APOD: Hints of Higgs from the Large Hadron... (2011 Dec 18)

[Chris Peterson]

I don't believe it is. If it were, the letters in the scaffolding would be reversed (mirrored). As it is, they're simply upside-down on the larger one in the lower left. But that's likely just the way it was assembled. The smaller scaffold in the center of the far right side is correct, suggesting the image is correctly oriented.

Besides "Layher" (the scaffolding maker) being correct in two places, there is a bit of other text scattered around, which is also correct. The image is certainly not mirrored.

[Zippy]

I see Seven people

[Chris Peterson]

Look at 7:45 position, just outside and beyond the big sensor wheel at back center: two faces, next to each other, one in front removing helmet, the other bare headed. They look Indian.

atlas_cern_3008_clip.jpg

It's plausible. I don't know about the helmet, but it does look kind of like a couple of heads back there. And you're right... they do look a bit Indian! Hard to say for sure, though- there just isn't much information in those pixels. If they are people, I'd say both are bare-headed, with the one in front a woman, and behind is a man.

[taoscincy]

I see two!!

[neptunium]

Gee wiz, neptunium. There's at least a kabillion universes in parallel with ours, all 3 1/2 years out of synch with each other and us.

Not in there!

Not to mention the ones that are 2 minutes apart or 17 microns apart or 183,622 orders of magnitude larger or smaller, ad infinitum.

Obviously you don't understand what I said. I was talking about the "universe" that Sandstone was pointing out.

Of course they have something different to be 'seen' in them but they have lots of things the same, too.

I understand that. Wouldn't there have been, though, something different seen in that "universe"?

You don't get around much.

Watch more TV.

Sometimes I watch too much, thank you very much.

[Farinada]

Ok I acknowledge finding Higgs, and the details about Higgs, is a Very Big Deal. But dammit they also want to make black holes with that, and while they say they're sure those black holes will then quickly evaporate there's a really, really big downside if they are wrong.

There is no danger. None at all, and the "knowledgeable people" who are concerned are being foolish.

First of all, so what if they create black holes that don't evaporate? They are still just subatomic particles with incredibly tiny masses. They aren't going to absorb other mass, because their event horizons are so small they virtually never intersect with other matter. You need something like hundreds of times the age of the Universe for such tiny black holes to grow to macroscopic diameters.

Second, if the energies produced in the LHC are sufficient to produce microscopic black holes, then we must be surrounded by them- without apparent problem. Because the energies are nothing extraordinary. Cosmic rays of similar or higher energy occur all the time, and occasionally collisions must occur. We're still here, the Universe is still here, there's no evidence of things disappearing into spontaneously created black holes.

<--- What he said. (Thank you for typing all of this so I didn't have to.)

[Flase]

I've found some evidence of the damage black holes can do on Earth (sadly the image isn't very good. I think the copyright owners are overzealous)

http://victoria.rasc.ca/events/2007/200 ... age151.gif
The caption should read:

Suddenly, through forces not yet fully understood, Darren Belsky's apartment became the center of a new black hole.

[Flase]

What about the results that suggested particles could travel faster than light? Was Einstein wrong?

[Chris Peterson]

What about the results that suggested particles could travel faster than light? Was Einstein wrong?

Probably not. Most likely the neutrinos were not traveling faster than c. Most people seem to think that there are too many timing uncertainties in the experiment to come to that conclusion.

And even if the neutrinos are going faster than c, that doesn't necessarily mean that Einstein was wrong. There are things that move faster than light... so more would need to be known about the neutrino behavior to understand how this all fits into special relativity.

[Flase]

What moves faster than light? I've always imagined tugging a cord of an inflexible substance a lightyear long and sending a message to someone at the other end simultneously. I don't know much about string theory but could you tweak one of them thar superstrings and influence something lightyears away?

[bystander]

What about the results that suggested particles could travel faster than light? Was Einstein wrong?

viewtopic.php?f=31&t=25345

[Chris Peterson]

What moves faster than light?

