In the most stringent test yet of differences between protons and antiprotons, scientists investigated the ratio of electric charge to mass in about 6,500 pairs of these particles over a 35-day period. To keep antimatter and matter from coming into contact, the researchers trapped protons and antiprotons in magnetic fields. Then they measured how these particles moved in a cyclical manner in those fields, a characteristic known as their cyclotron frequency, which is proportional to both the charge-to-mass ratio of those particles and the strength of the magnetic field.
(Technically, the researchers did not use simple protons in the experiments, but negative hydrogen ions, which each consist of a proton surrounded by two electrons. This was done to simplify the experiments — antiprotons and negative hydrogen ions are both negatively charged, and so respond the same way to magnetic fields. The scientists could easily account for the effects these electrons had during the experiments.
The scientists found the charge-to-mass ratio of protons and antiprotons "is identical to within just 69 parts per trillion," Ulmer said in a statement. This measurement is four times better than previous measurements of this ratio.
In addition, the researchers also discovered that the charge-to-mass ratios they measured do not vary by more than 720 parts per trillion per day, as Earth rotates on its axis and travels around the sun. This suggests that protons and antiprotons behave the same way over time as they zip through space at the same velocity, meaning they do not violate what is known as charge-parity-time, or CPT symmetry.
[...]
Using more stable magnetic fields and other approaches, the scientists plan to achieve measurements that are at least 10 times more precise than what they found so far, Ulmer said.
If matter and anti-matter are mirrors of each other, and were created in equal measure by the Big Bang, then where did all the anti-matter go?
See our related story: Time-Symmetric Formulation of Quantum Theory Provides New Understanding of Causality.
Related Stories
From the press release:
The laws of classical mechanics are independent of the direction of time, but whether the same is true in quantum mechanics has been a subject of debate. While it is agreed that the laws that govern isolated quantum systems are time-symmetric, measurement changes the state of a system according to rules that only appear to hold forward in time, and there is difference in opinion about the interpretation of this effect.
Now theoretical physicists at the Université libre de Bruxelles have developed a fully time-symmetric formulation of quantum theory which establishes an exact link between this asymmetry and the fact that we can remember the past but not the future – a phenomenon that physicist Stephen Hawking has named the "psychological" arrow of time.
The study offers new insights into the concepts of free choice and causality, and suggests that causality need not be considered a fundamental principle of physics. It also extends a cornerstone theorem in quantum mechanics due to Eugene Paul Wigner, pointing to new directions for search of physics beyond the known models. The findings by Ognyan Oreshkov and Nicolas Cerf have been published this week in the journal Nature Physics.
The paper is pay-walled, but the preprint is free.
According to an article posted on a major news aggregator in 2015, Matter and Antimatter Are Mirror Images
As it turns out, maybe, but not so much inside
Physicists in the College of Arts and Sciences at Syracuse University have confirmed that matter and antimatter decay differently for elementary particles containing charmed quarks.
Distinguished Professor Sheldon Stone says the findings are a first, although matter-antimatter asymmetry has been observed before
[...]Using LHC data, they identified both versions of the particle, well into the tens of millions, and counted the number of times each particle decayed into new byproducts.
"The ratio of the two possible outcomes should have been identical for both sets of particles, but we found that the ratios differed by about a tenth of a percent," Stone says. "This proves that charmed matter and antimatter particles are not totally interchangeable."
Adds Polyakov, "Particles might look the same on the outside, but they behave differently on the inside. That is the puzzle of antimatter."
Matter and antimatter behaving differently is not a new concept and has been observed before in particles with strange quarks and with beauty quarks:
What makes this study unique, Stone concludes, is that it is the first time anyone has witnessed particles with charmed quarks being asymmetrical: "It's one for the history books."
A step closer, but still no where close to explaining the disparity between matter and antimatter.
Bearded Spock is laughing at us.
According to Wikipedia: CP violation:
In particle physics, CP violation is a violation of CP-symmetry (or charge conjugation parity symmetry): the combination of C-symmetry (charge conjugation symmetry) and P-symmetry (parity symmetry). CP-symmetry states that the laws of physics should be the same if a particle is interchanged with its antiparticle (C symmetry) while its spatial coordinates are inverted ("mirror" or P symmetry).
(Score: -1, Troll) by Anonymous Coward on Friday August 14 2015, @02:58AM
Give me grant money!
(Score: 0) by Anonymous Coward on Friday August 14 2015, @02:26PM
OK, please write a grant money application, detailing the current state of research, your own previous work on that area, a detailed research program, and what types of results you expect.
