I need some things described in Layman's terms

[neko]

I was reading about the Large Hadron Collider (http://en.wikipedia.org/wiki/Large_Hadron_Collider) and then about black holes. (http://en.wikipedia.org/wiki/Black_hole) I am a little bit confused about these two things.

First of all, can someone explain to me in really simple terms how the Large Hadron Collider can apparently destroy Earth or even the entire universe? It says:

As with the Relativistic Heavy Ion Collider (RHIC), people both inside and outside of the physics community have voiced concern that the LHC might trigger one of several theoretical disasters capable of destroying the Earth or even the entire Universe. These include:

* Creation of a stable black hole[7]
* Creation of strange matter that is more stable than ordinary matter
* Creation of magnetic monopoles that could catalyze proton decay
* Triggering a transition into a different quantum mechanical vacuum (see False vacuum)


I don't understand what any of those things are and reading the wiki entries on them doesn't make any sense either.

Second of all, black holes just confuse the shit out of me. I know very basic things about them such as that if you go past the event horizon there's no way to get back, that light can't escape, you'll get crushed immediately, etc etc. Apart from those I just don't understand them at all. I just need someone to really explain them to me.

Thirdly, I am confused about the Universe. Inside the Universe there are obviously places like galaxies that hold stars and such, but what is between every galaxy? Are there just random stars between galaxies or is there something that holds the galaxies too that isn't just the universe (for example something that holds galaxies in it in the same manner that galaxies hold stars)?

[Ch33zy]

Black holes arnt actualy holes. Just ultra dense matter. You would just get ripped to pieces at the atomic level. And in between galaxies I would imagine there is an incalculable amount of matter simply too far from a major source of gravity to do anything.

[pk!]

Between the galaxies are stars, hydrogen and immense clouds of pure alcohol.

Galaxies are just collections of stars - they don't hold things in themselves, they just are, like a town is a collection of buildings - not a net that contains them.

As for black holes, common sense doesn't apply there, so you can't get an intuitive feel for them - areas of such extreme gravity are so far outside our normal experience that we lack the mental tools to deal with them except mathematically.

Any black hole crated by the LHC would soon disappear through Hawking radiation http://en.wikipedia.org/wiki/Hawking_radiation because the hole would be so small that quantum positional uncertainty can take things beyond the event horizon.

Magnetic monopoles, strange matter and the quantum groundstate are things beyond my ability to explain or properly understand.

MG and Kelvin will probably explain it all better.

[FaKToR]

First of all, can someone explain to me in really simple terms how the Large Hadron Collider can apparently destroy Earth or even the entire universe?
AFAIK it can't I would imagine this concerns are along the lines of those who thought detonating an atomic bomb would ignite the atmosphere.

Second of all, black holes just confuse the shit out of me. I know very basic things about them such as that if you go past the event horizon there's no way to get back, that light can't escape, you'll get crushed immediately, etc etc. Apart from those I just don't understand them at all. I just need someone to really explain them to me.
It's all just gravity at work, except a fuck ton of it. I'm not really sure what you mean when you say you don't understand them. What part are you not understanding?

Thirdly, I am confused about the Universe. Inside the Universe there are obviously places like galaxies that hold stars and such, but what is between every galaxy? Are there just random stars between galaxies or is there something that holds the galaxies too that isn't just the universe (for example something that holds galaxies in it in the same manner that galaxies hold stars)?
First off there is nothing that "holds" things in place besides their gravitational attraction to one another. In the large scale of the universe there is no fixed space, that is it's not like there is an immutable coordinate system. Everything keeps on expanding and moving, think of it like a balloon with dots on it being inflated. As it expands, the dots move farther away from each other.

If this is all just for your own personal knowledge I would suggest you pick up A Brief History of Time.

[Apoc]

False vacuum:

http://en.wikipedia.org/wiki/False_vacuum#Vacuum_metastability_event

In their paper, Coleman and de Luccia noted:

The possibility that we are living in a false vacuum has never been a cheering one to contemplate. Vacuum decay is the ultimate ecological catastrophe; in the new vacuum there are new constants of nature; after vacuum decay, not only is life as we know it impossible, so is chemistry as we know it. However, one could always draw stoic comfort from the possibility that perhaps in the course of time the new vacuum would sustain, if not life as we know it, at least some structures capable of knowing joy. This possibility has now been eliminated.[2]

The possibility that we are living in a false vacuum has been considered. If a bubble of lower energy vacuum were nucleated, it would approach at nearly the speed of light and destroy the Earth instantaneously, without any forewarning. Thus, this vacuum metastability event is a theoretical doomsday event. This was used in a science-fiction story by Geoffrey A. Landis in 1988 [7].

