In physics, Gauss's law, also known as Gauss's flux theorem, is a law relating the distribution of electric charge to the resulting electric field. The surface under consideration may be a closed one enclosing a volume such as a spherical surface.
The combination of Bayesian statistics and neural networks has proven to excel in predictive analytics. Blue Yonders solution NeuroBayes was developed and applied first in the field of particle physics but it can be successfully applied to a broad range of everyday problems for example demand prediction in retail. In this talk we introduce the basic concepts and explain the structure, components, and operations that build up an application for prediction.
In physics, Gauss's law, also known as Gauss's flux theorem, is a law relating the distribution of electric charge to the resulting electric field. The surface under consideration may be a closed one enclosing a volume such as a spherical surface.
The combination of Bayesian statistics and neural networks has proven to excel in predictive analytics. Blue Yonders solution NeuroBayes was developed and applied first in the field of particle physics but it can be successfully applied to a broad range of everyday problems for example demand prediction in retail. In this talk we introduce the basic concepts and explain the structure, components, and operations that build up an application for prediction.
It covers all the Maxwell's Equation for Point form(differential form) and integral form. It also covers Gauss Law for Electric Field, Gauss law for magnetic field, Faraday's Law and Ampere Maxwell law. It also covers the reason why Gauss Laws are also known as Maxwell's Equation.
definition, speed, production, properties of electromagnetic waves and electromagnetic spectrum. waves in EM spectrum and their application in daily life.
This is an introduction to modern quantum mechanics – albeit for those already familiar with vector calculus and modern physics – based on my personal understanding of the subject that emphasizes the concepts from first principles. Nothing of this is new or even developed first hand but the content (or maybe its clarity) is original in the fact that it displays an abridged yet concise and straightforward mathematical development that provides for a solid foundation in the tools and techniques to better understand and have a good appreciation for the physics involved in quantum theory and in an atom!
Maxwells equation and Electromagnetic WavesA K Mishra
These slide contains Scalar,Vector fields ,gradients,Divergence,and Curl,Gauss divergence theorem,Stoks theorem,Maxwell electromagnetic equations ,Pointing theorem,Depth of penetration (Skin depth) for graduate and Engineering students and teachers.
It covers all the Maxwell's Equation for Point form(differential form) and integral form. It also covers Gauss Law for Electric Field, Gauss law for magnetic field, Faraday's Law and Ampere Maxwell law. It also covers the reason why Gauss Laws are also known as Maxwell's Equation.
definition, speed, production, properties of electromagnetic waves and electromagnetic spectrum. waves in EM spectrum and their application in daily life.
This is an introduction to modern quantum mechanics – albeit for those already familiar with vector calculus and modern physics – based on my personal understanding of the subject that emphasizes the concepts from first principles. Nothing of this is new or even developed first hand but the content (or maybe its clarity) is original in the fact that it displays an abridged yet concise and straightforward mathematical development that provides for a solid foundation in the tools and techniques to better understand and have a good appreciation for the physics involved in quantum theory and in an atom!
Maxwells equation and Electromagnetic WavesA K Mishra
These slide contains Scalar,Vector fields ,gradients,Divergence,and Curl,Gauss divergence theorem,Stoks theorem,Maxwell electromagnetic equations ,Pointing theorem,Depth of penetration (Skin depth) for graduate and Engineering students and teachers.
The fundamental theory of electromagnetic field is based on Maxwell.pdfinfo309708
The fundamental theory of electromagnetic field is based on Maxwell\'s equations. These
equations govern the electromagnetic fields, E, D, H, and there relations to the source, f and p_v.
In a source-free region, list the Maxwell\'s equations for time-harmonic fields: Given the Phaser
from of the electric field E? For the above given electric field, is B varying with time? Why?
