New Bounds On the Higgs Boson Mass 173
As the LHC continues to run at half power for the next year+, the US-based Tevatron continues to crank out results. Reader hweimer writes "Three new papers in Physical Review Letters present the latest results for the Higgs boson mass coming from Fermilab's Tevatron. The new data mandates that the Higgs boson mass within the standard model lies between 115 and 150 GeV." A year back we discussed the Tevatron's previous shrinking of the search space for the Higgs "God particle."
To be clear what this means. (Score:5, Interesting)
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And by the way, does it makes sense to talk about the mass of a particle that seems to be implicated in the origins of mass itself?!
(Ok, maybe it does, still...)
Re:To be clear what this means. (Score:4, Informative)
It makes sense. It 'gives' mass to other particles by interacting with them, 'knocking them back' when they start to move (simplified, but that's the basic idea). It also interacts with itself, giving itself mass in the exact same way it gives mass to other particles.
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As in, "each Higgs boson interacts with *other* Higgs bosons, giving them mass in the same way" ? Or does each particle literally interact with itself to give itself mass ?
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Maybe he made an intelligent, informed comment on Apple or some other heinous sin.
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How about just talking about its energy. That would be similar to e.g. talking about photon energy and atoms. So it would be a nice wording symmetry.
Re:To be clear what this means. (Score:5, Funny)
These are bounds for the mass of the Higgs boson assuming it exists. If it doesn't exist, this data is meaningless.
Film narrator: Remember, it's up to us. Bigfoot is a crucial part of the ecosystem, if he exists. So let's all help keep Bigfoot possibly alive for future generations to enjoy unless he doesn't exist. The end!
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that we'll narrow the mass down to a very tiny bound (if it exists) which would be strong evidence for its existence.
No it wouldn’t. Because that would be like saying: We searched the whole world for Bigfoot, except for this little hut here. So he must be in that hut.
No he doesn’t. Because you still haven’t proven that he exists at all. :)
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The extend the analogy:
We searched the whole world for Bigfoot, except for this little hut here. There's something we've never seen before inside the hut. So Bigfoot must be in that hut.
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The LHC goes to eleven (Score:3, Funny)
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Re:The LHC goes to eleven (Score:4, Insightful)
"why not build two for twice the price?"/crazy scientist cancer guy from "Contact"
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can a Higgs Boson fly Southwest? (Score:4, Funny)
Or is it massive enough that it must purchase two seats?
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Bounds are Complicated (Score:4, Informative)
The new data mandates that the Higgs boson mass within the standard model lies between 115 and 150 GeV."
No, it doesn't. Look at this graph [aps.org]. At a "3 sigma" level (and don't believe any new science that is not at the 3 sigma level or better), the mass of the Higgs (assuming it exists) is roughly between 115 and 225 GeV. To put it another way, a mass greater than the Tevatron exclusion zone at ~160 GeV is by no means ruled out.
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> At a "3 sigma" level (and don't believe any new science that is not at the 3
> sigma level or better),
So I guess you reject pretty much all of biochemistry and medicine?
Re:Bounds are Complicated (Score:5, Informative)
2 sigma means a 95% certainty, and 3sigma means a 99.7% certainty.
So at just 2 sigma, 1 in 20 times you will get it wrong/fail. I would hope that in medicine and biochemistry, where it matters, that they do use 3 sigma certainty.
In particle physics, a 5 or 6 sigma certainty is usually used for confirming a new particle, which means that you're wrong only once in a couple of million times (although guessing at the errors is probably itself the most significant error.
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2 sigma means a 95% certainty, and 3sigma means a 99.7% certainty.
So at just 2 sigma, 1 in 20 times you will get it wrong/fail.
It doesn't work that way...
I would hope that in medicine and biochemistry, where it matters, that they do use 3 sigma certainty.
No, they use usually btw 90/95% (if not lower).
Also, WHAT, 3sigma is a huge space (especially in this kind of experiment).
