Weak nuclear force is less weak
January 13, 2011 By Phillip F. Schewe
Credit: versageek via flickr
The force that governs some of the reactions that keep our sun shining is not quite as weak as scientists had previously thought. As a consequence, our estimation of how energetic the sun actually is just went up by a tiny amount.
The evidence for this weak nuclear force comes from the decay of muons, essentially heavier cousins of the electron, one of the building blocks of atoms.
Just as biologists sometimes study the tiniest and most ephemeral of organisms such as fruit flies, which live for barely a day, to learn things about human disease, so physicists often study the properties of particles that last a fraction of a second to learn about the universe.
The muon lives only about 2 millionths of a second -- 2 microseconds -- far from the realm of human sensation but long enough for scientists to make detailed measurements. The state of digital electronics is so advanced that measurements far shorter than this, even down to trillionths of a second or less, can easily be made.
Watching muons decay is not like propping up a Geiger counter next to a box full of radioactive uranium. That's because muons are so short lived they have to be made anew, as if they were medical isotopes. At the Paul Scherrer Institute in Switzerland a dedicated proton beam was used to create muons amid collisions with a graphite target.
Researchers then gathered a fine spray of muons, directed them and stopped them in their own metal target which was surrounded by a detector that could track the muons' demise. The decay of over 2 trillion muons provided the best yet value for the average muon lifetime. It comes out to 2.1969803 microseconds.
"This is the most precise lifetime determination of any state in the atomic or subatomic world," said David Hertzog, one of the leaders of the experiment and a professor at the University of Washington in Seattle.
This lifetime, known to an uncertainty of one part per million, is so precise that it can be used to make a new determination of the intrinsic strength of the weak nuclear force, which operates over only a very short range inside the nucleus of atoms.
Scientists know of four physical forces. Gravity, a form of mutual attraction, keeps the Earth going around the sun and keeps us from floating into space. The electromagnetic force is responsible for holding atoms together, for bonding atoms into molecules, for impelling the movement of electrons through wires in the form of electricity, and for light waves. The strong nuclear force holds nuclei together and is responsible for some kinds of radioactivity.
The weak nuclear force, the fourth and last force to be discovered by physicists in the twentieth century, helps to turn protons into neutrons inside the sun, a necessary step in converting those protons into heavier elements like helium and releasing the radiant energy that makes its way to Earth. The weak force also acted billions of years ago inside exploding stars known as supernovas to make the elements such as oxygen and carbon found in our own bodies and other natural things on Earth.
The strength of the weak force is encapsulated in a number called the Fermi constant, named for the Italian-American scientist Enrico Fermi. Hertzog said that the new value for the Fermi constant is about 0.00075 percent greater than the previous value. Thus the weak force is just a tiny bit stronger than we thought.
William Marciano, a scientist at the Brookhaven National Laboratory on Long Island, N.Y. was impressed by the muon experiment.
"It was a difficult but beautiful measurement carried out by a very experienced and talented group of researchers," Marciano said.
Marciano also points out that muons, short lived as they might be, are interesting in their own right, and actually practical. Muons were used to study the pyramids in Egypt. Muons can be created in the atmosphere by incoming cosmic rays, mysterious streams of particles from deep space. Because these muons can penetrate great amounts of material without stopping, even during their short lives, they were used as a sort of "medical scanner" for probing for hidden cavities inside the pyramid by setting up detectors above and in the basement.
Marciano said that muons might also be useful for medical imaging and for scanning cargo containers for hidden nuclear materials.
Another expert on the weak force, University of Wisconsin professor Michael Ramsey-Musolf, considers the muon experiment to be a tour-de-force piece of work. The important thing for him is that the uncertainty of the muon lifetime has now dropped by a factor of ten. But he also said that a more precise lifetime and a more precise knowledge of the strength of the weak nuclear force tells us just a bit more about nature.
"This implies that the sun does indeed burn more brightly and that the decay of nuclei is somewhat faster," Ramsey-Musolf said.
The new muon results are scheduled to be published in the journal Physical Review Letters.
