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If an asteroid were heading towards Earth, could you avert disaster?

New Scientist Feed - Wed, 11/06/2024 - 8:55am
In this choose-your-own-adventure game, it's up to you to protect the planet. From nuclear strikes to giant spikes, find out what would give us the best chance of survival
Categories: Science

Jesus ‘n’ Mo ‘n’ racism

Why Evolution is True Feed - Wed, 11/06/2024 - 7:30am

The latest Jesus and Mo cartoon, called “racism”, came with the sentence, “Happy Islamophobia Awareness Month!:

Ahmadiyya Muslims, by the way, have teachings distinct from those of Sunni and Shiite Muslims, including the resurrection of Jesus and the denial of “abrogation”: the view that the later-written verses of teh Qur’an supersede the earlier ones.

 

Categories: Science

2024 is set to be the first year that breaches the 1.5°C warming limit

New Scientist Feed - Wed, 11/06/2024 - 6:00am
This year’s average global temperature is almost certain to exceed 1.5°C above pre-industrial times – a milestone that should spur urgent action, say climate scientists
Categories: Science

Some Data on Fluoride

Science-based Medicine Feed - Wed, 11/06/2024 - 5:13am

David Gorski wrote yesterday about the threat that a second Trump term holds for American health, specifically if he keeps his promise to give RFK Jr. some high level position over public health. Unfortunately, we have seen this movie before, although the sequel promises to be much worse. Putting a pseudoscientist, crank, conspiracy theorist, anti-vaxxer in charge of the organizations that are […]

The post Some Data on Fluoride first appeared on Science-Based Medicine.
Categories: Science

Republicans win everything

Why Evolution is True Feed - Wed, 11/06/2024 - 5:10am

Like many Americans (and readers) this morning, I woke up, fumbled for my computer, and read the results in a state of shock.  The Republicans had won everything: the Presidency, the Senate, and, most likely, the House (see NYT results below).  As one of my friends wrote me, in the first email of the day, “I did not see this coming.”  Neither did I. Click the headline below to see the NYT story (archived here for free)

A pessimistic take from the NYT:

Donald J. Trump rode a promise to smash the American status quo to win the presidency for a second time on Wednesday, surviving a criminal conviction, indictments, an assassin’s bullet, accusations of authoritarianism and an unprecedented switch of his opponent to complete a remarkable return to power.

Mr. Trump’s victory caps the astonishing political comeback of a man who was charged with plotting to overturn the last election but who tapped into frustrations and fears about the economy and illegal immigration to defeat Vice President Kamala Harris.

His defiant plans to upend the country’s political system held appeal to tens of millions of voters who feared that the American dream was drifting further from reach and who turned to Mr. Trump as a battering ram against the ruling establishment and the expert class of elites.

In a deeply divided nation, voters embraced Mr. Trump’s pledge to seal the southern border by almost any means, to revive the economy with 19th-century-style tariffs that would restore American manufacturing and to lead a retreat from international entanglements and global conflict.

Now, Mr. Trump will serve as the 47th president four years after reluctantly leaving office as the 45th, the first politician since Grover Cleveland in the late 1800s to lose re-election to the White House and later mount a successful run. At the age of 78, Mr. Trump has become the oldest man ever elected president, breaking a record held by President Biden, whose mental competence Mr. Trump has savaged.

His win ushers in an era of uncertainty for the nation.

To roughly half the country, Mr. Trump’s rise portends a dark turn for American democracy, whose future will now depend on a man who has openly talked about undermining the rule of law. Mr. Trump helped inspire an assault on the Capitol in 2021, has threatened to imprison political adversaries and was denounced as a fascist by former aides. But for his supporters, Mr. Trump’s provocations became selling points rather than pitfalls.

As of early Wednesday, the results showed Mr. Trump improving on his 2020 showing in counties all across America with only limited exceptions. Mr. Trump had secured the necessary swing states — including Georgia, North Carolina and Pennsylvania — to guarantee him the 270 Electoral College votes needed to win the White House.

Republicans also picked up at least two Senate seats, in Ohio and West Virginia, to give the party a majority in the Senate. Control of the House of Representatives was still too close to call.