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So at just 2 sigma, 1 in 20 times you will get it wrong/fail. I would hope that in medicine and biochemistry, where it matters, that they do use 3 sigma certainty.
I hate to burst your bubble, but in medicine you can't create cancer patients by blasting metals with cathode rays or however you make your particles in your accelerators. You also can store a sample of a quintillion patients in an ion trap. Sample sizes are just a tiny bit smaller in most clinical trials when compared to particle colliders.
Clin
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If it is new science, and it is not at least "3 sigma," it is simply not proven IMHO.
Things are different if you are talking about using scientific results to guide action. Part of the art of leadership is making decisions in the face of incomplete information. So if my oncologist, say, says that there is a 75% chance that my cancer may respond to some new treatment, that may well be good enough. Heck, even 50% may be good enough, depending on how dire my case is. But for the new treatment to be considered
I'm lost. (Score:4, Interesting)
I would imagine this is how my family and friends feel when I start speaking computer gibberish. I'd consider myself relatively competent to understand basic principles like gravity, mass, weight, etc, but can someone dumb this down?
http://en.wikipedia.org/wiki/Standard_Model [wikipedia.org]
I know that's probably a hopeless request without some sort of basis in this field, but can someone give the "particle physics for dummies" equivalent here?
I get the impression this is a hunt for some as yet unknown particle?
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http://simple.wikipedia.org/wiki/Standard_Model [wikipedia.org]
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Sometimes I'm still amazed at the oddest places that exist on the internet. I find this simple.wikipedia.org link much more 'readable' to the laymen.
So if I'm reading the 'simple' version correctly, they are tying to narrow down the mass of the mysterious 4th Higgs Boson? These Bosons are the 'conduit' (I apologize if the terminology doesn't fit properly) that this energy flows through from fermion to fermion?
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At one level, all you need to know is that the Standard Model "needs" this particle - no Higgs Boson, and the Standard Model may fall. Finding the Higgs (and thus its mass) should also help in making predictions in other areas, such as cosmology.
As for why the Higgs Boson is needed, you might find this [ucl.ac.uk] interesting.
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Is this Higgs particle increasing in mass because the fermion is passing through/near it, or does the fermion increase in mass as a result of passing through/near this Higgs particle? Or am I misunderstanding the mechanics of this and the additional mass is due to the 'clustering' of these fermions in close proximity to each other?
Thanks for the link [ucl.ac.uk]. It does help visualize this a bit better.
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You never see "naked" particles in QFT - they are always surrounded by a cloud of virtual particles attracted to them by various forces. The particle you can measure (say, an electron in a cathode ray tube) is always really a composite - the naked particle and its cloud of hangers on. So, the answer to your question is "yes" in both cases.
The Higgs field was invented to give bosons mass (in the context of the standard model). The story (which I have heard several times, but don't know if it's true) is that
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This would be a good start: :)
http://btjunkie.org/torrent/TTC-VIDEO-Quantum-Mechanics/3952ebd7c605f10e9562955b4905c88b576299e71a57 [btjunkie.org]
(Very simplified, but as I said: A good start.
Re:I'm lost. (Score:5, Informative)
particle physics for dummies
ALL (anti)matter, ALL forces, fields and waves and everything you can think of consists of particles. I'm not talking about neutrons and protons and the such, but even smaller particles known as subatomic particles or elementary particles. Most of us know the group of particles called quarks, but there are more groups of particle with cool names like leptons (an electron is a lepton) and bosons (a photon is a boson).
We know that a LOT of nature shows some kind of symmetry; this is the same in elementary particle physics. From this, it has been deduced that several particles not yet detected must exist in order to fill in the gaps in the symmetry. It is those particles we are looking for and they are predicted by the Standard Model, which is an enourmous collection of theories that together attempt to describe our entire universe (with the exception of gravity) (and to unify the newtonian and einsteinian physics).
