What are Gravitational Waves ?

Gravitational Waves are assumptions from the curious minds ever, Albert Einstein. They are the ripples caused in space-time sheet due to the motion of masses.

Gravitational waves are produced whenever masses accelerate, changing the distortion of space-time fabric. Everything with mass and /or energy can cause ripples. As gravitational waves rolls by it will squeeze and stretch anything in its path but in a very infinitesimally small change which makes it extremely difficult to detect.

So to detect these ripples we use the idea of the time taken by the light to travel is more when the distance increases and less when distance decreases, which is what the principle used in the interferometer. Thus LIGO experiment comes into the picture.

LIGO - Laser Interference Gravitational-wave Observatory.

Here 4km long tunnels are set up where lasers are used to measure the change in distance between the ends of the tunnels.

So when Gravitational wave comes in contact, it elongates space in one direction and squeezes in another direction. By measuring the interference of lasers physicists can precisely conclude about these waves and its incredible as we surely need a smart analysis as it can easily be confused with the other existing waves and disturbances as they are very minuscule.

 Here is the data recorded from LIGO Livingston and LIGO Hanford.

Gravitational waves are helpful in detecting the universe in a whole new way. 
They are significant.


So to know more deeply :
https://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.116.061102






“The important thing is not to stop questioning. Curiosity has its own reason for existence. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvellous structure of reality. It is enough if one tries merely to comprehend a little of this mystery each day."

Casimir Effect

Scientists are often astonished observing the moment of things around, on their own with no visible force acting on them. 
When two mirrors which are later called the Casimir plates, placed in a strong box maintaining one-atmosphere pressure at 100 nanometers apart move towards each other with no well-known forces between. Here comes the Casimir effect into the picture.
This was discovered by Hendrick Casimir in 1948 and named after him.

To understand the Casimir effect we have to first know these bullet points:

• Heisenberg's Uncertainty Principle proposes that both the position and momentum of a subatomic particle cannot be determined simultaneously.                                                                                                                                                   And also energy and duration cannot be predicted simultaneously. Thus particles don't have both nill energy and duration. Therefore particles that don't exist can even have a high chance of having huge energy causing duration and forcing them to exist for a very short period. These are called virtual particles which further turn up into matter and antimatter to annihilate rapidly.
• Wave-Particle Duality says us that particles can turn into waves and again into their particle nature.
• Stationary wave theory tells us that only a finite number of waves can exist in closed space which is generally termed as Harmonics.
• Infinities are distinct which means decimal infinities are greater than real number infinities. Thus a number of waves exist outside the mirror
• Force exerted is generally defined to be the change in momentum times the inverse of time. We know that there are a number of virtual particles outside the Casimir plates than in between and thus they exert more force than the particles in between them.