Earth could shrink to 330ft if particle accelerator fails

Anything that doesn't fit anywhere else below.

Moderators: Calilasseia, ADParker

Earth could shrink to 330ft if particle accelerator fails

#1  Postby the_5th_ape » Oct 01, 2018 6:57 pm

Earth could be reduced to a dense mass measuring just 330 feet across if particle accelerators set off a catastrophic chain of events, the astronomer royal has warned.

In his latest book, On The Future: Prospects for Humanity, Prof Lord Martin Rees, outlines the existential threats facing the planet, which include climate change, nuclear war and artificial intelligence.

https://www.telegraph.co.uk/science/201 ... periments/
Thanking God for sparing you in a natural disaster is like
sending a thank-you note to a serial killer for stabbing the family next door

Question: If you could live forever, would you and why? Best Answer
User avatar
the_5th_ape
THREAD STARTER
 
Posts: 3527
Male

Print view this post

Ads by Google


Re: Earth could shrink to 330ft if particle accelerator fails

#2  Postby scott1328 » Oct 01, 2018 8:27 pm

At least that would finally answer the question: do the continents wind back to a sphere

Also click bait bull shit
User avatar
scott1328
 
Name: Some call me... Tim
Posts: 8227
Male

United States (us)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#3  Postby Keep It Real » Oct 01, 2018 8:30 pm

Perhaps the £££ the Royal as... makes from this book could be formed into an even smaller sphere.
"If liberty means anything at all, it means the right to tell play people what they do not want to hear" - George Orwell

It's not the money that's the problem - it's the occupational therapy.
User avatar
Keep It Real
 
Posts: 6834
Age: 37
Male

England (eng)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#4  Postby Thommo » Oct 01, 2018 8:32 pm

I've never understood these "micro black holes could suck in Earth" claims, last time I studied black holes (and I admit my understanding is lacking in some departments) I was given to believe that the solution in the region exterior to the Schwarzschild radius of a non rotating black hole was identical to that exterior to any spherically symmetric body of the same mass, so I've never understood how the supposed collapse is supposed to take place.

Edit: I really need to fix the spellcheck on my browser. I'm missing far too many typos. :oops:
Last edited by Thommo on Oct 02, 2018 4:09 pm, edited 2 times in total.
User avatar
Thommo
 
Posts: 24727

Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#5  Postby newolder » Oct 01, 2018 8:43 pm

For a mass M, the Schwarzschild radius is (2 G M)/c2.
For an Earth mass that gives about 9 millimetres.
Geometric forgetting gives me loops. - Nima A-H
User avatar
newolder
 
Name: Albert Ross
Posts: 5366
Age: 7
Male

Country: Feudal Estate number 9
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#6  Postby Thommo » Oct 01, 2018 8:55 pm

Sure, but the whole premise (that I don't understand) of these micro black hole conjectures is that some fairly trivial mass (much less than a kilogram) could collapse to a black hole, and then that black hole could expand and feed on the mass of the Earth until there's an Earth mass black hole, destroying the planet in the process.

I do not understand how the gravitational force of a tiny black hole could even theoretically do that. Surely the other forces (electric, nuclear) would prevent that from happening, as the attractive force of a sub kilogram mass is still tiny.
User avatar
Thommo
 
Posts: 24727

Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#7  Postby Keep It Real » Oct 01, 2018 9:01 pm

I don't understand how people can believe in the virgin birth.
"If liberty means anything at all, it means the right to tell play people what they do not want to hear" - George Orwell

It's not the money that's the problem - it's the occupational therapy.
User avatar
Keep It Real
 
Posts: 6834
Age: 37
Male

England (eng)
Print view this post

Ads by Google


Re: Earth could shrink to 330ft if particle accelerator fails

#8  Postby Calilasseia » Oct 01, 2018 9:25 pm

Didn't Hawking establish that micro black holes have a short lifespan? A lifespan of the order of 10-12 seconds or even less?
Signature temporarily on hold until I can find a reliable image host ...
User avatar
Calilasseia
RS Donator
 
Posts: 21855
Age: 56
Male

Country: England
United Kingdom (uk)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#9  Postby scott1328 » Oct 01, 2018 9:46 pm

Thommo wrote:I've never undestood these "micro black holes could suck in Earth" claims, last time I studied black holes (and I admit my understanding is lacking in some departments) I was given to believe that the solution in the region exterior to the Schwarzschild radius of a non rotating black hole was identical to that exterior to any spherically symmetric body of the same mass, so I've never understood how the supposed collapse is supposed to take place.

