The biggest gap in scientific understanding of the universe is what happened in the period called the ‘Cosmic Dawn‘.
Have you ever had to explain to someone where babies come from? Saying a baby comes from Mummy’s tummy might suffice as an explanation for a small child but is is inadequately lacking in detail for helping anyone growing up understand the origins of life.
Scientific explanation for a ‘Big Bang’ from which everything in the known universe was formed seems inadequate until it can be expounded upon in more technical detail.
It seems that black holes are the foundation for understanding what powers quasars, as quasars in Big Bang theory turn into galaxies, galaxies gradually form into solar systems and planets, our planet contains people, people came from babies, and you know how to explain the rest.
There are just parts of space scientists’ explanations unable to account for what really happened in the period from about 50 million years to a billion years after what scientists call the Big Bang. The lack of scientific observation of what happened in the ‘Cosmic Dawn’ leaves everyone puzzled, just in the same way children are often left puzzled about how a baby got into Mummy’s tummy.
For years scientists have run theoretical simulations to create models / predictions of what they think happened to space in the past during the ‘Cosmic Dawn’. As well as making theoretical simulations, it is also possible for scientists and astronomers to be able to observe the past in space.
Telescopes can see the past
Observing the past is quite a hard concept to comprehend, but observing the past is something that astronomers can do with powerful telescopes and space. If you sit across a table and look at someone opposite you right now, you are seeing them in the present.
However, let’s say you are now gazing through the world’s most powerful telescope, the person you are observing right now is not a few meters across from you, but rather you are watching them on another planet billions of light years away, scientists would say that you are not observing that person in the present, but rather the actions of what that person was doing in the past, they could even be billions of years dead.
If it was possible to observe alien civilizations billions of light years away we would not be seeing them as they currently are, but as they once were, the same is true for observing anything else in space, whether it is a galaxy, a star, a black hole. Scientists get very excited when they see something further away than they have seen before.
The past is changing
Space scientists and astronomers try and look further and further back into space, because the further they can see back in space, the further they believe that they can see in the past.
The simple answer to finding out what really happened in the ‘Cosmic Dawn’ on one level is a very straight forward one. The bigger and better the telescopes scientists have, the further they can see into space, the further they can see into space, then the further they can see back in time.
However, it would be a straightforward issue as this, but for two factors, dark matter, and the fact that space is expanding. While humans are building bigger and better telescopes the rapid expansion of space and our lack of ability to understand dark matter, the harder it is to observe and explain what the ‘Big Bang’ really was or look far enough back into space and time to see events close to the time of the ‘Big Bang’.
Certainly, it is hard to see what black holes were doing around the time of the ‘Big Bang’ because black holes unless they are reacting with light, are black. No scientist can really lay the claim that they have seen the furthest black hole away ever, when there is nothing to see but black unless the black holes are actively drawing in light.
Astronomers cannot necessarily use powerful telescopes to see-through atmospheres of planets or in granular detail of what is going on in galaxies and black holes, they are mostly working with light, radio waves, and describing light.
The latest theory since observing the furthest star ever seen, is scientists now think that the big bang may have happened around 14 billion years ago. This is the target point astronomers want to be able to observe back to, to see the original effects of the ‘Big Bang’.
Observing a black hole in the past can tell us a lot about our future
If a scientist can see evidence of a remote black hole reacting with light such as a luminous quasar at a distance that puts it in the period of 13 billion years ago, they are much closer to seeing and understanding the beginning, the role and the effect of black holes in the ‘Cosmic Dawn’. This is exactly what is happening now with the lights that they have observed in an area of space scientists have named GNz7q.
In the early universe quasars were highly luminous objects powered by supermassive black holes. When quasars finished accreting surrounding dust and gas, quasars became ordinary galaxies, of which there are billions of galaxies in the universe. The galaxy which we live in is called the Milky way is just one among billions. Each galaxy is gigantic and consists of dust, gas, billions of solar systems for billions of stars. The Milky Way our galaxy also has a supermassive black hole in the middle. What scientists can learn about this distant black hole will teach them a lot about what happens next in the Milky way.
What scientist Fujimoto has observed now in the remotest part of the universe, happened around 13 billion years ago, because that is how long they believe light takes to travel back to them. What Fujimoto has observed recently is back at that time, the host galaxy of GNz7q was incredibly active, forming around 1,600 solar masses of stars per year. This would be consistent with ‘Big Bang’ theory belief of many formations caused by the effect of the ‘Big Bang’. Fujimoto can observe an early black hole rapidly growing into a supermassive black hole.
The interactions of this black hole and the light around it in GNz7q, is happening at a time that Fujimoto believes was 750 million years after the Big Bang, making it in scientific estimation the earliest black hole ever observed.
That black hole in GNz7q, 13 billion years later in our present time may still be lurking around, but it will be exponentially bigger. It could be like the two Blazars that scientists have recently predicted will collide in 10,000 years time, or even bigger like TON 618 which has a mass of 66 billion solar masses.
The interesting thing about this finding is that GNz7q aligns with theoretical predictions of what scientist Fujimoto believed an ‘ancestor’ to supermassive black holes might look like. Fujimoto thinks there could be many more like it.
Feature image credit: NASA, ESA, N. Bartmann