The Black Hole Tipping Point

This video is about the Schwarzschild radius of a black hole, (its "event horizon"), and how much mass and density is required to reach the point of no return where an object like a star, neutron star, red giant, etc will collapse into a black hole singularity. You can calculate it yourself using just the volume equation for a sphere, and the equation for the Schwarzschild radius (and knowing the speed of light and Newton's gravitational constant).

REFERENCES

MinutePhysics is on twitter - @minutephysics

Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!

Created by Henry Reich

[John_NYT]

I like how cats are an official unit of measurement on the internet.

[thewatcherinthecloud]

Medicine's preferred test animal: Mice
Biology's preferred test animal: Frogs
Mathematics' preferred test animal: Rabbits
Physics' preferred test animal: Cats

I wonder what chemistry's preferred test animal is.

[theCodyReeder]

A cat has a density of just less than 1g/cm^2 no math needed I just put a cat in a tub of water. I am regretting that decision though.

[ShirleyCurryTheOlderGamer]

In reading the comments I'm so happy to see how many know about Schrodinger's Cat, the double-slit experiment, and String Theory!!

[colinsmith]

... "How to turn your cat into a black hole." ... Awesome, man.

[thenotflatearth]

If I fall into a black hole, will my family receive money from the insurance company?
Because the lawyers and everyone in the company will observe from the outside of the black hole, meaning they can always see my red shifted shape on the event horizon. Which means to them, the accident hasn’t happened and never will, because they will never see me fall into the black hole, but only me falling but slowing down and becoming redder constantly. But from my perspective I did,

[MegaPhester]

Internet police will scratch their heads when they see the thousands of searches on cat density and nuclear physics...

[ElisaCecconello]

"Ferb, I know what we are gonna do today!"

[stevehenderson]

4:10
Google is going to wonder why so many people are looking the the density of a cat

[TheOneTrueLeo]

So do I feed the cat until it becomes big enough to collapse into a black hole or do I start rolling up enough cats in a ball? Please clarify!

[billrussell]

This is one of the best simple physics videos I've seen in a while that actually shows some of the mathematics, and recognizes the man that gave it to us!!! Thanks so much for producing it!!!

[Dandelion_Stitches]

TIL cats aren't as dense as rocks. I don't know if my observational data corroborates that though, at least not when they jump on my chest at 3 in the morning.

[yanivhekter]

Let's assume that cats' density is exactly 1 g/cm3, the mass of the black hole will be 136, 000, 000 sun masses with a radius of 401, 200, 000 km.

[bismoose]

"Cats, The Sun and Earth aren't black joles... *yet* "

Ok, Henry, calm down

[mikew]

I live with two black cats. To one of them, I explained what a yoctometer is. To the other, I described the difference in density between cats and rock. Despite the small sample size, I'm confident that I measured a nearly identical effect for each. Both cats ignored me, one slightly more emphatically than the other but within the range of error. Cats don't care about black holes, Henry. Even black cats.

[kenj]

Assume a spherical cat of uniform density...

[thechaosgardener]

Lots of theoretical cats are getting theoretically harmed in theoretical physics.

[HotelPapa]

1:57 It's actually the other way around. In a supernova the mass of the star is so large that, lacking more radiation pressure of new fusion, it collapses into a black hole anyway. The supernova is a result of the rebound of neutrinos generated in the process racing through the material of the star still outside the Schwarzschild-radius.

[beastslayer]

4:10 - I challenge you....
Me - challenge declined

[chimkinNuggz]

Why make blacks holes out of cats when u can just put a cat in a box and predict it is alive and a blackhole at the same time