Toggle light / dark theme

The world’s most precise atomic clock has confirmed that the time dilation predicted by Albert Einstein’s theory of general relativity works on the scale of millimetres.

Physicists have been unable to unite quantum mechanics – a theory that describes matter at the smallest scales – with general relativity, which predicts the behaviour of objects at the largest cosmic scales, including how gravity bends space-time. Because gravity is weak over small distances, it is hard to measure relativity on small scales.

But atomic clocks, which count seconds by measuring the frequency of radiation emitted when electrons around an atom change energy states, can detect these minute gravitational effects.

Jared Isaacman, the billionaire founder of payments company Shift4 who flew on the first private SpaceX flight to orbit last year, has purchased as many as three more flights from Elon Musk’s company.

The first mission in the so-called Polaris Program is set to launch a four-person crew led by Isaacman in the fourth quarter with the company’s Falcon 9 rocket and Crew Dragon spacecraft. According to the program’s website, the augural flight, Polaris Dawn, will be the first of up to three missions, with the final one to be the first crewed spaceflight of SpaceX’s Starship rocket.

“The Polaris Program is an important step in advancing human space exploration while helping to solve problems through the use of innovative technology here on Earth,” Isaacman said in a statement.

Jared Isaacman — the billionaire CEO of payments processing company Shift 4 — is buying three more flights with SpaceX, the first of which is scheduled for this year and could put Isaacman and SpaceX on track to travel deeper into space than any human has traveled in a half century.

The first flight in the series of missions, which are being called “Polaris” after the North Star, is planned for late this year and will last up to five days and include a crew of Isaacman and three other people. It’s expected to travel out to the Van Allen radiation belt, which has an inner band that stretches from about 400 to 6,000 miles above Earth, in part to help the crew research how radiation in space affects the human body. Radiation remains a serious concern for spaceflights to the moon and Mars, as SpaceX says it aims to do, because they would require prolonged exposure to radiation, which can lead to an “increased risk of cancer and degenerative diseases” and other long-term impacts, according to NASA.

When asked on a press call Monday, Isaacman said the Gemini missions of the 20th century, which set altitude records at the time, are a guidepost for how high the first Polaris mission will travel. Gemini missions reached as high as about 850 miles — or about three times higher than where the International Space Station orbits. Isaacman declined to share a specific altitude for the flight.

Amid a maelstrom set off by a prominent AI researcher saying that some AI may already be achieving limited consciousness, one MIT AI researcher is saying the concept might not be so far-fetched.

Our story starts with Ilya Sutskever, head scientist at the Elon Musk cofounded research group OpenAI. On February 9, Sutskever tweeted that “it may be that today’s large neural networks are slightly conscious.”

In response, many others in the AI research space decried the OpenAI scientist’s claim, suggesting that it was harming machine learning’s reputation and amounted to little more than a “sales pitch” for OpenAI work.

A nanomaterials-engineered penetrating sealer developed by Washington State University researchers is able to better protect concrete from moisture and salt—the two most damaging factors in crumbling concrete infrastructure in northern states.

The novel sealer showed a 75% improvement in repelling water and a 44% improvement in reducing salt damage in laboratory studies compared to a commercial sealer. The work could provide an additional way to address the challenge of aging bridges and pavements in the U.S.

“We focused on one of the main culprits that compromises the integrity and durability of concrete, which is moisture,” said Xianming Shi, professor in the Department of Civil and Environmental Engineering who led the work. “If you can keep concrete dry, the vast majority of durability problems would go away.”

A light in the dark — If quantum computers continue to advance, and perform more calculations for less steep costs, Rinaldi and his team might be able to reveal what happens inside of black holes, beyond the event horizon — a region immediately surrounding a black hole’s singularity, within which not even light, nor perhaps time itself, can escape the immense force of gravity.

In practical terms, the event horizon prevents all conventional, light-based observations. But, and perhaps more compelling, the team hopes that further advances in this line of inquiry will do more than peek inside a black hole, and unlock what physicists have dreamed of since the days of Einstein: a unified theory of physics.

Astronomers have been waiting decades for the launch of the James Webb Space Telescope, which promises to peer farther into space than ever before. But if humans want to actually reach our nearest stellar neighbor, they will need to wait quite a bit longer: a probe sent to Alpha Centauri with a rocket would need roughly 80,000 years to make the trip.

Igor Bargatin, Associate Professor in the Department of Mechanical Engineering and Applied Mechanics, is trying to solve this futuristic problem with ideas taken from one of humanity’s oldest transportation technologies: the sail.

As part of the Breakthrough Starshot Initiative, he and his colleagues are designing the size, shape and materials for a sail pushed not by wind, but by .

Believe it or not, graphics card prices seem to be headed down. 3D Center has been tracking and reporting pricing trends for GPUs in Germany and Austria. There’s good news: prices are indeed on a downward slope. Even better; this is the third month in a row they have declined, so we can’t just write it off as a one one-time fluke. That said, here’s the bad news: even if this trend continues, which is a big if, prices are still so inflated that months of “progress” may only result in GPUs returning to MSRP, supply issues notwithstanding. At this point we’ll take what we can get.

The report by 3D Center for February mirrors the company’s report from last month, which we covered here. There’s a noticeable downward trend in pricing for both AMD and Nvidia GPUs. It’s almost shocking to see after so many reports of price increases. The trend is undeniable. According to 3D Center, the February price of AMD’s Radeon RDNA2 cards has fallen 18 percent, to 145 percent over MSRP. For Nvidia’s Ampere GPUs, prices fell 20 percent, leaving them 157 percent over MSRP.