NASA Astronomy Picture of the Day - What is this in front of the Sun?

Just see the NASA's  Astronomy Picture Of the Day on July 15 absolutely gorgeous and spotless sun in HD. But without googling it could you guess what is that spot that seems to be hanging there in the top upper left limb of the sun's image?

If you guessed it right could you calculate its' distance from the Earth with the aid of a bit of googling.

A new challenge ! Work it out...

NASA APOD - JULY 15 - THE SPOTLESS SUN WITH A TWIST
CREDIT:Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman (FOR THE EDUCATIONAL PURPOSE ONLY)

Fresnel Diffraction of Green Laser Light by Floating Dust Specks on Polymer Gel Balls

These Fresnel diffraction patterns of minuscule dust particles can be easily observed by passing green laser through polymer gel balls and projecting the image on a screen,wall or ceiling. The dust specks floating on the surface of the polymer balls got very much enlarged in their image by the lens action of the transparent polymer balls beyond the diffraction limit. As a result one can see beautiful alternating bright and dark rings around the image of dust specks which overlap with each other to produce a mesmerizing effect. 

A humble demonstration set up I used at home is shown below:

A few of the diffraction images obtained with the method are show below:

Finally the Magic only a 3D Surface Plot can do...

 

THE CASTLE OF DIFFRACTION WHERE THE GRAND MAGICIAN HAD HIDDEN THE PRINCESS RESOLUTION

ANOTHER FRESNEL LANDSCAPE

A History of Our Sistor (((P)un)intended) Who Transcends Limits

Fresnel Lens

FRESNEL LENS AT A LIGHT HOUSE

Challenge of the Month - July 2019

Here we are beginning another new section in our blog. There would be simple physics problems posed in this section and the challenge is to solve them in the most elegant manner possible.

Watch the following video carefully and try answering the questions that follow:

Q1. What is the physical fact the video demonstrates?

Q2. What is the length of the rope the guys are swinging with? 

The answer can be posted in the comment box or my students can approach me in person to provide a solution to the problem or more enthusiastic friends can contact me @ kazsyednew@gmail.com.I can't reward the problem solvers but I shall site their answers with credits.