Provided by
Inside Science News Service
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Jan 13, 2011
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Jan 13, 2011
Rank: 3.6 / 5 (12)
Coo coo ca choo!
Jan 13, 2011
Rank: 3 / 5 (2)
Jan 13, 2011
Rank: not rated yet
Maybe the range is very small.
Jan 13, 2011
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Jan 13, 2011
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Jan 13, 2011
Rank: 5 / 5 (3)
Gesunheit
Jan 13, 2011
Rank: 5 / 5 (6)
The point is, there is the strong possibility we will never reach that goal of ultimate knowledge, we will never know everything. Theories are refined with time and are always disprovable, otherwise they would be law. This is the basis of science, always going deeper, refining (not soldifying) our understanding of the universe.
Is the standard model 100% wrong, obviously not. Is it 100% right, no. Neither are any other theories, its why they are called theories.
Jan 13, 2011
Rank: 5 / 5 (9)
Good question. All measurements have a degree of uncertainty - either intrinsic or often the major contribution due to random noise. In my work when I don't see noise in data I worry and investigate what's going on (usually indicates a problem) The measurement is made many times - this case 2 trillion times - the data should fit a distribution (plot and it should be usually gaussian or lorentzian shape). The low end or the high end is due to a fluctuation in the electronics or whatever is used to make the measurement, thus we use the average as the result with a criteria for the error (in this case 1 part per million). If the data distribution does not fit the shape, there is something else going on either in detection or the things we're examining and requires investigation.
Jan 13, 2011
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"I am the Walrus!"
Jan 13, 2011
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The Feynman quote is a good one, and rebuffs a point made by the normally unassailable Stephen Fry on "QI"
- that there is no way we could inform a distant civilisation what we consider to be right or left, or clockwise/counterclockwise.
Jan 13, 2011
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Jan 13, 2011
Rank: 1.5 / 5 (6)
Darn someone bet me to the punch on that one...
Anyway science isn;t 100% accurate -- every ten years we learn that something we took for granted is in fact different or changed. Scientists accept this fact and keep moving saying of course of course the knowledge base changes.
On a philosophical note - people aren;t as forgiving of religions and it's inconsistances. Granted one is based on observation and the other on faith with no observation but the process of assimilation information is the same. I offer to extend this line of reasoning to all institutional matters - education, science, finance/economy, religion, language,
Jan 13, 2011
Rank: 4 / 5 (1)
What about the right hand rule? =] (We'd just need to send them a picture of our hands and indicate which one is right)
Jan 13, 2011
Rank: 4.3 / 5 (11)
My only point was that a value within the model changing due to more refined data isn't an invalidation of the model, just a refinement of it. Quantum_Conundrum has a tendency to rant at the scientific community in general anytime some variable is refined by a part per million. I believe he does this to lend credence to his own religiously tinted beliefs. "Well if scientists were .0000000000001 off on variable X they are probably off by several orders of magnitude on the age of the universe!" goes his reasoning.
Jan 13, 2011
Rank: 1.6 / 5 (14)
Actually, that has nothing to do with my reasoning.
Let's take a look at something. Let's take the relatively very close star Betelgeuse and look at just how imprecise the measurements of the star's distance and mass really are.
0.043 to 0.056 arcseconds for diameter
497 to 789 ly for distance.
So they haven't even gone 1/100th of the alleged distance across the galaxy, and already the margin of error in measurement of distance is off by plus or minus 23%.
The fact that astronomers cannot accurately measure the size and position of this relatively nearby star proves it is a joke to even speculate on the distance to many of the other objects they study, which are allegedly thousands or even ten million times farther away.
Jan 13, 2011
Rank: 1.5 / 5 (15)
Betelgeuse is an example of the ridiculous and absurd speculation that goes on in astronomy, and indeed the entire scientific community, since you will admit you can't measure this thing correctly, but then expect people to take it seriously when you claim to measure something that you claim is thousands or millions of times farther away.
I mean, they admit they are off by at least plus or minuse 23% even when dealing with a star that's visible to the naked eye. Why should any sane person believe they have any clue whatsoever about the position of anything farther away?
