Author: Aeon Magazine

This article was originally published at Aeon and has been republished under Creative Commons.

Would it be immoral to send out a generation starship?

Post author By Aeon Magazine
Post date March 15, 2020
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If human beings are ever to colonize other planets – which might become necessary for the survival of the species, given how far we have degraded this one – they will almost certainly have to use generation ships: spaceships that will support not just those who set out on them, but also their descendants. The vast distances between Earth and the nearest habitable planets, combined with the fact that we are unlikely ever to invent a way of traveling that exceeds the speed of light, ensure that many generations will be born, raised, and die on board such a ship before it arrives at its destination.

Mars Space Exploration

How to optimize your headspace on a mission to Mars

Post author By Aeon Magazine
Post date February 23, 2020
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Interplanetary Transport System - Spaceship Close to Mars — The "interplanetary module” on top of the Interplanetary Transport System will be nearly as long as two Boeing 747 aircraft. It could initially carry up to 100 passengers

Imagine being confined to a metal cell with a couple of other people and few amenities for months or even years. Maybe after that, you’ll be moved to a new compound, but you still have no privacy and extremely limited communication with your family and anyone else in the outside world. You feel both crowded and lonely at the same time, and yet no one comes to treat your emerging mental-health problems.

Environment Climate Life on Earth Planet Earth

Forget the Anthropocene: we’ve entered the synthetic age

Post author By Aeon Magazine
Post date November 2, 2019
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The Asian tiger mosquito has been genetically altered in lab experiments with CRISPR technology in an attempt to limit the spread of disease. CRISPR (clustered regularly interspaced short palindromic repeats) is a family of DNA sequences found within the genomes of prokaryotic organisms such as bacteria and archaea.[2] These sequences are derived from DNA fragments of bacteriophages that have previously infected the prokaryote and are used to detect and destroy DNA from similar phages during subsequent infections. Hence these sequences play a key role in the antiviral (i.e. anti-phage) defense system of prokaryotes.

One fact about our time is becoming increasingly well-known. No matter how far you travel, no matter in which direction you point, there is nowhere on Earth that remains free from the traces of human activity. The chemical and biological signatures of our species are everywhere. Transported around the globe by fierce atmospheric winds, relentless ocean currents, and the capacious cargo-holds of millions of fossil-fuel-powered vehicles, nowhere on Earth is free from humanity’s imprint. Pristine nature has permanently blinked out of existence.

Physics

Why we can stop worrying and love the particle accelerator

Post author By Aeon Magazine
Post date October 2, 2019
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The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator. It first started up on 10 September 2008 and remains the latest addition to CERN’s accelerator complex. The LHC consists of a 27 km (16.8 mi) ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. The beams travel in opposite directions in separate beam pipes – two tubes kept at ultrahigh vacuum. They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets. The electromagnets are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy. This requires chilling the magnets to ‑271.3°C – a temperature colder than outer space. For this reason, much of the accelerator is connected to a distribution system of liquid helium, which cools the magnets, as well as to other supply services. housands of magnets of different varieties and sizes are used to direct the beams around the accelerator. These include 1232 dipole magnets 15 meters in length which bend the beams, and 392 quadrupole magnets, each 5-7 meters long, which focus the beams. Just prior to collision, another type of magnet is used to "squeeze" the particles closer together to increase the chances of collisions. The particles are so tiny that the task of making them collide is akin to firing two needles 10 km apart with such precision that they meet halfway. All the controls for the accelerator, its services and technical infrastructure are housed under one roof at the CERN Control Centre. From here, the beams inside the LHC are made to collide at four locations around the accelerator ring, corresponding to the positions of four particle detectors – ATLAS, CMS, ALICE and LHCb. Image and text: CERN

What would happen if you stuck your body inside a particle accelerator? The scenario seems like the start of a bad Marvel comic, but it happens to shed light on our intuitions about radiation, the vulnerability of the human body, and the very nature of matter. Particle accelerators allow physicists to study subatomic particles by speeding them up in powerful magnetic fields and then tracing the interactions that result from collisions. By delving into the mysteries of the Universe, colliders have entered the Zeitgeist and tapped the wonders and fears of our age.