One scenario is that, rather than quantum tunneling, a particle accelerator, which produces very high energies in a very small area, could create sufficiently high energy density as to penetrate the barrier and stimulate the decay of the false vacuum to the lower energy vacuum. Hut and Rees,[8] however, have determined that because we had observed cosmic ray collisions at much higher energies than those produced in terrestrial particle accelerators, that these experiments will not, at least for the foreseeable future, pose a threat to our vacuum. Particle accelerations have reached energies of only approximately four thousand billion electron volts (4 ×103 GeV). Cosmic ray collisions have been observed at and beyond energies of 1011 GeV, the so-called Greisen-Zatsepin-Kuzmin limit. John Leslie has argued[9] that if present trends continue, particle accelerators will exceed the energy given off in cosmic ray collisions by the year 2150.

This event would be contingent on our living in a metastable vacuum, an issue which is far from resolved.[10] Worries about the vacuum metastability event are reminiscent of the controversy about turning the Relativistic Heavy Ion Collider on.

[PsychoMantis]

I wish I could have gotten to this thread sooner, my astronomy class hit cosmic theory pretty hard towards the final. At least Faktor said everything I wanted to say. (Now I can't have my moment of glory.)

[neko]

Ok I got another question which is kind of hard to word:

How come there is nothing like a dinosaur around today? It seems so strange that dinosaurs even existed and it doesn't make any sense. I know that they went extinct (duh) but how come after that extinction event we didn't get dinosaurs again but rather the ancestors of birds and rodents (is that correct?) It just seems so weird that dinosaurs were just some kind of one time thing and then just died out and there hasn't been anything like them since then.

[FaKToR]

Ok I got another question which is kind of hard to word:

How come there is nothing like a dinosaur around today? It seems so strange that dinosaurs even existed and it doesn't make any sense. I know that they went extinct (duh) but how come after that extinction event we didn't get dinosaurs again but rather the ancestors of birds and rodents (is that correct?) It just seems so weird that dinosaurs were just some kind of one time thing and then just died out and there hasn't been anything like them since then.

A new evolutionary path that didn't favor their particular type of species, in particular their size? It would make as much sense to ask how come there were not primates (I assume there weren't, but this is not my field) when dinosaurs roamed the earth.

[siddy]

Ok I got another question which is kind of hard to word:

How come there is nothing like a dinosaur around today? It seems so strange that dinosaurs even existed and it doesn't make any sense. I know that they went extinct (duh) but how come after that extinction event we didn't get dinosaurs again but rather the ancestors of birds and rodents (is that correct?) It just seems so weird that dinosaurs were just some kind of one time thing and then just died out and there hasn't been anything like them since then.

We still kinda do. Alligators are similar to dinosaurs. There have also been new discoveries of 'feathered dinosaurs'. They believe modern birds might be the descendant of those beasts.

edit: Also, think of it this way. Evolution may not be the 'survival of the fittest' but 'survival of the luckiest'. The most adept to thrive in a certain situation will flourish. So imagine now that we're evolving from primordial ooze again. What is to say the circumstances that dictate evolution will be exactly the same as last time?

[Prowl]

the alligator thing isn't true, their direct ancestors predated the dinosaurs. They are not from the same tree.

However that is to say that things from the time of dinosaurs are actually still around, and not very much changed at all.

There are more things that have died out than just the dinosaurs, 90% of species died out at the end of the Permian period, which means that all current species are descended from the surviving 10% in the first place.

The ecological niche which dinosaurs existed in no longer exists, or if it does, the fact is that evolution has no imperative to recreate something similar anyway. Part of the problem is that they over simplify evolution in schools, it's also a large part of the reason that the nutjobs a.k.a. creationists hold such sway over people, most people just don't appreciate the timescales and intricacies involved.

There's always talk of life evolving to occupy niches and conditions, but it isn't forced to, which means you don't get new species just because there is a niche that they *could* occupy. The dinosaurs would get on fine in the modern world, plenty of easy prey for the carnivores, nothing big enough to predate on the larger one, a relatively high oxygen content in the atmosphere.