Jan 13, 2011
Rank: 1.1 / 5 (13)
For example, since the margin of error for betelgeuse' distance is so large, the margin of error in it's mass and absolute magnitude are much larger. The margin of error in it's absolute magnitude is more than an entire point, or a factor of 2.55
So in this case, a 23% error in one measurement can produce a 155% error in a calculation...
Jan 13, 2011
Rank: 5 / 5 (8)
I think that the difference is more that Science is verifiable by observation, Science also continually looks at it's self and corrects it's self when needed. On the other hand, since, as you pointed out, observation is not a part of Religion, change, self assessment, and growth are not a part of the equation.
Jan 13, 2011
Rank: 4.7 / 5 (15)
First take a simple statistics course.
Second, take a good science course.
Third, take a good physics course.
Finally, take a good astronomy course.
Then you will be able to make sense out of the complexities of using a variable massive young star (which won't get much older) like Betelgeuse and trying to compare it to observations of the Universe and work that back to the Weak force. Without some background in the basic sciences you just come up with science-fiction type conclusions. There are things that are difficult to measure and we are all trying to improve the measurements. However, you cannot invalidate the estimated measurement of the age of the Universe by the difficulty in the measurement of the size of Betelgeuse. Keep us amused though.
Jan 13, 2011
Rank: 5 / 5 (13)
Jan 13, 2011
Rank: 3 / 5 (3)
Or is something else happening, such as time-dilation??
I'll defer to those of you who are trained in this stuff to comment.
tkjtkj@gmail.com
Jan 13, 2011
Rank: 5 / 5 (8)
The muons are being produced when cosmic rays collide with atoms in the Earth's atmosphere. The muons are just a component of the particle "shower" that emanates from the point of impact.
Cosmic rays indeed move at very close to light-speed; so do the muons created in these collisions. Indeed, it is time dilation that keeps these muons "alive" long enough to pass through the atmosphere and reach the ground.
Jan 13, 2011
Rank: 4.8 / 5 (4)
Jan 14, 2011
Rank: 1 / 5 (2)
Jan 14, 2011
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Jan 14, 2011
Rank: 1 / 5 (3)
Also just the fact that they admit there is a 1/50million chance that the LHC will produce a black hole that has the ability to stabilize on a scale larger than the plank length in the operating lifetime is reason enough to wait a while until we understand the science better. The old argument of "Well we need to do this to understand the science" doesn't really apply when you consider the fate of our solar system is at risk.
Jan 14, 2011
Rank: 5 / 5 (7)
Two things QC:
1. People take it seriously because the % error isn't hidden, and that a long with the measurements certainly givens us a much clearer view of the universe than we would have had before.
2. ....Based on your reasoning, wouldn't your arguements be far more valid for religon, not science, which attempts to explain everything without a single measurement or observation? Shouldn't you be more concerned about why people take religion seriously?
Jan 14, 2011
Rank: 3.8 / 5 (8)
So let's compare this to the margin of error on your belief that the planet is 6,000 years old.(Let's not forget he's a YEC.)
4.45 to 4.5 billion years old by all observations within all fields of science is the accepted figure.
Your marginal percentage is of by 1,300,000%.
In short:
How dare you, sir, take issue with any measurement when your core measurement is off by such a laughable degree. Not even the vaccuum catastrophy is that far off.
Jan 14, 2011
Rank: 4.5 / 5 (6)
QC.
I don't disagree with your notion our measurements aren't perfect, but I take offense when you claim scientists are only trying to make money for themselves or have any ill agenda. We are only trying to determine why we are here, why must you troll to try and stop us? You don't see us on the religious blogs claiming all preachers want is money and all followers want is an easy solution to the universe regardless of accuracy or beleivablility.
What are you trying to accomplish? Would you like us to stop trying? Well, F-off because we won't.
In regards to my personal beliefs, I think it is obvious that if there is a god, he does not work by magic, but by math.
Jan 14, 2011
Rank: 1.4 / 5 (13)
Scientism is full of sacred dogmas and its keepers acting exactly as high priests. We like to pretend that we are a year or two away.from having it all nailed down but nothing could be further.from the.truth. our current mode of thinking has.left us circling the cul de sac since the 1930s in America.
