Black Holes and White Holes!

By S. Raghavan, Class 8, Ramana Vidyalaya

When and how does a star die?

When a massive star reaches the end of its life, its core starts running out of fuel. The core is no longer able to hold the star back, resulting in its collapse. The star's core loses the energy needed to push outward against gravity. Gravity, the force that pulls everything inward, becomes dominant. As gravity takes over, the core starts to squeeze. This compression leads to a significant increase in temperature.

Supernova:

Normally, stars create new elements in their core by squishing atoms together. However, when the core gets extremely hot, this process halts, and the star can no longer generate new elements. In some cases, after the core collapse, the star undergoes a spectacular explosion known as a supernova. This explosion is a powerful release of energy and can outshine entire galaxies for a brief period.

The Black hole:

The collapsing core becomes incredibly dense, forming what scientists call a singularity — a tiny point with infinite density. The singularity's immense mass creates gravity so strong that nothing, not even light, can escape it. The region around the singularity establishes a boundary called the event horizon. Once something crosses this boundary, it is pulled in, and its presence becomes invisible from the outside. The mysterious object created by this process is known as a black hole. Thus, we can say that a black hole is born when a star dies.

Do you know the distance of the nearest Black hole to Earth?

As of the last update in January 2022, a black hole is situated in the constellation Monoceros, which is approximately 3,000 light-years (2838×10^13 km) away from Earth.

Hypothetically, what if you fell into a Black hole?

If you were to fall into a black hole, the experience would be extreme and, according to our current understanding of physics, quite peculiar. According to Einstein's theory of general relativity, time near a massive object, like a black hole, passes more slowly than in regions with weaker gravity. As you get closer to the black hole, time would appear to pass more slowly for an observer outside the black hole. For you, falling in, time would seem to pass normally.

Once you cross the event horizon, there is no turning back. The event horizon is the point of no return, and anything that passes beyond it is inevitably pulled into the singularity at the center of the black hole. What happens to an object inside the singularity is not well-understood. Some theories suggest that the object's mass becomes part of it.

Are there any White Holes?

As a matter of fact; yes! White holes are hypothetical objects in theoretical physics that are essentially the reverse of black holes and which is also know as the black hole’s neglected twin. White holes are theorized to be objects from which nothing can enter, and considered to expel matter and energy out of it.

What are Wormholes? Do they really exist?

Wormholes are speculative structures arising from Einstein's equations in theoretical physics. They operate within the framework of general relativity. This theory states that mass and energy can curve the fabric of spacetime forming the basis for the potential existence of wormholes which are tunnel-like structures connecting distinct points. This speculation raises prospects for novel forms of travel, including the theoretical potential for time travel and teleportation faster than light, utilizing the curvature of spacetime near these structures.

This idea envisions a shortcut through spacetime. Wormholes could hypothetically connect a black hole on one end to a white hole on the other.

But as of now, there is no experimental evidence confirming the existence of wormholes.