I have learnt that the electric field that is responsible for current flow is generated inside a conductor as soon as the two ends of the conductor are connected or brought in contact with the two terminals of the battery. I have also learnt about the hydraulic analogy according to which the electric field is established across the conductor in the same way as hydrostatic pressure is transmitted across a fluid.  But I'm not convinced with this analogy neither can I see any mechanism by which the electric field is established across the conductor.  I reflected that the electric field may be established by some induction, i.e. maybe the electrons in the vicinity of the electrodes are drifted towards or away from the charged electrodes and this drift of charge carriers and the subsequent development of a non - zero charge in that region  induces the electrons in a farther region to respectively drift towards or away from the nearer electrode. Am I correct in my thinking?
On a systems level, I understand that as electrons are pushed into a wire, there is a net field and a net electron velocity.  And I've read that the net electron drift is slow.  But electricity travels through the wire, essentially at c, and I want to understand that mechanism.  My apologies if my question is poorly stated, I know bare bones undergraduate quantum theory circa 1990s but it doesn't explain the motion of electricity in detail.  Here's my conception, I'm hoping someone will fill in the holes, ha ha.  An electron moves into the wire.  It's got a kinetic energy.  After travelling a short distance, it spontaneously emits a photon, which hits another electron in a valence shell.  That electron then presumably does the same.  If this conception is simply wrong, please enlighten me.  The questions that arise:   Presumably at this level, electrons are acting more like waves and less like particles, but is there any classical component in the picture, ie are electrons coming in imparting other electrons with kinetic energy through repulsion, or does it not work that way? If electrons momentarily have energy, then pass it on by a photon, what determines when that photon is emitted, and what frequency it will be?  I assume that electrons in this cloud are not limited by any kind of exclusion principal, and that any frequencies are possible? Why should a photon emitted by an electron be in the direction of travel?  Conservation of momentum tells me that if an electron is moving, the photon should be emitted in that direction, slowing the electron, but could an electron emit a photon in the opposite direction?  If it did, I assume it would somehow have had to absorb energy from elsewhere? That sounds possible by analogy with quantum tunneling. What is the mechanism by which electrons propagating increase the temperature of the material?  Are they transmitting energy to the electrons in the valence shell, which tug at the nucleus, do some photons hit the nuclei directly, or is there some other way?  Presumably, electricity travels slower than light, because there is some time in each exchange, and some time when electrons are moving at sublight speeds before emitting a photon.  By how much is this slower than light, and what is the speed of each interaction?
Is a business card necessary for a graduate student? I know some PhD students have their own business cards, but I don't know if it is a standard practice for PhD students to have their own business cards. I think a business card can be useful for networking in conference or collaborating with some industrial partners. So, is are business cards necessary for a PhD student or other graduate students attending conferences?   PS: in case it is field-specific, I would like to know the different practices in different fields Graphing $y = \frac{x^2-4}{x-2}$ I'm trying to graph the function $y = \frac{x^2-4}{x-2}$.  I factored the numerator into $(x+2)(x-2)$, and then canceled the common factor (x-2), leaving the function as $y = x + 2$.    Is it acceptable to graph the original function as $y = x + 2$, a straight line with domain and range all real numbers?  Or do you have to restrict the domain as in the original function?  