Here are the results by state, with a few still undecided (the last update was at 5:45 a.m. Eastern time). As everyone expected, Illinois, as well as most of New England, went blue, while all the swing states with called elections (notably Pennsylvania, Wisconsin, and Georgia) went for Trump. But he already has 277 Electoral-College votes, 7 more than he needs to win. Harris has not yet conceded nor made any announcement, though I heard on the news that she will speak this morning. Click on the map to see the state-by-state results:

Yes, America elected a man who, I think, is unstable and afflicted with narcissistic personality disorder. He is the first felon elected as President of the United States.  Who knows what will happen?  I was never a big fan of Kamala Harris, but I see Trump as unpredictable enough to plunge us into war.  For the next four years we will face the Republicans enacting their agenda, making their laws and verifying them via a Republican-controlled Supreme Court.

I am not a political pundit, so all I can do is give my own personal reactions. Until recently, I thought that this election was Trump’s to lose, even though I knew it would be a squeaker. But Trump’s behavior over the last few weeks—the dark language, the execrable performance during the one debate, his laughter at the idea that reporters might be shot, the vows to overturn America starting on Day 1—all of this made me think that there is no way Americans could elect such a man.

They did.

On the other hand, I sometimes thought that this election was Harris’s to lose.  What the American people wanted, I thought, was not only somebody likable (I don’t see Harris that way, but as someone who panders and dissimulates), and, most important, we—and by that I mean centrists, Democrats, and Republicans who don’t like Trump—wanted Harris to espouse a policy. But instead of hearing that, we heard a woman unable to answer questions, who pandered to the electorate using identity politics (which she’d seemingly foresworn), who seemed to be hiding the fact that she was really on the Progressive Left, and, in general, did not seem able to convince the public that she could handle the most important job in the world. She did not earn her nomination, but inherited it, and subsequently did nothing to show that she deserved it.

Still, all along I felt that she was a far better candidate than was Trump.  She lost, I think, because she was not sufficiently centrist, and because she didn’t show, as Presidents must, that she had the ability to think on her feet.  If there is a lesson for Democrats here, it is to recalibrate their message and move towards the center, and listen to the American people when they speak about things like immigration and the economy (no, tariffs—also Trump’s solution—are not the way to solve that)

Did wokeness cost Harris the election? Who knows, and I’m not prepared to assert it. (Note that the NYT above considers this a blow against “the elite.”) But I think the era of identity politics (an integral part of wokeism) has come to an end. Harris largely avoided them, but she still lost, for she did not lay out a program that would appeal to all Americans, which was what she promised to do. Perhaps, given the divisions in America, such a program is impossible.

The Free Press ponders why Harris lost:

Donald Trump ended his first term in disgrace, hit with a second impeachment after his supporters stormed the Capitol on January 6, 2021. The 2022 midterm candidates he endorsed—Herschel Walker, Mehmet Oz, Kari Lake—all went down in flames. In 2023, he was declared guilty of sexually assaulting the writer E. Jean Carroll in a civil case. This past May, he was convicted in a Manhattan court on 34 felony counts for improperly reporting hush money payments. Overall, he has faced 116 indictments. Even now, the New York State attorney general is trying to punish the Trump Organization with nearly $500 million in fines, claiming that he unlawfully inflated the value of his properties.

And yet here he is: America’s 47th president.

. . . . Trump’s mastery of political imagery [they describe four “iconic photographs,” including his punching-the-air photo after a bullet nicked his ear] stands in sharp contrast to Vice President Kamala Harris, who kept making gaffes when she needed to demonstrate basic competence. One such howler came at a rally in Ann Arbor, Michigan, eight days before Election Day. As the crowd chanted “Ka-ma-la! Ka-ma-la!” the vice president implored her fans: “Now I want each of you to shout your own name. Do that.” The cheers stopped. Then Harris offered an awkward laugh and, like a comic having to explain a joke that didn’t land, she said, “’cause it’s about all of us.”

In one stumble, you have a synopsis of what went wrong for the Harris-Walz ticket in 2024. Here was a friendly audience, raring to go, in a must-win state, brought to stunned silence because the candidate apparently hadn’t thought through a throwaway line at a rally. In the home stretch of the election, Harris couldn’t close the deal even as the media graded her on a curve.

