Exploring ‘Ripples on the Cosmic Ocean’ by Dagomar DeGroot: Insights and Reflections This Week

This stunning photo mosaic created from images captured by NASA spacecraft showcases six planets of the solar system along with Earth's moon. In the foreground, Earth rises above the moon, displaying a solar flare at its edge. Venus is positioned above the moon, with Jupiter, Mercury, Mars, and Saturn arranged from top left to right. Photo credits: Earth - Apollo 17, Moon - Apollo 8; Sun - Apollo 12. Venus - Pioneer Venus. Jupiter - Voyager I; Mercury - Mariner 10; Saturn - Pioneer 11.

The solar system’s influence on humanity

NASA/Bettman Archive/Getty Images

Ripples in the Cosmic Ocean
Dagomar DeGroot
Viking, UK. Belknap Press, USA

For those captivated by extraterrestrial news, if you’re an avid reader of New Scientist, you might be aware of recent discoveries hinting at life’s potential on distant planets. Perhaps you’ve heard about a Mars rover uncovering signs of ancient life in uniquely patterned rock or recalled that moment last year when an asteroid appeared to threaten Earth.

While these cosmic revelations are undoubtedly thrilling, they often quickly dissolve into distant echoes, overshadowed by pressing global matters like conflicts and climate crises. The chance of alien microbes emitting gases from a planet trillions of kilometers away may ignite your imagination for a fleeting moment, but what real significance do these cosmic findings hold for our lives on Earth?

Climate historian Dagomar DeGroot argues that our fascination with the cosmos has profoundly shaped human history in his new book, Ripples in the Cosmic Ocean: How the Solar System Shaped Human History – and Might Save the Planet.


Venus’ runaway greenhouse effect prompts the question: could Earth face a similar fate?

Although DeGroot may not be a scientist, he represents a new generation of interdisciplinary historians, serving as an environmental historian at Georgetown University.

His book delves into how shifts in the cosmic environment have influenced human events, drawing from archives of renowned and obscure scientists alike to construct a detailed narrative of scientific advancement. DeGroot argues for the need to observe our surroundings with a cosmic lens: “We cannot deny the existence of the ocean, both because its waves reach us without us seeking them, and because only by gazing into the abyss can we truly comprehend our isolated island.”

Our understanding of Earth’s climate, past ice ages, and potential global warming would be drastically diminished without our planetary neighbors illuminating the night sky. Recognizing the challenges posed by existential threats such as nuclear conflict and catastrophic asteroid impacts is crucial. Furthermore, we could find ourselves embroiled in theological disputes over heliocentrism.

DeGroot highlights the impactful influence a single planet can possess. For instance, Venus is depicted as a hostile environment with temperatures soaring above 460 degrees Celsius and active volcanoes releasing sulfur dioxide.

This perception has evolved. Initially, astronomers faced difficulties in observing Venus due to its dense atmosphere, yet by the 19th century, many agreed on the existence of cloud cover.

This misinformation fueled speculation about a habitable world under its clouds, significantly contributing to the rise of cosmic pluralism—the idea that Earth is not the sole cradle of life.

As our observational equipment improved and the harsh reality of Venus was unveiled, urgent questions emerged: Is this a warning for Earth’s future?

Understanding Venus’ extreme temperatures caused by a runaway greenhouse effect raises concern about the possibility for Earth to face a similar crisis. Numerous scientists, including astronomer Carl Sagan and climatologist James Hansen, dedicated their careers to studying Venus, which in turn sparked serious warnings about climate change on Earth.

DeGroot’s book overflows with instances like these, illustrating how Martian dust storms have compelled scientists to consider the ramifications of nuclear conflict. In 1994, the spectacle of comet Shoemaker-Levy 9 colliding with Jupiter emphasized the urgency of defending Earth against similar threats.

Ripples in the Cosmic Ocean captivates readers with its exploration of lesser-known tales in the history of scientific ideas, showcasing peculiar and vibrant figures. One such figure is Immanuel Velikovsky, an American-Russian psychoanalyst whose peculiar theories about Venus generated intriguing predictions but also controversy within the scientific community from the 1950s to the 1970s.

Ripples in the Cosmic Ocean

DeGroot compellingly makes the case for looking beyond our world, yet he admits that navigating future space exploration and observations presents challenges. We now live in a time of remarkable space exploration, notably advanced by billionaire-funded companies like Elon Musk’s SpaceX and Jeff Bezos’ Blue Origin.

He argues for an alternative approach that avoids exploiting space solely for affluent interests. Historically, colonial powers exploited knowledge for empire expansion. In a refreshing perspective, DeGroot suggests that we should foster life on Earth and cultivate “a vision of the ocean that creates and sustains communities in the cosmos for the collective benefit of all.”

