Black Hole ‘Hum’ Offers New Way to Measure the Universe’s Expansion
Scientists might have found a new way to measure the universe. They are looking at black hole collisions. This method could solve a big problem in cosmology. It is called the “Hubble tension.”
What Is the Hubble Tension?
First, we need to understand the expansion of the universe. It is happening right now. But how fast is it expanding? That number is the Hubble constant. The problem is that different measurements give different answers. One method looks at the early universe. It uses light from the Big Bang. This gives a slower expansion rate. Another method looks at nearby stars and supernovas. This gives a faster rate. This disagreement is the Hubble tension. It is a major puzzle for experts.
Black Holes as New Tools
Now, researchers are using gravitational waves. These are ripples in space-time. They happen when black holes merge. These mergers are extremely powerful. Scientists call these events “standard sirens.” They tell us how far away a crash happened. Usually, we also need to know the galaxy to measure expansion. But a new method uses the background “hum” of all black holes.
Physicists from the University of Illinois and the University of Chicago developed this idea. They call it the “stochastic siren” method. It looks at signals from many faint black holes. We cannot see them individually. However, their combined hum is powerful. The strength of this hum depends on the universe’s expansion. If the universe expands slowly, there are more collisions in a smaller space. This makes the hum louder. By studying this sound, scientists can rule out slow expansion rates.
A New Path Forward
This method is still new. However, it is already helping. It provides an independent way to check the numbers. As detectors get better, the measurements will improve too.
Therefore, we might solve the Hubble tension soon. For now, this gives cosmologists a fresh perspective. It proves that black holes are not just cosmic vacuums. They are also tools for understanding our universe.