In some ways, the Democratic Party should have seen all of this coming. In the perilous four weeks between Biden’s disastrous debate performance and the selection of Harris to replace him on the ticket, a number of Democratic insiders publicly proposed an abbreviated primary campaign to avoid anointing the vice president. Harris was seen by many Democrats as a liability. At the beginning of the summer she had a 37.9 approval rating, along with a reputation for being terrible to her staff and pathetic when it came to thinking on her feet.

A key part of her strategy was a disciplined avoidance of the media. Harris didn’t do her first solo television interview as her party’s nominee until five weeks after her selection on September 13. And until October, she largely avoided saying what she would do if she won the White House.

That turned out to be a good strategy. Because once Harris started to open her mouth, she reverted to form. Consider her October 8 appearance on The View, when she was asked the most obvious question of a vice president serving in an unpopular administration: What would you have done differently than President Biden? Her response: “There is not a thing that comes to mind in terms of—and I’ve been a part of most of the decisions that have had impact.”

Is there any good news? Only that we won’t have a January 6 situation again! But joking aside, and despite all the anguish of my friends and most Democrats, I am strangely hopeful—hopeful that yes, the Republic can and will withstand four years of Trump and Republican rule. Somehow my faith in America has immunized me against the results of this election.

Beyond that, I can make no predictions save that Trump will not be elected again.

Here are the results of our poll from two days ago, and some readers have already sent anguished comments and emails. Harris was favored by more than six to one, and she was predicted to win by 62% of those who voted:

Finally, I listened to most of this two-hour podcast yesterday, created by The Free Press and moderated by Bari Weiss. It shows Sam Harris making the case for electing Kamala Harris, and Ben Shapiro making the case for Trump.  This is about the best discussion I’ve heard, and I was convinced by Harris, especially his arguments against Trump. But Shapiro was no slouch, even though his case against Harris was better than his case for Trump.

Again, all I can think is this: “Our Republic will stand.” Ceiling Cat bless us all.

You are welcome to comment below. I’ll put up the Hili dialogue in an hour or so.

Categories: Science

Report from Death Valley, and the Bermuda Triangle

Skeptoid Feed - Wed, 11/06/2024 - 2:00am

A report from the recent Skeptoid Adventures trip to Death Valley, including how many brave souls we lost in the desert and how they met their fate; and announcing the next Skeptoid Adventures trip to the Bermuda Triangle! Reserve your spot now at https://skeptoid.com/events/30285

Categories: Critical Thinking, Skeptic

New Report Details What Happened to the Arecibo Observatory

Universe Today Feed - Tue, 11/05/2024 - 5:05pm

In 1963, the Arecibo Observatory became operational on the island of Puerto Rico. Measuring 305 meters (~1000 ft) in diameter, Arecibo’s spherical reflector dish was the largest radio telescope in the world at the time – a record it maintained until 2016 with the construction of the Five-hundred-meter Aperture Spherical Telescope (FAST) in China. In December 2020, Arecibo’s reflector dish collapsed after some of its support cables snapped, leading the National Science Foundation (NSF) to decommission the Observatory.

Shortly thereafter, the NSF and the University of Central Florida launched investigations to determine what caused the collapse. After nearly four years, the Committee on Analysis of Causes of Failure and Collapse of the 305-Meter Telescope at the Arecibo Observatory released an official report that details their findings. According to the report, the collapse was due to weakened infrastructure caused by long-term zinc creep-induced failure in the telescope’s cable sockets and previous damage caused by Hurricane Maria.

The massive dish was originally called the Arecibo Ionospheric Observatory and was intended for ionospheric research in addition to radio astronomy. The former task was part of the Advance Research Projects Agency’s (ARPA) Defender Program, which aimed to develop ballistic missile defenses. By 1967, the NSF took over the administration of Arecibo, henceforth making it a civilian facility dedicated to astronomy research. By 1971, NASA signed a memo of understanding to share the costs of maintaining and upgrading the facility.

Radar images of 1991 VH and its satellite by Arecibo Observatory in 2008. Credit: NSF

During its many years of service, the Arecibo Observatory accomplished some amazing feats. This included the first-ever discovery of a binary pulsar in 1974, which led to the discovery team (Russell A. Hulse and Joseph H. Taylor) being awarded the Nobel Prize in physics in 1993. In 1985, the observatory discovered the binary asteroid 4337 Arecibo in the outer regions of the Main Asteroid Belt. In 1992, Arecibo discovered the first exoplanets, two rocky bodies roughly four times the mass of Earth around the pulsar PSR 1257+12. This was followed by the discovery of the first repeating Fast Radio Burst (FRB) in 2016.

