Could a black hole evaporate?
(By Ali Yazbek)
Actually, we are talking about Hawking radiation; a theoretical phenomenon proposed by physicist Stephen Hawking back in 1974.
It suggests that a black hole could emit radiation due to quantum effects near their event horizon.
(By Ali Yazbek)
Actually, we are talking about Hawking radiation; a theoretical phenomenon proposed by physicist Stephen Hawking back in 1974.
It suggests that a black hole could emit radiation due to quantum effects near their event horizon.
This implies that the black holes are not completely black and could eventually evaporate over time!
Let's break it down:
Let's break it down:
The quantum effects that we're taking about here are quantum fluctuations (see that empty space is not really empty! It is field by quantum fluctuations- this is where particles and anti-particles pair constantly "pop" in and out of existence.
this particles are known as "virtual particles" and there are pretty fundamental aspect of quantum field theory!)
normally these particles would just "annihilate" each other pretty much immediately,
normally these particles would just "annihilate" each other pretty much immediately,
but what Hawking was suggesting that if the pair production happens very close to the event horizon of a black hole, the intense gravitational field could separate them, so if one particle in a pair was to fall into the black hole and the other particle was to escape
the particle that escapes becomes real -converting it from a virtual particle to a real particle in our universe- and this escaped particle is what we call "Hawking radiation".
Now, how does this lead to evaporating black holes?!
In order to conserve energy, the particle that falls into the black hole effectively, has a negative energy, and this means that the black hole loses a tiny amount of its energy or mass every time it emits Hawking radiation.
In order to conserve energy, the particle that falls into the black hole effectively, has a negative energy, and this means that the black hole loses a tiny amount of its energy or mass every time it emits Hawking radiation.
Over astronomical time scales this could lead to a decrease in the black holes mass and energy, theoretically, causing it to evaporate completely. Although this process would actually take much longer than the current age of our universe.
We haven't actually "observed" this directly...
The radiation would be so faint even for a typical stellar black hole, detecting it from earth is just way beyond our current capabilities and technology.
The radiation would be so faint even for a typical stellar black hole, detecting it from earth is just way beyond our current capabilities and technology.
But the concept it self is really significant in theoretical physics because it's one of the very few phenomena that connect quantum mechanics i.e virtual particle with general relativity black holes gravitational field,
it highlights a possible way in which this two fundamental theories could actually be united.
Loading suggestions...