Ancient Black Holes: Furnaces of the Universe

black hole

Black holes take the role of “furnaces of the universe.” This is because black holes are responsible for a process known as “cosmic heating.” Cosmic heating occurs when a black hole heats the gas left over from an exploded star and smears it throughout the universe. This is not to be confused with the cosmic microwave background radiation, which is the uniformly distributed heat imprinted into radio waves left over from the initial big bang. Until recently, scientists believed cosmic heating occurred early in the history of the universe, serving as a kind of archaic space heater. However, recent research suggests cosmic heating occurred later in the history of the universe than previously believed.

The study was recently published in Nature and was co-authored by a pair of scientists from Columbia University and Harvard College. When and how the earliest stars formed is a very exciting field of study in astronomy. Unlike archeologists, astronomers can directly observe the past. This is because light travels at a finite speed. The further away an object is, the longer it takes for the light emitted by that object to reach the human eye. When scientists peer into the depths of space, they are peering into the past. The hydrogen that comprised the first stars in the early universe is imprinted in radio waves. Therefore, the team of researchers observed the first stars in the universe by measuring the hydrogen emission in radio waves.

Since the research suggests that cosmic heating occurred later than previously believed in the universe’s history, astronomers do not have to stare as far into space to observe the first stars. In addition, cosmic heating can help astronomers gain a better grasp regarding the earliest black holes to populate the universe.

Cosmic heating is believed to be fueled by “binary black holes.” This occurs when two stars are tied into each others’ orbit, like two fiery brethren strung together into a single cosmic dance. Yet the happiness of this couple soon ends. Eventually, the downward gravitational pull of one of the stars overcomes the nuclear reactions upholding the star. This causes the star to collapse into a black hole. A black hole causes the space and time within its vicinity to funnel down into a void of nothingness. So it is an extraordinary disturbance in the very fabric of space and time. Our intuitions about the nature of the universe are abandoned somewhere between the horizon of a black hole and a singularity. In addition, the black hole chews, swallows and spits out the gas left over by its fiery brethren, thus causing the universe to heat up.

Large international groups of astronomers have constructed radio telescopes on the assumption that cosmic heating occurred early in the universe. This is because it was thought that the hydrogen atoms emitted by black holes would have been broken up and spread between galaxies. The researchers findings overturn this common view and suggest these telescopes will be able to detect the heat emitted by the vestiges of the oldest black holes in the universe.

By Nathan Cranford


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