The observatory was also responsible for sending the famous Arecibo Message, the most powerful broadcast ever beamed into space and humanity’s first true attempt at Messaging Extraterrestrial Intelligence (METI). The pictorial message, which was crafted by a group of Cornell University and Arecibo scientists, which included Frank Drake (creator of the Drake equation), famed science communicator and author Carl Sagan, Richard Isaacman, Linda May, and James C.G. Walker, was aimed at the globular star cluster M13.

According to the Committee report, the structural failure began in 2017 when Hurricane Maria hit the Observatory on September 20th, 2017:

“Maria subjected the Arecibo Telescope to winds of between 105 and 118 mph, with the source of this uncertainty in wind speed discussed below... Based on a review of available records, the winds of Hurricane Maria subjected the Arecibo Telescope’s cables to the highest structural stress they had ever endured since it opened in 1963.”

However, inspections conducted after the hurricane concluded that “no significant damage had jeopardized the Arecibo Telescope’s structural integrity.” Repairs were nonetheless ordered, but the report identified several issues that caused these repairs to be delayed for years. Even so, the investigation indicated that due to the misdirection of repairs “toward components and replacement of a main cable that ultimately never failed,” these would not have prevented the Observatory’s collapse regardless.

Aerial view of the damage to the Arecibo Observatory following the collapse of the of the telescope platform on December 1st, 2020. Credit: Deborah Martorell

Moreover, in August and November of 2020, an auxiliary and main cable suffered a structural failure, which led to the NSF announcing that they would decommission the telescope through a controlled demolition to avoid a catastrophic collapse. They also stated that the other facilities in the observatory would remain operational, such as the Ángel Ramos Foundation Visitor Center. Before that could occur, however, more support cables buckled on December 1st, 2020, causing the instrument platform to collapse into the dish.

This collapse also removed the tops of the support towers and partially damaged some of the Observatory’s other buildings. Mercifully, no one was hurt. According to the report, the Arecibo Telescope’s cable spelter sockets had degraded considerably, as indicated by the previous cable failures. They also explain that the collapse was triggered by “hidden outer wire failures,” which had already fractured due to shear stress from zinc creep (aka. zinc decay) in the telescope’s cable spelter sockets.

This issue was not identified in the post-Mariah inspection, leading to a lack of consideration of degradation mechanisms and an overestimation of the potential strength of the other cables. According to NSF statements issued in October 2022 and September 2023, the observatory will be remade into an education center known as Arecibo C3, focused on Ciencia (Science), Computación (Computing), and fostering Comunidad (Community). So, while the observatory’s long history of radio astronomy may have ended, it will carry on as a STEM research center, and its legacy will endure.

Further Reading: National Academies Press, Gizmodo

The post New Report Details What Happened to the Arecibo Observatory appeared first on Universe Today.

Categories: Science

Election update!

Why Evolution is True Feed - Tue, 11/05/2024 - 4:31pm

Categories: Science

Despite its impressive output, generative AI doesn't have a coherent understanding of the world

Matter and energy from Science Daily Feed - Tue, 11/05/2024 - 4:18pm
Large language models can achieve incredible performance on some tasks without having internalized a coherent model of the world or the rules that govern it, researchers find. This means these models are likely to fail unexpectedly if they are deployed in situations where the environment or task slightly changes.
Categories: Science

Despite its impressive output, generative AI doesn't have a coherent understanding of the world

Computers and Math from Science Daily Feed - Tue, 11/05/2024 - 4:18pm
Large language models can achieve incredible performance on some tasks without having internalized a coherent model of the world or the rules that govern it, researchers find. This means these models are likely to fail unexpectedly if they are deployed in situations where the environment or task slightly changes.
Categories: Science

Vampire bats run on a treadmill to reveal their strange metabolism

New Scientist Feed - Tue, 11/05/2024 - 4:01pm
Experiments where vampire bats were made to run on a treadmill have revealed how they extract energy from protein in their latest blood meal
Categories: Science