Thanks, Sean What is wrong with the De Broglie–Bohm theory a.k.a "Causal Interpretation" of quantum theory? Possible Duplicate:          I've heard of De Broglie–Bohm theory a.k.a causal interpretation of quantum theory. The predictions match accurately with with the nondeterministic quantum theory.  As a philosophy buff this one seems just like the classical universe. No funny new-age religion style gimmicks.  So why don't people use this interpretation instead of the Copenhagen "magic" interpretation?  P.S. I'm not an expert. I possess only superficial knowledge of quantum physics. After seeking clarification about linear model coefficients  I have a follow up question concerning non-signficant (high p value) for coefficients of factor levels.  Example: If my linear model includes a factor with 10 levels, and only 3 of those levels have significant p values associated with them, when using the model to predict Y can I choose to not include the coefficient term if the subject falls in one of the non-signficant level?  More drastically, would it be wrong to lump the 7 non-significant levels into one level and re-analyze? Layover at Narita, Japan. Do I need a transit visa? I will be transferring between two international flights at Tokyo Narita airport. I'm scheduled to depart the same day I arrive. I am planning to stay within the airport during the layover. Does anyone know if I will require a transit visa at Narita? "GPT detected. Please create a BIOS-Boot partition" while using boot-repair Since I updated Windows to 8.1 my Grub menu disappeared. I ran Ubuntu using Live USB, I used Boot-Repair but something went wrong. If I click on Reccomended repair I get this error:     GPT detected. Please create a BIOS-Boot partition (>1MB, unformatted filesystem, bios_grub flag). This can be performed via tools such as Gparted. Then try again. Alternatively, you can retry after activating the [Separate /boot/efi partition:] option.   So I tried to set my sda9 (I think that it's the Ubuntu system partition, since it's ext4) with the bios_grub flag and then to run Boot-Repair again. It didn't work.  I don't know what to do. My Grub was working fine (using UEFI) before I updated Windows.  I removed the bios_grub flag. Then I used fsck and it didn't find any error. So I tried again with Boot-Repair but it always gives me the "GPT detected" error. My boot is on UEFI mode, Secure Boot is "off".  When I boot my PC with SecureBoot OFF, I can reach the GRUB menu. But it's empty (the only voice is "System Setup").  I mounted my Ubuntu system disk:  sudo mount /dev/sda9 /mnt   and the other things:  sudo mount --bind /dev /mnt/dev sudo mount --bind /proc /mnt/proc sudo mount --bind /sys /mnt/sys   I logged on the system with chroot:  sudo chroot /mnt   I re-installed grub:  grub-install /dev/sda update-grub2   But it still doesn't work. Is a set without limit points necessarily closed? According to the definition on Rudin' Principles of Mathematicial Analysis, closed set is defined as:      $E$ is closed if every limit point of $E$ is a point of $E$.   Then I have a question: if a set has no limit point, is it necessarily closed? I think this idea doesn't contradict the definition of closed sets. Am I right?  And another question is #10 in Chap.2 of Rudin's:      Let $X$ be an infinite set. For $p\in X$ and $q\in X$, define    $d(p,q)=0$ when $p=q$. Otherwises,$d(p,q)=1$.    I have known that every set in the metric space is closed. To prove it, we can show that the complement of any set is open, which is quite trivial. My question is: how can we prove that every set is closed just by checking according to the definition of closed set, i.e. how can we show that every limit point of any arbitrary set $E$ in the metric space is a point of $E$?   Thanks in advanced! Cannot get specific WMS to display in Leaflet or OpenLayers 3 Combinef in R HTS package- constrain to keep forecasts positive? When using the combinef function from Rob Hyndman's very useful  for forecasting hierarchical and grouped time series, there does not seem to be a way to constrain the optimally combined forecasts to be positive- the starting forecasts can be positive, but can go negative through the reconciliation process.  The forecast.gts and forecast.hts functions have an argument to keep forecasts positive, but this does not seem to be an option when using combinef by itself with forecasts obtained by other methods.  