[YAPA] black holes

[Norma Holowach]

My son is asking the following questions:


How can anything fall into a black hole, ever?

I ask this question because time dilation at the event horizon is infinite. This means that an object approaching the black hole will need an infinite amount of time to pass the event horizon (time being that of an observer, such as a telescope on Earth, not the proper time of the object falling in).

This then leads to the follow up question: how can black holes form, ever?

If it takes an infinite amount of time to actually get past the event horizon, how does an event horizon ever form in the first place? Take a collapsing star as an example. Wouldn’t the in-falling matter keep slowing down as time dilation increased towards infinity (from an external observer perspective) and never actually reach the density required to form a black hole?

Am I missing something? Please help!

Norma Holowach, M.Ed
National Board Certified Teacher
Science Department Chairperson
Lakeview High School
300 Hillman Drive
Cortland, OH 44410
(330)637-4921
"Connecting with nature is an essential part of being alive."
National Geographic.


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