Bach, Mozart or jazz

Matter and energy from Science Daily Feed - Tue, 11/05/2024 - 2:47pm
Physicists have investigated to which extent a piece of music can evoke expectations about its progression. They were able to determine differences in how far compositions of different composers can be anticipated. In total, the scientists quantitatively analyzed more than 550 pieces from classical and jazz music.
Categories: Science

Distant dwarf planet Makemake might have a surprising ice volcano

New Scientist Feed - Tue, 11/05/2024 - 12:26pm
A small world in the outer solar system appears to have volcanic activity possibly spurred by liquid water
Categories: Science

We Understand Rotating Black Holes Even Less Than We Thought

Universe Today Feed - Tue, 11/05/2024 - 11:44am

Black holes are real. We see them throughout the cosmos, and have even directly imaged the supermassive black hole in M87 and our own Milky Way. We understand black holes quite well, but the theoretical descriptions of these cosmic creatures still have nagging issues. Perhaps the most famous issue is that of the singularity. According to the classical model of general relativity, all the matter that forms a black hole must be compressed into an infinite density, enclosed within a sphere of zero volume. We assume that somehow quantum physics will avert this problem, though without a theory of quantum gravity, we aren’t sure how. But the singularity isn’t the only infinite problem. Take, for example, the strange boundary known as the Cauchy horizon.

When you get down to it, general relativity is a set of complex differential equations. To understand black holes, you must solve these equations subject to a set of conditions such as the amount of mass, rotation, and electromagnetic charge. The equations are so complex that physicists often focus on connecting solutions to certain mathematical boundaries, or horizons. For example, the event horizon is a boundary between the inside and outside of a black hole. It’s one of the easier horizons to explain because if you happen to cross the event horizon of a black hole, you are forever trapped within it. The event horizon is like a cosmic Hotel California.

For a simple, non-rotating black hole, the event horizon is the only one that really matters. But for rotating black holes, things get really weird. To begin with, the singularity becomes a ring, not a point. And rather than a single event horizon, there is an outer and an inner horizon. The outer one still acts as an event horizon, forever trapping what dares to cross its boundary. The inner one is what’s often called the Cauchy horizon. If you cross the inner horizon, you are still trapped within, but you aren’t necessarily doomed to fall ever closer toward the singularity. Within the Cauchy horizon, spacetime can behave somewhat normally, though it is bounded.

Horizon structure for a rotating black hole. Credit: Simon Tyran, via Wikipedia

The Cauchy horizon can cause all sorts of strange things, but one of them is that the horizon is unstable. If you try to determine perturbations of the horizon, the calculated mass within the horizon diverges, an effect known as mass inflation. It’s somewhat similar to the way the singularity approaches infinite density in the classical model. While this is frustrating, physicists can sweep it under the rug by invoking the principle of cosmic censorship. It basically says that as long as some basic conditions hold, all the strange behaviors like singularities and mass inflation are always bounded by an event horizon. There may be an infinity of mathematical demons in a black hole, but they can never escape, so we don’t really need to worry about them.

But a new paper may have handed those demons a key. The paper shows that mass inflation can occur even without a Cauchy horizon. Without an explicit Cauchy horizon, those basic conditions for cosmic censorship don’t necessarily apply. This suggests that the black hole solutions we get from general relativity are flawed. They can describe black holes that exist for a limited time, but not the long-lasting black holes that actually exist.

What this means isn’t entirely clear. It might be that this impermanent loophole is just general relativity’s way of pointing us toward a quantum theory of gravity. After all, if Hawking radiation is real, all black holes are impermanent and eventually evaporate. But the result could also suggest that general relativity is only partially correct, and what we need is an extension of Einstein’s model the way GR extended Newtonian gravity. What is clear is that our understanding of black holes is incomplete.

Reference: Carballo-Rubio, Raúl, et al. “Mass inflation without Cauchy horizons.” Physical Review Letters 133.18 (2024): 181402.

The post We Understand Rotating Black Holes Even Less Than We Thought appeared first on Universe Today.

Categories: Science

Habitable Worlds are Found in Safe Places

Universe Today Feed - Tue, 11/05/2024 - 11:30am

When we think of exoplanets that may be able to support life, we hone in on the habitable zone. A habitable zone is a region around a star where planets receive enough stellar energy to have liquid surface water. It’s a somewhat crude but helpful first step when examining thousands of exoplanets.

