APOD: Inside a Daya Bay Antineutrino Detector (2016 May 23)

[APOD Robot]

Inside a Daya Bay Antineutrino Detector

Explanation: Why is there more matter than antimatter in the Universe? To better understand this facet of basic physics, energy departments in China and the USA led in the creation of the Daya Bay Reactor Neutrino Experiment. Located under thick rock about 50 kilometers northeast of Hong Kong, China, eight Daya Bay detectors monitor antineutrinos emitted by six nearby nuclear reactors. Featured here, a camera looks along one of the Daya Bay detectors, imaging photon sensors that pick up faint light emitted by antineutrinos interacting with fluids in the detector. Early results indicate an unexpectedly high rate of one type of antineutrino changing into another, a rate which, if confirmed, could imply the existence of a previously undetected type of neutrino as well as impact humanity's comprehension of fundamental particle reactions that occurred within the first few seconds of the Big Bang.

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[geckzilla]

This is one of those things that I'm positive I have no clue what I'm looking at.

[Ann]

I had never heard of it either.

But any discoveries that can shed any light on the nature of the universe are welcome to me.

Ann

[heehaw]

Wow, thanks! I'd not heard of this preliminary result! There are 3 known neutrino types, and each neutrino oscillates from one type to another among the three. There has long been speculation about the existence of a fourth type ('sterile neutrino') and this seems to be a hint that such exists....

[sheriffofnothingham]

it is said that neutrinos pass right through the earth unhindered. the major source of neutrinos being the sun. this calls for an experiment to determine exactly what is happening on any given moment on tihe side of the earth facing the sun and the side facing night. two neutrino detectors will be needed to measure neutrino flux supposedly entering the earth and neutrino flux leaving the earth. according to theory the neutrino flux entering and leaving the earth should be the same.

[neufer]

'No one trusts a model except the man who wrote it;
everyone trusts an observation, except the man who made it.'

'Theories crumble, but good observations never fade.'

https://www.sciencenews.org/article/rea ... h-neutrino

<<In 1907, at the age of 22, Harlow Shapley (November 2, 1885 – October 20, 1972) went to study journalism at the University of Missouri. When he learned that the opening of the School of Journalism had been postponed for a year, he decided to study the first subject he came across in the course directory. Rejecting Archaeology, which Harlow later explained he couldn't pronounce, Harlow chose the next subject, Astronomy.

Shapley used RR Lyrae stars to correctly estimate the size of the Milky Way Galaxy and the sun's position within it. He participated in the (April 26, 1920) "Great Debate" with Heber D. Curtis on the nature of nebulae and galaxies and the size of the Universe. Shapley took the side that spiral nebulae (what are now called galaxies) are inside our Milky Way, while Curtis took the side that the spiral nebulae are 'island universes' far outside our own Milky Way and comparable in size and nature to our own Milky Way. In 1953 he proposed his "liquid water belt" theory, now known as the concept of a habitable zone.>>

[isoparix]

The Daya web site is listed as 'Dangerous - don't visit' by Symantech. Good enough for me....

[neufer]

it is said that neutrinos pass right through the earth unhindered. the major source of neutrinos being the sun. this calls for an experiment to determine exactly what is happening on any given moment on the side of the earth facing the sun and the side facing night. two neutrino detectors will be needed to measure neutrino flux supposedly entering the earth and neutrino flux leaving the earth. according to theory the neutrino flux entering and leaving the earth should be the same.

Every solar neutrino detector on Earth spends half its measurement time facing the sun and half its measurement time side facing night. The Sun's output is quite constant so there is no need to take the measurements simultaneously.

[ygmarchi]

It was copied from a sci-fi movie, I just can't recall which.

[Joe25]

The Neutrino, "The pirouette that left the stage without the dancer." - John L. Dobson

[gmPhil]

banana for scale required....

[neufer]

'No one trusts a model except the man who wrote it;
everyone trusts an observation, except the man who made it.'

'Theories crumble, but good observations never fade.'

https://www.sciencenews.org/article/rea ... h-neutrino

<<There are three known types (flavors) of neutrinos: electron neutrino ν_e, muon neutrino ν_μ and tau neutrino ν_τ, named after their partner leptons in the Standard Model. The current best measurement of the number of neutrino types comes from observing the decay of the Z⁰ boson. This particle can decay into any light neutrino and its antineutrino, and the more types of light neutrinos available, the shorter the lifetime of the Z⁰ boson. Measurements of the Z⁰ lifetime have shown that the number of light neutrino types is 3. The correspondence between the six quarks in the Standard Model and the six leptons, among them the three neutrinos, suggests to physicists' intuition that there should be exactly three types of neutrino. However, actual proof that there are only three kinds of neutrinos remains an elusive goal of particle physics.

The possibility of sterile neutrinos—relatively light neutrinos which do not participate in the weak interaction but which could be created through flavor oscillation—is unaffected by these Z⁰-boson-based measurements, and the existence of such particles is in fact hinted by experimental data from the LSND experiment. However, the currently running MiniBooNE experiment suggested, until recently, that sterile neutrinos are not required to explain the experimental data, although the latest research into this area is on-going and anomalies in the MiniBooNE data may allow for exotic neutrino types, including sterile neutrinos. A recent re-analysis of reference electron spectra data from the Institut Laue-Langevin has also hinted at a fourth, sterile neutrino. Recently analyzed data from the Wilkinson Microwave Anisotropy Probe of the cosmic background radiation is compatible with either three or four types of neutrinos. It is hoped that the addition of two more years of data from the probe will resolve this uncertainty.>>

[Fred the Cat]

The answer to why an asymmetric universe is unsettling may one day be discovered to be as simple as a mirror universe. Its odd features may be stranger than we can imagine; even with the best Star Trek writers.

