In free fall—the question

2021 ◽  
Vol 57 (1) ◽  
pp. 017002
Author(s):  
David Featonby ◽  
Rute Oliveira
Keyword(s):  
Free Fall ◽  
Physical Laws ◽  
As If

Abstract In free fall objects seem to behave as if the physical laws of gravity have been suspended. Here are some experiments which demonstrate the phenomenon, and test the imagination.

scholarly journals The aerodynamic wall

2014 ◽  
Vol 470 (2161) ◽  
pp. 20130497 ◽  
Author(s):  
Caroline Cohen ◽  
Baptiste Darbois-Texier ◽  
Guillaume Dupeux ◽  
Eric Brunel ◽  
David Quéré ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Initial Velocity ◽  
Free Fall ◽  
Terminal Velocity ◽  
Large Reynolds Number ◽  
As If

We study the trajectory of dense projectiles subjected to gravity and drag at large Reynolds number. We show that two types of trajectories can be observed: if the initial velocity is smaller than the terminal velocity of free fall, we observe the classical Galilean parabola: if it is larger, the projectile decelerates with an asymmetric trajectory first drawn by Tartaglia, which ends with a nearly vertical fall, as if a wall impeded the movement. This regime is often observed in sports, fireworks, watering, etc. and we study its main characteristics.

Improvement of an artificial test substrate technique for evaluation of em immunocytochemical labeling

1987 ◽  
Vol 45 ◽  
pp. 762-763
Author(s):  
G. D. Gagne ◽  
M. F. Miller
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Artificial Substrate ◽  
Chemical Fixation ◽  
As If

We recently described an artificial substrate system which could be used to optimize labeling parameters in EM immunocytochemistry (ICC). The system utilizes blocks of glutaraldehyde polymerized bovine serum albumin (BSA) into which an antigen is incorporated by a soaking procedure. The resulting antigen impregnated blocks can then be fixed and embedded as if they are pieces of tissue and the effects of fixation, embedding and other parameters on the ability of incorporated antigen to be immunocyto-chemically labeled can then be assessed. In developing this system further, we discovered that the BSA substrate can also be dried and then sectioned for immunolabeling with or without prior chemical fixation and without exposing the antigen to embedding reagents. The effects of fixation and embedding protocols can thus be evaluated separately.

As-If Test

1956 ◽  
Author(s):  
Theodore R. Sarbin ◽  
Donal S. Jones
Keyword(s):  
As If

State special primary acceleration measurement standard for gravimetry GET 190-2019

2020 ◽  
pp. 3-8
Author(s):  
L.F. Vitushkin ◽  
F.F. Karpeshin ◽  
E.P. Krivtsov ◽  
P.P. Krolitsky ◽  
V.V. Nalivaev ◽  
...  
Keyword(s):  
High Precision ◽  
Free Fall ◽  
Measurement Range ◽  
Measurement Standard ◽  
Acceleration Measurement ◽  
Measurement Systems ◽  
Free Fall Acceleration ◽  
Investigation Methods ◽  
Measurement Results ◽  
Upper Level

The State special primary acceleration measurement standard for gravimetry (GET 190-2019), its composition, principle of operation and basic metrological characteristics are presented. This standard is on the upper level of reference for free-fall acceleration measurements. Its accuracy and reliability were improved as a result of optimisation of the adjustment procedures for measurement systems and its integration within the upgraded systems, units and modern hardware components. A special attention was given to adjusting the corrections applied to measurement results with respect to procedural, physical and technical limitations. The used investigation methods made it possibled to confirm the measurement range of GET 190-2019 and to determine the contributions of main sources of errors and the total value of these errors. The measurement characteristics and GET 90-2019 were confirmed by the results obtained from measurements of the absolute value of the free fall acceleration at the gravimetrical site “Lomonosov-1” and by their collation with the data of different dates obtained from measurements by high-precision foreign and domestic gravimeters. Topicality of such measurements ensues from the requirements to handle the applied problems that need data on parameters of the Earth gravitational field, to be adequately faced. Geophysics and navigation are the main fields of application for high-precision measurements in this field.

Galilean Reflections on Milton Friedman’s "Methodology of Positive Economics", with Thoughts on Vernon Smith’s "Economics in the Laboratory"

2007 ◽  
pp. 55-70 ◽  
Author(s):  
E. Schliesser
Keyword(s):  
Experimental Evidence ◽  
Experimental Economics ◽  
Nobel Prize ◽  
Free Fall ◽  
Nobel Prize Winner ◽  
Theoretical Physics ◽  
History Of ◽  
Positive Economics

The article examines in detail the argument of M. Friedman as expressed in his famous article "Methodology of Positive Economics". In considering the problem of interconnection of theoretical hypotheses with experimental evidence the author illustrates his thesis using the history of the Galilean law of free fall and its role in the development of theoretical physics. He also draws upon methodological ideas of the founder of experimental economics and Nobel prize winner V. Smith.

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