
Scientists make rare achievement in study of antimatter - digital55
https://www.symmetrymagazine.org/article/scientists-make-rare-achievement-in-study-of-antimatter
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excalibur
> “According to our understanding of the Standard Model [of particle physics],
> the Big Bang should have created exactly the same amount of matter and
> antimatter, but [for the most part] only matter remains,” says BASE
> Spokesperson Stefan Ulmer. This is strange because when matter and
> antimatter meet, they annihilate one another. Scientists want to know how
> matter came to dominate our universe.

We don't have any evidence that matter DOES dominate the universe. Distant
galaxies could easily be composed of antimatter. Since the Big Bang should
have created equal amounts of both, you would expect that in the vast majority
of cases they would annihilate one another, leading to a universe
overwhelmingly dominated by (wait for it) empty space.

We have tons of evidence that matter dominates our neck of the woods. Regions
where one form is dominant over the other may be in the minority, but you
would have to enter such a region to find stars, planets, and galaxies. The
fact that we're here means that this must be an area where one type is
everywhere and the other is almost completely absent. But as best we can tell,
the fact that we're all made of matter rather than antimatter is the result of
a very old coin flip. The probability that all of the galaxies we can see
landed on the matter side of the coin is infinitesimal.

~~~
dwaltrip
I'm pretty sure they have very compelling reasons to believe that distant
galaxies are NOT made of anti-matter.

Here is one I found in a quick search:

The boundary between any group of anti-matter galaxies and the region of space
where matter is dominant should emit gamma rays, as the intergalactic wind
pushes dust particles made of regular matter into one of the anti-matter
galaxies. We don't see such gamma ray emissions in our observations of the
cosmos.

Source:
[https://www.forbes.com/sites/briankoberlein/2016/12/27/could...](https://www.forbes.com/sites/briankoberlein/2016/12/27/could-
some-distant-galaxies-be-made-of-antimatter/)

~~~
philipov
What if all the antimatter-dominated regions are outside our cosmological
horizon and are no longer in causal contact with matter-dominated regions?

~~~
Retric
That just creates the same questions for why this region of space is so
dominated by 'matter' while adding a new one that another vast region of space
is dominated by 'anti-matter'.

If you can come up with some compelling mechanism for it then sure it may be
possible, but currently that seems to be more complex and fails to provide any
support of any kind.

~~~
philipov
It's pure speculation, but I am suggesting that instead of some sort of
annihilation imbalance, the mechanism might be a sorting process that causes
antimatter and matter to collect into horizon-shaped pockets.

If there were such a sorting process that was inherently linked to
cosmological horizons, it could explain both where the antimatter went, and
why we don't see an annihilation zone where the boundaries meet.

~~~
Retric
The problem is your sorting process is identical to your original statement.
It's like saying "why is the sky blue" > "air is blue". You need to make
predictions that are different from your observations.

On the other hand if you say something like "Air becomes blue when it's
colder." Then you can actually test what's going on and falsify the statement
which may lead to progress.

Suppose you suggest the output of this experiment will change over time. Now,
waiting a billion years is not going to happen but adding even more digits of
accuracy may be possible.

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peterburkimsher
tl;dr "The results confirm that the [proton and antiproton] behave exactly the
same, as the laws of physics would predict. So the mystery of the imbalance
between matter and antimatter remains."

~~~
orclev
alternate TL;DR: Science was done, no new data was generated that couldn't
have been predicted from existing laws, existing mysteries remain.

Basically this is the "boring" science, not the exciting "hmm, that's odd"
science. It's very important science of course, the sort that you need for
science to actually work, but it is rather boring from the perspective of
someone outside looking in on the process.

~~~
indubitable
Something I'm rather curious about. Are you disinterested in it, because of
its nature? Similarly, are you excited by the day in day out 'hot' studies?
And by 'hot', I mean things like 'researchers discover amazing new way to
destroy cancer cells' given what you know to expect of such a study.

It seems to me that so often we apply, in completely good faith, base
characteristics to others when considering them as a group, yet simultaneously
it seems like few would ever say those characteristics actually apply to
themselves.

Mostly just a random thought that occurred when reading your post. It's
interesting to consider things like all movies becoming explosions and CG
because 'everybody else loves that stuff' even though ticket sales have
declined by 30% since 2002 (gross receipts are up thanks to substantial
increases in price). Or similarly at the same time everybody focuses on 'hot'
science, trust and arguably (and paradoxically) even interest seems to be
rapidly declining.

~~~
orclev
Well, mostly disinterested in that it's really just a more precise
measurement. The "breakthrough" in this case is a ridiculously precise
measurement, which is very impressive, and is a huge step forward for particle
physics as a science because it opens the door to measure even more stuff, but
in this particular case it hasn't contributed anything "new" in terms of data.

There's a famous quote out there that goes something like 'the most exciting
words in science aren't "Eureka", they're "that's odd"', and I feel that's
highly applicable in this case. There's no "that's odd" event here, everything
is exactly as expected, it all worked perfectly and produced exactly the
result that was expected. That's great for affirming that all our theories are
correct, and as I said this is a breakthrough in the quality of measurements
we can achieve, but it's not a new mystery to explore, or an unexpected result
that we can use to refine or develop new theories. Basically everything we
didn't know before this experiment we still don't know, and we don't have any
new data points except for having eliminated an area of uncertainty that new
interesting data might have been hiding in.

~~~
Retric
I would argue that it is odd. We assume there must be something separating
matter and anti-matter, but the list of possibilities is getting really short.

Sort of like a murder misery where everyone at a party has a reliable alibi.
Suggesting something even odder must be going on.

~~~
Retra
Sure, but it give you no leads...

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rubayeet
Possibly relevant[0]: What is the difference between Accuracy and
Precision?(video)

[0]
[https://www.youtube.com/watch?v=hRAFPdDppzs](https://www.youtube.com/watch?v=hRAFPdDppzs)

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madengr
Storing the anti-protons for 400 days; reminds me of the magnetic bottle in
Star Trek. Has anti-hydrogen been created?

~~~
Sniffnoy
It sure has:
[https://en.wikipedia.org/wiki/Antihydrogen#Experimental_hist...](https://en.wikipedia.org/wiki/Antihydrogen#Experimental_history)