It is my understanding that a 1 kg sub atomic sized black hole would evaporate into a blaze of Hawking radiation before it could ever do much damage.
User avatar
scott1328
 
Name: Some call me... Tim
Posts: 8227
Male

United States (us)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#10  Postby newolder » Oct 01, 2018 10:05 pm

An Earth mass BH has a Hawking temperature around a few hundredths Kelvin - much colder than the current background temperature of 2.7-ish K so, it shouldn't evaporate for a good while. Getting the Earths mass into a tiny BH produced in a collider is not going to happen for the reasons given already (they are very much hotter and evaporate really quickly) and the topic story is just click bait (also as already noted).
Geometric forgetting gives me loops. - Nima A-H
User avatar
newolder
 
Name: Albert Ross
Posts: 5366
Age: 7
Male

Country: Feudal Estate number 9
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#11  Postby Matt_B » Oct 01, 2018 10:16 pm

Hawking radiation relies upon a blend of quantum mechanics and general relativity, that we already know are irreconcilable theories, in an environment that we've got absolutely no experience of. As such, it's not exactly a rock-solid scientific theory but rather a hypothesis without much in the way of supporting evidence. Until someone detects an evaporating black hole, it's basically just a highly impressive exercise in mathematics.

That said, I'm not too worried about particle accelerators generating micro black holes because they're not even remotely close to the energies that would be required to condense matter sufficiently to form them. Rather, you've got to engage in some similarly speculative physics, the evidence for which is even thinner on the ground than for Hawking radiation, and explain why the universe isn't already chock full of persistent micro black holes when such energies occur naturally in many places, e.g. supernovae and accretion discs.
User avatar
Matt_B
 
Posts: 4242
Male

Country: Australia
Australia (au)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#12  Postby zulumoose » Oct 02, 2018 4:09 am

Thommo wrote:
I do not understand how the gravitational force of a tiny black hole could even theoretically do that. Surely the other forces (electric, nuclear) would prevent that from happening, as the attractive force of a sub kilogram mass is still tiny.


If you had a tiny black hole on the surface of a planet, what would stop that mass from falling to the centre of the planet, gathering mass it encounters along the way as everything close enough to it collapsed into it, clearing a pathway? Once it reaches pressurised molten core or even water it would swallow mass at an exponentially increasing rate.

I don't understand how a black hole can have low mass to start with though, how does it begin if it doesn't have the mass to create itself?
User avatar
zulumoose
 
Posts: 3175

Country: South Africa
South Africa (za)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#13  Postby Matt_B » Oct 02, 2018 5:41 am

zulumoose wrote:I don't understand how a black hole can have low mass to start with though, how does it begin if it doesn't have the mass to create itself?


Purely in terms of general relativity, there is no minimum mass for a black hole. The Schwarzschild radius scales linearly with the amount of mass, so any amount of matter just needs to be above a given density - known as the Schwarzschild density - and you'll get a black hole.

Once you throw some quantum mechanics into the mix though, you can predict a minimum size of black holes at about 21.8 micrograms, because objects can only be so spatially compact before they'd start to violate the Heisenberg uncertainty principle. As ever though, be extremely wary of any physics that combines features of QM and GR.

In terms of what might create them, you'd just need enough extremely high energy collisions to produce a region that exceeds the Schwarzschild density. As mentioned in my previous post, that's somewhat above what you'd expect from any earthbound particle accelerator, but not beyond what might find in some extreme astrophysical environments.
User avatar
Matt_B
 
Posts: 4242
Male

Country: Australia
Australia (au)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#14  Postby zulumoose » Oct 02, 2018 6:09 am

Makes sense I guess, just a bit counterintuitive.

explain why the universe isn't already chock full of persistent micro black holes


How would anyone be able to tell if it was? As long as they weren't frequently encountering suns, they would be undetectable wouldn't they?

In fact if you were in a spaceship and ran into one with enough speed, wouldn't it just pass through the ship, and potentially even your body without being noticed? It wouldn't have enough mass or gravity to be captured and would leave a hole too small for even gas molecules to escape. Right?
User avatar
zulumoose
 
Posts: 3175

Country: South Africa
South Africa (za)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#15  Postby Arcanyn » Oct 02, 2018 7:58 am

zulumoose wrote:
Thommo wrote:
I do not understand how the gravitational force of a tiny black hole could even theoretically do that. Surely the other forces (electric, nuclear) would prevent that from happening, as the attractive force of a sub kilogram mass is still tiny.