Jan 14, 2011
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Jan 14, 2011
Rank: 5 / 5 (7)
Actually, the maximum energies attainable by the LHC are like 10^13 volts; utrahigh energy cosmic rays hit the atmosphere on a daily basis and have energies on the order of 10^20 volts. If the LHC could generate micro black
holes, it's been happening on a daily basis for a long long time. We're still here. Chill out.
Jan 14, 2011
Rank: 5 / 5 (5)
On the age of the earth (as opposed to the universe), the YECs are off be a factor of 3/4 of a milion, or 75,000,000 percent, so you understated the YEC's error by a factor of 60.
On the other hand the energy density of the vacuum differs from the prediction by over 100 orders of magnitude, which is far bigger than the YEC's age error.
Of course scientists label this humongous factor a catastrophe and acknowledge that their theories are still incomplete, while the YECs overlook a factor of 75,000,000 and don't acknowledge that there could possibly be a problem with their 'facts'...
As long as the YECs insist that the time periods referred in Genesis were 'days' rather than 'eras' they will be forced to deny reality.
Jan 14, 2011
Rank: 5 / 5 (6)
Jan 14, 2011
Rank: 1 / 5 (3)
Even though I do not believe in the Big Bang Theory, the numbers can still be mathematically calculated. Obviously, Time does not stand still, but Pink Elephant, I am unaware of "deep gravitational wells (where time passes slower)" as you state, happening in Empty Space. Not being privy to this information, I'll just use plain math.
Jan 14, 2011
Rank: 3 / 5 (6)
That's true. However...
that bit, not so much. In the first quote you speak of age (13.7 Gyr), but in the second quote you speak of distance (seeing farther). In the 13.7 Gyr AGE of the universe, light has travelled a lot farther than 13.7 Gly due to cosmic expansion (or about 46 Gly).
Jan 14, 2011
Rank: 2 / 5 (4)
But even shithouse drunk I know better than QC. Isn't that sad?
(to all you sad little children who'd rather guess than check, an old drunk man is better at this reality game than you are. Doesn't that just make you want to best him? Really, where the hell is your pride?)
Jan 16, 2011
Rank: 5 / 5 (2)
Jan 17, 2011
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Jan 17, 2011
Rank: 5 / 5 (1)
-Faith and science do not work well together, I am not a man of faith, I am a man of proof. Scientists attempt to prove, religions do not, faith is unnecessary and a distraction.
-MANY outright frauds? Please, provide examples and names. As for the Gatekeeper thoughts, every profession has it. Its called Old vs New, but your blowing it out of proporations.
-As for revisionist history, I think that figure is far better pointed at religios organisations. Any Proof?
-You do, why? We have a long way to go, we may never reach the end. You think we will have all the answers in a year or two?
Jan 17, 2011
Rank: 5 / 5 (4)
Therefore, positive knowledge (that a theory is right) is not possible, but negative knowledge (that a theory is wrong) is perfectly possible.
Hence, the non-existence of positive proofs is a common trait of science and non-science (metaphysics, philosophy, religion, relationships).
What separates science from metaphysics instead is the principle of falsifiability - the possibility to disprove.
Never fallen in love?
Jan 17, 2011
Rank: 5 / 5 (5)
Instead, we see the other galaxy as it had been some billion years ago.
The best visualization helps (for me) are in the wikipedia article "Metric expansion of space".
Jan 17, 2011
Rank: 5 / 5 (1)
-I stand coorected, you are right. But it only addeds to my preference of science over faith.
-I was speaking in regards to the sciencentific method. I do have certain faith. For example, I do beleive that if their is a god, he is good (in our eyes) and not an evil spahgetti monster who's choosen people are fat people because they taste better. I have no proof either way, but I do have faith the later is false. That being said, it wouldn't surprise me in the least if the entire purpose of the universe is food for a spahgetti monster, anything is possible at this point. I should've been using the term absolute faith, which is only required by a few religions, and which blocks out the infinite possibilities, permanently.
Jan 17, 2011
Rank: 5 / 5 (1)
"What's the purpose of life?"
"It keeps meat fresh."