Oh, you have no idea about the current state of research, have never done anything in that field, have no idea what to do except for throwing out claims, and the only result you expect is to get more money? Sorry, application declined.
(Score: 0) by Anonymous Coward on Friday August 14 2015, @03:01AM
Hey, I read all about this in "Angels and Demons"! Pro-tip, learn to fly a helicopter, or fly using plastic tarps.
(Score: 0, Interesting) by Anonymous Coward on Friday August 14 2015, @03:05AM
They annihilated my missing socks!
(Score: 1, Funny) by Anonymous Coward on Friday August 14 2015, @03:22AM
tsop tsrf
(Score: 0) by Anonymous Coward on Friday August 14 2015, @03:24AM
MOOB
(Score: 4, Insightful) by khallow on Friday August 14 2015, @03:28AM
(Score: -1, Troll) by Anonymous Coward on Friday August 14 2015, @03:31AM
You're just jealous.
(Score: 3, Touché) by wonkey_monkey on Friday August 14 2015, @07:27AM
you probably aren't going to see it by using protons with a couple of electrons attached.
Well, they say they can:
The scientists could easily account for the effects these electrons had during the experiments.
And I'm going to give them the benefit of the doubt for now.
systemd is Roko's Basilisk
(Score: 2, Insightful) by khallow on Friday August 14 2015, @03:07PM
Well, they say they can:
Point is that they aren't measuring anti-protons no matter what they are saying. And when you're trying to measure very subtle phenomena to parts per trillion (or less), that distinction matters.
I would guess here that that they're really proving the concept right now and then planning to hook the apparatus up to a source of anti-protons, say at one of the major particle accelerators.
(Score: 0) by Anonymous Coward on Friday August 14 2015, @03:41PM
And as a professional physicist, I would call them on that claim. Otherwise all they've done is noted that there is no difference between protons traveling different directions around a cyclotron, to at least 69 parts per trillion. There is probably interesting things to infer from that, but it doesn't say a lot about antiprotons.
I suspect that is the case too, or I hope that is the case. Otherwise, their current result is not as interesting as the article suggests.
(Score: 2) by mcgrew on Friday August 14 2015, @07:33PM
They already did; scroll down, I provided a link.
mcgrewbooks.com mcgrew.info nooze.org
(Score: 1) by khallow on Friday August 14 2015, @09:58PM
(Score: 2) by mcgrew on Sunday August 16 2015, @10:39PM
The neutrino experiment was the one.
mcgrewbooks.com mcgrew.info nooze.org
(Score: 2, Informative) by Anonymous Coward on Friday August 14 2015, @07:34AM
I think those hydrogen ions were stand ins for the protons, not for the anti-protons. The idea being that a negative ion is more like an anti-proton (which is also negative).
The differences between hydrogen ions and protons alone are already known, and can easily be factored out of the equation.
(Score: 0) by Anonymous Coward on Friday August 14 2015, @06:37PM
Pardon my ignorance, but what is the difference between a hydrogen ion (1H+, ie 1 proton) and a proton (1 proton)?
(Score: 0) by Anonymous Coward on Friday August 14 2015, @07:21PM
Come on, it is right in the fucking summary for you to read.
This was a different Hydrogen ion, i.e. one with two electrons, thus giving it a negative charge like the anti-proton.
(Score: 1) by khallow on Monday August 17 2015, @01:37AM
(Score: 0) by Anonymous Coward on Friday August 14 2015, @04:10AM
The anti matter went to the other side. What? The universe is big you don't think it could have an anti-matter version on some distant boundary equally large, created by some immense magnetic field from the earliest event?
(Score: 2) by mhajicek on Friday August 14 2015, @04:51AM
If there were such a boundary there would be either bright walls where matter and anti collide, or dark spans with neither, or both. Unless most of the anti went the other direction in time.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 2) by gnuman on Friday August 14 2015, @05:16AM
Antimatter doesn't go in other direction in time. That's kind of easy to show - just look at the experiment. It went forward in time along with the experiment. Same everything, except charge.
So where did all the antimatter go? Best answer is - we don't know!
(Score: 2) by mhajicek on Friday August 14 2015, @05:41AM
How do you know it was going forward? Physics works backwards just the same as forwards.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 3, Funny) by tftp on Friday August 14 2015, @06:05AM
How do you know it was going forward? Physics works backwards just the same as forwards.
Perhaps because in this experiment, and in many others, the antiprotons did not appear before they were created. Only thiothimoline does that.