Chemistry

Why synthetic chemicals seem more toxic than natural ones

Post author By Aeon Magazine
Post date September 2, 2019
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Many people believe that chemicals, particularly the man-made ones, are highly dangerous. After all, more than 80,000 chemicals have been synthesised for commercial use in the United States, and many have been released into the environment without proper safety testing. Should we be afraid of the synthetic chemicals that permeate our world?

Geology

What kills you when a volcano erupts? [It’s not what you think]

Post author By Aeon Magazine
Post date July 8, 2019
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Pyroclastic activity at Mount Sinabung, on 24 June 2016 in Karo, Indonesia. Photo by Getty Images A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that moves away from a volcano about 100 km/h (62 mph) on average but is capable of reaching speeds up to 700 km/h (430 mph). The gases can reach temperatures of about 1,000 °C (1,830 °F). Pyroclastic flows are a common and devastating result of certain explosive eruptions; they normally touch the ground and hurtle downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. Source: Pyroclastic flow on Wikipedia

The blockbuster movie Jurassic World: Fallen Kingdom (2018) involves more than just dinosaurs wreaking havoc. Humans are sent in to rescue some prehistoric critters on the volcanic island of Isla Nublar, and chaos soon begins. The volcano erupts, and everyone runs away as a roiling cloud called a pyroclastic flow approaches. At one point the main character disappears into the cloud. Luckily, some dinosaurs and humans in a strange glass ball fall over a cliff into the sea, and our hero splashes in not long after.

Space Exploration Mars Moon Landing

Space exploration is still the brightest hope-bringer we have

Post author By Aeon Magazine
Post date June 10, 2019
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Apollo 11 launch (cropped) — The Apollo 11 Saturn V lifts off at 9:32 a.m. EDT July 16, 1969, from Kennedy's Launch Complex 39A. As of 2018, Saturn V launch vehicle still remains the tallest, heaviest, and most powerful rocket ever built. This is a cropped image. You can see the full image at: NASA The Apollo 11 mission, the first manned lunar mission, launched from the Kennedy Space Center, Florida via the Marshall Space Flight Center (MSFC) developed Saturn V launch vehicle on July 16, 1969 and safely returned to Earth on July 24, 1969. The Saturn V vehicle produced a holocaust of flames as it rose from its pad at Launch complex 39. The 363 foot tall, 6,400,000 pound (2,902,991 kg) rocket hurled the spacecraft into Earth parking orbit and then placed it on the trajectory to the moon for the humanity's first lunar landing. Aboard the space craft were astronauts Neil A. Armstrong, commander; Michael Collins, Command Module pilot; and Edwin E. Aldrin Jr., Lunar Module pilot. With the success of Apollo 11, the national objective to land humans on the Moon and return them safely to Earth had been accomplished.

I am one of the few African-American aerospace engineers who helped design the Apollo spaceships that took men to the Moon. My great-grandfather was a slave in Claiborne, Alabama, who used primitive tools to work the land. My father was born in Alabama before the Wright brothers made mankind’s first flight. He lived to see men walk on the Moon, twin robotic biology labs land on Mars, and a fleet of four space probes on their way to the stars. But many black people, like the late Reverend Ralph Abernathy, felt that the money used to make these amazing things happen would have been better spent on helping the poorest descendants of American slaves.

Climate Global Warming History People

Did European Colonisation precipitate the Little Ice Age?

Post author By Aeon Magazine
Post date May 1, 2019
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Little Ice Age. The Frozen Thames. — From the Little Ice Age. The Frozen Thames, looking Eastwards towards Old London Bridge (1677) by Abraham Hondius. Courtesy the Museum of London. Abraham Danielsz. Hondius (about 1631 - 17 September 1691) was a Dutch Golden Age painter known his depictions of animals. He was the son of a city stonemason, Daniel Abramsz de Hondt. Hondius was born in Rotterdam and trained under Pieter de Bloot (1601-1658) and Cornelis Saftleven. He lived in Rotterdam until 1659 and moved then to Amsterdam. He moved to London in 1666, where he spent the rest of his life. Hondius combined throughout his career several stylistic influences and struggled to develop a style of his own. He however specialized somehow in animal pieces: more than two-thirds of his paintings, etchings and drawings are hunting scenes, animals fighting and animal studies. He also executed landscapes, genre and religious scenes. Hondius most likely moved to London in 1666 where he spent the rest of his life and died. He painted views of London such as The Frozen Thames and London Bridge. His last known work is Ape and Cat Fighting over Dead Poultry, dated 1690.

