser is an atheist . He has emphysema due to smoking cigarettes in his youth. Theoretical physics The advancement of science generally depends on the interplay between experimental studies and theory . In some cases, theoretical physics adheres to standards of mathematical rigour while giving little weight to experiments and observations. For example, while developing special relativity , Albert Einstein

1440-421: Is exported. In comparison, methane has not increased appreciably, and N 2 O by 0.25% y . Using different base years for measuring emissions has an effect on estimates of national contributions to global warming. This can be calculated by dividing a country's highest contribution to global warming starting from a particular base year, by that country's minimum contribution to global warming starting from

1512-633: Is responsible for around 73% of emissions. Deforestation and other changes in land use also emit carbon dioxide and methane . The largest source of anthropogenic methane emissions is agriculture , closely followed by gas venting and fugitive emissions from the fossil-fuel industry . The largest agricultural methane source is livestock . Agricultural soils emit nitrous oxide partly due to fertilizers . Similarly, fluorinated gases from refrigerants play an outsized role in total human emissions. The current CO 2 -equivalent emission rates averaging 6.6 tonnes per person per year, are well over twice

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1584-454: Is the dominant emitted greenhouse gas, while methane ( CH 4 ) emissions almost have the same short-term impact. Nitrous oxide (N 2 O) and fluorinated gases (F-gases) play a lesser role in comparison. Greenhouse gas emissions are measured in CO 2 equivalents determined by their global warming potential (GWP), which depends on their lifetime in the atmosphere. Estimations largely depend on

1656-563: Is the first major source of greenhouse gas emissions from transportation, followed by aircraft and maritime. Waterborne transportation is still the least carbon-intensive mode of transportation on average, and it is an essential link in sustainable multimodal freight supply chains . Buildings, like industry, are directly responsible for around one-fifth of greenhouse gas emissions, primarily from space heating and hot water consumption. When combined with power consumption within buildings, this figure climbs to more than one-third. Within

1728-449: Is the main greenhouse gas resulting from human activities. It accounts for more than half of warming. Methane (CH 4 ) emissions have almost the same short-term impact. Nitrous oxide (N 2 O) and fluorinated gases (F-gases) play a lesser role in comparison. Emissions of carbon dioxide, methane and nitrous oxide in 2023 were all higher than ever before. Electricity generation , heat and transport are major emitters; overall energy

1800-665: Is very complex, and is affected by how carbon sinks are allocated between regions and the dynamics of the climate system . The graphic shows the logarithm of 1850–2019 fossil fuel CO 2 emissions; natural log on left, actual value of Gigatons per year on right. Although emissions increased during the 170-year period by about 3% per year overall, intervals of distinctly different growth rates (broken at 1913, 1945, and 1973) can be detected. The regression lines suggest that emissions can rapidly shift from one growth regime to another and then persist for long periods of time. The most recent drop in emissions growth – by almost 3 percentage points –

1872-539: The EPR thought experiment , simple illustrations of time dilation , and so on. These usually lead to real experiments designed to verify that the conclusion (and therefore the assumptions) of the thought experiments are correct. The EPR thought experiment led to the Bell inequalities , which were then tested to various degrees of rigor , leading to the acceptance of the current formulation of quantum mechanics and probabilism as

1944-572: The Scientific Revolution gathered pace, the concepts of matter , energy, space, time and causality slowly began to acquire the form we know today, and other sciences spun off from the rubric of natural philosophy . Thus began the modern era of theory with the Copernican paradigm shift in astronomy, soon followed by Johannes Kepler 's expressions for planetary orbits, which summarized the meticulous observations of Tycho Brahe ;

2016-568: The philosophy of quantum mechanics . Clauser worked as a research physicist mainly at Lawrence Livermore and Berkeley from 1975 to 1997. In 1976 he carried out the world's second experimental test of the CHSH-Bell's Theorem predictions. Clauser was awarded the Wolf Prize in Physics in 2010 together with Alain Aspect and Anton Zeilinger . The three were also jointly awarded the 2022 Nobel Prize in Physics . In May 2023, Clauser joined

2088-461: The two-fluid theory of electricity are two cases in this point. However, an exception to all the above is the wave–particle duality , a theory combining aspects of different, opposing models via the Bohr complementarity principle . Physical theories become accepted if they are able to make correct predictions and no (or few) incorrect ones. The theory should have, at least as a secondary objective,