Jan 17, 2011
Rank: 2 / 5 (1)
-think your misunderstanding my words. If I were instantiously sent 13.7B lightyears away, I would see these galaxies, now local, in a modern form similar to what we see here. However, the CMBR we see from earth is the early universe as seen +13.7B light years away. Since the CMBR is still evolving into atoms and galaxies today, and we are really looking 13.7B years in the past, then if we stand 13.7B lightyears away now, we would see another 13.7B lightyears worth of galaxies in the opposite direction of earth. i.e., the universe is significantly larger than 13.7B lightyears, implying it is also older since light can't travel faster.
Jan 17, 2011
Rank: 5 / 5 (3)
It's incorrect to state that light has _traveled_ more than ~13.7 light-years since the Big Bang. The distance from us to the farthest visible objects may well be much larger today, but that's because space has been expanding behind the photons of light that have been racing toward us. The photons themselves, of course, can only travel at the speed of light, and can only cover so much space over so much time.
@gunslingor1,
CMBR doesn't evolve into anything; it consists of originally high-energy photons released at the moment of re-ionization (which followed the cosmic "Dark Ages" period). These photons have been stretched out (red-shifted) as they traveled in every direction (including toward us) through expanding space since the Big Bang, until they became low-frequency microwaves. CMBR is the "fossil", "first light" of our known universe, and variations in it carry information about the observable universe's earliest large-scale inhomogeneities and structures.
Jan 17, 2011
Rank: not rated yet
With BB theories we travel magically instantly 13.7 B LY away and we see stars extending away from us in opposite direction.
Your travel plans do not take into account universe expansion at varying rates.
the Universe apparently has expanded to size far greater then the 13.7 BLY than you would suppose. observationally we can probably see further than 13.7 BLY even now.
Take into account the universal expansion rate and then say we travel instantly 40 BLY in any direction and then try and describe what you would see.
Jan 17, 2011
Rank: not rated yet
Just thinking about "Scientists know of four physical forces"
we have:
gravity: attractive force
Strong: attractive force
Weak: attractive force
Electroforce +-: attractive force
four forces
but is ++ repulsive force the same as +- attractive force?
what about -- is that the same force as ++?
Where does neutron repulsion come into it?
can a repulsion force and attractive force be caused by the same thing?
Jan 18, 2011
Rank: not rated yet
-Well, if photons were generated to produce the CMBR, they had to be generated from somewhere... matter. You can't really generate radiation without the presence of matter. You say these photons were created at the moment of reionization [of quark-gluon plasma right?], which did occur everywhere and lead to the galaxies we see today. The matter from which these photons were generated has probably evolved.
-I am a laymen, I cld b wrng
Jan 18, 2011
Rank: 2.3 / 5 (3)
Jan 18, 2011
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Jan 18, 2011
Rank: 1 / 5 (1)
The point I am trying to make, is the universe is deffinitely bigger.
As for the matter-eneergy-space thing, you sound a little to certain. All this is theoretical and largely based on appearance with a goal of unification in mind.
I'm not saying your theory is wrong, but I am certain its not 100% accurate; more like a mathematical model that will give you right answers most of the time, there are probably an infitite number of these models that will work MOST of the time once the underlying principles are truely understood if ever.
Jan 18, 2011
Rank: 1 / 5 (5)
As for the speed of light, the verdict is still out as to its speed in our environment versus a different speed in a different location. But using our number is just fine for measurement.
My question is: How can "a" photon originally generated 13.7B years ago survive the journey through the cosmos to our eyes? I am a complete skeptic. Remember, Bose argued that photons were indistinguishable and could not be labeled.
Jan 18, 2011
Rank: 5 / 5 (6)
ctd.
Jan 18, 2011
Rank: 5 / 5 (5)
More holistically, the universe is an integral entity. Matter-energy cannot be defined in absence of space-time, while space-time has no meaning in absence of matter-energy. These are all interlocking facets of a single whole (and there may well be yet more facets, of which we aren't even aware at present, or whose existence we can only suspect -- like Dark Matter, and Dark Energy.)
Jan 18, 2011
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Jan 19, 2011
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