Such particles have many hard-to-understand properties like spin, charge, mass etc. What we are looking for, however, is their specific energy. We do this by accelerating matter (protons typically) to incredible speed and then colliding it. In such a collision, enormous energies occur that cause elementary particles to cease to exist and create new elementary particles. All kinds of particles can sort of randomly be created during such a collision, but obviously the collision itself has to be powerful enough to reach at least the energy the particle we're looking for has. So we keep building more and more powerful particle accelerators in order to find these things. What we call the energy of such a particle is a bit complex; it sort of comparable to mass*speed, but that's not all there is to say about this; for example many particles have a fixed speed, namely the speed of light. Therefore, their mass is equivalent to their energy. That's the GeV number we're talking about here. Note that this is incredibly simplified; for example we don't really know the mass of the photon (except that it is 0 in rest, but photons don't exist in rest) but we DO know its' energy since we can measure that. Also, the charge is not factored into this equation. But, in general, elementary particle physicists think in "energy", not in "mass" or "speed".
Anyway, around the point of collision, enormous detectors have been built that attempt to trap the particles created in the collision. These detectors generate a small electric current comparable to the energy of the particle that collided, which is measured. Think about them as antenna's. After millions and millions of such collisions, patterns start to emerge and we can deduce a specific particle has been created in our collisions. For example, you see a lot of collisions with this energy and a lot with that energy, but none with energy such and so. The result is sort of like a spectrogram (but again, it's way more complex than that).
So in the case of the Higgs Boson, in this "spectrogram", we're looking for a peak somewhere between 115 and 150 GeV. This is obviously an incredibly simplified explanation, but I think this should make you understand just a bit more.
The "particles" word is unfortunate (Score:4, Interesting)
Most people use the word "particle" to mean a small solid object, and I think it is fair to say that quarks, gluons, and the Higgs can't meaningfully be categorised in this way. It is not surprising that early mathematical physicists often emphasised concentrating on the wave equations and not trying to assign physical meanings.
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Thanks mate. Not only you helped parent, but many of us who are legos in this matter. Thanks for taking the time to write it.
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It's not a proton but a photon that has a mass of zero at rest. But photons never are at rest. The question therefore is merely philosofical in nature and one might even say it is bullshit;-)
A couple of errors here... (Score:2)
1) You can't get to absolute zero - to get something that cold would require you to chill it with something even colder, which is impossible by definition.
2) Even if you could get to absolute zero, all molecular motion doesn't stop - the particles still have what's called "zero-point" energy, which means they would still be moving a little. For them to be completely stopped would violate the uncertainty principle: you'd know their position and momentum exactly.
3) Obviously, just because things stop moving d
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Apart from that you're completely right, I couldn't resist the urge to come up with some far-fetched counterarguments:Pp
1) That's not quite true. It is perfectly possible to cool something with "superhot" laser beams; no need to have something even cooler. Therefore, reaching absolute zero is not impossible by that definition. It is only the law of entropy that prevents us from reaching absolute zero. Or so it says.
2) Since we're reached the purely theoretical/philosophical discussion... zero-point energy o
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I know that's probably a hopeless request without some sort of basis in this field, but can someone give the "particle physics for dummies" equivalent here?
No, probably not, but if you're interested, I heartily recommended
Warped Passages [amazon.com] by Lisa Randall. She spends first 80 or so pages reviewing physics in a manner accessible to those of us who took it in high school but need a refresher/update. But it does take those 80 or so pages under your belt so you can understand the rest of her book. Hence my appr
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can someone give the "particle physics for dummies" equivalent here?
I think you'll find that this page [timecube.com] makes it all pretty clear.
Unanswered questions still (Score:2)
Determining the mass is fine, I guess, but what about size - is it bigger than a breadbox?
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US voltage (Score:2)
Please stop this "God particle" nonsense (Score:2)
I doubt any physicist would refer to the Higgs boson as "God particle" and that's obviously not the case in TFA. So why kdawson is feeding this idiotic meme ?