2160-429: The 19th century. Another important event in the 19th century was the discovery of electromagnetic theory , unifying the previously separate phenomena of electricity, magnetism and light. The pillars of modern physics , and perhaps the most revolutionary theories in the history of physics, have been relativity theory and quantum mechanics . Newtonian mechanics was subsumed under special relativity and Newton's gravity

2232-520: The 2030 Paris Agreement increase of 1.5 °C (2.7 °F) over pre-industrial levels. While cities are sometimes considered to be disproportionate contributors to emissions, per-capita emissions tend to be lower for cities than the averages in their countries. A 2017 survey of corporations responsible for global emissions found that 100 companies were responsible for 71% of global direct and indirect emissions , and that state-owned companies were responsible for 59% of their emissions. China is, by

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2304-476: The Dutchmen Snell and Huygens. In the 18th and 19th centuries Joseph-Louis Lagrange , Leonhard Euler and William Rowan Hamilton would extend the theory of classical mechanics considerably. They picked up the interactive intertwining of mathematics and physics begun two millennia earlier by Pythagoras. Among the great conceptual achievements of the 19th and 20th centuries were the consolidation of

2376-498: The EU, the agricultural sector presently accounts for roughly 10% of total greenhouse gas emissions, with methane from livestock accounting for slightly more than half of 10%. Estimates of total CO 2 emissions do include biotic carbon emissions, mainly from deforestation. Including biotic emissions brings about the same controversy mentioned earlier regarding carbon sinks and land-use change. The actual calculation of net emissions

2448-587: The Earth ) or may be an alternative model that provides answers that are more accurate or that can be more widely applied. In the latter case, a correspondence principle will be required to recover the previously known result . Sometimes though, advances may proceed along different paths. For example, an essentially correct theory may need some conceptual or factual revisions; atomic theory , first postulated millennia ago (by several thinkers in Greece and India ) and

2520-474: The Earth can cool off. The major anthropogenic (human origin) sources of greenhouse gases are carbon dioxide (CO 2 ), nitrous oxide ( N 2 O ), methane and three groups of fluorinated gases ( sulfur hexafluoride ( SF 6 ), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs, sulphur hexafluoride (SF 6 ), and nitrogen trifluoride (NF 3 )). Though the greenhouse effect is heavily driven by water vapor , human emissions of water vapor are not

2592-718: The US accounted for 28% of emissions; the EU, 23%; Japan, 4%; other OECD countries 5%; Russia, 11%; China, 9%; India, 3%; and the rest of the world, 18%. The European Commission adopted a set of legislative proposals targeting a reduction of the CO 2 emissions by 55% by 2030. Overall, developed countries accounted for 83.8% of industrial CO 2 emissions over this time period, and 67.8% of total CO 2 emissions. Developing countries accounted for industrial CO 2 emissions of 16.2% over this time period, and 32.2% of total CO 2 emissions. However, what becomes clear when we look at emissions across

2664-552: The US are gradually decreasing over time. Emissions in Russia and Ukraine have decreased fastest since 1990 due to economic restructuring in these countries. 2015 was the first year to see both total global economic growth and a reduction of carbon emissions. Annual per capita emissions in the industrialized countries are typically as much as ten times the average in developing countries. Due to China's fast economic development, its annual per capita emissions are quickly approaching

2736-419: The ability of oceans and land sinks to absorb these gases. Short-lived climate pollutants (SLCPs) including methane, hydrofluorocarbons (HFCs) , tropospheric ozone and black carbon persist in the atmosphere for a period ranging from days to 15 years; whereas carbon dioxide can remain in the atmosphere for millennia. Reducing SLCP emissions can cut the ongoing rate of global warming by almost half and reduce

2808-419: The applications of relativity to problems in astronomy and cosmology respectively . All of these achievements depended on the theoretical physics as a moving force both to suggest experiments and to consolidate results — often by ingenious application of existing mathematics, or, as in the case of Descartes and Newton (with Leibniz ), by inventing new mathematics. Fourier's studies of heat conduction led to