(Score: 0) by Anonymous Coward on Friday August 14 2015, @02:29PM
Ah, but if only thiotimoline does it, then clearly antithiotimoline doesn't do it. So that's clearly an asymmetry between matter and antimatter. Puzzle solved! :-)
(Score: 2) by opinionated_science on Friday August 14 2015, @11:26AM
that's where entropy comes in....
(Score: 0) by Anonymous Coward on Friday August 14 2015, @05:24AM
But we can only see as far as light will allow us in the expanding universe. There could be a dark boundary between the universes that's so far away we will never see it. Not a satisfying answer but possible and could explain the mystery.
(Score: 2, Interesting) by Anonymous Coward on Friday August 14 2015, @08:51AM
If the antimatter is behind the cosmic horizon, we can't see it. We just assume that the complete universe is the same as the visible universe, we can't prove it. But I don't see a fundamental reason why it could not have inhomogeneities on length scales much larger than the visible universe. Such inhomogeneities would not even necessarily mean that the universe is inhomogeneous at the largest possible scales; it could be that they are still local compared to the actual size of the universe. There could be other parts of the universe, unobservable to us, dominated by antimatter (with antihumans wondering where all the matter has gone — well, they'd call our antimatter "matter" and our matter "antimatter" and wonder where the antimatter went, just as we do), and yet other parts where there's no matter or antimatter (and clearly no intelligent life, for lack of matter to make it of).
(Score: 3, Interesting) by tibman on Friday August 14 2015, @02:45PM
Other large structures seem to produce two jets of radiation/matter around a central spinning axis (black hole, quasar, pulsar, and all large quantities of mass). I don't see why the big bang couldn't be similar. Except matter in one direction and anti-matter in the other. Where the clouds of hydrogen and anti-hydrogen meet they annihilate and form a pseudo-boundary wall that is denser when closer to the big bang origin.
That would end up with your theory where there are two "universes" of mostly similar matter types. They share a boundary but by the time enough fusion happens to support complex life we'd be so far away that we couldn't see it. Just like how we currently have no idea which direction is the center of the universe (as in the origin, i get the whole "space is expanding and the center is where you are" thing).
SN won't survive on lurkers alone. Write comments.
(Score: 0) by Anonymous Coward on Friday August 14 2015, @07:24PM
You can picture them standing there in their lab coats, stroking their goatees and wondering aloud whether they're the only intelligent life in the universe, and if maybe there's evil copies of themselves, without goatees, out there somewhere.
(Score: 1, Interesting) by Anonymous Coward on Friday August 14 2015, @05:56AM
(Score: 1, Interesting) by Anonymous Coward on Friday August 14 2015, @05:29PM
Positive and negative charges move in opposite directions in a magnetic field. And what is being described is the largest magnetic field ever possible. Also you describe the early universe as small then ask how there could be enough strength to separate all the charged particles when at that point (the magnetic moment) would be occurring instantaneously when the explosion in the first moments occurred(at the speed of light to be exact). The positive and negatively charged particles then parted like the jets that spring from black holes and the universes were pushed immense distances apart, much further than the span of their diameters. This would create 2 differently charged universes propelled in opposing directions from a central point with momentum (or the effect of expanding space) preventing them from re-colliding from their respective electrostatic attractions.
(Score: 0) by Anonymous Coward on Saturday August 15 2015, @05:30AM
(Score: 3, Funny) by Ayn Anonymous on Friday August 14 2015, @04:15AM
> where did all the anti-matter go?
Redmond, WA 98052-6399. UNITED STATES
(Score: 2, Interesting) by hopp on Friday August 14 2015, @05:34AM
Of course, the matter is on the other side of the event horizon.
(Score: 5, Insightful) by bradley13 on Friday August 14 2015, @06:16AM
Where did all the antimatter go? Our understanding of the universe at cosmological scales is at the level of phlogiston.
There was a documentary on TV last night, about the search for dark matter. Which is sort of like the one-time search for ether: it seems pretty clear that it doesn't exist, but we look for it anyway. Why? Because we lack the necessary theories to explain what we see any other way.
There are various wild theories out there, such as a variable speed of light [livescience.com]. We just have the problem that it's a bit difficult to make useful comparative measurements. It would be awfully nice to get some real-time data from a few million light years away.
tl;dr: We're missing something. Probably something that will seem obvious in retrospect.
Everyone is somebody else's weirdo.
(Score: 2, Insightful) by beernutz on Friday August 14 2015, @06:37AM
Isn't that why they call it "dark matter"? Because the don't know what it is? Seems like they KNOW they are missing something, and intentionally describing that something as "dark matter"/
(Score: 3, Informative) by zocalo on Friday August 14 2015, @06:43AM
UNIX? They're not even circumcised! Savages!