However, there’s a lot more to habitability than that.

In a dense stellar environment, planets in habitable zones have more than their host star to contend with. Stellar flybys and exploding supernovae can eject habitable zone exoplanets from their solar systems and even destroy their atmospheres or the planets themselves.

New research examines the threats facing the habitable zone planets in our stellar neighbourhood. The study is “The 10 pc Neighborhood of Habitable Zone Exoplanetary Systems: Threat Assessment from Stellar Encounters & Supernovae,” and it has been accepted for publication in The Astronomical Journal. The lead author is Tisyagupta Pyne from the Integrated Science Education And Research Centre at Visva-Bharati University in India.

The researchers examined the 10-parsec regions around the 84 solar systems with habitable zone exoplanets. Some of these Habitable Zone Systems (HZS) face risks from stars outside of the solar systems. How do these risks affect their habitability? What does it mean for our notion of the habitable zone?

“Among the 4,500+ exoplanet-hosting stars, about 140+ are known to host planets in their habitable zones,” the authors write. “We assess the possible risks that local stellar environment of these HZS pose to their habitability.”

This image from the research shows the sky positions of exoplanet-hosting stars projected on a Molleweide map. HZS are denoted by yellow-green circles, while the remaining population of exoplanets is represented by gray circles. The studied sample of 84 HZS, located within 220 pc of the Sun, is represented by crossed yellow-green circles. The three high-density HZS located near the galactic plane are labeled 1, 2 and 3 in white. The colour bar represents the stellar density, i.e., the number of stars having more than 15 stars within a radius of 5 arc mins. Image Credit: Pyne et al. 2024.

We have more than 150 confirmed exoplanets in habitable zones, and as exoplanet science advances, scientists are developing a more detailed understanding of what habitable zone means. Scientists increasingly use the terms conservative habitable zone and optimistic habitable zone.

The optimistic habitable zone is defined as regions that receive less radiation from their star than Venus received one billion years ago and more than Mars did 3.8 billion years ago. Scientists think that recent Venus (RV) and early Mars (EM) both likely had surface water.

The conservative habitable zone is a more stringent definition. It’s a narrower region around a star where an exoplanet could have surface water. It’s defined by an inner runaway greenhouse edge where stellar flux would vaporize surface water and an outer maximum greenhouse edge where the greenhouse effect of carbon dioxide is dominated by Rayleigh scattering.

Those are useful scientific definitions as far as they go. But what about habitable stellar environments? In recent years, scientists have learned a lot about how stars behave, the characteristics of exoplanets, and how the two are intertwined.

“The discovery of numerous extrasolar planets has revealed a diverse array of stellar and planetary characteristics, making systematic comparisons crucial for evaluating habitability and assessing the potential for life beyond our solar system,” the authors write.

To make these necessary systematic comparisons, the researchers developed two metrics: the Solar Similarity Index (SSI) and the Neighborhood Similarity Index (NSI). Since main sequence stars like our Sun are conducive to habitability, the SSI compares our Solar System’s properties with those of other HZs. The NSI compares the properties of stars in a 10-parsec region around the Sun to the same size region around other HZSs.

This research is mostly based on data from the ESA’s Gaia spacecraft, which is building a map of the Milky Way by measuring one billion stars. But the further away an HZS is, or the dimmer the stars are, the more likely Gaia may not have detected every star, which affects the research’s results. This image shows Gaia’s data completeness. The colour scale indicates the faintest G magnitude at which the 95% completeness threshold is achieved. “Our sample of 84 HZS (green circles) has been overlaid on the map to visually depict the completeness of their respective neighbourhoods,” the authors write. Image Credit: Pyne et al. 2024.

These indices put habitable zones in a larger context.

“While the concept of HZ is vital in the search for habitable worlds, the stellar environment of the planet also plays an important role in determining longevity and maintenance of habitability,” the authors write. “Studies have shown that a high rate of catastrophic events, such as supernovae and close stellar encounters in regions of high stellar density, is not conducive to the evolution of complex life forms and the maintenance of habitability over long periods.”

