ERGOSPHERE
- SCI & TECH
News:
Ergosphere: Making a
rotating black hole work
What's
in the news?
●
Rotating
black holes (a.k.a. Kerr black holes) have a unique
feature - a region outside their outer event horizon called the ERGOSPHERE.
Key
takeaways:
●
A black hole is formed when a really massive star runs out of fuel to fuse,
blows up, leaving its core to implode under its weight to form a black hole.
●
The centre of a black hole is a gravitational singularity, a point
where the general theory of relativity breaks down, i.e. where its predictions
don’t apply.
●
A black hole’s great gravitational pull
emerges as if from the singularity.
●
It is possible to extract matter and
energy from the ERGOSPHERE as per some scientists.
ERGOSPHERE:
●
It comes from the Greek word ‘ergon’ that
means ‘work’.
●
It has got its name because it is possible
to get energy and even mass from this
place.
●
It is the region in between the event
horizon and the stationary limit.
●
Event
Horizon - It is a sphere around the singularity of a Black
Hole. When anything enters this sphere, it can’t escape unless it travels
faster than light (which is impossible).
●
Stationary
Limit - It is a surface around the outside of a rotating
black hole.
Shape:
●
An ERGOSPHERE is shaped like an oblate
spheroid, or a pumpkin.
Features
of Ergosphere:
●
In this region, space-time itself is
dragged along with the rotation of the black hole.
●
Objects within the ergosphere are forced to rotate along with the black
hole’s spin due to the distortion of spacetime caused by its immense
gravitational pull.
Significance:
●
It is possible to send an object into the
ergosphere. The object then can be allowed to accelerate there along the black
hole’s direction of rotation. This may allow the object to come out moving
faster. This energy ‘gain’ will translate to the black hole to lose some
angular momentum. Hence, it may be possible to extract matter and energy from
the black hole.
Go
back to basics:
Black
hole:
●
It is a region of spacetime where gravity is so strong that even light can not escape.
Gravitational
Singularity:
●
The centre of a black hole has a
gravitational singularity, a one-dimensional
point.
●
This point contains a huge mass in an
infinitely small space, where density
and gravity become infinite. Here, laws of physics cease to operate.