2880-423: The board of the CO 2 Coalition , a climate change denial organization. Later that year, Clauser called himself a "climate denier" and claimed "there is no climate crisis". Clauser has never published a peer-reviewed article on the climate, and his views on climate change have been described as "pseudoscience". His belief that cloud cover has more of an impact on Earth's temperature than carbon dioxide emissions

2952-514: The body of knowledge of both factual and scientific views and possess a usual scientific quality of the tests of repeatability, consistency with existing well-established science and experimentation. There do exist mainstream theories that are generally accepted theories based solely upon their effects explaining a wide variety of data, although the detection, explanation, and possible composition are subjects of debate. The proposed theories of physics are usually relatively new theories which deal with

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3024-516: The case of Jupiter , or from its host star as in the case of the Earth . In the case of Earth, the Sun emits shortwave radiation ( sunlight ) that passes through greenhouse gases to heat the Earth's surface. In response, the Earth's surface emits longwave radiation that is mostly absorbed by greenhouse gases. The absorption of longwave radiation prevents it from reaching space, reducing the rate at which

3096-667: The concentration of carbon dioxide and other greenhouse gases. Emissions have grown rapidly since about 1950 with ongoing expansions in global population and economic activity following World War II. As of 2021, measured atmospheric concentrations of carbon dioxide were almost 50% higher than pre-industrial levels. The main sources of greenhouse gases due to human activity (also called carbon sources ) are: Global greenhouse gas emissions are about 50 Gt per year and for 2019 have been estimated at 57 Gt CO 2 eq including 5 Gt due to land use change. In 2019, approximately 34% [20 GtCO 2 -eq] of total net anthropogenic GHG emissions came from

3168-413: The difference between a country's exports and imports. For many richer nations, the balance is negative because more goods are imported than they are exported. This result is mostly due to the fact that it is cheaper to produce goods outside of developed countries, leading developed countries to become increasingly dependent on services and not goods. A positive account balance would mean that more production

3240-761: The emissions globally are large oil and gas companies . Emissions from human activities have increased atmospheric carbon dioxide by about 50% over pre-industrial levels. The growing levels of emissions have varied, but have been consistent among all greenhouse gases . Emissions in the 2010s averaged 56 billion tons a year, higher than any decade before. Total cumulative emissions from 1870 to 2022 were 703 GtC (2575 GtCO 2 ), of which 484±20 GtC (1773±73 GtCO 2 ) from fossil fuels and industry, and 219±60 GtC (802±220 GtCO 2 ) from land use change . Land-use change , such as deforestation , caused about 31% of cumulative emissions over 1870–2022, coal 32%, oil 24%, and gas 10%. Carbon dioxide (CO 2 )

3312-440: The energy supply sector, 24% [14 GtCO 2 -eq] from industry, 22% [13 GtCO 2 -eq]from agriculture, forestry and other land use (AFOLU), 15% [8.7 GtCO 2 -eq] from transport and 6% [3.3 GtCO 2 -eq] from buildings. Global carbon dioxide emissions by country in 2023: The current CO 2 -equivalent emission rates averaging 6.6 tonnes per person per year, are well over twice the estimated rate 2.3 tons required to stay within

3384-489: The entire life cycle from the production of a good or service along the supply chain to its final consumption. Carbon accounting (or greenhouse gas accounting) is a framework of methods to measure and track how much greenhouse gas an organization emits. The greenhouse effect occurs when greenhouse gases in a planet's atmosphere insulate the planet from losing heat to space, raising its surface temperature. Surface heating can happen from an internal heat source as in

3456-414: The estimated rate 2.3 tons required to stay within the 2030 Paris Agreement increase of 1.5 °C (2.7 °F) over pre-industrial levels. Annual per capita emissions in the industrialized countries are typically as much as ten times the average in developing countries. The carbon footprint (or greenhouse gas footprint ) serves as an indicator to compare the amount of greenhouse gases emitted over

3528-488: The first observation of sub-Poissonian statistics for light (via a violation of the Cauchy–Schwarz inequality for classical electromagnetic fields), and thereby, for the first time, demonstrated an unambiguous particle-like character for photons . Starting in 1973, Clauser published the newsletter Epistemological Letters , which was created because mainstream academic journals were relunctant to publish articles about

