Ask Dr Bec: What are black holes and why are they so scary?

What are black holes and why are they so scary? Katarina, age 15

Black holes are some of our universe’s most mysterious, and somewhat terrifying, phenomena!

Imagine a star that’s way bigger than our sun—over 100,000 times bigger—running out of fuel and collapsing under its own gravity.

When this happens, it squeezes the leftover material into a point called a singularity, which is super tiny but has an insane amount of mass.

This creates a gravitational pull so strong that nothing can escape it—not even light itself.

Surrounding the singularity is something called the “event horizon”, which acts as an invisible boundary.

There’s no turning back for anything crosses this line no matter if it’s a Rocketship, a star, or a beam of light.

Their incredible power to pull things inwards means that they can warp space and time, pulling everything nearby into their depths.

While not every galaxy has one, many spiral galaxies, like our Milky Way, have a supermassive black hole at their center, like Sagittarius A*, which is over 4 million times the mass of our sun.

The reason that the earth doesn’t fall into it is because we’re too far away. 25,000 light years to be exact.

You’ll be glad to know that our sun won’t actually turn into a black hole when it eventually dies—it’s simply not big enough.

Instead, once it has exhausted all of its nuclear fuel it will turn into a white dwarf, which is far less dramatic and will cool down over billions of years.

Black holes can be both fascinating and, sometimes a little frightening, reminding us just how wild and mysterious the cosmos can be!

Narrabri-based scientist Dr Bec Thistlethwaite will contribute a regular column to The Courier on the science in our daily lives. Readers are invited to send their science questions in to Dr Bec via [email protected]