Next time we speak about serious science are we going to refer the research subject's as "pixie dust" or "Satan ichor" ?
Re:Please stop this "God particle" nonsense (Score:5, Informative)
Except that the phrase was coined by Nobel Prize-winning physicist Leon Lederman.
It's fair to say, though... (Score:2)
The rhic has also done some cool Science (Score:2)
Great, finally I understand this: (Score:2)
http://xkcd.com/702/ [xkcd.com]
Well ...
... maybe not.
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Re:Conversion to mass in kg (Score:5, Informative)
I didn't preview my previous comment and so it came out all wrong.
Re:Conversion to mass in kg (Score:5, Funny)
You should consider cosmology. That's the only field I know of where errors at the 10^54 level might be acceptable.
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You should consider climatology. That's the only field I know of where errors at the 10^54 level is not only acceptable but believed as gospel by the world's governments.
FTFY
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You should consider climatology. That's the only field I know of where errors at the 10^54 level is not only acceptable but believed as gospel by the world's governments.
You can't say THAT!
[insert character assassination as appropriate; don't question the establishment bro!]
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So 150 GeV would be just over 50 elephants!
Well, that certainly explains why the LHC has to be so big, but... oh wait, I see, it was a typo. In that case, it's slightly smaller than a sugar molecule, I think?
Re:Conversion to mass in kg (Score:5, Funny)
I don't think that means what you think it means (Score:2, Informative)
Troll? Seriously? It was a joke -- if you laughed then mod the guy funny, if not then leave him alone.
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I wish summary articles were written so that most people could understand the terms used.
The trouble is that 10^-27 isn't a tremendously intuitive number. Even being extremely familiar with scientific notation, the magnitude is so small that it really defies any intuitive sense of scale. GeV may not be nearly as familiar as kg but eV (electron volts) are an appropriate unit when dealing with particle energies and so are used in most articles regarding accelerators. Given the choice, I would take eV so that people who are following the progress of the LHC and Tevatron colliders can compare betwe
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I agree that GeV is the appropriate unit. Though it wouldn't hurt to have a paragraph explaining to people not well versed in physics how 1 GeV is roughly the mass of a hydrogen atom.
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Could somebody explain to me, then, how the Higgs Boson is supposed to be responsible for the existence of mass? Until reading this, I had always heard that the Higgs is responsible for mass and I just assumed that massive particles contained Higgs Bosons - that the Higgs was the mass quantum. If they're many times more massive than other particles we know to be massive, in what manner are they responsible for mass?
Re:Conversion to mass in kg (Score:5, Informative)
The higgs is sort of the measureable side effect of the physics that 'give' particles mass.
Think of it this way. The Electro Magnetic field "gives" particles charge. (or the charge in a particle interacts with other charges through the EM field).
There are some particles that sorta 'show up' in the equations when you're dealing with the EM fields (photon, W & Z bosons).
The same sort of things happens with mass. Some physicists came up with an addendum to the current equations that would explain how the mass of particles interacts. These equations have in them (depending on version) 1 or more particles (Higgs bosons).
So it's not so much that the Higgs gives particles mass, but by detecting the Higgs, we prove the existence of the Higgs field which allows mass in particles to interact.
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Is there any chance this "Higgs field" could allow us to create artificial gravity? (Forgive me if this is a stupid question, I'm a sci-fi fan, not a physicist.)
Space itself is not a field (Score:2)
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It's really really really tiny, but it would hurt like crazy if you touched it.
Simplistic enough for you ?
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To make it understandable, the energy can be converted into a relative "human" form so a person can understand it.
For example, 1TeV is about the kinetic energy of a flying mosquito. While the equivalent of 15% of the kinetic energy of a flying mosquito isn't much (150GeV) it is a LOT of energy for a single subatomic particle.
As a comparison, the Planck energy is about the equivalent of the energy released from burning a full tank of fuel in a typical family car. It shows that even our most powerful atom sma
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That's all well and good for you Yanks but can you convert that into Double-Decker-Buses for use Limeys?