3600-416: The highest order, writing Principia Mathematica . In it contained a grand synthesis of the work of Copernicus, Galileo and Kepler; as well as Newton's theories of mechanics and gravitation, which held sway as worldviews until the early 20th century. Simultaneously, progress was also made in optics (in particular colour theory and the ancient science of geometrical optics ), courtesy of Newton, Descartes and

3672-455: The idea of energy (as well as its global conservation) by the inclusion of heat , electricity and magnetism , and then light . The laws of thermodynamics , and most importantly the introduction of the singular concept of entropy began to provide a macroscopic explanation for the properties of matter. Statistical mechanics (followed by statistical physics and Quantum statistical mechanics ) emerged as an offshoot of thermodynamics late in

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3744-824: The importing country, rather than the exporting, country. A substantial proportion of CO 2 emissions is traded internationally. The net effect of trade was to export emissions from China and other emerging markets to consumers in the US, Japan, and Western Europe. Emission intensity is a ratio between greenhouse gas emissions and another metric, e.g., gross domestic product (GDP) or energy use. The terms "carbon intensity" and " emissions intensity " are also sometimes used. Emission intensities may be calculated using market exchange rates (MER) or purchasing power parity (PPP). Calculations based on MER show large differences in intensities between developed and developing countries, whereas calculations based on PPP show smaller differences. Carbon accounting (or greenhouse gas accounting)

3816-474: The lapse of formerly declining trends in carbon intensity of both developing and developed nations. China was responsible for most of global growth in emissions during this period. Localised plummeting emissions associated with the collapse of the Soviet Union have been followed by slow emissions growth in this region due to more efficient energy use , made necessary by the increasing proportion of it that

3888-675: The late 1920s. In the aftermath of World War 2, more progress brought much renewed interest in QFT, which had since the early efforts, stagnated. The same period also saw fresh attacks on the problems of superconductivity and phase transitions, as well as the first applications of QFT in the area of theoretical condensed matter. The 1960s and 70s saw the formulation of the Standard model of particle physics using QFT and progress in condensed matter physics (theoretical foundations of superconductivity and critical phenomena , among others ), in parallel to

3960-721: The levels of those in the Annex I group of the Kyoto Protocol (i.e., the developed countries excluding the US). Africa and South America are both fairly small emitters, accounting for 3-4% of global emissions each. Both have emissions almost equal to international aviation and shipping. There are several ways of measuring greenhouse gas emissions. Some variables that have been reported include: These measures are sometimes used by countries to assert various policy/ethical positions on climate change. The use of different measures leads to

4032-500: The main international treaty on climate change (the UNFCCC ), countries report on emissions produced within their borders, e.g., the emissions produced from burning fossil fuels. Under a production-based accounting of emissions, embedded emissions on imported goods are attributed to the exporting, rather than the importing, country. Under a consumption-based accounting of emissions, embedded emissions on imported goods are attributed to

4104-459: The major source of greenhouse gas emissions in the EU . Greenhouse gas emissions from the transportation sector continue to rise, in contrast to power generation and nearly all other sectors. Since 1990, transportation emissions have increased by 30%. The transportation sector accounts for around 70% of these emissions. The majority of these emissions are caused by passenger vehicles and vans. Road travel

4176-419: The process of becoming established and some proposed theories. It can include speculative sciences. This includes physics fields and physical theories presented in accordance with known evidence, and a body of associated predictions have been made according to that theory. Some fringe theories go on to become a widely accepted part of physics. Other fringe theories end up being disproven. Some fringe theories are

4248-607: The rise of medieval universities , the only acknowledged intellectual disciplines were the seven liberal arts of the Trivium like grammar , logic , and rhetoric and of the Quadrivium like arithmetic , geometry , music and astronomy . During the Middle Ages and Renaissance , the concept of experimental science, the counterpoint to theory, began with scholars such as Ibn al-Haytham and Francis Bacon . As

4320-484: The study of physics which include scientific approaches, means for determining the validity of models and new types of reasoning used to arrive at the theory. However, some proposed theories include theories that have been around for decades and have eluded methods of discovery and testing. Proposed theories can include fringe theories in the process of becoming established (and, sometimes, gaining wider acceptance). Proposed theories usually have not been tested. In addition to

