Category Archives: Physics

The chances are about 1 in 100 billion per year

NPR: A meteorite crashes through a home in Canada, barely missing a woman’s head. “It turns out that the 2.8-pound space rock, about the size of a small cabbage, was part of a meteor shower identified by Alan Hildebrand, a planetary scientist in the Department of Geoscience at the University of Calgary, and his colleagues. The group said the trajectory of the meteorite that hit Hamilton’s house would have made it visible throughout southeastern British Columbia and central and southern Alberta.”

Victoria News: B.C. woman awakes to a hole in her roof and a space rock on her pillow.

Second link via MetaFilter.

More than you ever thought you wanted to know about submarines

Smarter Every Day: Nuclear Submarine Deep Dive is a series of nine videos that Destin Sandlin filmed while aboard a US Navy Nuclear Submarine in the Arctic (ICEX 2020) and released over the course of a year. The last one came out yesterday. They’re all worth watching!

Here are the episodes:

  1. How I Boarded a US Navy Nuclear Submarine in the Arctic (ICEX 2020) (Episode 237, 34:39min, June 14, 2020)
  2. Boarding a US Navy Nuclear Submarine in the Arctic – Smarter Every Day 240 (Episode 240, 29:24min, July 26 , 2020)
  3. Crawling Down A Torpedo Tube -US Navy Nuclear Submarine (Episode 241, 20:32min, August 16, 2020)
  4. How to Fight Fire or Flooding on a Nuclear Submarine (Episode 244, 27:00min, October 4, 2020)
  5. How to Make Pizza on a Submarine (Episode 246, 16:28min, November 1, 2020)
  6. How Sonar Works (Submarine Shadow Zone) (Episode 249, 26:41min, December 26, 2020)
  7. How Do Nuclear Submarines Make Oxygen? (Episode 251, 29:33min, February 21, 2021)
  8. How to Poop on a Nuclear Submarine (Episode 256, 23:24min, May 9, 2021)
  9. How to Surface a Submarine in the Arctic Ocean (Episode 260, 42:01min, July 30, 2021)

Schwarze Löcher

… sind weder schwarz noch Löcher.

Anlässlich der “Black Hole Week” von NASA veröffentlichte Markus Pössel im April auf seinem Blog eine Reihe zu schwarzen Löchern:

Relativ einfach: Woche der Schwarzen Löcher. 1: Sicherheitshinweise, 2: Akkretion, 3: Schattenrisse mit dem Event Horizon Telescope, 4: Wellenschlag mit LIGO, Virgo & Co., 5: Singularitäten als Wissenslücke.

100SekundenPhysik: Wie schwarze Löcher wirklich aussehen. (YouTube, 4min)

It’s not 2.00233183620 but 2.00233184122

The g-factor of the muon, that is.

Physics Girl: This result could change physics forever. (YouTube, 13min) “Explaining the exciting new Fermilab muon result to my production team.”

Here is the press release: Fermilab: First results from Fermilab’s Muon g-2 experiment strengthen evidence of new physics.

“The accepted theoretical values for the muon are:
g-factor: 2.00233183620(86)
anomalous magnetic moment: 0.00116591810(43)
[uncertainty in parentheses]

The new experimental world-average results announced by the Muon g-2 collaboration today are:
g-factor: 2.00233184122(82)
anomalous magnetic moment: 0.00116592061(41)

The combined results from Fermilab and Brookhaven show a difference with theory at a significance of 4.2 sigma, a little shy of the 5 sigma (or standard deviations) that scientists require to claim a discovery but still compelling evidence of new physics. The chance that the results are a statistical fluctuation is about 1 in 40,000.”