Solution
Maxwell’s equations simplify considerably in the case of harmonic time dependence. Through
the inverse Fourier transform, general solutions of Maxwell’s equation can be built as linear
combinations of single-frequency solutions:† E(r, t)= E(r, )ejt d2 (1) Thus, we assume that all
fields have a time dependence ejt: E(r, t)= E(r)ejt, H(r, t)= H(r)ejt where the phasor amplitudes
E(r), H(r) are complex-valued. Replacing time derivatives by t j, we may rewrite Eq. in the
form:
× E = jB
× H = J + jD
· D =
· B = 0
(Maxwell’s equations) (2) In this book, we will consider the solutions of Eqs. (.2) in three
different contexts: (a) uniform plane waves propagating in dielectrics, conductors, and
birefringent media, (b) guided waves propagating in hollow waveguides, transmission lines, and
optical fibers, and (c) propagating waves generated by antennas and apertures
Next, we review some conventions regarding phasors and time averages. A realvalued sinusoid
has the complex phasor representation: A(t)= |A| cos(t + ) A(t)= Aejt (3) where A = |A|ej. Thus,
we have A(t)= Re A(t) = Re Aejt . The time averages of the quantities A(t) and A(t) over one
period T = 2/ are zero. The time average of the product of two harmonic quantities A(t)= Re Aejt
and B(t)= Re Bejt with phasors A, B is given by A(t)B(t) = 1T T0 A(t)B(t) dt = 12 Re AB] (4) In
particular, the mean-square value is given by: A2(t) = 1T T0 A2(t) dt = 12 Re AA]= 12|A|2 (5)
Some interesting time averages in electromagnetic wave problems are the time averages of the
energy density, the Poynting vector (energy flux), and the ohmic power losses per unit volume.
Using the definition) and the result (.4), we have for these time averages:
w = 1 2 Re 12E · E + 12H · H (energy density) P = 1/ 2 Re E × H (Poynting vector) dPloss dV =
1/ 2 Re Jtot · E (ohmic losses) (6) where Jtot = J + jD is the total current in the right-hand side of
Amp`ere’s law and accounts for both conducting and dielectric losses. The time-averaged
version of Poynting’s theorem is discussed in Problem 1.5. The expression (1.9.6) for the energy
density w was derived under the assumption that both and were constants independent of
frequency. In a dispersive medium, , become functions of frequency. In frequency bands where
(), () are essentially real-valued, that is, where the medium is lossless,that the timeaveraged
energy density generalizes to: w = 1/ 2 Re 1/2 d() d E · E + 1/2 d() d H · H (lossless case) (.7)
The derivation of (.7) is as follows. Starting with Maxwell’s equations (1.1.1) and without
assuming any particular constitutive relations, we obtain:.
The fundamental theory of electromagnetic field is based on Maxwell.pdfRBMADU
The fundamental theory of electromagnetic field is based on Maxwell\'s equations. These
equations govern the electromagnetic fields, E, D, H, and there relations to the source, f and p_v.
In a source-free region, list the Maxwell\'s equations for time-harmonic fields: Given the Phaser
from of the electric field E? For the above given electric field, is B varying with time? Why?
Solution
Maxwell’s equations simplify considerably in the case of harmonic time dependence. Through
the inverse Fourier transform, general solutions of Maxwell’s equation can be built as linear
combinations of single-frequency solutions:† E(r, t)= E(r, )ejt d2 (1) Thus, we assume that all
fields have a time dependence ejt: E(r, t)= E(r)ejt, H(r, t)= H(r)ejt where the phasor amplitudes
E(r), H(r) are complex-valued. Replacing time derivatives by t j, we may rewrite Eq. in the
form:
× E = jB
× H = J + jD
· D =
· B = 0
(Maxwell’s equations) (2) In this book, we will consider the solutions of Eqs. (.2) in three
different contexts: (a) uniform plane waves propagating in dielectrics, conductors, and
birefringent media, (b) guided waves propagating in hollow waveguides, transmission lines, and
optical fibers, and (c) propagating waves generated by antennas and apertures
Next, we review some conventions regarding phasors and time averages. A realvalued sinusoid
has the complex phasor representation: A(t)= |A| cos(t + ) A(t)= Aejt (3) where A = |A|ej. Thus,
we have A(t)= Re A(t) = Re Aejt . The time averages of the quantities A(t) and A(t) over one
period T = 2/ are zero. The time average of the product of two harmonic quantities A(t)= Re Aejt
and B(t)= Re Bejt with phasors A, B is given by A(t)B(t) = 1T T0 A(t)B(t) dt = 12 Re AB] (4) In
particular, the mean-square value is given by: A2(t) = 1T T0 A2(t) dt = 12 Re AA]= 12|A|2 (5)
Some interesting time averages in electromagnetic wave problems are the time averages of the
energy density, the Poynting vector (energy flux), and the ohmic power losses per unit volume.
