How did 'escape velocity' contribute to the idea of black holes?

The idea of black holes goes back to the 1780s and 1790s. There were two physicists working at the time that had the same idea independently of each other. One was a clergyman called John Michell and the other was the great French mathematician, Pierre-Simon Laplace. And they were both thinking in terms of an idea called 'escape velocity.' The escape velocity is the speed you have to travel to completely escape the gravitational pull of an object. Physicist Brian Cox on how escape velocity lead to the idea of black holes.

[L.I.T.H.I.U.M]

Never heard a better explanation of black holes. Brilliant!

[nianov]

I've been studying astronomy for more than ten years and this is the best explanation of blackholes I've ever heard

[cenkcankaya]

When this guy explain something, no matter how hard it is, I understand it😂

[vedurupakamourya]

The perfect explanation/ introduction to the idea of black hole ❤

[sunshinelizard]

This is the first time I understand why we can't see black holes - the light can't escape the gravity. I've never understood that before but he provided the most basic, simple example. TY!

[scw]

Never considered that Black Hole could be emitting light, but their gravity prevents it leaving its event horizon.

[Jay-njrq]

I’ve watched endless content talking on black holes, but I never heard this way of thinking. You just blew my mind

[georgesheffield]

Excellent and different way of explaining why a black hole is a black hole .

[faluffel]

I've been interested in this stuff for ages, but this is the first time I have heard such an elegant presentation of the concept. It's not even scary to think of it in this way 😂

[polycrystallinecandy]

This is a great explanation. There's something I'd like to clarify: escape velocity is the velocity needed to escape an object's gravity if you're NOT constantly applying a force. For example, if you threw a ball up at 11 km/s, it'd escape earth's gravity. However, if you attached a rocket engine to it which continuously pushes it, it can escape the gravity even at a lower speed. In fact, if you had a very tall ladder, you could climb up it out of the gravity well at a leisurely pace, since your legs keep applying force. However, with a black hole, there's no coming out of it even if you are constantly pushing.

[germinatorz]

I might be wrong, but I believe the term for this back then was “dark star”.

[georgeallee]

Absolutely BRILLIANT way to explain it

[drumset]

I took Earth/Space science many years ago. This video, in less than 60 seconds, was eye opening for me about black holes.

[tonyjohnson]

The logic in this is so primal you ponder why was the idea of blackholes ever doubted

[techwsina]

I've been familiar with it for years, but I didn't know this explanation! Makes a lot of sense.

[adamthestimator]

I’ve never heard an explanation of a black hole before.
I’m glad this is the first one I heard.
It’s done so well that I can understand it well enough to tell someone else.
Well done!

[MrPretends]

It almost felt like a plot twist at the end 🔥

[pcbasics]

Thanks to Professor Cox’s simple explanation I now have a much better understanding of what is referred to as a Black Hole. Thank you Prof. Cox!

[rpomphdez]

Beautifuly explained! Thanks for sharing!

[RayOpp]

Never imagined the concept. So brilliant that you can take something people can read the principles and theories of and grasp to some existent, and tell them something that totally makes sense they have never seen articles or heard in lectures which helps them imagine it conceptually