Many of us think that rapid environmental change is a quintessentially modern crisis. Today, temperatures are soaring, topsoil is washing away, phosphorous is being diluted, forests are retreating, pesticides are sterilising farmland, fertilisers are choking waterways, and biodiversity is plummeting under the onslaught of overpopulated, industrialised societies. Some of these changes are indeed truly new. But many others have deep roots and distant echoes in the early modern period, the years between around 1400 and 1800 when much of the world began to assume its present form. Recently, scientists, geographers, historians, and archaeologists have combined expertise and evidence to reveal just how profound early modern environmental transformations really were.

Astronomy

What high-speed astronomy can tell us about the galactic zoo

Post author By Aeon Magazine
Post date April 16, 2019
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An artist's conception of the primary mirror of the Large Synoptic Survey Telescope (LSST). Large Synoptic Survey Telescope is a wide-field survey reflecting telescope with an 8.4-meter primary mirror that will photograph the entire available sky every few nights. The word synoptic is derived from the Greek words σύν (syn "together") and ὄψις (opsis "view"), and describes observations that give a broad view of a subject at a particular time. The construction began on April 14, 2015, with engineering first light anticipated in 2019, science first light in 2021, and full operations for a ten-year survey commencing in January 2022. The Large Synoptic Survey Telescope, unlike almost all previous large astronomical observatories, has committed to making all data public as soon as it is taken. In their words *"By providing immediate public access to all the data it obtains, it will provide everyone, the professional and the “just curious” alike, a deep and frequent window on the entire sky."* The goal of the Large Synoptic Survey Telescope (LSST) project is to conduct a 10-year survey of the sky that will deliver a 200 petabyte set of images and data products that will address some of the most pressing questions about the structure and evolution of the universe and the objects in it. The LSST survey is designed to address four science areas: -Understanding the Mysterious Dark Matter and Dark Energy -Hazardous Asteroids and the Remote Solar System -The Transient Optical Sky -The Formation and Structure of the Milky Way

For most of human history, the distant ‘celestial sphere’ was regarded as perfect and unchanging. Stars remained in place, planets moved predictably, and the few rogue comets were viewed as atmospheric phenomena. This began to change with the Danish astronomer Tycho Brahe’s observation of the supernova of 1572 – apparently, a new star – and his studies of the Great Comet of 1577, which he proved was actually a distant object. Nonetheless, the impression of permanence is strong. There are very few astronomical objects that noticeably vary to the naked eye: only the brightest comets, novae, and supernovae. For observers in the northern hemisphere, the last naked-eye supernova was in 1604.

Astronomy Physics

How many great minds does it take to invent a telescope?

Post author By Aeon Magazine
Post date February 2, 2019
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Isaac Newton's reflecting telescope of 1671. The Newtonian telescope, also called the Newtonian reflector or just the Newtonian, is a type of reflecting telescope invented by the English scientist Sir Isaac Newton (1642-1727), using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design makes it very popular with amateur telescope makers. Photo ©The Royal Society

On 11 January 1672, the Fellows of the British Royal Society were treated to a demonstration of Isaac Newton’s reflecting telescope, which formed images with mirrors rather than with the lenses that had been used since the time of Galileo. Afterward, the fellows hailed Newton as the inventor of this marvelous new instrument, an attribution that sticks to the present.

However, this linear historical account obscures a far more interesting, convoluted story. Newton’s claim was immediately challenged on behalf of two other contenders, James Gregory, and Laurent Cassegrain. More confounding, the earliest known concept of using a curved mirror to focus light predated Newton by more than 1,500 years; the final realisation of a practical reflecting telescope post-dated him by more than a half-century.