Using the definition) and the result (.4), we have for these time averages:
w = 1 2 Re 12E · E + 12H · H (energy density) P = 1/ 2 Re E × H (Poynting vector) dPloss dV =
1/ 2 Re Jtot · E (ohmic losses) (6) where Jtot = J + jD is the total current in the right-hand side of
Amp`ere’s law and accounts for both conducting and dielectric losses. The time-averaged
version of Poynting’s theorem is discussed in Problem 1.5. The expression (1.9.6) for the energy
density w was derived under the assumption that both and were constants independent of
frequency. In a dispersive medium, , become functions of frequency. In frequency bands where
(), () are essentially real-valued, that is, where the medium is lossless,that the timeaveraged
energy density generalizes to: w = 1/ 2 Re 1/2 d() d E · E + 1/2 d() d H · H (lossless case) (.7)
The derivation of (.7) is as follows. Starting with Maxwell’s equations (1.1.1) and without
assuming any particular constitutive relations, we obtain:.
Derivation of Schrodinger and Einstein Energy Equations from Maxwell's Electr...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
A general approach is presented to describing nonlinear classical Maxwell electrodynamics with conformal symmetry. We introduce generalized nonlinear constitutive equations, expressed in terms of constitutive tensors dependent on conformal-invariant functionals of the field strengths. This allows a characterization of Lagrangian and non-Lagrangian theories. We obtain a general formula for possible Lagrangian densities in nonlinear conformal-invariant electrodynamics. This generalizes the standard Lagrangian of classical linear electrodynamics so as to preserve the conformal symmetry.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Quality defects in TMT Bars, Possible causes and Potential Solutions.
Maxwell's contribution to physics
1. Maxwell’s contribution to
physics
Presented By:
Mayank panchal & Suhrid Mathur
Topics that will be covered:
About Maxwell
Maxwell’s Equations
Displacement current
Integral Form
Poynting Theorm
Time Harmonic Electric Field
2. James Clerk Maxwell
• Born in Edinburgh,
Scotland in 1831
• Attended Edinburgh
Academy, The
University of
Edinburgh, and
Cambridge University
• Published by the
young age of 14
3. More on Maxwell
• Maxwell differed from his contemporaries
in the nineteenth century
• Faraday & Ampere contributed to
Maxwell’s theories
• Much of his important work was
accomplished between the ages of 29 and
35
4. Maxwell’s equations
The behavior of electric and magnetic waves can be fully
described by a set of four equations (which we have learned
already).
B
E
t
∂
∇× = −
∂
D
H J
t
∂
∇× = +
∂
vD ρ∇ =g
0B∇ =gGauss’s Law for
magnetism
Gauss’s Law for
electricity
Ampere’s Law
Faraday’s Law of
induction
5. And the constitutive relations:
D Eε=
B Hµ=
J Eσ=
They relate the electromagnetic field to the properties of the material, in which
the field exists. Together with the Maxwell’s equations, the constitutive
relations completely describe the electromagnetic field.
Even the EM fields in a nonlinear media can be described through a
nonlinearity existing in the constitutive relations.
6. Conflict could be resolved by modifying Ampere’s
Law so that both electric current and displacement
current generate the magnetic field:
Displacement Current
7. For a time dependent electric field, a material medium
would become polarized, just as a dielectric does
- +
E
For a constant E field, each pair of charges soon
equilibrates as shown above
If the E field varies with time, then the charge
configurations are constantly in motion – displacement
current
8. L s
B
E dl ds
t∆ ∆
∂
= −
∂∫ ∫g gÑ
Gauss’s Law for
magnetism
Gauss’s Law for
electricity
Ampere’s Law
Faraday’s Law of
induction
Integral form
L s
D
H dl J ds
t∆ ∆
∂
= − + ÷
∂
∫ ∫g gÑ
v
S v
D ds dvρ
∆ ∆
=∫ ∫gÑ
0
S
B ds
∆
=∫ gÑ
9. It is frequently needed to determine the direction the power is
flowing. The Poynting’s Theorem is the tool for such tasks.
