Query: The authors seem to have jumped right  into statistical  analysis without proposing a physical mechanism that  works.

Relevant passages:
Sensor-based sorting <=SEP=> Sensor-based sorting , is an umbrella term for all applications where particles are singularly detected by a sensor technique and rejected by an amplified mechanical , hydraulic or pneumatic process . The technique is generally applied in the three industries mining , recycling and food processing and used in the particle size range between 0.5 and . Since sensor-based sorting is a single particle separation technology , the throughput is proportional to the average particle size and weight fed onto the machine .

Scientific method <=SEP=> The scientific method is a body of techniques for investigating phenomena , acquiring new knowledge , or correcting and integrating previous knowledge . To be termed scientific , a method of inquiry is commonly based on empirical or measurable evidence subject to specific principles of reasoning . The Oxford Dictionaries Online define the scientific method as `` a method or procedure that has characterized natural science since the 17th century , consisting in systematic observation , measurement , and experiment , and the formulation , testing , and modification of hypotheses '' . Experiments need to be designed to test hypotheses . The most important part of the scientific method is the experiment .   The scientific method is a continuous process , which usually begins with observations about the natural world . Human beings are naturally inquisitive , so they often come up with questions about things they see or hear and often develop ideas ( hypotheses ) about why things are the way they are . The best hypotheses lead to predictions that can be tested in various ways , including making further observations about nature . In general , the strongest tests of hypotheses come from carefully controlled and replicated experiments that gather empirical data . Depending on how well the tests match the predictions , the original hypothesis may require refinement , alteration , expansion or even rejection . If a particular hypothesis becomes very well supported a general theory may be developed .   Although procedures vary from one field of inquiry to another , identifiable features are frequently shared in common between them . The overall process of the scientific method involves making conjectures ( hypotheses ) , deriving predictions from them as logical consequences , and then carrying out experiments based on those predictions . A hypothesis is a conjecture , based on knowledge obtained while formulating the question . The hypothesis might be very specific or it might be broad . Scientists then test hypotheses by conducting experiments . Under modern interpretations , a scientific hypothesis must be falsifiable , implying that it is possible to identify a possible outcome of an experiment that conflicts with predictions deduced from the hypothesis ; otherwise , the hypothesis can not be meaningfully tested .   The purpose of an experiment is to determine whether observations agree with or conflict with the predictions derived from a hypothesis . Experiments can take place anywhere from a college lab to CERN 's Large Hadron Collider . There are difficulties in a formulaic statement of method , however . Though the scientific method is often presented as a fixed sequence of steps , it represents rather a set of general principles .  Not all steps take place in every scientific inquiry ( or to the same degree ) , and are not always in the same order . Some philosophers and scientists have argued that there is no scientific method , such as Lee Smolin and Paul Feyerabend ( in his Against Method ) . Nola and Sankey remark that `` For some , the whole idea of a theory of scientific method is yester-year 's debate '' .