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Actually, one Dolly Parton's bosom (DDb) just happens to be exactly the same mass as that of a Double Decker Bus (DDB). Confusing, but convenient!
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Not entirely true - suppose you wanted to estimate something on a macroscopic scale, such as the effects on a spacecraft or asteroid from absorbing a Ultra-high-energy cosmic ray (as do exist). Knowing that the biggest one yet detected carried about 50 Joules of energy is likely to be more informative than knowing it was 3 x 10^11 GeV.
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I'm sure if the US cuts the funding, those scientists will get job offers elsewhere, and the United States will be well on the way to becoming a main provider of cheap labor for Mexico and Canada.
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Yeah, that's working out really well for Africa and the middle east so far! Sure will be a lot of fun if your economy completely tanks and you have all those guns lying around..
Re:wasteful (Score:5, Insightful)
wasteful science at it's worst. trying to detect something we can't see, 99.999% (at least) of the worlds population wouldn't care if it was found and finding it would have zero impact on the worlds population. the world of physics and physicists needs to take a good long hard look at itself... and try and work out what it's going to do when the funding runs out... next year
I'm sure nobody technically gives a fuck about electromagnetic waves either, until we made radios and wireless and microwaves and cell phones
I'm sure nobody technically gives a fuck about electrons either, until we made TVs and computer monitors (and electricity itself)
I'm sure nobody technically gives a fuck about photons either, until we made lasers and optical fibers to be the backbone of the Internet
They're literally trying to understand what creates mass. If you don't think anything useful or cool can come out of that, you seriously lack imagination. But since you're ACing I assume you're trolling and I just bought it.
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You misspelled "education."
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The only thing I think will be useful to come out of this is the coincidental visit of Lexx (http://www.youtube.com/watch?v=LVshOOG2hcc)
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Whenever anyone questions the value of a particular line of scientific enquiry I remind that we had lasers sat around in research labs for a long time before anyone thought of anything useful to do with them. Now the average person has a few at home, and they form part of the backbone of our entire communications network.
Just because we can't think of anything practical to do with it now doesn't mean it won't be life-changing at some point in the future.
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They're literally trying to understand what creates mass
No no no, they've already figured that out. Decades ago. You even know the name, "Higgs". We also roughly know the mass. There's very little we don't claim to know, and discovering that doesn't teach us anything.
The only success we should hope for at LHC is that they *don't* find the Higgs. Then the HEP world will have to face the fact that everyone knows but won't publicly admit, that the SM is almost certainly incomplete. But since we have no idea what would replace it, few are willing to come out and say
Re:wasteful (Score:5, Funny)
Seriously, what planet are you fucking on? You reckon (laughing to myself) that nobody gave a fuck about electrons until 'we made TVs' ?!?
He's posting on slashdot. Chances are, he's not fucking on *any* planet.
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Funny? I'd mod this insightful
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You reckon (laughing to myself) that nobody gave a fuck about electrons until 'we made TVs' ?!?
Well to be quite specific I was thinking of electron beams like CRTs, things that'd require you to actually know something about electrons. You can do tons with say chemistry, but you don't really need to know about electrons to mix various compounds. Including making a battery and thus electricity, which predates the discovery of the electron.
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Re:wasteful (Score:5, Insightful)
Guess What - Your perfect world doesn't exist. whilst 99% of the population may not care (I disagree with this statistic also, by the way) the discoveries made will be beneficial to the future populations of this planet.
You may not care about that; however you would not be on the internet, you would not have electric power, you would not have a motor vehicle, you would not have a large market full of goods from around the globe, you would actually have a pretty terrible life if it wasn't for early greek mathematicians Pythagoras, Euclid, Archimedes, to name a (very small) few.
You owe your current lifestyle to these men; and our future generations will owe their lifestyle to our mathematicians and physists - only if they get the funding they need, ney the funding the DESERVE.
