Chiara Marletto is trying to build a master theory — a set of ideas so fundamental that all other theories would spring from it. Her first step: Invoke the impossible.
Category: physics – Page 190
An international team of researchers has made the world’s most precise measurement of the neutron’s lifetime, which may help answer questions about the early universe.
An international team of physicists led by researchers at Indiana University Bloomington has announced the world’s most precise measurement of the neutron’s lifetime.
The results from the team, which encompasses scientists from over 10 national labs and universities in the United States and abroad, represent a more than two-fold improvement over previous measurements — with an uncertainty of less than one-tenth of a percent.
An international team of physicists led by researchers at Indiana University Bloomington has announced the world’s most precise measurement of the neutron’s lifetime.
A new study showing how the explosion of a stripped massive star in a supernova can lead to the formation of a heavy neutron star or a light black hole resolves one of the most challenging puzzles to emerge from the detection of neutron star mergers by the gravitational wave observatories LIGO and Virgo.
The first detection of gravitational waves by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2017 was a neutron star merger that mostly conformed to the expectations of astrophysicists. But the second detection, in 2,019 was a merger of two neutron stars whose combined mass was unexpectedly large.
“It was so shocking that we had to start thinking about how to create a heavy neutron star without making it a pulsar,” said Enrico Ramirez-Ruiz, professor of astronomy and astrophysics at UC Santa Cruz.
For decades, we’ve dreamed of visiting other star systems. There’s just one problem – they’re so far away, with conventional spaceflight it would take tens of thousands of years to reach even the closest one.
Physicists are not the kind of people who give up easily, though. Give them an impossible dream, and they’ll give you an incredible, hypothetical way of making it a reality. Maybe.
In a new study by physicist Erik Lentz from Göttingen University in Germany, we may have a viable solution to the dilemma, and it’s one that could turn out to be more feasible than other would-be warp drives.
Professor Hasselmann developed a method for satellite ocean wave measurements.
This year’s Nobel Prize in Physics laureate Klaus Hasselmann helped to shape a ground-breaking Earth-observation mission that paved the way for the modern study of our planet’s environment.
The German oceanographer and climate modeler was awarded the coveted prize for his contribution to the physical modeling of Earth’s climate that has enabled scientists to quantify the climate’s natural variability and better predict climate change. Hasselman won half of the 2021 Nobel Prize for Physics last week, with the other half shared by scientists Syukuro Manabe and Giorgio Parisi for their own research on disorder and fluctuations in physical systems.
In a scene from season one, Jim Holden shows exquisite command of high school physics as he maneuvers himself onto a spaceship gangway.
As a fan of science fiction and science, I have to say that The Expanse has a bunch of great science. It’s not just the science in the show. The characters also seem to demonstrate an understanding of physics. One scene from the first season stands out in particular as a classic physics example.
I guess I should give a spoiler alert, but I’m not really giving away any major plot elements. But you have been warned.
OK, since you are still here let me describe the scene. Two main characters (Jim and Naomi) are running on a gangway connected to a spaceship. This gangway is inside a bigger ship that is accelerating (with the engines on) to produce artificial gravity. But wait! They are under fire. Some other dude wants to stop them from getting into the ship, so he fires his weapon. Eventually, someone shoots an important part of the bigger spaceship and its engines cut off. With no thrust, Jim and Naomi lose their artificial gravity and start floating off the gangway. They have magnetic boots, but the boots only work on the gangway. They are doomed.
Would we act as naturally inside a spacecraft immobile in space as in the series?
Whenever I watch “The Expanse,” I pay attention to the physics. As the production is meticulous — if you notice the scenes where whiskey is served on the Moon this last season, you will see that the liquid falls according to lunar gravity’s acceleration — I always have some good surprises. Unfortunately, the series is taped on Earth, so some things would be too expensive to reproduce convincingly.
Jeffrey Shainline is a physicist at NIST. Please support this podcast by checking out our sponsors:
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Note: Opinions expressed by Jeff do not represent NIST.
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OUTLINE:
0:00 — Introduction.
0:44 — How are processors made?
20:02 — Are engineers or physicists more important.
22:31 — Super-conductivity.
38:18 — Computation.
42:55 — Computation vs communication.
46:36 — Electrons for computation and light for communication.
57:19 — Neuromorphic computing.
1:22:11 — What is NIST?
1:25:28 — Implementing super-conductivity.
1:33:08 — The future of neuromorphic computing.
1:52:41 — Loop neurons.
1:58:57 — Machine learning.
2:13:23 — Cosmological evolution.
2:20:32 — Cosmological natural selection.
2:37:53 — Life in the universe.
2:45:40 — The rare Earth hypothesis.
SOCIAL:
Circa 2018 o.o
Rockets with nuclear bombs for propulsion sounds like a Wile E. Coyote cartoon, but it has been seriously considered as an option for the space program. Chemical rockets combust a fuel with an oxidizer within themselves and exhaust the result out the back, causing the rocket to move in the opposite direction. What if instead, you used the higher energy density of nuclear fission by detonating nuclear bombs?
Detonating the bombs within a combustion chamber would destroy the vehicle so instead you’d do so from outside and behind. Each bomb would include a little propellant which would be thrown as plasma against the back of the vehicle, giving it a brief, but powerful push.
That’s just what a group of top physicists and engineers at General Atomic worked on between 1958 and 1965 under the name, Project Orion. They came close to doing nuclear testing a few times and did have success with smaller tests, exploding a series of chemical bombs which pushed a 270-pound craft up 185 feet as you’ll see below.