Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: physics – Page 4

Telescopes in Chile Capture Images of the Earliest Galaxies in the Universe

Thanks to observatories like the venerable Hubble Space Telescope (HST) and its next-generation cousin, the James Webb Space Telescope (JWST), astronomers are finally getting the chance to study galaxies that existed just one billion years after the Big Bang. This period is known as “Cosmic Dawn” because it was during this period that the first stars formed and came together to create the first galaxies in the Universe. The study of these galaxies has revealed some surprising and fascinating things that are allowing astronomers to learn how large-scale structures in the Universe came to be and how they’ve evolved since.

For the longest time, it was thought that this cosmological period could only be seen by space telescopes, as they don’t have to deal with interference from Earth’s atmosphere. With advanced technologies ranging from adaptive optics (AO) and coronagraphs to interferometry and spectrometers, ground-based telescopes are pushing the boundaries of what astronomers can see. In recent news, an international team of astronomers using the Cosmology Large Angular Scale Surveyor (CLASS) announced the first-ever detection of radiation from the cosmic microwave background (CMB) interacting with the first stars in the Universe. These findings shed light on one of the least understood periods in cosmological history.

The study that details their findings, which recently appeared in The Astrophysical Journal, was led by Yunyang Li — an observational cosmologist from the Kavli Institute for Cosmological Physics (University of Chicago) and The William H. Miller III Department of Physics and Astronomy at Johns Hopkins University (JHU). He was joined by many JHU colleagues, as well as astrophysicists from the National Institute of Standards and Technology, the Argonne National Laboratory, the Los Alamos National Laboratory, the Harvard-Smithsonian Center for Astrophysics, the Massachusetts Institute of Technology (MIT), the NASA Goddard Space Flight Center, and many prestigious universities.

With potential implications for mechanical systems, study reveals physics of the ‘nick shot’ in squash

In squash, the “nick shot” is an emphatic, point-ending play in which a player strikes a ball that ricochets near the bottom of the wall and rolls flat along the floor instead of bouncing, leaving an opponent with no chance to return it.

While the shot is as old as the game itself, a team of researchers has now revealed the physics behind it, showing how perfect placement and just the right roll conspire to kill the ball’s bounce.

The research, led by Brown University Professor of Engineering Roberto Zenit, was published in Proceedings of the National Academy of Sciences. While the findings could be useful in developing shock-dampening technologies, Zenit says the work grew out of his interest in using science to explain the everyday world.

The Center of Our Universe Does Not Exist. A Physicist Explains Why

About a century ago, scientists were struggling to reconcile what seemed a contradiction in Albert Einstein’s theory of general relativity.

Published in 1915, and already widely accepted worldwide by physicists and mathematicians, the theory assumed the Universe was static – unchanging, unmoving and immutable. In short, Einstein believed the size and shape of the Universe today was, more or less, the same size and shape it had always been.

But when astronomers looked into the night sky at faraway galaxies with powerful telescopes, they saw hints the Universe was anything but that. These new observations suggested the opposite – that it was, instead, expanding.

Earth-based telescopes offer a fresh look at Cosmic Dawn

For the first time, scientists have used Earth-based telescopes to look back over 13 billion years to see how the first stars in the universe affect light emitted from the Big Bang.

Using telescopes high in the Andes mountains of northern Chile, astrophysicists have measured this polarized microwave light to create a clearer picture of one of the least understood epochs in the history of the universe, the Cosmic Dawn.

“People thought this couldn’t be done from the ground. Astronomy is a technology-limited field, and from the Cosmic Dawn are famously difficult to measure,” said Tobias Marriage, project leader and a Johns Hopkins professor of physics and astronomy. “Ground-based observations face additional challenges compared to space. Overcoming those obstacles makes this measurement a significant achievement.”

There’s an infinite amount of energy locked in the vacuum time. Could we ever use it?

The bottom line is that no matter what the zero-point energy is, it’s the background of the universe on top of which all of physics takes place. Just as you can’t go lower than the ground floor of a building with no basement, you can’t get lower than the ground state of the universe — so there’s nothing for you to extract, and there’s no way to leverage that into useful applications of energy.

So, unfortunately, any work you do in the universe will have to be done the old-fashioned way.

Self-learning neural network cracks iconic black holes

A team of astronomers led by Michael Janssen (Radboud University, The Netherlands) has trained a neural network with millions of synthetic black hole data sets. Based on the network and data from the Event Horizon Telescope, they now predict, among other things, that the black hole at the center of our Milky Way is spinning at near top speed.

The astronomers have published their results and methodology in three papers in the journal Astronomy & Astrophysics.

In 2019, the Event Horizon Telescope Collaboration released the first image of a supermassive black hole at the center of the galaxy M87. In 2022, they presented an image of the black hole in our Milky Way, Sagittarius A*. However, the data behind the images still contained a wealth of hard-to-crack information. An international team of researchers trained a neural network to extract as much information as possible from the data.

Galactic Empire Psychology

We now know that the Galaxy is full of potentially habitable planets. So why do we see no signs that any civilizations have come before us? Matt O’Dowd, astrophysicist and host of PBS Space Time, explains why Fermi’s paradox really is so surprising, and he offers a new piece of evidence that may point towards the solution.

Astrophysicist Matthew O’Dowd spends his time studying the universe, especially really far-away things like Quasars, super-massive black holes and evolving galaxies. He completed his Ph.D. at NASA´s Space Telescope Science Institute, followed by work at the University of Melbourne and Columbia University. Currently he is a professor at the City University of New York´s Lehman College and an Associate at the American Museum of Natural Historys Hayden Planetarium.

Thumbnail © Nadja Niemiec.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community.