Physics: Experiment maybe finds dark matter, or maybe has flaws

Introversion · Jun 17, 2020

Researchers say there are three possible explanations for the anomalous data. One is mundane. Two would revolutionize physics.

Quanta Magazine said:
The physicists who run the world’s most sensitive experimental search for dark matter have seen something strange. They have uncovered an unexpected excess of events inside their detector that could fit the profile of a hypothetical dark matter particle called an axion. Alternately, the data could be explained by novel properties of neutrinos.

More mundanely, the signal could come from contamination inside the experiment.

“Despite being excited about this excess, we should be very patient,” said Luca Grandi, a physicist at the University of Chicago and one of the leaders of the 163-person experiment, which is called XENON1T. The experiment’s successor will be needed to rule out possible contamination from tritium atoms, Grandi said. That experiment is expected to begin later this year.

Outside experts say that whenever there’s a boring explanation, it’s usually right. But not always — and the mere possibility that XENON1T has made a discovery merits attention.

“If this turns out to be a new particle, then it’s a breakthrough we have been waiting for for the last 40 years,” said Adam Falkowski, a particle physicist at Paris-Saclay University in France who was not involved in the experiment. “You cannot overstate the importance of the discovery, if this is real.”

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dickson · Jun 18, 2020

Axion dark matter--maybe?

Introversion said:
Researchers say there are three possible explanations for the anomalous data. One is mundane. Two would revolutionize physics.

This is intriguing news. XENON1T is the latest in series of dark matter search experiments. "1T" refers to the mass of liquid xenon used as in the detector, currently 1 metric ton(fiducial mass--the total Xe mass is 2-3 times greater, but events in the extra volume are not scored.). Details may be found at www.xenon1t.org

A XENONnT instrument is in the works: 6 times the active volume of XENON1T.

The cautious nature of the announcement is normal science: The first time I heard an announcement of the possible discovery of the axion was in February, 1981 at the Rutherford-Appleton Labs topical conference on massive neutrinos in Chilton, Oxfordshire. You read the date correctly.

That meeting was personally memorable for me on two counts: It was the first time I presented results of my research at a scientific meeting (on enhanced neutrino magnetic moments as it happens, which is one of the possible explanations of the XENON1T results) and the first time I met Stephen Hawking. A bunch of us went to the local that evening, during the course of which Stephen polished off a half-pint.

God only knows what Hawking thought of me; looking back, I can see how wet behind the ears I was then!

MaeZe · Jun 19, 2020

dickson said:
This is intriguing news. XENON1T is the latest in series of dark matter search experiments. "1T" refers to the mass of liquid xenon used as in the detector, currently 1 metric ton(fiducial mass--the total Xe mass is 2-3 times greater, but events in the extra volume are not scored.). Details may be found at www.xenon1t.org

A XENONnT instrument is in the works: 6 times the active volume of XENON1T.

The cautious nature of the announcement is normal science: The first time I heard an announcement of the possible discovery of the axion was in February, 1981 at the Rutherford-Appleton Labs topical conference on massive neutrinos in Chilton, Oxfordshire. You read the date correctly.

That meeting was personally memorable for me on two counts: It was the first time I presented results of my research at a scientific meeting (on enhanced neutrino magnetic moments as it happens, which is one of the possible explanations of the XENON1T results) and the first time I met Stephen Hawking. A bunch of us went to the local that evening, during the course of which Stephen polished off a half-pint.

God only knows what Hawking thought of me; looking back, I can see how wet behind the ears I was then!

I saw Hawking speak in Seattle; took my son. There were people out front with signs asking for tickets. That was amazing.

dickson · Jun 20, 2020

Stephen Hawking

MaeZe said:
I saw Hawking speak in Seattle; took my son. There were people out front with signs asking for tickets. That was amazing.

I think the last time I saw Hawking was at the memorial for Richard Feynman, at Caltech in Beckman Auditorium. He parked his wheelchair in the last row of the main floor.

If you haven't seen these video clips, I hope you find them interesting:
https://www.cambridge-news.co.uk/ne...se-stephen-hawking-funeral-cambridge-14479329
shows highlights from Hawking's funeral. The Caius College porters who assisted Hawking while he was in residence were asked by his family to serve as pallbearers.
https://www.cambridge-news.co.uk/news/cambridge-news/stephen-hawking-funeral-choir-caius-14478897
This song was to be sung at the funeral; I believe it was performed for him for his seventy-sixth birthday.

MaeZe · Jun 20, 2020

Those are great, thanks.

These are the only lyrics I could find:

“Up beyond the

Night sky, an

Indigo darkness like

Velvet

Embraces the farthest

Reaches of the mind,

Sun, moon, stars,

Everything”

https://serenademagazine.com/features/beyond-the-night-sky-music-for-stephen-hawking-1942-2018/

Physics: Experiment maybe finds dark matter, or maybe has flaws

Introversion

Pie aren't squared, pie are round!

dickson

Hairy on the inside

MaeZe

dickson

Hairy on the inside

MaeZe