(Score: 3, Touché) by Zinho on Friday August 14 2015, @02:46PM
Minor nit, but you mean "aether"; ether (R-O-R') is very real.
Sorry, you are conflating being American with being wrong. In American English the Latin spelling for luminiferous (a)ether has been deprecated,[1] and is simply spelled "ether".[2][3] You'll probably have as much luck convincing bradley13 to add an extra I to aluminum[4] or use commas as decimal points[5] as you are to get them to add an extra "A" to "ether".
[1] source: aether at Merriam-Webster online [merriam-webster.com]
[2] source: ether at Merriam-Webster online [merriam-webster.com]
[3] source: ether at Collins American English Dictionary [collinsdictionary.com]
[4] source: aluminium at Merriam-Webster online [merriam-webster.com]
[5] source: decimal mark use at Wikipedia [wikipedia.org]
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 0) by Anonymous Coward on Friday August 14 2015, @08:21PM
This is pretty common, most of the world conflates being American with being wrong.
(Score: 4, Informative) by stormwyrm on Friday August 14 2015, @07:32AM
No, it seems pretty clear that dark matter does exist. There is quite a bit of indirect evidence for it, which I have written of in detail in a elsewhere [soylentnews.org]. There doesn't seem to be any other way to explain stuff like the sort of gravitational lensing seen in things like the Bullet Cluster [wikipedia.org]. Even modified gravity theories like MOND and TeVeS cannot explain it without recourse to what essentially amounts to some form of dark matter. The situation with dark matter is a bit like solar system astronomy in the past. They saw perturbations in the orbit of Uranus and inferred that there was some sort of "dark matter" there which they couldn't see, until better telescopes saw the planet Neptune. They saw other perturbations in the orbit of Mercury and thought that there might be some other planet even closer to the sun, which they called 'Vulcan', which turned out not to exist. A new, modified theory of gravity, General Relativity, explained those perturbations nicely. In the same way I'd think that there must be some sort of new, modified theory of gravity out there (there has to be: GR is incompatible with quantum mechanics) that explains some aspects, and some form of dark matter must also be present as well.
Can't really argue with the general spirit of the post though.
Numquam ponenda est pluralitas sine necessitate.
(Score: 3, Funny) by jasassin on Friday August 14 2015, @08:09AM
What else could have possibly created Dick Cheney's soul?
jasassin@gmail.com GPG Key ID: 0xE6462C68A9A3DB5A
(Score: 3, Interesting) by PiMuNu on Friday August 14 2015, @09:03AM
...another interesting experiment they are doing is measuring gravitational force in matter vs antimatter.
Current limit, I believe, is that -100 G_{+}/G_{-} 100. It should be 1 if force is the same, -1 if force is opposite...
(Score: 2) by PiMuNu on Friday August 14 2015, @09:06AM
-100 lt G_{+}/G_{-} lt 100
meta: Is there any documentation on soylent markup? I never know how it is supposed to work...
(Score: 0) by Anonymous Coward on Friday August 14 2015, @09:23AM
Just use standard HTML entities and supported html tags (see the list below the comment form). However what is not discoverable (it was once published on a meta post, but otherwise seems to be documented nowhere, unfortunately) is the very useful fact that also the <sub> and <sup> tags are supported. So you could have written your line as
−100 < G<sub>+</sub>/G<sub>−</sub> < 100
to get
−100 < G+/G− < 100
But are the bounds really −100 and 100? Seem to be quite imprecise bounds to me.
(Score: 2) by gnuman on Saturday August 15 2015, @12:29AM
How do you expect someone to measure G on anti-matter?
"I get 1kg of anti-matter suspended by a magic string so I can measure G .... "
probably will no go well on a grant application.
(Score: 0) by Anonymous Coward on Friday August 14 2015, @09:09AM
From the dept-line-got-anihillated dept?
(Score: 2) by The Mighty Buzzard on Friday August 14 2015, @10:15AM
Yep, janrinok put up the dept and martyb put up its anti-dept. martyb's mission in life is to make the servers explode in a spectacular fashion.
My rights don't end where your fear begins.
(Score: 2) by mcgrew on Friday August 14 2015, @07:31PM
https://en.wikipedia.org/wiki/Neutrino_oscillation [wikipedia.org]
http://www.spacedaily.com/reports/Fermilab_experiment_sees_neutrino_oscillation_999.html [spacedaily.com]
mcgrewbooks.com mcgrew.info nooze.org