Artificial intelligence <=SEP=> Artificial intelligence ( AI ) is intelligence exhibited by machines . In computer science , the field of AI research defines itself as the study of `` intelligent agents '' : any device that perceives its environment and takes actions that maximize its chance of success at some goal . Colloquially , the term `` artificial intelligence '' is applied when a machine mimics `` cognitive '' functions that humans associate with other human minds , such as `` learning '' and `` problem solving '' .   As machines become increasingly capable , mental facilities once thought to require intelligence are removed from the definition . For instance , optical character recognition is no longer perceived as an example of `` artificial intelligence '' , having become a routine technology . Capabilities currently classified as AI include successfully understanding human speech , competing at a high level in strategic game systems ( such as chess and Go ) , self-driving cars , intelligent routing in content delivery networks , military simulations , and interpreting complex data .   AI research is divided into subfields that focus on specific problems , approaches , the use of a particular tool , or towards satisfying particular applications .   The central problems ( or goals ) of AI research include reasoning , knowledge , planning , learning , natural language processing ( communication ) , perception and the ability to move and manipulate objects . General intelligence is among the field 's long-term goals . Approaches include statistical methods , computational intelligence , and traditional symbolic AI . Many tools are used in AI , including versions of search and mathematical optimization , logic , methods based on probability and economics . The AI field draws upon computer science , mathematics , psychology , linguistics , philosophy , neuroscience , artificial psychology plus many others .   The field was founded on the claim that human intelligence `` can be so precisely described that a machine can be made to simulate it '' . This raises philosophical arguments about the nature of the mind and the ethics of creating artificial beings endowed with human-like intelligence , issues which have been explored by myth , fiction and philosophy since antiquity . Some people also consider AI a danger to humanity if it progresses unabatedly . Attempts to create artificial intelligence have experienced many setbacks , including the ALPAC report of 1966 , the abandonment of perceptrons in 1970 , the Lighthill Report of 1973 , the second AI winter 1987 -- 1993 and the collapse of the Lisp machine market in 1987 .   In the twenty-first century , AI techniques , both hard ( using a symbolic approach ) and soft ( sub-symbolic ) , have experienced a resurgence following concurrent advances in computer power , sizes of training sets , and theoretical understanding , and AI techniques have become an essential part of the technology industry , helping to solve many challenging problems in computer science . Recent advancements in AI , and specifically in machine learning , have contributed to the growth of Autonomous Things such as drones and self-driving cars , becoming the main driver of innovation in the automotive industry .

Free will <=SEP=> Free will is the ability to choose between different possible courses of action . It is closely linked to the concepts of responsibility , praise , guilt , sin , and other judgments which apply only to actions that are freely chosen . It is also connected with the concepts of advice , persuasion , deliberation , and prohibition . Traditionally , only actions that are freely willed are seen as deserving credit or blame . There are numerous different concerns about threats to the possibility of free will , varying by how exactly it is conceived , which is a matter of some debate .   Some conceive free will to be the capacity to make choices in which the outcome has not been determined by past events . Determinism suggests that only one course of events is possible , which is inconsistent with the existence of such free will . This problem has been identified in ancient Greek philosophy , and remains a major focus of philosophical debate . This view that conceives free will to be incompatible with determinism is called incompatibilism , and encompasses both metaphysical libertarianism , the claim that determinism is false and thus free will is at least possible , and hard determinism , the claim that determinism is true and thus free will is not possible . It also encompasses hard incompatibilism , which holds not only determinism but also its negation to be incompatible with free will , and thus free will to be impossible whatever the case may be regarding determinism .   In contrast , compatibilists hold that free will is compatible with determinism . Some compatibilists even hold that determinism is necessary for free will , arguing that choice involves preference for one course of action over another , requiring a sense of how choices will turn out . Compatibilists thus consider the debate between libertarians and hard determinists over free will vs determinism a false dilemma . Different compatibilists offer very different definitions of what `` free will '' even means , and consequently find different types of constraints to be relevant to the issue . Classical compatibilists considered free will nothing more than freedom of action , considering one free of will simply if , had one counterfactually wanted to do otherwise , one could have done otherwise without physical impediment . Contemporary compatibilists instead identify free will as a psychological capacity , such as to direct one 's behavior in a way responsive to reason . And there are still further different conceptions of free will , each with their own concerns , sharing only the common feature of not finding the possibility of determinism a threat to the possibility of free will .

Chemistry <=SEP=> Chemistry is a branch of physical science that studies the composition , structure , properties and change of matter . Chemistry includes topics such as the properties of individual atoms , how atoms form chemical bonds to create chemical compounds , the interactions of substances through intermolecular forces that give matter its general properties , and the interactions between substances through chemical reactions to form different substances .   Chemistry is sometimes called the central science because it bridges other natural sciences , including physics , geology and biology . For the differences between chemistry and physics see comparison of chemistry and physics .   The history of chemistry can be traced to alchemy , which had been practiced for several millennia in various parts of the world .