It's not just evolution, but chance has a large part to play, If the dinosaurs hadn't suffered the extinction event(s), far more recognisable descendants would likely be thriving today (at our expense).

[pk!]

The "mainstream dinosaurs" died out for many reasons, but one is the rise of rodents, making it difficult for any animal that hatches out of a big egg. The ecological niche ocupied by the large dinosaurs was taken up for a while with very large mammals, until our ancestors ate them all with the invention of fire, spears and nets.

[neko]

Ahh that makes more sense now. I knew about birds being descendants of dinosaurs but it just seems so weird how most of them were such a once in a life time thing.

[Modest Genius]

Most of your original queries have been answered, and the discussion has moved on somewhat, but two things were missed:


Strange matter

'Normal' matter is made out of electrons, protons and neutrons. Electrons are 'fundamental', that is they aren't made up of anything smaller. However, protons and neutrons are not - they're made out of quarks. The proton is made of two 'up' quarks and one 'down' quarks, whilst the neutron is made of two down and one up.

So, normal matter is essentially electrons, ups and downs. These are all so-called 'first generation' particles. There are second and third generations, which are essentially heavier versions (for example, the second generation muon is basically just a heavy electron, whilst the third generation tauon is an even heavier version). See http://en.wikipedia.org/wiki/Standard_Model#Particles_of_Matter .

Now, when you turn on a particle accelerator, it creates particles up to a certain mass, which depends on how much energy it can accelerate particles up to (from E=mc^2). Once you get to a certain level (which is fairly low actually) you start to form the second generation particles. The second generation version of the down quark is the first to be made, and is called the 'strange' quark. The name comes from when people first started to make these things, and they saw all sorts of things that behaved a bit strangely - these were referred to as 'strange particles' and were later understood to be just like normal matter but containing strange quarks as well as up and down ones.

So, 'strange matter' is just like normal matter but with added strange quarks. Unfortunately, if you now try to build atoms and molecules out of them, it works but the properties are very different. Therefore, if all matter was turned into strange matter life as we know it would be very different or non-existent.

Now comes the problem: a bunch of particle physicists came up with a theory a while back which says that if you chuck a piece of strange matter (referred to as a 'strangelet') at some normal matter, you could get a chain reaction. It would turn some of the normal matter into strange matter, and release more strangelets, which would go on to convert everything to strange matter.

So, why hasn't this happened already? Well, they claim that you need to create a large amount of strange matter with very high energy to start the reaction going. Their predictions for how much and how high this would be were about the same as the amount of strangelets predicted to be generated by the Brookhaven and LHC accelerators.

If correct, the theory suggest that once we turn on the accelerator, the chain reaction will start, converting first the accelerator and then the whole Earth into strange matter, destroying life.

There are a few reasons why we shouldn't be worried:
- hardly anyone believes the theory
- Brookhaven didn't do it
- if this is possible, we should see stars (particularly neutron stars, which are just like giant nuclei) made of strange matter; every one investigated has been found to be normal matter
- big and powerful as Brookhaven and the LHC are, they will actually generate less powerful strangelets than cosmic rays (http://en.wikipedia.org/wiki/Cosmic_rays) hitting the atmosphere


Magnetic monopoles

Are a bit more complicated and I know less about, plus I can't be bothered to write about them now. maybe later.

hope that helps

[Noirceur]

Asking for "Layman's terms" describing black holes is kind of like asking for "layman's terms" describing quantum physics; they don't exist.

[neko]

The whole false vacuum thing makes no sense and all I got from magnetic monopole is that they have one pole that has a net magnetivity rather than 2 different magnetivities (I am pretty sure I just bastardized the scientific lingo used for describing magnets)

[Prowl]

yes, MONOpole means one pole. From mono meaning one, and pole meaning pole.

[PsychoMantis]

Asking for "Layman's terms" describing black holes is kind of like asking for "layman's terms" describing quantum physics; they don't exist.

I think they covered it pretty well here. The idea behind the black hole isn't hard, it's the visualization of the effects it has upon matter when you consider Einstein's relativity with space-time. Say for example if you were to witness matter entering a black hole, supposedly you would never actually see it enter from the safety of your viewpoint, yet whatever matter would travel within the black hole would see time move at normal speed as it was torn down to the atomic level.

[BlindSite]

Lol, its when I start to think about this stuff I go find porn to watch,