When radiation and high-energy particles from a distant source reach a planet in a habitable zone, they can cause severe damage to Earth-like planets. Supernovae are a dangerous source of radiation and particles, and if one were to explode close enough to Earth, that would be the end of life. Scientists know that ancient supernovae have left their mark on Earth, but none of them were close enough to destroy the atmosphere.

“Our primary focus is to investigate the effects of SNe on the atmospheres of exoplanets or exomoons assuming their atmospheres to be Earth-like,” the authors write.

The first factor is stellar density. The more stars in a neighbourhood, the greater the likelihood of supernova explosions and stellar flybys.

“The astrophysical impacts of the stellar environment is a “low-probability, high-consequence” scenario
for the continuation of habitability of exoplanets,” the authors write. Though disruptive events like supernova explosions or close stellar flybys are unlikely, the consequences can be so severe that habitability is completely eliminated.

When it came to the supernova threat, the researchers looked at high-mass stars in stellar neighbourhoods since only massive stars explode. Pyne and her colleagues found high-mass stars with more than eight solar masses in the 10-parsec neighbourhoods of two HZS: TOI-1227 and HD 48265. “These high-mass stars are potential progenitors for supernova explosions,” the authors explain.

Only one of the HZS is at risk of a stellar flyby. HD 165155 has an encounter rate of ?1 in 5 Gyr period. That means it’s at greater risk of an encounter with another star that could eject planets from its habitable zone.

The team’s pair of indices, the SSI and the NSI, produced divergent results. “… we find that the stellar environments of the majority of HZS exhibit a high degree of similarity (NSI> 0.75) to the solar neighbourhood,” they explain. However, because of the wide variety of stars in HZS, comparing them to the Sun results in a wide range of SSI values.

We know the danger supernova explosions pose to habitability. The initial burst of radiation could kill anything on the surface of a planet too close. The ongoing radiation could strip away the atmospheres of some planets further away and could also cause DNA damage in any lifeforms exposed to it. For planets that are further away from the blast, the supernova could alter their climate and trigger extinctions. There’s no absolutely certain understanding of how far away a planet needs to avoid devastation, but many scientists say that within 50 light-years, a planet is probably toast.

We can see the results of some of the stellar flybys the authors are considering. Rogue planets, or free-floating planets (FPPs), are likely in their hapless situations precisely because a stellar interloper got too close to their HZS and disrupted the gravitational relationships between the planets and their stars. We don’t know how many of these FPPs are in the Milky Way, but there could be many billions of them. Future telescopes like the Nancy Grace Roman Space Telescope will help us understand how many there truly are.

An artist’s illustration of a rogue planet, dark and mysterious. Image Credit: NASA

Habitability may be fleeting, and our planet may be the exception. It’s possible that life appears on many planets in habitable zones but can’t last long due to various factors. From a great distance away, we can’t detect all the variables that go into exoplanet habitability.

However, we can gain an understanding of the stellar environments in which potentially habitable exoplanets exist, and this research shows us how.

The post Habitable Worlds are Found in Safe Places appeared first on Universe Today.

Categories: Science

New Glenn Booster Moves to Launch Complex 36

Universe Today Feed - Tue, 11/05/2024 - 11:21am

Nine years ago, Blue Origin revealed the plans for their New Glenn rocket, a heavy-lift vehicle with a reusable first stage that would compete with SpaceX for orbital flights. Since that time, SpaceX has launched hundreds of rockets, while Blue Origin has been working mostly in secret on New Glenn. Last week, the company rolled out the first prototype of the first-stage booster to the launch complex at Cape Canaveral Space Force Station. If all goes well, we could see a late November test on the launch pad.

The test will be an integrated launch vehicle hot-fire which will include the second stage and a stacked payload.

Images posted on social media by Blue Origin CEO Dave Limp showed the 57-meter (188-foot)-long first stage with its seven BE-4 engines as it was transported from the production facility in Merritt Island, Florida — next to the Kennedy Space Center — to Launch Complex 36 at Cape Canaveral. Limp said that it was a 23-mile, multiple-hour journey “because we have to take the long way around.” The booster was carried by Blue Origin’s trailers called GERT (Giant Enormous Rocket Truck).