We consider an arbitrary
shaped volume:
B
E
t
∂
∇× = −
∂
D
H J
t
∂
∇× = +
∂
Recall:
We take the scalar product of E and subtract it from the scalar
product of H. B D
H E E H H E J
t t
∂ ∂
∇× − ∇× = − − + ÷
∂ ∂
g g g g
(6.9.1)
(6.9.2)
Poynting’s Theorem
10. Using the vector identity
( )A B B A A B∇ × = ∇× − ∇×g g g
Therefore:
( )
B D
E H H E E J
t t
∂ ∂
∇ × = − − −
∂ ∂
g g g g
( ) ( )2 21 1
2 2
B D
H E H H E E H E
t t t t
µ ε µ ε
∂ ∂ ∂ ∂
− − = − + = − +
∂ ∂ ∂ ∂
g g g g
11. ( )2 21
( )
2v v v
E H dv H E dv E Jdv
t
µ ε
∂
∇ × = − + −
∂∫ ∫ ∫V V V
g g
Application of divergence theorem and the Ohm’s law lead
to the PT:
( )2 2 21
( )
2s v v
E H ds H E dv E dv
t
µ ε σ
∂
× = − + −
∂∫ ∫ ∫V V V
gÑ
Here S E H= ×
is the Poynting vector – the power density
and the direction of the radiated EM fields
in W/m2
.
(6.11.3)
12. The Poynting’s Theorem states that the power that leaves a region is equal to
the temporal decay in the energy that is stored within the volume minus the
power that is dissipated as heat within it – energy conservation.
EM energy density is 2 21
2
w H Eµ ε = +
Power loss density is 2
Lp Eσ=
The differential form of the Poynting’s
Theorem:
L
w
S p
t
∂
∇ + = −
∂
g
13. Time-harmonic EM fields
Frequently, a temporal variation of EM fields is harmonic; therefore, we
may use a phasor representation:
( , , , ) Re ( , , )
( , , , ) Re ( , , )
j t
j t
E x y z t E x y z e
H x y z t H x y z e
ω
ω
=
=
It may be a phase angle between the electric and the magnetic
fields incorporated into E(x,y,z) and H(x,y,z).
Maxwell’s Eqn in
phasor form:
( ) ( )E r j H rωµ∇× = −
( ) ( ) ( )H r j E r J rωε∇× = +
( ) ( )vE r rρ ε∇ =g
( ) 0B r∇ =g
14. Power is a real quantity and, keeping in mind
that: Re ( ) Re ( ) Re ( ) ( )j t j t j t j t
E r e H r e E r e H r eω ω ω ω
× ≠ ×
Since [ ]
*
Re
2
A A
A
+
=
complex conjugate
[ ] [ ]
* *
* * * *
( ) ( ) ( ) ( )
Re ( ) Re ( )
2 2
( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )
4
E r E r H r H r
E r H r
E r H r E r H r E r H r E r H r
+ +
× = × ÷ ÷
× + × + × + ×
=
Taking the time average, we obtain the average
power as: *1
( ) Re ( ) ( )
2
avS r E r H r = ×
15. Therefore, the Poynting’s theorem in phasors is:
( ) ( )* 2 2 2
( ) ( )
s v v
E r H r ds j H E dv E dvω µ ε σ× = − − −∫ ∫ ∫V V V
gÑ
Total power radiated
from the volume
The power dissipated
within the volume
The energy stored
within the volume
Indicates that the power (energy) is reactive
16. Conclusion
• Maxwell provided us with modern physical
and mathematical equations
• Many contributions to physics even though
his belief in the existence of aether was not
valid
• Michelson-Morley experiment proved aether
wrong
• LIGO today uses similar apparatus and
encounters similar problems
Moving idle wheels with vortices
“The mathematics of these “moveable particles” turned out very neatly, but Maxwell nevertheless had to admit that the hypothesis could be regarded only as ‘provisional’
He conceded that the conception was awkward and did not bring it forward as a mode of connection existing in nature or ever as that which he would willingly assent to as an electrical hypothesis
- from Siegel book