If you had a tiny black hole on the surface of a planet, what would stop that mass from falling to the centre of the planet, gathering mass it encounters along the way as everything close enough to it collapsed into it, clearing a pathway? Once it reaches pressurised molten core or even water it would swallow mass at an exponentially increasing rate.


An sub-kilogram mass black hole is so tiny, that it would probably take billions of years for it to have a chance of colliding with anything. And if it did happen to collide with a nucleus, what would happen is that the black hole would acquire a positive charge, which would cause it to repel any further nuclei, and any electrons it manages to pick up would simply orbit around it like they do in any other atom. Such a black hole would therefore end up being bound in chemical compounds, and looking just like an element of atomic number equal to that black hole's charge, just a lot, lot heavier.
Power doesn't corrupt, it reveals. Only when someone is free from constraints and consequences do they show their true character.

Sign the petition for the William Lane Craig/David Icke debate here:
http://www.ipetitions.com/petition/craigickedebate/signatures
User avatar
Arcanyn
 
Posts: 1410
Age: 34
Male

Australia (au)
Print view this post

Ads by Google


Re: Earth could shrink to 330ft if particle accelerator fails

#16  Postby Cirrhosis » Oct 10, 2018 2:06 am

the_5th_ape wrote:Earth could be reduced to a dense mass measuring just 330 feet across if particle accelerators set off a catastrophic chain of events, the astronomer royal has warned.

In his latest book, On The Future: Prospects for Humanity, Prof Lord Martin Rees, outlines the existential threats facing the planet, which include climate change, nuclear war and artificial intelligence.

https://www.telegraph.co.uk/science/201 ... periments/


I was pretty sure that article was by the deplorable Sarah (klickbait) Knapton before I opened the link. As for Martin Rees, I lost all respect for that guy when he took the Templeton shilling.
Cirrhosis
 
Name: Bill Smith
Posts: 5
Male

Country: England
United Kingdom (uk)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#17  Postby Cito di Pense » Oct 10, 2018 2:36 pm

The stupidest thing about crap like this is that electromagnetism is a much stronger force than gravity is at short range. If you wanted to worry about the gas phase, you could assess what temperature is sufficient such that thermal kinetic energy is greater than gravitational potential energy. This means that a black hole of a few kg mass is basically a non-entity when it's surrounded by a bunch of other condensed matter.
Хлопнут без некролога. -- Серге́й Па́влович Королёв

Translation by Elbert Hubbard: Do not take life too seriously. You're not going to get out of it alive.
User avatar
Cito di Pense
 
Name: Ivar Poäng
Posts: 26932
Age: 22
Male

Country: The Heartland
Mongolia (mn)
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#18  Postby newolder » Oct 10, 2018 5:08 pm

zulumoose wrote:Makes sense I guess, just a bit counterintuitive.

explain why the universe isn't already chock full of persistent micro black holes


How would anyone be able to tell if it was? As long as they weren't frequently encountering suns, they would be undetectable wouldn't they?

Apart from their evaporation, they'd be detectable by their gravitational lensing proclivities and there are insufficient to account for more than 40% of the dark matter: https://www.sciencedaily.com/releases/2 ... 102723.htm
Black holes ruled out as universe's missing dark matter

Statistical analysis shows black holes can make up no more than 40 percent of dark matter

Date: October 2, 2018
Source: University of California - Berkeley

Summary:

If dark matter consists of a plethora of primordial black holes, then their gravitational lensing -- magnifying and brightening distant objects -- should be detectable. Physicists analyzed 740 known supernovas to find the handful that should have been magnified and brightened by black holes, and found none. This puts a strong upper limit, 40, on the percent of dark matter that can consist of black holes, and suggests that none of it is.

... Full story @ link.
Geometric forgetting gives me loops. - Nima A-H
User avatar
newolder
 
Name: Albert Ross
Posts: 5366
Age: 7
Male

Country: Feudal Estate number 9
Print view this post

Re: Earth could shrink to 330ft if particle accelerator fails

#19  Postby Thommo » Oct 10, 2018 6:20 pm

That's really interesting.
User avatar
Thommo
 
Posts: 24727

Print view this post


Return to General Science & Technology

Who is online

Users viewing this topic: No registered users and 1 guest