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and finding it would have zero impact on the worlds population
Do as you say, troll.
If you don't think computers are of any impact, then you should give yours away and get off the Internet. Both are technology that exists because of science which as you say is pointless.
I guess to a troll, that statement pretty much is true. One can be an asshole without the aid of any technology.
Re:wasteful (Score:4, Interesting)
Seriously, the applications for a lot of this stuff doesn't become apparent until after it's been discovered, I'm not sure what people thought they'd be able to do with Maxwell's equations, but I doubt very much that they thought we'd get super colliders and computers out of it.
You're making it worse (Score:2)
Seriously, the applications for a lot of this stuff doesn't become apparent until after it's been discovered, I'm not sure what people thought they'd be able to do with Maxwell's equations, but I doubt very much that they thought we'd get super colliders and computers out of it.
You just told the average idiot that the science they think is useless led to the invention of a giant money-wasting useless science machine, and a toy.
Here is the list of worthwhile results of science to the average moron:
Fire, as used in cooking
Paper, ink
Firearms
Automobiles
Cameras
Telephones
Computers (including gaming consoles), as used for facebooking, twittering, porn, gaming
Cell phones, particularly iPhones and Blackberries
Try to include some of these technologies into your justifications for scientific
Re:wasteful (Score:5, Insightful)
From the Congressional Joint Committee on Atomic Energy, April 17, 1969, regarding the justification for funding the then-unbuilt Fermilab:
Senator John Pastore: Is there anything connected with the hopes of this accelerator that in any way involves the security of the country?
Robert Wilson: No sir, I don't believe so.
Pastore: Nothing at all?
Wilson: Nothing at all.
Pastore: It has no value in that respect?
Wilson: It has only to do with the respect with which we regard one another, the dignity of men, our love of culture. It has to do with: Are we good painters, good sculptors, great poets? I mean all the things we really venerate in our country and are patriotic about. It has nothing to do directly with defending our country except to make it worth defending.
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Re:wasteful (Score:5, Funny)
The banking sector aren't that dissimilar from quantum physicists ... they deal with gigantic magnitudes of imaginary "wealth" that ceases to exists as soon as someone actually scrutinizes the figures and collapses the waveform, causing it all to disappear.
Still at least we've managed to capture the Madoff Particle.
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The banking sector aren't that dissimilar from quantum physicists ... they deal with gigantic magnitudes of imaginary "wealth" that ceases to exists as soon as someone actually scrutinizes the figures and collapses the waveform, causing it all to disappear.
Still at least we've managed to capture the Madoff Particle.
Yay, thanks for that. Now I'm scared to check my bank account balance. So long as I don't look, the money might still be there...
Schrodinger's Savings and Loans anyone?
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No, no, no! That money should be going to GOD! He's a bit strapped for cash and forgot how to make more after his narcotics binge in the dark ages.
Re:Aw shucks... (Score:5, Informative)
Re:Aw shucks... (Score:4, Interesting)
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So where is your falsifiability? You're saying "If we don't find it this time, keep looking." Well, maybe there IS NO higgs boson, and you need to re-write the standard model. Oh. Well. Popper. Read him.
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i'd agree, but being from the country that shut down the SSC halfway through building, i can't talk. we probably would have already found the higgs by now.
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If you're referring to the XKCD I think you are, I hope you realize that it in turn was a pop culture reference itself.
Recycling colliders (Score:2)
every single one of these colliders will be recycled and reprocessed into long term and far more useful gear like wind turbines
You are right in the first part of that statement, the colliders are being recycled. However I am not aware of any being turned into wind turbines.
I know someone on the D0 group at Fermi, and was talking about collider fate with him recently. He pointed out that many of the facilities that are now serving as synchrotons (or high-energy light sources, such as Cornell's CHESS [cornell.edu]) which make significant contributions to structural biology. Currently we have less than 10 synchrotrons in the US - and many mor