Black Holes aren't really Holes in space!?

 Structure of Black Holes in space - Explained

Black holes in space: Ruptures in spacetime?

It is no surprise that there are a lot of misconceptions when it comes to mysterious deep space objects like black holes. This is partly because we still don't have a completely accurate idea about their properties or their strange effects on space and time. 

But one of the most popular misconceptions about black holes is their structure and conformation in the 3-D space. 

Do we really know what a black hole looks like in space? And no, we're not talking about the funnel-shaped black hole diagrams that we find on internet images or magazines, nor do they show the accurate representation of a black hole's 3-D structure. 

So, if those are not an accurate representation of a black hole, then what is the real depiction of a black hole?  Or can we even imagine what a black hole in 3-D space would really look like?'

Black holes are not what they seem to be...

 Black holes are clearly not what they seem to be, starting with their name. To understand the structure and orientation of a black hole in space, we need to first digest the fact that a black hole is NOT a hole in the first place! 

A black hole is a region in spacetime where gravity is so intense that not even light can escape from it.

To be more specific, a black hole is a 'point' in 3-D spacetime that is so dense that its gravitational pull causes the spacetime to distort around the region. This means that this region of a black hole can be thought of as a sphere rather than a 'hole' or a 'funnel' which is how it's commonly depicted in figures. The reason why it's portrayed as a funnel or a hole is to show the extent of curvature of spacetime around a black hole and to identify its boundary or the event horizon. This might be a bit hard to process if we think about the existence of hypothetical physical entities like white holes and wormholes, similar to black holes. But since we haven't yet directly (or indirectly) observed these seemingly mathematical entities, let's just not worry about it for now.

The effect of curved 3-D spacetime caused by a black holes' gravitational field can cause weird optical illusions around it, effects like gravitational lensing and time warp, which is why it is so popular in sci-fi culture. But then again, it would be hard to deny the fact that the depiction of black holes in sci-fi movies like Interstellar has fully done justice to its majestic structure and appearance of what it would look like in spacetime. 

A property that most affects a black hole's appearance (that depends on its orientation in space) is the mind-boggling phenomenon of 'bending of light'. It is important to note that the light is not necessarily being 'bent' around a black hole, rather, it is just the curved spacetime that compels the light to travel in a curved distorted path. 

The fact that light travels in a straight line through our spacetime is only applicable when the spacetime is linear (without any curvature). But in extreme conditions, when spacetime is extremely distorted (like in a black hole or a neutron star) the light is actually travelling in a straight line, but because the spacetime itself is distorted, light appears to follow the same curved, distorted path around such massive objects. This is the same phenomenon occurring in gravitational lensing and time dilation. 

That being said, due to these effects of distorted spacetime, the image of the accretion disk around an active black hole can also appear as distorted for an observer. Moreover, the orientation at which an observer is viewing the black hole could also affect the appearance of that black hole. 

For example, the first image of the black hole M87 captured by the Event Horizon Telescope shows the silhouette of a bright ring (the accretion disk) surrounding the black hole. This is because the image was captured from an angle perpendicular to the plane of the vent horizon of M87. 

                                

However, if the image was captured from any other random angle other than 90°, we'd get an image that looks like Gargantua, the Interstellar black hole! In this case, the image of the part of the accretion disk that is behind the black hole is visible around the 'circumference' of the black hole, since the light emerging from the accretion disk follows the curved path of spacetime which is orbiting the black hole. This is why scientists claim that you can see the back of your head if you're near the event horizon of a black hole since the light that forms an image of the back of your head actually travels (orbits) all the way around the black hole and reaches where it started off. Pretty mindblowing isn't it? 

Well, if you're feeling too overwhelmed by these optical illusions produced by black holes, better get used to it. Because who knows? - there might come a time when we travel through extra dimensions and alternate universes through wormholes and futuristic space ships!

Want to know more about the black hole image?  

Visit How to Understand the Black Hole Image - Veritasium

To read more about Time Warp in Black holes - CLICK HERE