STEM

[Saturio]

Tesla Reinvents Carmaking With Quiet Breakthrough
Posted by BeauHD on Thursday September 14, 2023 @06:30PM from the no-easy-feat dept.

An anonymous reader quotes a report from Reuters:

Tesla has combined a series of innovations to make a technological breakthrough that could transform the way it makes electric vehicles and help Elon Musk achieve his aim of halving production costs, five people familiar with the move said. The company pioneered the use of huge presses with 6,000 to 9,000 tons of clamping pressure to mold the front and rear structures of its Model Y in a "gigacasting" process that slashed production costs and left rivals scrambling to catch up. In a bid to extend its lead, Tesla is closing in on an innovation that would allow it to die cast nearly all the complex underbody of an EV in one piece, rather than about 400 parts in a conventional car, the people said.

The know-how is core to Tesla's "unboxed" manufacturing strategy unveiled by Chief Executive Musk in March, a linchpin of his plan to churn out tens of millions of cheaper EVs in the coming decade, and still make a profit, the sources said. While Tesla has said its unboxed model involves producing large sub-assemblies of a car at the same time and then snapping them together, the size and make-up of the modular blocks is still the subject of speculation. Two of the sources said Tesla's previously unreported new design and manufacturing techniques meant the company could develop a car from the ground up in 18 to 24 months, while most rivals can currently take anywhere from three to four years.

The five people said a single large frame -- combining the front and rear sections with the middle underbody where the battery is housed -- could be used in Tesla's small EV which it aims to launch with a price tag of $25,000 by the middle of the decade. Tesla was expected to make a decision on whether to die cast the platform in one piece as soon as this month, three of the sources said, though even if they do press ahead the end product could change during the design validation process. The breakthrough Tesla has made centers on the how the giant molds for such a large part are designed and tested for mass production, and how casts can incorporate hollow subframes with internal ribs to cut weight and boost crashworthiness.

To overcome the obstacles associated with this manufacturing technique, Tesla is collaborating with firms that use 3D printing technology to create sand molds for casting, which is cost-effective and allows for rapid design iterations. The sand casting process significantly reduces design cycle times compared to traditional metal mold prototypes.

Tesla also plans to use solid sand cores within the molds to create hollow subframes, addressing weight and crashworthiness concerns. However, there is still a decision to be made regarding the type of press to use for casting large body parts, with trade-offs between productivity and quality.

Saludos.

Os paso el contacto por si queréis compraros una de esas revolucionarias gigaprensas. Hay que fijarse en los colorcitos de la banderita. Tecnología Italiana.

https://idragroup.com/en/gigapress


Por cierto, IDRA, una de esas empresas que no van de molonas pero que son la espina dorsal de la industria europea. 180 empleados dicen que tienen. No creo que tengan sala de meditación ni mesa de ping-pong.

Pero quién quiere trabajar diseñando y fabricando prensas cuando puedes disromper a diestro y siniestro.

[Cadavre Exquis]

José Luis Cava | El Uranio ha iniciado un ciclo alcista. 30/9/23

Microsoft Needs So Much Power to Train AI That It's Considering Small Nuclear Reactors
Posted by EditorDavid on Saturday September 30, 2023 @11:34PM from the seeking-a-reaction dept.

An anonymous reader shares this report from Futurism:

Training large language models is an incredibly power-intensive process that has an immense carbon footprint. Keeping data centers running requires a ludicrous amount of electricity that could generate substantial amounts of greenhouse emissions — depending, of course, on the energy's source. Now, the Verge reports, Microsoft is betting so big on AI that its pushing forward with a plan to power them using nuclear reactors. Yes, you read that right; a recent job listing suggests the company is planning to grow its energy infrastructure with the use of small modular reactors (SMR)...

But before Microsoft can start relying on nuclear power to train its AIs, it'll have plenty of other hurdles to overcome. For one, it'll have to source a working SMR design. Then, it'll have to figure out how to get its hands on a highly enriched uranium fuel that these small reactors typically require, as The Verge points out. Finally, it'll need to figure out a way to store all of that nuclear waste long term...

Other than nuclear fission, Microsoft is also investing in nuclear fusion, a far more ambitious endeavor, given the many decades of research that have yet to lead to a practical power system. Nevertheless, the company signed a power purchase agreement with Helion, a fusion startup founded by OpenAI CEO Sam Altman earlier this year, with the hopes of buying electricity from it as soon as 2028.

Saludos.

[Cadavre Exquis]

https://elpais.com/babelia/2023-09-30/elon-musk-el-guardian-de-la-mazmorra.html

Saludos.