#NewGlenn’s GS1 is on the move! Our transporter comprises two trailers connected by cradles and a strongback assembly designed in-house. There are 22 axles and 176 tires on this transport vehicle. It’s towed by an Oshkosh M1070, a repurposed U.S. Army tank transporter, with 505… pic.twitter.com/4Qq7Ofq2g2

— Dave Limp (@davill) October 30, 2024

“Our transporter comprises two trailers connected by cradles and a strongback assembly designed in-house,” said Limp on X. “There are 22 axles and 176 tires on this transport vehicle…The distance between GERT’s front bumper and the trailer’s rear is 310’, about the length of a football field.”

Limp said the next step is to put the first and second stages together on the launch pad for the fully integrated hot fire dress rehearsal. The second stage recently completed its own hot fire at the launch site.

An overhead view of the New Glenn booster heading to launch complex 36 at Cape Canaveral during the night of Oct. 30, 2024. Credit: Blue Origin/Dave Limp.

Hopefully the test will lead to Blue Origin’s first ever launch to orbit. While the New Glenn rocket has had its share of delays, it seems Blue Origin has also taken a slow, measured approach to prepare for its first launch. In February of this year, a boilerplate of the rocket was finally rolled onto the launch pad at Cape Canaveral for testing.  Then in May 2024, New Glenn was rolled out again for additional testing. Now, the fully integrated test in the next few weeks will perhaps lead to a launch by the end of the year.

New Glenn’s seven engines will give it more than 3.8 million pounds of thrust on liftoff. The goal is for New Glenn to reuse its first-stage booster and the seven engines powering it, with recovery on a barge located downrange off the coast of Florida in the Atlantic Ocean.

New Glenn boosters are designed for 25 flights.

Blue Origin says New Glenn will launch payloads into high-energy orbits. It can carry more than 13 metric tons to geostationary transfer orbit (GTO) and 45 metric tons to low Earth orbit (LEO).

For the first flight, Blue Origin will be flying its own hardware as a payload, a satellite deployment technology called Blue Ring. Even though it doesn’t have a paying customer for the upcoming launch, it would be — if successful — the first of two required certification flights needed by the rocket by the U.S. Space Force so it could potentially be awarded future national security missions along with side SpaceX and United Launch Alliance (ULA.)

Additional details can be found at PhysOrg and NASASpaceflight.com.

The post New Glenn Booster Moves to Launch Complex 36 appeared first on Universe Today.

Categories: Science

Where to watch the election

Why Evolution is True Feed - Tue, 11/05/2024 - 10:49am

If you don’t want to be glued to the tube, I’ve learned from Luana of a good site to see the election returns in real time—that is, if you’re a fanatic about these things. It’s called 270towin, and shows a map giving votes in the states as they come in, and, at the same time, the latest Electoral College vote. For example, here’s what I see right now, a dead heat.

The color palette to the right tells you which states are considered safe, up for grabs, or (in tan) tossups when you click on them in real time.

When the count reaches 270, we have a winner. You can toggle back and forth between “live results” and “forecast”.

Feel free to blow off steam or elation below. It’s going to be a long night, and I have a feeling that the election won’t be settled when I wake up tomorrow.

Categories: Science

AI-powered system detects toxic gases with speed and precision

Computers and Math from Science Daily Feed - Tue, 11/05/2024 - 8:43am
Researchers have developed an AI-powered system that mimics the human sense of smell to detect and track toxic gases in real time. Using advanced artificial neural networks combined with a network of sensors, the system quickly identifies the source of harmful gases like nitrogen dioxide that poses severe respiratory health risks.
Categories: Science

AI-powered system detects toxic gases with speed and precision

Matter and energy from Science Daily Feed - Tue, 11/05/2024 - 8:43am
Researchers have developed an AI-powered system that mimics the human sense of smell to detect and track toxic gases in real time. Using advanced artificial neural networks combined with a network of sensors, the system quickly identifies the source of harmful gases like nitrogen dioxide that poses severe respiratory health risks.
Categories: Science

Bio-based fibers could pose greater threat to the environment than conventional plastics

Matter and energy from Science Daily Feed - Tue, 11/05/2024 - 8:43am
New research has shown that bio-based fibers caused higher mortality, and reduced growth and reproductivity, among earthworms -- a species critical to the health of soils globally -- than conventional plastics. It has led scientists to suggest that materials being advocated as alternatives to plastic should be tested thoroughly before they are used extensively in a range of products.
Categories: Science

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