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Higgs Boson Discovered?!

MattusMaximus said:
... are you referring to simply forgoing the intervening space and putting all those particles together into the smallest volume possible? If so, then I have to agree with the statement above that you're likely moving towards something akin to either a neutron star or black hole.
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Wouldn't a black hole be a singularity if it were all those particles together in the smallest volume possible?

Are neutron stars the same density as black holes? (I know the BH has more mass unless it evaporates or whatever they do.)

Black holes = infinitely dense?

Sorry, I know this is all basic stuff but the answers I find on Google aren't exactly the ones I'm asking.
 
Skeptic Ginger said:
Are neutron stars the same density as black holes? (I know the BH has more mass unless it evaporates or whatever they do.)

Black holes = infinitely dense?
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If you define density for a black hole as mass divided by volume enclosed by the event horizon then black holes have finite density. And they can come in a very wide variety of densities, including as low density as hydrogen gas here on Earth if they are very large black holes.

Both black holes and neutron stars come in a variety of masses. Though neutron stars are subject to more constraints that lead to a lesser range of mass and densities.
 
Skeptic Ginger said:
We tend to view solid things as taking up the amount of space that their visible mass occupies. But there's a lot space between the molecules, and a lot of space between the protons and electrons within the molecules and a lot of space between the particles that make up the protons and neutrons and so on. I was just wondering what you'd have left if you squeezed all the proverbial air out of the molecule balloons.
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It's simply not a good way of dealing with it. I know it's common to say that "an atom is mostly empty space" but it isn't, really. The electrons in the atom are, in some sense, "filling" all the space in it already.

Why do people say electrons are tiny and/or pointlike? Well, if you hit them with a really short-wavelength probe, you can sort of force them to behave as tiny and pointlike. But an atom isn't doing that, an atom is letting them hang around with long wavelengths.

How about all the stuff whereby an alpha particle can "go right through" an atom "without hitting anything"? That has nothing to do with spatial gaps between things, or emptiness, or hollowness---it's just a statement about how strong the alpha/electron interaction is.
 
RecoveringYuppy said:
If you define density for a black hole as mass divided by volume enclosed by the event horizon then black holes have finite density. And they can come in a very wide variety of densities, including as low density as hydrogen gas here on Earth if they are very large black holes.
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Very large black holes have effectively infinite volumes. A completely classical (nonevaporating) black hole has infinite spatial volume.
 
Vorpal said:
Very large black holes have effectively infinite volumes. A completely classical (nonevaporating) black hole has infinite spatial volume.
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You're not applying the definition of volume that would most commonly be used to determine a black holes density, are you?
 
RecoveringYuppy said:
You're not applying the definition of volume that would most commonly be used to determine a black holes density, are you?
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I am. There is an ambiguity for black holes because we're taking the volume of a spatial region at some instant in time, and the 'instant in time' is frame-dependent, but allowing for some small caveats my statement was correct.
 
Vorpal said:
I am. There is an ambiguity for black holes because we're taking the volume of a spatial region at some instant in time, and the 'instant in time' is frame-dependent, but allowing for some small caveats my statement was correct.
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If you're applying the most common definition of volume used to compute black hole density then why aren't black hole density citations a lot closer to zero?

http://en.wikipedia.org/wiki/Sagittarius_A*
http://www.sciencemag.org/content/304/5671/704.abstract

Neither of those density citations appear to be using a nearly infinite volume for Sagittarius A*.
 
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Vorpal said:
At a guess, they have a specialized definition of density disconnected from physical volume of a spatial region. Why?
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The "specialized version" they appear to be applying would be the mass divided by the volume of a sphere using the formula taught in elementary school (such school's typically located outside of black holes).
 
RecoveringYuppy said:
The "specialized version" they appear to be applying would be the mass divided by the volume of a sphere using the formula taught in elementary school (such school's typically located outside of black holes).
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Alright. That's rather specialized because, as I've said, that formula has absolutely nothing to do with the spatial volume of the region enclosed by the horizon. It may give an empirically interesting measurement (in fact it's just a rescaling of surface area), but it is not the volume in any physically meaningful sense.
 
Vorpal said:
Alright. That's rather specialized because, as I've said, that formula has absolutely nothing to do with the spatial volume of the region enclosed by the horizon. It may give an empirically interesting measurement (in fact it's just a rescaling of surface area), but it is not the volume in any physically meaningful sense.
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In fact, it leads to a perfectly good answer to the question that was asked by Skeptic Ginger.
 
RecoveringYuppy said:
In fact, it leads to a perfectly good answer to the question that was asked by Skeptic Ginger.
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I'm not in any way contradicting that large black holes can be reasonably said to have low density, since they're actually defined by the horizon and not the singularity. I'm simply saying your conclusion was even more true than you suggested.

Though the singularity itself has no volume, so in the other sense it has infinite density (or very large, since we don't know what happens before that).
 
Okay, sorry. I think in the context of the original question we're having an "I think our minds may be too highly trained Majikthise" moment.
 
edd said:
Incidentally my jaw nearly fell off this morning when the BBC posted an article online that got it spot on - it's such a common error it's honestly astounding when the media gets it right!
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Is this the article?

http://www.bbc.co.uk/news/world-18702455

(This one helped me understand the sigma stuff.)

I like this part:

They claimed that by combining two data sets, they had attained a confidence level just at the "five-sigma" point - about a one-in-3.5 million chance that the signal they see would appear if there were no Higgs particle.

However, a full combination of the CMS data brings that number just back to 4.9 sigma - a one-in-two million chance.

Prof Joe Incandela, spokesman for the CMS, was unequivocal: "The results are preliminary but the five-sigma signal at around 125 GeV we're seeing is dramatic. This is indeed a new particle," he told the Geneva meeting.
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RecoveringYuppy said:
Okay, sorry. I think in the context of the original question we're having an "I think our minds may be too highly trained Majikthise" moment.
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As I see the difference between you, Vorpal in the context of Skeptic Ginger's question ...

Inside the event horizon anything can be regarded as "volume" from our point of view, because out here we're protected from it. In our protected space we can fly around outside the horizon, take GPS measurements to get the volume, weigh the singularity by other means and come up with a density. Our protection guarantees that everything remains consistent with the evidence we're able to gather. No judge will yet provide a warrant to search beyond the horizon.

There's a name for this which I've forgotten, but the general principle helps keep me sane.
 
ben m said:
The Higgs boson is an unstable (something like 10^-25 seconds) particle whose interactions are, in the context of the Standard Model, 100% known.
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Many bosons died to bring us this information. :cool:
 
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