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Proton's radius revised downward - Surprise measurement may point to new physics
Science News ^ | January 24, 2013 | Andrew Grant

Posted on 01/25/2013 11:04:41 PM PST by neverdem

Only in physics can a few quintillionths of a meter be cause for uneasy excitement. A new measurement finds that the proton is about 4 percent smaller than previous experiments suggest. The study, published in the Jan. 25 issue of Science, has physicists cautiously optimistic that the discrepancy between experiments will lead to the discovery of new particles or forces.

“Poking at small effects you can’t explain can be a way of unraveling a much bigger piece of physics,” says Carl Carlson, a theoretical physicist at the College of William and Mary in Williamsburg, Va., who was not involved in the study. “And this case is particularly intriguing.”

For years, physicists have used two indirect methods to determine the size of the proton. (Unfortunately, there is no such thing as a subatomic ruler.) They can fire an electron beam at protons and measure how far the flying particles get deflected. Alternatively, physicists can study the behavior of electrons in hydrogen atoms. They shoot a laser at an atom so that the one electron jumps to a higher, unstable energy level; when the electron returns to a low-energy state, it releases X-rays whose frequency depends on the size of the proton. Both methods suggest the proton has a radius of about 0.88 femtometers, or 0.88 quadrillionths of a meter.

That measurement was not in doubt until 2010, when physicist Aldo Antognini at ETH Zurich and his team developed a new technique to probe proton size. They also used hydrogen atoms, but replaced the electrons with muons — particles similar to electrons but more than 200 times as massive. Muons’ additional heft enhances their interaction with protons and makes their behavior more dependent on proton size. After measuring the X-rays emitted by muons shifting between energy states, Antognini’s team published a paper...

(Excerpt) Read more at sciencenews.org ...


TOPICS: Science
KEYWORDS: physics; protonradius
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1 posted on 01/25/2013 11:04:48 PM PST by neverdem
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To: neverdem
That's it. I refuse to memorize any more numbers... they'll just change.

What's next? Planck's constant?

It so a cook can't keep up with physics anymore.

/johnny

2 posted on 01/25/2013 11:16:24 PM PST by JRandomFreeper (Gone Galt)
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To: neverdem

Odd how this ‘measurement’ of the proton is very similar to our claims of the size, orbit, and viability of planets around other stars.

We can’t see the planets.
We only have light detectors that give us a reading of very minute dimming in the light, which we assume to be a planet.
Based on the length and extent of the dimming, we claim to know the planet’s size and orbit.

Amazing how continuously wrong we are about things we search for the truth.


3 posted on 01/25/2013 11:16:32 PM PST by UCANSEE2 (What difference does it make (if they eat cake)?)
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To: UCANSEE2

Amazing how continuously wrong we are about things AS we search for the truth.

(that’s a sign I should go to bed. Goodnight all)


4 posted on 01/25/2013 11:19:44 PM PST by UCANSEE2 (What difference does it make (if they eat cake)?)
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To: JRandomFreeper; Salamander

So ..... How long before they realize that it isn’t really there at all?


5 posted on 01/25/2013 11:21:21 PM PST by shibumi (Cover it with gas and set it on fire.)
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To: shibumi
I gripe about the details, but the theories work fairly well at the macro level.

GPS is based on an earth centered concept... Not true, but it does get us within a few meters of where we want to go.

/johnny

6 posted on 01/25/2013 11:27:30 PM PST by JRandomFreeper (Gone Galt)
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To: JRandomFreeper

They will just come out with a Planck’s Constant Compensator to account for the difference.


7 posted on 01/25/2013 11:27:40 PM PST by Jonty30 (What Islam and secularism have in common is that they are both death cults.)
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To: Jonty30
Right now, on a somewhat blurry Saturday morning, I'm ok with +/- 12%. Tomorrow, I might insist on POM 10%.

It's a working theory. That's all we have. I gripe, but that's a good-natured swirly.

We see through a glass, darkly. I seem to recall someone saying that...

/johnny

8 posted on 01/25/2013 11:31:57 PM PST by JRandomFreeper (Gone Galt)
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To: El Gato; Ernest_at_the_Beach; Robert A. Cook, PE; lepton; LadyDoc; jb6; tiamat; PGalt; Dianna; ...
Non-coding Mutations May Drive Cancer

Researchers show how cells' DNA repair machinery can destroy viruses

Immune system molecule with hidden talents

With Shakespeare's help, researchers show potential of DNA for storing digital information

FReepmail me if you want on or off my health and science ping list.

9 posted on 01/25/2013 11:33:51 PM PST by neverdem ( Xin loi min oi)
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To: El Gato; Ernest_at_the_Beach; Robert A. Cook, PE; lepton; LadyDoc; jb6; tiamat; PGalt; Dianna; ...
Non-coding Mutations May Drive Cancer

Researchers show how cells' DNA repair machinery can destroy viruses

Immune system molecule with hidden talents

With Shakespeare's help, researchers show potential of DNA for storing digital information

FReepmail me if you want on or off my health and science ping list.

