Example 5.7; Application of Ampere’s law.

The following problem is an interesting application of Ampere’s law apart from usual applications found in honors syllabus (eg infinite straight conductor, Solenoid and Torroid). This is to be found the excellent book by Griffith on Electrodynamics. 

Find the magnetic field of an infinite uniform surface current K (vect) = K i-cap, flowing over the XY-plane.

Lets first visualize the problem. This will help us solve the problem. We chose a Cartesian coordinate system as shown. Our infinite surface current is a sheet that is concurrent with the XY-plane. We also show the Ampere loop which is a rectangle of length l parallel to the y-axis. This loop is half above the XY-plane and half below. 

Why light would curve under gravity?

Everyone was thinking in terms of physics (i.e. force). Einstein knew one part of that is maths, pure maths. Force is physics because of mass. But acceleration is geometry, its the shape of your trajectory and its maths.

Imagine a pipe which is horizontally fitted across a wall. Now water jet is flowing through it, inside of it. Now that wall is on a rotating base. You rotated the wall downwards. The pipe is inclined downward, water streams across downward.

Now imagine you have a torch light fixed to one end cap. You get a horizontal output of light. Now the wall is rotated downward, obviously the light will also stream across downwards.

The mass of the water or light did not matter. Because they are guided by the pipe and wall.

The same thing happens in the universe. The space is what carries mass, and it carries all physical phenomena including light. When that space itself is inclined (warped, rotated or receded or whatever) light would follow a curved trajectory just like any object of mass would. Space is what holds them, matter and light. Space curves under gravity.

User experience @ M DASH F dot ORG — optimization issues.

I was doing some research on optimization of my website. This is what I found.

Good news: My website is optimized for mobile devices, 15% better than some of the best blogs around the world. That means if you have been accessing my websites on your mobiles, you have been happy about your loading experience.

Bad news: My website optimization for desktop is 25% worse than these other sites.

If you have accessed my website from a desktop computer please don’t use curse words.

I am trying to fix the issues. — Its due to 3rd party rendering issues, like Java script and CSS styling codes.

Aerial view of Bhabanipatana

The video shows a beautiful video of the city of Bhabanipatana — alternated to  Bhawanipatna due to influence of Hindi, in the district of Kalahandi of the state of Odisha. The name Kalahandi might invoke a stark sense of depravity as it brings to memory the notoriety of poverty associated with the KBK districts and the perpetual image of the state itself as a residence of the poorest of poor. But reality is as startlingly contrasting as this video shows.