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New design tool 3D-prints woven metamaterials that stretch and fail predictably

Metamaterials—materials whose properties are primarily dictated by their internal microstructure, and not their chemical makeup—have been redefining the engineering materials space for the last decade. To date, however, most metamaterials have been lightweight options designed for stiffness and strength.

New research from the MIT Department of Mechanical Engineering introduces a computational design framework to support the creation of a new class of soft, compliant, and deformable metamaterials. These metamaterials, termed 3D woven metamaterials, consist of building blocks that are composed of intertwined fibers that self-contact and entangle to endow the material with unique properties.

Silicon as strategy: the hidden battleground of the new space race

In the consumer electronics playbook, custom silicon is the final step in the marathon: you use off-the-shelf components to prove a product, achieve mass scale and only then invest in proprietary chips to create differentiation, improve operations, and optimize margins.

In the modern satellite communications (SATCOM) ecosystem, this script has been flipped. For the industry’s frontrunners, custom silicon is the starting line where the bets are high, and the rewards are even higher, not a late-stage luxury. Building custom silicon is just a small piece of the big project when it comes to launching a satellite constellation and the fact there are very limited off the shelf options.

The shift toward custom silicon is no longer a theoretical debate; it is a proven competitive requirement. To monetize the massive capital expenditure of a constellation, market leaders are already driving aggressive custom silicon programs for beamformers and modems from the very beginning. The consensus is clear: while commercial off-the-shelf (COTS) and field-programmable gate arrays (FPGAs) served as useful stopgaps, they have become a strategic liability that compromises price and power efficiency. If the industry is to scale to the mass market, operators must commit to bespoke silicon programs now — or risk being permanently priced out of the sky by competitors who have already optimized their hardware for the unit economics of space.

The Milky Way is embedded in a ‘large-scale sheet’ and this explains the motions of nearby galaxies

Computer simulations carried out by astronomers from the University of Groningen in collaboration with researchers from Germany, France and Sweden show that most of the (dark) matter beyond the Local Group of galaxies (which includes the Milky Way and the Andromeda Galaxy) must be organised in an extended plane. Above and below this plane are large voids. The observed motions of nearby galaxies and the joint masses of the Milky Way and the Andromeda Galaxy can only be properly explained with this ‘flat’ mass distribution. The research, led by PhD graduate Ewoud Wempe and Professor Amina Helmi, was published today in Nature Astronomy.

Almost a century ago, astronomer Edwin Hubble discovered that virtually all galaxies are moving away from the Milky Way. This is important evidence for the expansion of the universe and for the Big Bang. But even in Hubble’s time, it was clear that there were exceptions. For example, our neighbouring galaxy, Andromeda, is moving towards us at a speed of about 100 kilometres per second.

In fact, for half a century, astronomers have been wondering why most large nearby galaxies – with the exception of Andromeda – are moving away from us and do not seem to be affected by the mass and gravity of the so-called Local Group (the Milky Way, the Andromeda Galaxy and dozens of smaller galaxies).

A mesoscale optogenetics system for precise and robust stimulation of the primate cortex

Li et al. present a microLED-based mesoscale optogenetic system for centimeter-scale, million-pixel primate cortical stimulation. Optogenetically evoked saccades with accurate retinotopic organization remain stable for over a year, demonstrating precise, robust, and durable neuromodulation and charting a path toward next-generation optical brain-computer interfaces and visual prostheses.

Nothing Is Real: The Simulation Hypothesis

Are we living inside a computer simulation? The evidence is more compelling than you think.

In this deep exploration of the Simulation Hypothesis, we examine the scientific and philosophical arguments that suggest our reality might be code. From Nick Bostrom’s groundbreaking trilemma to quantum mechanics acting like a computer program, from the fine-tuned constants of physics to Elon Musk’s probabilistic arguments—we follow the evidence wherever it leads. Whether we’re simulated or not, the question reveals profound truths about consciousness, reality, and what it means to be human.