4392-629: The summit of the United Nations Environment Programme reached a legally binding accord to phase out hydrofluorocarbons (HFCs) in the Kigali Amendment to the Montreal Protocol . The use of CFC-12 (except some essential uses) has been phased out due to its ozone depleting properties. The phasing-out of less active HCFC-compounds will be completed in 2030. Starting about 1750, industrial activity powered by fossil fuels began to significantly increase

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4464-472: The theories like those listed below, there are also different interpretations of quantum mechanics , which may or may not be considered different theories since it is debatable whether they yield different predictions for physical experiments, even in principle. For example, AdS/CFT correspondence , Chern–Simons theory , graviton , magnetic monopole , string theory , theory of everything . Fringe theories include any new area of scientific endeavor in

4536-664: The violation of Bell inequalities and pioneering quantum information science". Clauser was born in Pasadena , California . His father, Francis H. Clauser, was a professor of aeronautical engineering who founded and chaired the aeronautics department at Johns Hopkins University . He later served as the Clark Blanchard Millikan Professor of Engineering at the California Institute of Technology (Caltech). His mother, Catharine McMillan,

4608-539: The vision provided by pure mathematical systems can provide clues to how a physical system might be modeled; e.g., the notion, due to Riemann and others, that space itself might be curved. Theoretical problems that need computational investigation are often the concern of computational physics . Theoretical advances may consist in setting aside old, incorrect paradigms (e.g., aether theory of light propagation, caloric theory of heat, burning consisting of evolving phlogiston , or astronomical bodies revolving around

4680-530: The works of these men (alongside Galileo's) can perhaps be considered to constitute the Scientific Revolution. The great push toward the modern concept of explanation started with Galileo , one of the few physicists who was both a consummate theoretician and a great experimentalist . The analytic geometry and mechanics of Descartes were incorporated into the calculus and mechanics of Isaac Newton , another theoretician/experimentalist of

4752-457: The world today is that the countries with the highest emissions over history are not always the biggest emitters today. For example, in 2017, the UK accounted for just 1% of global emissions. In comparison, humans have emitted more greenhouse gases than the Chicxulub meteorite impact event which caused the extinction of the dinosaurs . Transport, together with electricity generation , is

4824-582: The year 1995). A country's emissions may also be reported as a proportion of global emissions for a particular year. Another measurement is of per capita emissions. This divides a country's total annual emissions by its mid-year population. Per capita emissions may be based on historical or annual emissions. One way of attributing greenhouse gas emissions is to measure the embedded emissions (also referred to as "embodied emissions") of goods that are being consumed. Emissions are usually measured according to production, rather than consumption. For example, in

4896-406: Was at about the time of the 1970s energy crisis . Percent changes per year were estimated by piecewise linear regression on the log data and are shown on the plot; the data are from The Integrated Carbon Observation system. The sharp acceleration in CO 2 emissions since 2000 to more than a 3% increase per year (more than 2 ppm per year) from 1.1% per year during the 1990s is attributable to

4968-569: Was concerned with the Lorentz transformation which left Maxwell's equations invariant, but was apparently uninterested in the Michelson–Morley experiment on Earth 's drift through a luminiferous aether . Conversely, Einstein was awarded the Nobel Prize for explaining the photoelectric effect , previously an experimental result lacking a theoretical formulation. A physical theory

5040-422: Was given a kinematic explanation by general relativity . Quantum mechanics led to an understanding of blackbody radiation (which indeed, was an original motivation for the theory) and of anomalies in the specific heats of solids — and finally to an understanding of the internal structures of atoms and molecules . Quantum mechanics soon gave way to the formulation of quantum field theory (QFT), begun in

5112-590: Was occurring within a country, so more operational factories would increase carbon emission levels. Emissions may also be measured across shorter time periods. Emissions changes may, for example, be measured against the base year of 1990. 1990 was used in the United Nations Framework Convention on Climate Change (UNFCCC) as the base year for emissions, and is also used in the Kyoto Protocol (some gases are also measured from

5184-540: Was the humanities librarian at Caltech and sister of 1951 Nobel Prize in Chemistry laureate Edwin McMillan . He received a Bachelor of Science in physics from Caltech in 1964, where he was a member of Dabney House . He received a Master of Arts in physics in 1966 and a Doctor of Philosophy in physics in 1969 from Columbia University under the direction of Patrick Thaddeus . From 1969 to 1975, he worked as

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