One of his innovative ideas involves generating solar power from space, such as deploying solar panels on the moon to transmit energy back to Earth. Although the feasibility of such projects remains debatable, DeGroot underscores the necessity of choosing a path forward. Drawing from our solar system’s historical influence, he states, “Humanity’s journey has been partly driven by ripples in the cosmic ocean. Regardless of our actions, new waves will approach. Now, we hold the power to create our own waves. Our future may hinge on how we choose to shape those waves.”

3 Must-Read Books on the Solar System

Pale Blue Dot A Vision of Humanity’s Future in Space
Carl Sagan
Astronomer Carl Sagan explores the significance of our solar system in shaping human understanding and our place in the universe in this evocative meditation.

Space War
H.G. Wells
This classic features prominently in DeGroot’s book (see main review), recounting the famous radio adaptation that led to widespread panic among listeners who believed Earth was truly under Martian threat.

Mars City
Kelly Weinersmith & Zach Weinersmith
This dynamic duo, a cartoonist and biologist, explores the harsh realities of life on Mars through scientific facts and beautiful illustrations, revealing the challenges of living beyond Earth.

Topic:

Source: www.newscientist.com

ALMA discovers earthquake-like ripples in the disk of an old barred spiral galaxy

astronomer using Atacama Large Millimeter/Submillimeter Array ALMA observed disk bending waves in BRI 1335-0417, the oldest known spiral galaxy, more than 12 billion years old. This unprecedented observation reveals the galaxy’s dynamic growth pattern, showing the motion of a vertically oscillating disk similar to ripples in a pond. This study is the first time such a phenomenon has been detected in an early galaxy.

This simulation shows how the galactic disk is disturbed and seismic ripples propagate throughout the disk. Image credit: Brand-Hawthorne & Tepper-Garcia, University of Sydney.

Bar structures play an important role in driving galaxy evolution and forming disk structures.

In galaxies, axisymmetric stellar bars exert a gravitational torque on the gas, driving it toward the galactic center and forming concentrated stellar structures such as bulges and core disks.

This process may also promote the accretion of gas onto black holes, which are observed as active galactic nuclei.

Bars can also cause radial migration of gas and stars, which is essential for explaining the stellar kinematics observed in galaxies similar to the Milky Way.

“Thanks to a cutting-edge telescope called ALMA, we have been able to observe the ancient galaxy BRI 1335-0417 in greater detail,” said lead author Dr Takafumi Tsukui, an astronomer at the Australian National University.

“In particular, we were interested in how gas moves within and across galaxies.”

“Gas is a key component for star formation and provides important clues about how galaxies actually drive star formation.”

In this case, Dr. Tsukui and his colleagues were not only able to capture the movement of gas around BRI 1335-0417, but also revealed the formation of seismic waves, a first for this type of early galaxy.

The galaxy’s disk moves similar to the ripples in a pond after a stone is thrown into it.

ALMA detected emission from carbon ions in the galaxy BRI 1335-0417. Image credit: ALMA / ESO / NAOJ / NRAO / T. Tsukui & S. Iguchi, doi: 10.1126/science.abe9680.

“The vertical oscillatory motion of the disk is due to external factors, such as new gas flowing into the galaxy or contact with other small galaxies,” Tsukui said.

“Both possibilities would bombard the galaxy with new fuel for star formation.”

“Furthermore, our study revealed rod-like structures within the disk.”

“The galactic rods can destroy gas and transport it towards the center of the galaxy.”

“The bar discovered at BRI 1335-0417 is the most remote known structure of its kind.”

“Taken together, these results point to the dynamic growth of young galaxies.”

“We know that early galaxies formed stars at much faster rates than modern galaxies,” said co-author Dr Emily Wisnioski, also from the Australian National University.

“This is also true for BRI 1335-0417, which has a similar mass to our Milky Way galaxy but forms stars hundreds of times faster.”

“We wanted to understand how gas is supplied to keep up with this rapid rate of star formation.”

“Spiral structures are rare in the early Universe, and exactly how they form remains unknown.”

“This study also provides important information about the most likely scenario.”

“While it is impossible to directly observe the evolution of galaxies, our observations only provide snapshots, so computer simulations can help piece together the story.”

of findings will appear in Royal Astronomical Society Monthly Notices.

_____

Takafumi Tsukui other. 2024. Disk bending waves detected in a barred spiral galaxy at redshift 4.4. MNRAS 527 (3): 8941-8949; doi: 10.1093/mnras/stad3588

Source: www.sci.news