CHAPTERS:

0:00 — The Uncomfortable Question.

4:47 — Nick Bostrom’s Trilemma: The Logical Trap.

9:34 — The Ancestor Simulation Scenario.

Experiments Hint on Time Being an Illusion

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Hello and welcome! My name is Anton and in this video, we will talk about experimental evidence that time may be an illusion.
Links:
https://arxiv.org/pdf/2310.13386
https://journals.aps.org/prd/pdf/10.1103/qfns-48vq.
https://en.wikipedia.org/wiki/Problem_of_time.
https://journals.aps.org/prl/pdf/10.1103/5rtj-djfk.
https://journals.aps.org/prx/pdf/10.1103/PhysRevX.11.021029
https://journals.aps.org/prx/pdf/10.1103/PhysRevX.7.031022
#time #physics #universe.

0:00 Time — what is it?
1:20 Time in general relativity (Einstein)
2:10 Quantum mechanics time.
2:40 The problem of time.
3:30 Page Wootters mechanism — is time emergent?
5:00 Experiments and possible proofs — entropy and quantum dots.
7:40 Large scale system.
8:30 What this suggests and how black holes can help.
9:50 Conclusions.

Enjoy and please subscribe.

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Cryogenic cooling material composed solely of abundant elements reaches 4K

In collaboration with the National Institute of Technology (KOSEN), Oshima College, the National Institute for Materials Science (NIMS) succeeded in developing a new regenerator material composed solely of abundant elements, such as copper, iron, and aluminum, that can achieve cryogenic temperatures (approx. 4K = −269°C or below) without using any rare-earth metals or liquid helium.

By utilizing a special property called “frustration” found in some magnetic materials, where the spins cannot simultaneously satisfy each other’s orientations in a triangular lattice, the team demonstrated a novel method that replaces the conventional rare-earth-dependent cryogenic cooling technology.

The developed material holds promise for responding to the lack of liquid helium as well as for stable cooling in medical magnetic resonance imaging (MRI) and quantum computers, which are expected to see further growth in demand. The results are published in Scientific Reports.

Niobium’s superconducting switch cuts near-field radiative heat transfer 20-fold

When cooled to its superconducting state, niobium blocks the radiative flow of heat 20 times better than when in its metallic state, according to a study led by a University of Michigan Engineering team. The experiment marks the first use of superconductivity—a quantum property characterized by zero electrical resistance—to control thermal radiation at the nanoscale.

Leveraging this effect, the researchers also experimentally demonstrated a cryogenic thermal diode that rectifies the flow of heat (i.e., the heat flow exhibits a directional preference) by as much as 70%.

“This work is exciting because it experimentally shows, for the very first time, how nanoscale heat transfer can be tuned by superconductors with potential applications for quantum computing,” said Pramod Sangi Reddy, a professor of mechanical engineering and materials science and engineering at U-M and co-corresponding author of the study published in Nature Nanotechnology.

Ultra-thin metasurface chip turns invisible infrared light into steerable visible beams

The invention of tiny devices capable of precisely controlling the direction and behavior of light is essential to the development of advanced technologies. Researchers at the Advanced Science Research Center at the CUNY Graduate Center (CUNY ASRC) have taken a significant step forward with the development of a metasurface that can turn invisible infrared light into visible light and aim it in different directions—without any moving parts. The details of their work are explained in a paper published in the journal eLight.

The novel metasurface is constructed of an ultra-thin chip patterned with tiny structures smaller than the wavelength of light. When hit with an infrared laser, the chip converts the incoming light to a higher color (or frequency) and sends the new light out as a narrow beam that can be steered simply by changing how the incoming light is polarized.

In their experiments, the team converted infrared light around 1,530 nanometers—similar to the light used in fiber-optic communications—into visible green light near 510 nanometers and steered it to chosen angles.

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