Βαπον Καρ

Terminal control Without mouse CTRL + A : come back cursor in first CTRL + E : move cursor in End of line CTRL + U : CUT and copy whole line typed in terminal CTRL + Y : Paste the whole line of commands CTRL + M : Enter SHIFT + CTRL + UP : Scroll up SHIFT + CTRL + DOWN : Scrolling down CTRL + : Zoom In CTRL - : Zoom Out c lear : Clear the terminal screen F10 : Opening File Window F11 : In and out of full screen TAB : predicted command or file DOWN : Last command history : history of last session history | grep test : Searching “test” in history !12 : Going to 12th line history command CTRL + ALT + T : Openup a new terminal window gnome-terminal : also openup a new terminal window CTRL + C : Cancel last job CTRL + D : Close a running job exit : close a terminal window SHIFT + CTRL + Q : To quit the window SHIFT + CTRL + F : To find anything in terminal SHIFT + CTRL + T : To Openup a new tab SHIFT + D : To close a tab SHIFT + CTRL +Q : To close a tab CT...

Hello Friends!  I am writing this blog as I have experienced some problem to installing a Java application which made with Processing IDE.I am using Ubuntu 18.04 LTS version.So in this post I am gonna showing how you can we write a program and install into our Device.First you should install Java into your device.If You are Ubuntu or any Linux User then open your terminal and type the following commands (i)  ~ $ sudo apt-get update (ii) ~ $ sudo apt instal default -jdk Verify the successful install of java by type (iii) ~ $ java version (without ~ $ ); Now let's go to create a linux application with Processcing. Step-1 :Write your Processing Program. Step-2 : Test your program by clicking on Run. Now all are good then move into next step. Step-3: Now click on File menu and go into Exporting Application. Now you select your suitable platform either Windows ,Linux or both.After successfully export you get the applications folder inside of your program fi...

The COVID-19 :The recent Corona virus tragedy in China proposing to ask some questions. 1. Was this a bio weapon?If this is Bio Weapon then who made this? Is it china itself ? Was it a accidental failure or intentional to reduce the population? Was it sprade by other country to get business profit?   It is sure that it is not natural virus which get evolved and become deadly.Is there any past incident where a natural virus get evolved and become deadly in this short time? Now everyone try to find out antidote of this flue .Due to Corona effect many person infected and already many one lost their life(Actually we may not have proper figure .I am saying this as we all know how the whistle blower Chinese doctor Li Wenliang is treated by chinese government and also how do chinese reporters get missing. This incidents may be questioning authenticity of the death and infected persons figures. ),many one lost their job and actually they suffering many many problems lik...

Thirty-one years ago , Dick Feynamn told me about his 'sum over histories' version of Quantum Mechanics.'The electron does anything it likes',he said, 'It goes in any direction at any speed,forward or backward in time,however it likes, and then add up the amplitudes and it gives the wave-function'. 'I said to him,'You're crazy'. But he was't.                                                             - F.J Dyson

Thomas and Fermi independently developed  a theory of complex many electrons atom or ion by choosing fermi gas of electron in ground state.The electrons confined in space by a central potential V(r) where V(r) is zero for large distance(r) from the nucleus. Apart from this assumption they also assumed the variation of potential is very slow in distance very much larger than de'Broglie wavelengths of electron and the thermal energy kT is much smaller than the potential energy in the boundary of the atom.In the near of nucleas potential remain constant .And for large distance its value is zero.Then Schrödinger equation becomes $$\frac{-\hbar^2\nabla^2\Psi}{2m}=E\Psi$$ Which solution gives $$\Psi=C\sin\left({k_x x}\right)\sin\left({k_y y}\right)\sin\left({k_z z}\right)$$ $$k^2=\frac{2mE}{\hbar^2}={k_x}^2+{k_y}^2+{k_z}^2$$ Where we are using the boundary conditions $$\Psi(x,y,0)=\Psi(x,y,L)=\Psi(x,0,z)=\Psi(x,L,z)=\Psi(0,y,z)=\Psi(L,y,z)=0$$ where the solution confined in a ...

The Einstien's mass-energy dispersion relation be$$E^2=c^2P^2+{m_0}^2c^4\space\space(1)$$ Now in Quantum mechanics $$E\rightarrow i\hbar\frac{\partial}{\partial t} \Rightarrow E^2 \rightarrow -\hbar^2\frac{\partial^2}{\partial t^2}$$and $$P\rightarrow -i\hbar\nabla\Rightarrow P^2\rightarrow -\hbar^2 \nabla^2$$ In this fashion we can write $$ -\hbar^2\frac{\partial^2}{\partial t^2}\psi=-\hbar^2c^2 \nabla^2\psi+{m_0}^2c^4$$ $$\Rightarrow  \frac{1}{c^2}\frac{\partial^2}{\partial t^2}\psi-\nabla^2\psi+\frac{{m_0}^2c^2}{\hbar^2}\psi=0\Rightarrow \Box\psi+\frac{{m_0}^2c^2}{\hbar^2}\psi=0$$ This is the Klein-Gordon  equation. This equation solutions  is $$Ae^\frac{i p^\mu x_\mu}{\hbar}=Ae^\frac{i \left(Et-\mathbf{p\cdot x}\right)}{\hbar}$$ Where A is a normalization constant. Now substituting this solution imto Klein-Gordon  equation gives $$E^2=c^2P^2+{m_0}^2c^4\Rightarrow E=\pm\sqrt{c^2P^2+{m_0}^2c^4}$$Therefore Klein-Gordon equation gives negative energy solu...

The Maxwell's  equations are $$(1)\nabla\cdot\mathbf{E}=\frac{\rho}{\epsilon_0}$$ $$(2)\nabla\cdot\mathbf{B}=0$$ $$(3)\nabla \times\mathbf{E}=-\frac{\partial \mathbf{B}}{\partial t}$$ $$(4)\nabla \times\mathbf{B}=-\mu_0\epsilon_0\frac{\partial \mathbf{E}}{\partial t}+\mu_0\mathbf{J}$$ From (3) we get: $$\nabla\times\mathbf{E}=-\frac{\partial}{\partial t}(\nabla\times\mathbf{A})[\because \mathbf{B}=\nabla\times\mathbf{A}]\Rightarrow\nabla\times \left(\mathbf{E}+\frac{\partial\mathbf{A}}{\partial t}\right )=0$$$$\Rightarrow\mathbf{E}+\frac{\partial\mathbf{A}}{\partial t}=-\nabla\phi\Rightarrow\mathbf{E}= -\left(\frac{\partial\mathbf{A}}{\partial t}+\nabla\phi\right)$$ Now electromagnetic field tensor defined as $$F^{\mu\nu}=\partial ^{\nu}A^{\mu}-\partial ^{\mu}A^{\nu}=\frac{\partial A^{\mu}}{\partial x_{\nu}}-\frac{\partial A^\nu}{\partial x_{\mu}}$$   Electromagnetic  Four  Potential  $$ \space A^{\mu\nu}=\{\frac{\phi}{c},A_x,A_y,A_z\}$$ $$F^{00}=...