Observations in Science

Observations of nature involve some level of uncertainty in most cases. As an analogy, consider the attendance at a football game. We may be able to count with 

Error in measurement is unavoidable. Again, characteristics of error fall into categories. Random error is fundamental to any measurement. Random error may make the measurement either too high or too low and is associated with the limitations of the equipment with which the measurement is made. Systematic error makes measurements consistently either too high or too low. This type of error is often associated with the existence of some unknown bias in the measurement apparatus. Impurities in metals provide one example of possible error sources. Suppose that an aluminum alloy contains very small amounts of another 

Not all experiments provide direct information about the questions they asL In many cases, we must infer answers fi om the data that are obtained. Two types of reasoning that are useful are inductive and deductive reasoning. 

We ll explore gases and the kinetic theory of gases in Chapter 5. 

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The emphasis on public observations in science has had a misleading quality insofar as it implies that any intelligent man can replicate a scientists observations. This may have been true early in the history of science, but nowadays only the trained observer can replicate many observations. I cannot go into a modern physicist s laboratory and confirm his observations, indeed, his talk of what he has found in his experiments (physicists seem to talk about innumerable invisible entities) would probably seem mystical to me, just as descriptions of internal states sound mystical to those with a background in the physical sciences.X41... 

The Science of Chemistry Observations and Models Observations in Science Interpreting Observations Models in Science... 

Figure Bl.26.23. Current-voltage curves observed in the retarding potential difference method of work-fimction Miboxfmeasurement] (Hudson J B 1992 Surface Science (Stoneham, MA Butterworth-Heinemaim)).

Ducin Y and P A Kollrtran 1998. Pathways to a Protein Folding Intermediate Observed in Microsecond Simulation in Aqueous Solution. Science 282 740-744. 

Classical and Quantum Mechanics. At the beginning of the twentieth century, a revolution was brewing in the world of physics. For hundreds of years, the Newtonian laws of mechanics had satisfactorily provided explanations and supported experimental observations in the physical sciences. However, the experimentaUsts of the nineteenth century had begun delving into the world of matter at an atomic level. This led to unsatisfactory explanations of the observed patterns of behavior of electricity, light, and matter, and it was these inconsistencies which led Bohr, Compton, deBroghe, Einstein, Planck, and Schrn dinger to seek a new order, another level of theory, ie, quantum theory. 

Y Duan, PA Kollman. Pathways to a protein folding intermediate observed in a 1-microsecond simulation m aqueous solution. Science 282 740-744, 1998. 

The molecular and liquid properties of water have been subjects of intensive research in the field of molecular science. Most theoretical approaches, including molecular simulation and integral equation methods, have relied on the effective potential, which was determined empirically or semiempirically with the aid of ab initio MO calculations for isolated molecules. The potential parameters so determined from the ab initio MO in vacuum should have been readjusted so as to reproduce experimental observables in solutions. An obvious problem in such a way of determining molecular parameters is that it requires the reevaluation of the parameters whenever the thermodynamic conditions such as temperature and pressure are changed, because the effective potentials are state properties. 

One of the most exciting and perhaps unexpected discoveries in science within the last decade has been the observation of superconductivity (the complete absence of resistivity to electric current) in metal oxides at temperature < 90 K. This tempera-... 

I have tried to stress the educational implications of the claims for the observation of orbitals in other articles and will not dwell on the issue here (Scerri, 2000 in Science and Education). 

Conclusions drawn from kinetics are. however, no more tenuous than those from other areas of measurement, for example, infrared spectra or magnetic susceptibilities. Lewis1 has pointed out that the subject of reaction mechanisms deserves no special censure on this point. After all. many models or hypotheses in science that have been advanced to explain a set of observations have never been proved unequivocally. The best one can do is to be as inventive as possible in devising tests to probe all the assumptions. 

How can one explain such a huge Faradaic efficiency, A, value As we shall see there is one and only one viable explanation confirmed now by every surface science and electrochemical technique, which has been used to investigate this phenomenon. We will see this explanation immediately and then, in much more detail in Chapter 5, but first let us make a few more observations in Figure 4.13. It is worth noting that, at steady-state, the catalyst potential Uwr, has increased by 0.62 V. Second let us note that upon current interruption (Fig. 4.13), r and UWr return to their initial unpromoted values. This is due to the gradual consumption of Os by C2H4. 

In the late 1970 s a very ambitious project to build a 10-m diameter segmented mirror telescope was begun, called the Keck Observatory. This project was formally begun in 1984 and completed and began science observations in 1993. 

The second telescope was completed in 1996 and began science observations in that year. Each of these telescopes has a suite of science instruments... 

The Lick AO system demonstrated the first wavefront correction using a Na LGS (Max et al., 1997), and engineering tests demonstrated LGS corrected Strehls of 0.5-0.6 at 2.2 m (Fig. 15, Gavel et al., 2003). In 2002, the LGS system was turned over to the Observatory staff for operation in science observing mode. It is used almost 100 nights per year. The first refereed science paper using a sodium LGS/AO system was published by Perrin et al. (2004). 

Figure 5.43 The total-ion-current (TIC) trace and reconstructed ion chromatograms from intense ions at m/z 483, 523 and 539 observed in spectra generated during the full-scan LC-MS analysis of an incubation of Indinavir with rat liver S9. Reprinted by permission of Elsevier Science from Identification of in vitro metabolites of Indinavir by Intelligent Automated LC-MS/MS (INTAMS) utilizing triple-quadrupole tandem mass spectrometry , by Yu, X., Cui, D. and Davis, M. R., Journal of the American Society for Mass Spectrometry, Vol. 10, pp. 175-183, Copyright 1999 by the American Society for Mass Spectrometry.

Figure 5.56 Structures of the three analytes pesticides used in an investigation of the matrix effects observed in LC-MS-MS. Reprinted from J. Chromatogr., A, 907, Choi, B. K., Hercnles, D. M. and Gnsev, A. I., Effect of liquid chromatography separation of complex matrices on liqnid chromatography-tandem mass spectrometry signal suppression , 337-342, Copyright (2001), with permission from Elsevier Science.

The terms laboratory work and practical work are used in the literatrrre without precise defirrition to embrace mtmerous activities in science irrstructioa According to Hodson (1990), the term practical work means tasks in which students observe or manipirlate real objects or materials for themselves (individually or in small groups) or by witnessing teacher demonstratiorrs. In an extended sense, practical work involves not orrly work in the formal chemistry laboratory or demonstratiorrs, but also ar r type of activity that involves tangible objects, and provides students the opportrrrrity to manipirlate and interact with chemicals and observe chemistry in action corrsequently, home laboratory kits and computer simulations of experiments are also included. 

The structural adaptation of the skeleton is one of the most fascinating problems in the history of science. Galileo observed in 1638 that longer bones had to be thicker than shorter ones to have the same structural... 

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