[gmPhil]

Yes, Fred, but in the mirror universe, do bananas bend the other way?

I wanna banana! (For scale - how big is this blasted thing?)

And, do mirrors there reverse only up and down and not left and right?

[Fred the Cat]

Yes, Fred, but in the mirror universe, do bananas bend the other way?

I wanna banana! (For scale - how big is this blasted thing?)

And, do mirrors there reverse only up and down and not left and right?

With a slight curve its facility seems a very a "peeling" place for research.

[BMAONE23]

It was copied from a sci-fi movie, I just can't recall which.

There was a similar device (Same??) used in the movie 2012 as an indicator that the Sun was about to catastrophically alter the EARTH

[Boomer12k]

Whoa.... too ... much.... science.... head.... exploding.....

I too would like to know WHAT we are looking at with all those "bead" looking things, and WHAT is up with the Ferris Wheel?????

But interesting project...

Neutrinos.... "This Island Earth"... one of my Favorites....

:---[===] *

[Guest]

Glad you identified it as a neutrino experiment. 'Cause it looks like the Hell'sJellyfish from Arcturus
and her babies.

[Ann]

The answer to why an asymmetric universe is unsettling may one day be discovered to be as simple as a mirror universe. Its odd features may be stranger than we can imagine; even with the best Star Trek writers.

I gave up on New Scientist after I concluded (possibly unfairly) that its articles on astronomy and cosmology are a wet dream for Star Trek scientists.

- Mr Sulu, lay in a course for the wormhole fourteen parsecs from the star on the left side in the morning; we will travel down its maw to the bottleneck point of minimum entropy known as the Big Bang, and we will explore the universe on the other side of it, where time flows backwards.

Ann

[rstevenson]

Several people have asked for some sense of scale and more details about what the picture shows. There is an article at Scholarpedia which helps a bit. (You can skip over the equations if you wish.)

From that article I find that the glass blobs (photo-multiplier tubes, PMTs) are 20 cm in diameter (about 8" in old speak). They are arranged in cylindrical containers (Antineutrino detectors, ADs) about 5 m (16.5') wide. There are 3 underground experimental halls, each of which contains either 2 or 4 ADs, so there are somewhere between 6 and 12 ADs in the facility.

Hope that helps.

Rob

[DavidLeodis]

In the information brought up through the 'could imply' link it states "Neutrinos, electrically neutral particles that sense only gravity and the weak nuclear force, interact so feebly with matter that 100 trillion zip unimpeded through your body every second". Wow

PS. I am unable to open the image that I think should be brought up through the 'Featured here' link, though I do get some text. Could someone please let me know if the image that should be seen (and so its text) is the same, or not, as the APOD. Thanks.

[Chris Peterson]

PS. I am unable to open the image that I think should be brought up through the 'Featured here' link, though I do get some text. Could someone please let me know if the image that should be seen (and so its text) is the same, or not, as the APOD. Thanks.

Well, the image is a TIFF, which isn't natively displayable in a browser. It's possible that the gallery software only works with JPEG, or that some sort of converter isn't working. But you can click on the download link on that page and get the 55 MB TIFF onto your own machine for viewing (and use the text description from the site).

[DavidLeodis]

PS. I am unable to open the image that I think should be brought up through the 'Featured here' link, though I do get some text. Could someone please let me know if the image that should be seen (and so its text) is the same, or not, as the APOD. Thanks.

Well, the image is a TIFF, which isn't natively displayable in a browser. It's possible that the gallery software only works with JPEG, or that some sort of converter isn't working. But you can click on the download link on that page and get the 55 MB TIFF onto your own machine for viewing (and use the text description from the site).

Thanks for your help Chris .

Initially then trying I did not seem to be getting anywhere but by chance I clicked on some text and that brought up lots of individual images in which I found that used for the APOD. In its related information it stated it was captured "June 28th 2011, 08:01 pm" so not recent that I would have expected.

[Fred the Cat]

I was listening to a “Theory of Everything” program describing how Paul Dirac proposed antimatter to be necessary to solve an issue where equations squared must have two solutions – one positive (1) and the other negative (-1). It made me look to see why the answer isn’t negative mass. Though overwhelmingly not the popular theory, some cosmologists appear not to rule it out.

Something fuels galaxy evolution and, if it isn’t electro-magnetism, could it push us to pursue negative mass to answer where anti-matter has gone and what would its function be in today's universe?

[neufer]

I was listening to a “Theory of Everything” program describing how Paul Dirac proposed antimatter to be necessary to solve an issue where equations squared must have two solutions – one positive (1) and the other negative (-1). It made me look to see why the answer isn’t negative mass. Though overwhelmingly not the popular theory, some cosmologists appear not to rule it out.

Something fuels galaxy evolution and, if it isn’t electro-magnetism, could it push us to pursue negative mass to answer where anti-matter has gone and what would its function be in today's universe?

Negative mass would really throw a monkey wrench into the situation.

Vacuum quantum mechanics easily generates dark energy by producing a sea of virtual particles;
the problem is that it generates way way too much dark energy.

Negative mass would only exacerbate that situation
(as well a possibly producing a sea of actual particles).

And when a photon temporarily transforms into a virtual particle pair
does it also temporarily become impervious to gravity