Lifeboat Foundation

The prestigious academic physics journal Physical Review Letters published a paper this week about cutting-edge laser tech — and, if bloggers are to be believed, it could have juicy ramifications.

The paper itself is dry and technical, but the prominent tech blog Ars Technica’s interpretation of its findings is anything but. According to Ars, in fact, the tech it describes could pulse a laser “through fabric of the Universe.”

From remote measurements of the Moon’s mass and radius, researchers also know its density is anomalously low, indicating it lacks iron. While about 30 percent of Earth’s mass is trapped in its iron-rich core, the Moon’s core accounts for only a few percent of its total mass. Despite this substantial difference in iron, Apollo samples later revealed that mantle rocks from the Moon and Earth have remarkably similar concentrations of oxygen.

And because these lunar and terrestrial rocks differ significantly from meteorites originating from Mars or the asteroid belt, it shows the Moon and Earth’s mantle share a past connection. Additionally, compared with Earth, lunar rocks are more depleted in so-called volatile elements — those that vaporize easily upon heating — which hints that the Moon formed at high temperatures.

Finally, researchers know that tidal interactions forced the Moon to spiral outward over time, which in turn caused Earth to spin more slowly. This implies the Moon formed much closer to Earth than it is now. Precise measurements of the Moon’s position using surface reflectors placed during the Apollo program subsequently confirmed this, verifying the Moon’s orbit expands by about 1.5 inches (3.8 centimeters) each year.

Earlier today, Genevieve O’Hagan updated Lifeboat readers on this week’s momentous event in Astronomy. At least, I find it fascinating—and so, I wish to add perspective…

30 years ago, astronomer Jack Hills demonstrated the math behind what has become known as the “Hills Mechanism”. Until this week, the event that he described had never been observed.* But his peer astronomers agreed that the physics and math should make it possible…

Hills explained that under these conditions, a star might be accelerated to incredible speeds — and might be even flung out of its galaxy:

• Suppose that a binary star passes close to a black hole, like the one at the center of our galaxy
• The pair of self-orbiting stars is caught up in the gravity well of a black hole, but not sucked in

If conditions are right, one star ends up orbiting the back hole while the other is jettisoned at incredible speed, yet holding onto its mass and shape. All that energy comes from the gravity of the black hole and the former momentum of the captured star. [20 sec animation] [continue below]

Continue reading “Ejected Star: How fast is fast?” »

Footage has since emerged capturing the US Space Force craft “following” the astronauts in the sky, conspiracists have claimed.

The study of Mars is a constant exercise in problem-solving, and NASA scientists have just been served up a doozy. Data from the Curiosity rover positioned within the planet’s Gale Crater has revealed wild seasonal swings in oxygen levels, something mission scientists neither expected or are able to explain.

This perplexing piece of intel comes courtesy of Curiosity’s Sample Analysis at Mars (SAM) tool, an onboard laboratory that has been sucking in the air over the Gale Crater for analysis over the course of three Martian years (almost six Earth years). This has enabled the team to piece together the composition of the planet’s thin atmosphere, with CO₂, nitrogen, argon, carbon monoxide and oxygen all part of the mix.

The concentrations of these gases increase and decrease as the weather changes on Mars, as the icy winters lower air pressure across the planet and the summer then raises them again. This leads to regular patterns of concentrations of gases like nitrogen and argon, and in examining the latest data, the scientists expected to see similar trends at play for oxygen.

No matter how elegant your theory is, experimental data will have the last word. Observations of the retrograde motion of the planets were fundamental to the Copernican revolution, in which the sun replaced Earth at the centre of the solar system. And the unusual orbit of Mercury provided a spectacular confirmation of the theory of general relativity. In fact, our entire understanding of the universe is built on observed, unexpected anomalies.

Light is the fastest way to distinguish right- and left-handed chiral molecules, which has important applications in chemistry and biology. However, ordinary light only weakly senses molecular handedness. Researchers from the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI), the Israel Institute of Technology (Technion) and Technische Universitaet Berlin (TU Berlin) now report a method to generate and characterize synthetic chiral light, which identifies molecules’ handedness exceptionally distinctly. The results of their joint work have just appeared in Nature Photonics.

Like left and right hands, some molecules in nature have mirror twins. However, while these twin molecules may look similar, some of their properties can be very different. For instance, the handedness—or chirality—of molecules plays an essential role in chemistry, biology, and drug development. While one type of a molecule can cure a disease, its mirror twin—or enantiomer—may be toxic or even lethal.

It is extremely hard to tell opposite chiral molecules apart because they look identical and behave identically unless they interact with another chiral object. Light has long been used to detect chirality—oscillations of the electromagnetic field draw a chiral helix in space along the light propagation direction. Depending on whether the helix twirls clockwise or counterclockwise, the light wave is either right- or left-handed. However, the helix pitch, set by the light wavelength, is about 1000 times bigger than the size of a molecule. So the light helix is a gigantic circle compared to the tiny molecules, which hardly react to its chirality.

RUDN University mathematicians have proven the Hardy-Littlewood-Sobolev (HLS) inequalities for the class of generalized Riesz potentials. These results extend the scope of these potentials in mathematics and physics because the main tools for working with such potentials are based on HLS inequalities. New mathematical tools can greatly simplify calculations in quantum mechanics and other fields of physics. The results of the study are published in the journal Mathematical Notes.

Modern physics describes the world in terms of fields and their potentials—that is, the values of the field at each point. But the physical quantities that we can measure are forces and accelerations, that is, derivatives of the second-order of the potential of the corresponding field. The problem of reconstructing the field configuration with the available values of forces and accelerations observed in experiments is complex and not always analytically solvable. Differentiation operations in multidimensional space—operators are usually used to describe the correlation between the potential of the field and the forces. In particular, electromagnetic and gravitational interactions are described in the language of operators.

Since the potential of the field can be determined up to a constant value, for the convenience of calculations, the initial value of the potential is taken at some point in multidimensional space, or on the border of any spatial area. But in some cases, mathematical models of such fields lead to a singularity, that is, at some points the value of the field becomes infinite, and therefore loses its physical meaning.

MIT researchers have developed a model that recovers valuable data lost from images and video that have been “collapsed” into lower dimensions.

The model could be used to recreate video from motion-blurred images, or from new types of cameras that capture a person’s movement around corners but only as vague one-dimensional lines. While more testing is needed, the researchers think this approach could someday could be used to convert 2-D medical images into more informative—but more expensive—3D body scans, which could benefit medical imaging in poorer nations.

“In all these cases, the visual data has one dimension—in time or space—that’s completely lost,” says Guha Balakrishnan, a postdoc in the Computer Science and Artificial Intelligence Laboratory (CSAIL) and first author on a paper describing the model, which is being presented at next week’s International Conference on Computer Vision. “If we recover that lost dimension, it can have a lot of important applications.”