Technically, we are talking about c here, not the speed of light. In a medium, it is common for particles to move faster than light. Most points in the Universe are moving away from most other points faster than c. When particles tunnel, they can do so faster than c. When particles are entangled, their quantum properties "communicate" with each other faster than c.

I've always imagined tugging a cord of an inflexible substance a lightyear long and sending a message to someone at the other end simultneously.

The problem is, there's no such thing as an inflexible substance.

I don't know much about string theory but could you tweak one of them thar superstrings and influence something lightyears away?

Assuming that such strings exist at all, they are all folded up in themselves, and are the smallest things in existence. Other than through the mechanism of quantum entanglement (which doesn't violate special relativity), there is no mechanism for widely separated strings to influence each other.

[Guest]

Technically, we are talking about c here, not the speed of light. In a medium, it is common for particles to move faster than light. Most points in the Universe are moving away from most other points faster than c. When particles tunnel, they can do so faster than c. When particles are entangled, their quantum properties "communicate" with each other faster than c.

I thought that if two bodies are moving at c, but away from one another, then according to the theory of relativity, their velocities added will still be c. It's time that changes speed

[Chris Peterson]

I thought that if two bodies are moving at c, but away from one another, then according to the theory of relativity, their velocities added will still be c. It's time that changes speed

Not when we are talking about the expansion of spacetime. Once two points are moving away from each other greater than c, they are causally disconnected. That's what defines the observable Universe- our horizon is the point where the edge, and everything beyond it, are moving faster than c with respect to us. Presumably, most of the Universe is on the other side of that horizon, moving faster than c and forever beyond our observation.

[Flase]

Not when we are talking about the expansion of spacetime. Once two points are moving away from each other greater than c, they are causally disconnected. That's what defines the observable Universe- our horizon is the point where the edge, and everything beyond it, are moving faster than c with respect to us. Presumably, most of the Universe is on the other side of that horizon, moving faster than c and forever beyond our observation.

Well, that confuses the hell out of me. So if all these things can break the lightspeed barrier, is it a barrier at all? Don't funny relativistic effects compensate and prevent it?

[Chris Peterson]

Well, that confuses the hell out of me. So if all these things can break the lightspeed barrier, is it a barrier at all? Don't funny relativistic effects compensate and prevent it?

There is no "lightspeed barrier"; there is a restriction on transmitting information faster than c. It is also impossible to accelerate one massive object to greater than c with respect to another (as doing so would require infinite energy). Neither of these conditions is violated by two points in the Universe moving apart at greater than c.

[Flase]

There is no "lightspeed barrier"; there is a restriction on transmitting information faster than c. It is also impossible to accelerate one massive object to greater than c with respect to another (as doing so would require infinite energy). Neither of these conditions is violated by two points in the Universe moving apart at greater than c.

I suppose there's a limit to what I need to understand, but surely for any two points in space, such as the Milky Way and the furthest galaxy to be travelling away from each other faster than light, such an infinite energy must have been applied.

It begs another question: How far away must a spaceship be from Earth before it may travel greater than c in relation to it? Even if it takes several billion years, could such a ship in theory use the slingshot effect at the galaxy centre to propel it towards a close galaxy (with redshift, say M104) and repeat the process until it is in another part of the universe travelling faster than c in relation to us?

[Chris Peterson]

I suppose there's a limit to what I need to understand, but surely for any two points in space, such as the Milky Way and the furthest galaxy to be travelling away from each other faster than light, such an infinite energy must have been applied.

Not at all. Indeed, it is possible that no energy is required (although it now appears that dark energy is responsible for increasing the expansion rate).

Paint three dots in a line on a balloon, and then blow it up. If you call the first dot your reference, the nearer dot will be moving away from that reference slower than the farther dot. Does it somehow take more energy to produce that increased speed? No. When space expands, and carries material apart, it isn't like normal, accelerated motion.