10 posted on 01/25/2013 11:34:53 PM PST by neverdem ( Xin loi min oi)
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To: neverdem

11 posted on 01/25/2013 11:41:13 PM PST by JoeProBono (A closed mouth gathers no feet - Mater tua caligas exercitus gerit ;-{)
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To: neverdem; JRandomFreeper
Researchers are desperate to discover new physics because, while successful in describing most of what we see in everyday life, the standard model[sic] is terrible at describing phenomena such as gravity at small scales and the accelerating expansion of the universe.

First: The Standard Model doesn't describe gravity, period.

Second: Physicists aren't desperate to "discover new physics." We're desperate to wring information out of experimental physics in new ways because the approach of reaching ever higher energies in our accelerators is simply not viable. We can't even get within orders of magnitude needed to investigate most speculative theories in high energy physics, and there is no prospect for doing so in sight.

We need new experimental results and we just aren't getting any. Hence micro-measurements of the difference between c and the speed of neutrinos in vacuum or anomalous results like this start to look intriguing. They seldom turn out to be anything but experimental artifacts.

And no, we aren't changing Planck's constant. In fact, in the new SI proposal, Planck's constant, the electric charge, Boltzmann's constant, and Avogadro's number are going to be set as defined constants; they will never change. What will happen instead is that the basic practical units (second, meter, kilogram, ampere, kelvin, mole, and candela) will change and we will be looking for ever sharper definitions of the practical units in terms of the atomic ones, instead of the other way around as we did in the past.

High energy physicists and cosmologists have been doing that for a long time already. In their unit system ħ = (h/2π) = c = 1.

12 posted on 01/25/2013 11:59:03 PM PST by FredZarguna ("The first thing we do, let's kill all the lawyers." -- Henry the Sixth Part II, 4.2.71-78)
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To: JoeProBono
Yup, what was so hard about doing like that?
Stupid scientist :)
13 posted on 01/26/2013 12:01:11 AM PST by The Cajun (Sarah Palin, Mark Levin......Nuff said.)
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To: neverdem

Question for Physics majors....

Is Particle Physics built on the idea that EVERY similar particle in the universe has EXACTLY the same weight, dimension, and charge as every other similar particle?

Or, is there some level of acceptable deviation?


14 posted on 01/26/2013 12:02:26 AM PST by zeestephen
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To: JoeProBono

Only the Japs could possibly make a caliper that small.


15 posted on 01/26/2013 12:08:30 AM PST by FredZarguna ("The first thing we do, let's kill all the lawyers." -- Henry the Sixth Part II, 4.2.71-78)
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To: zeestephen
Not only that. It is also required that the particles be completely indistinguishable. In other words, you get two of them close enough, and you actually have no way of knowing which is which.

In a quantum mechanical Three Card Monte Game, you cannot be cheated, because all three cards are the same, and all three cards occupy all three positions at the same time.

16 posted on 01/26/2013 12:12:18 AM PST by FredZarguna ("The first thing we do, let's kill all the lawyers." -- Henry the Sixth Part II, 4.2.71-78)
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To: FredZarguna
Cooks just need you to be close at the macro level. I've only had to delve into quantum physics twice in a working kitchen.

And one of those times, it turned out the dishwasher was twins that were switching out when I was expediting.

/johnny

17 posted on 01/26/2013 12:14:12 AM PST by JRandomFreeper (Gone Galt)
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To: FredZarguna; SunkenCiv; blam; All

SC - In case no one informed you of this new science post.


18 posted on 01/26/2013 12:14:52 AM PST by gleeaikin
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To: zeestephen
In his book, The Physics of Immortality, Tipler makes the argument that the physical reconstruction of human beings in a literal bodily resurrection is made possible by quantum mechanics, and is actually not possible in classical physics.

The reason is that in classical physics, when you reconstruct a person out of all of the constituent leptons and quarks, it is not the same person, because even though the particles are the same mass, charge, density, and so on, it's still possible to say the reconstructed person is nothing more than a very precise clone.

But in quantum physics, if I have two leptons (electrons for example) or two down quarks and an up quark (neutron, for example) those particles are in a much deeper sense identical: there is no physical experiment that can "label" two electrons as distinct particles in a two electron system. There is no electron-1 and elecvtron-2. There is just "two electrons."

So (his argument goes) when God reconstructs a person from quantum particles (all questions of whether he has a soul or not aside), it isn't just a perfect identical twin. It is literally the same person.

19 posted on 01/26/2013 12:19:48 AM PST by FredZarguna ("The first thing we do, let's kill all the lawyers." -- Henry the Sixth Part II, 4.2.71-78)
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To: JRandomFreeper

It’s a fundamental asymmetry in the universe: I, on the other hand have had to cook quite often.


20 posted on 01/26/2013 12:22:06 AM PST by FredZarguna ("The first thing we do, let's kill all the lawyers." -- Henry the Sixth Part II, 4.2.71-78)
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