[saturno]

La antimateria del experimento Alpha-G del Cern está sometida a la gravedad. Confirmado-

https://physics.aps.org/articles/v16/167

Antimatter Feels Gravity Just like Matter
September 27, 2023• Physics 16, 167
The first direct observations of antihydrogen atoms falling in Earth’s gravity show that they experience gravity in the same way as ordinary matter does.
Figure caption

Throw a ball into the air and the pull of Earth’s gravity will bring it crashing back down. But what about a ball of antimatter? Will it fall in the same way, or does it somehow experience gravity differently? Physicists have been exploring such questions for nearly a century but, until now, there had been no direct experimental test of antimatter in free fall. Releasing the results of observations of free-falling antihydrogen atoms, the Antihydrogen Laser Physics Apparatus (ALPHA) Collaboration at CERN in Switzerland shows that the particles experience the same gravitational pull as ordinary matter as they accelerate to Earth [1]. The collaboration says that the experiments are a landmark test of the weak equivalence principle, which states that all types of mass should react equivalently to the force of gravity.

“There’s no theoretical reason to expect [antimatter] to do anything else but fall with a regular acceleration,” says Holger Müller, a physicist at the University of California, Berkeley, who was not involved in the study. Still, he is pleased to see the expectation confirmed. “There is just no substitute for direct observation,” he says.

Antihydrogen is composed of one antiproton and one positron—the antiparticle of an electron—making it the simplest neutrally charged antimatter atom. As such, it is an ideal system for probing gravity, as other forces can be ignored: if the researchers had instead used a charged particle, for example, electric forces would have come into play and—because they are stronger—would have overpowered gravity’s pull. “Making a gravity measurement, you’re just overwhelmed by a bunch of forces you can’t control,” says Will Bertsche, a physicist at the University of Manchester, UK, and a member of the ALPHA Collaboration. “You need some antimatter that is neutral.”

At the center of the ALPHA-g setup used for the free-fall experiments sits a magnetic trap composed of a superconducting magnet, which generates a magnetic field in the radial direction, and two electromagnetic magnets, called mirror coils, which generate fields in the vertical direction. These three magnets are aligned such that they trap antihydrogen atoms at 0.5 K between the two mirror coils. Detectors designed to reconstruct particle trajectories surround the trap.

In order to subject the trapped antihydrogen atoms to gravity, the researchers weakened the magnetic fields holding them in place over a period of 20 seconds. As that happened, the antihydrogen atoms, which were jumping around inside the trap, streamed out of the device, moving both up and down. The team then detected the antiparticles through the energy released when they annihilated with matter particles.

Because gravity is such a weak force, some of the antihydrogen atoms that initially move up when released should continue to rise, just like baseballs thrown into the air, which the collaboration sees in its results. But the researchers also find that more antihydrogen atoms exit from the bottom of the trap, the expected result if gravity’s effect on antimatter and ordinary matter is the same. Statistical analysis of the observations put the gravitational acceleration of the antimatter particle to be within one standard deviation of that of ordinary matter.

While previous experiments performed by others have explored antimatter’s interaction with gravity, those tests were all indirect. “It was just thrilling to see that the predictions that we had made, in some cases a decade earlier, actually turned out to be true,” says Joel Fajans, a physicist at the University of California, Berkeley, and a member of the ALPHA Collaboration. Müller agrees. “Finally, this [experiment] has happened,” he says. “I’m just happy that this [result] exists.”

Now that the collaboration has confirmed that the experiments work, the researchers plan to upgrade their setup before running further measurements. They also plan to develop computer simulations that better predict the behavior of antimatter atoms exposed to gravity. With both advances in place, the hope is that the ALPHA team will reach its ultimate goal—obtaining the first precise measurement of the weight of an antimatter atom. Time will tell.

–Allison Gasparini

Allison Gasparini is a freelance science writer based in Santa Cruz, CA.


References

    E. K. Anderson et al., “Observation of the effect of gravity on the motion of antimatter,” Nature 621, 716 (2023).
http://dx.doi.org/10.1038/s41586-023-06527-1

En v/fr,  video de JP Petit afirmando ese resultado  ( 22 mn 38s )
https://www.youtube.com/watch?v=RXKONGBClY0&t=1355s

XGracias Sifar

[saturno]

Video famoso sobre las dimensiones comparadas del universo, desde la red sideral hasta la micromateria


Universe Size Comparison | Cosmic Eye (Original HD)
https://www.youtube.com/watch?v=8Are9dDbW24

10,187,163 views  May 1, 2018
This is the original landscape-format version of the short movie Cosmic Eye, designed by astrophysicist Danail Obreschkow. The movie zooms through all well-known scales of the universe from minuscule elementary particles out to the gigantic cosmic web. This project was inspired by a progression of increasingly accurate graphical representations of the scales of the universe, including the classical essay "Cosmic View" by Kees Boeke (1957), the short movie "Cosmic Zoom" by Eva Szasz (1968), and the legendary movie "Powers of Ten" by Charles and Ray Eames (1977). Cosmic Eye takes these historical visualisations to the state-of-the-art using real photographs obtained with modern detectors, telescopes, and microscopes. Other views are renderings of modern computer models. Vector-based blending techniques are used to create a seamless zoom.

This 2018-version of Cosmic Eye contains improved graphics and minor technical corrections compared to the 2011-version in portrait format.

XGracias Wasabi