The whole Universe is expanding uniformly. The farther apart two points, the greater their relative speed of separation. So there has to be a distance where the speed between two points exceeds c. That distance is what defines the observable Universe.

It begs another question: How far away must a spaceship be from Earth before it may travel greater than c in relation to it? Even if it takes several billion years, could such a ship in theory use the slingshot effect at the galaxy centre to propel it towards a close galaxy (with redshift, say M104) and repeat the process until it is in another part of the universe travelling faster than c in relation to us?

The ship can never accelerate to c with respect to the Earth. Given enough time, it could escape from the gravitationally bound region of space created by the galaxy cluster we belong to, at which point cosmological expansion will carry it away, eventually taking it across the horizon of our observable universe- currently, about 46 billion light years away.

[Flase]

Paint three dots in a line on a balloon, and then blow it up. If you call the first dot your reference, the nearer dot will be moving away from that reference slower than the farther dot. Does it somehow take more energy to produce that increased speed? No. When space expands, and carries material apart, it isn't like normal, accelerated motion.

Well it still does not compute. Surely the expansion of space is defined by the matter and energy in it, matter and energy propelled by the Big Bang like pieces of shrapnel from a grenade. If all of this matter exists in the same universe, then therefore it should all be subject to the same laws of nature, including relativistic effects preventing one body from travelling at c with repect to another object in the same universe.

The idea that whatever causes this balloon-like expansion needn't take any force or energy makes me imagine that it must be something outside this material universe. Maybe the galaxies are pimples on God's infinitely multi-dimensional belly and as he breathes or eats to celebrate his son's birthday, the universe expands from beyond the mundane material plane we feeble mortals inhabit, and bypasses the normal laws of physics. Let's hope he doesn't burp to express his satisfaction at the meal...

[Chris Peterson]

Well it still does not compute. Surely the expansion of space is defined by the matter and energy in it, matter and energy propelled by the Big Bang like pieces of shrapnel from a grenade.

This view comes from the all too common misconception of the Big Bang as an explosion. It was no such thing. Neither matter nor energy are being propelled anywhere. The spacetime they exist in is simply expanding. That process of expansion is not an inherently energetic process.

If all of this matter exists in the same universe, then therefore it should all be subject to the same laws of nature, including relativistic effects preventing one body from travelling at c with repect to another object in the same universe.

There is no law that prevents one body from traveling at c with respect to another object in the Universe. That is not part of special relativity at all. A ponderable body (one with a rest mass greater than zero) cannot be accelerated to greater than c with respect to its starting point. But bodies in the Universe that are moving apart due to cosmological expansion are unaccelerated. In a physical sense, they aren't even moving with respect to each other (and in fact, their relative Doppler shift is zero); it is space itself that is expanding. There is no reason that one part of space can't be moving faster than c with respect to another. Indeed, we can directly observe that when we view the horizon of the observable Universe.

The idea that whatever causes this balloon-like expansion needn't take any force or energy makes me imagine that it must be something outside this material universe.

Why? The underlying mechanism of the Big Bang is completely unknown. Any assumption would be a mistake. It isn't even known if conservation of energy holds true for the Universe as a whole! There is much yet to be understood.

[joe mac]

if our observeable universe limit is est 46 billion years, and the est time of big bang is 14 billion years ago. how can we observe beyond 14 billion years out. would this not indicate the expansion of the universe is moving faster than time itself. ?

[Chris Peterson]

if our observeable universe limit is est 46 billion years, and the est time of big bang is 14 billion years ago. how can we observe beyond 14 billion years out. would this not indicate the expansion of the universe is moving faster than time itself. ?

Because the Universe is expanding, the physical location of photons emitted 14 billion years ago (and seen today) is now 46 billion ly away.

[Lostinspace]

3 1/2 years (42 months) is frequently mentioned in the bible