Am I correct in this understanding, and if so is there a decent workaround? Solving an ODE in power series I am trying to remove the Facebook and Messenger apps from my Asus Zenphone Laser 2.  Unfortunately, in both cases, I seem to be unable to find the option to fully delete them from the device. I have disabled them, but the app management screen now shows the following:     How can I fully delete/uninstall them? Complex towers: $i^{i^{i^{...}}}$ So I'm trying to prove the following two inequalities: $$\frac{\sqrt{n}}{2} \leq \phi(n) \leq n.$$ The upper bound we get from simply noting that $\phi(n) = n \prod_{p | n}\left( 1 - \frac{1}{p}\right)$ and the fact that $(1 - \frac{1}{p}) \leq 1$. But how can we get the lower bound? I tried using the same expression for $\phi(n)$ but it seems to not really give me the inequality. Can you help? Solve the following equation in positive integers $x$ and $y$ Err 80 appears when I turn on my Canon EOS 5D Mark II Even though I have the latest Adobe Flash player 11.2 for Linux in Firefox -   - a particular online flash game still requests that I update to the latest flash player.  I've tried this online game on my laptop (Windows 8 with Flash Player 11.8) and it has no problems.  Is there a way to trick Ubuntu or this game into thinking Flash Player 11.8 is "installed"? Why should I "watch" a nearby Pokémon? How to make bash put prompt on a new line after cat command? What I get:  host:~ user$ cat example.txt some texthost:~ stas$   What I want to get:  host:~ user$ cat example.txt some text host:~ stas$   Is there a way I can make cat behave like this?  I'm using bash on Mac OS X. If I play a spell with {X} in the mana cost, and I have a card out that reduces the casting cost by 2 generic mana, what happens to the X? Does it start at -2?  For example: I have  in play. If I play  for just 1 blue mana, do we draw 2 cards? Page number in title page I want to add page number from 531 to 536 in my latex IEEE conference template. But page number appearing from page 2 i.e. 532.  \documentclass[conference]{IEEEtran} %\IEEEoverridecommandlockouts  \makeatletter \let\old@ps@headings\ps@headings \let\old@ps@IEEEtitlepagestyle\ps@IEEEtitlepagestyle \def\confheader#1{%     % for all pages except the first     \def\ps@headings{%         \old@ps@headings%         \def\@oddhead{\strut\hfill#1\hfill\strut}%         \def\@evenhead{\strut\hfill#1\hfill\strut}%     }%     % for the first page     \def\ps@IEEEtitlepagestyle{%         \old@ps@IEEEtitlepagestyle%         \def\@oddhead{\strut\hfill#1\hfill\strut}%         \def\@evenhead{\strut\hfill#1\hfill\strut}%     }%     \ps@headings% } \makeatother  \confheader{ 2020 IEEE International Conference on Computation, Automation and Knowledge Management (ICCAKM) }   %%footer %\usepackage[pscoord]{eso-pic} %\newcommand{\placetextbox}[3]{ %   \setbox0=\hbox{#3} %   \AddToShipoutPictureFG*{ \put(\LenToUnit{#1\paperwidth},\LenToUnit{#2\paperheight}){\vtop{{\null}\makebox[0pt][c]{#3}}} %   } %} %\placetextbox{.23}{0.055}{\small{978-1-5386-8007-0/19/\$31.00~\copyright 2019 IEEE}}     \usepackage{cite} \usepackage{amsmath,amssymb,amsfonts} \usepackage{algorithmic} \usepackage{graphicx} \usepackage{textcomp} \usepackage{xcolor} \usepackage{float} \usepackage[export]{adjustbox} \usepackage{subcaption}     % %\usepackage[pscoord]{eso-pic} %\newcommand{\placetextbox}[3]{ %   \setbox0=\hbox{#3} %   \AddToShipoutPictureFG{ \put(\LenToUnit{#1\paperwidth},\LenToUnit{#2\paperheight}){\vtop{{\null}\makebox[0pt][c]{#3}}} %   } %} %\placetextbox{.2}{0.055}{978-1-4799-5522-0/15/\$31.00~\copyright 2015 IEEE}   \IEEEoverridecommandlockouts \IEEEpubid{\makebox[\columnwidth]{978-1-7281-0666-3/20/\$31.00~\copyright~2020         IEEE \hfill} \hspace{\columnsep}\makebox[\columnwidth]{ }}      \thispagestyle{plain}     \pagestyle{plain}     \setcounter{page}{531}   \begin{document}  \title{Performance Analysis of Physically     Unclonable Function Based on Voltage Divider Arrays} \author{\IEEEauthorblockN{Sumit Chaudhary$^{1}$}     \IEEEauthorblockA{\textit{Dept. of Electronics and Communication} \\         \textit{MNIT Jaipur, India}\\         2016pev5165@mnit.ac.in}     \and     \IEEEauthorblockN{Chitrakant Sahu$^{2}$}     \IEEEauthorblockA{\textit{Dept. of Electronics and Communication} \\         \textit{MNIT Jaipur, India}\\         chitrakant.ece@mnit.ac.in}}  \maketitle   \end{document}