Latest news with #ChrisImpey
Yahoo
3 days ago
- General
- Yahoo
In space, no one can hear you scream — But it still gets incredibly noisy
You've probably heard astronauts talking to mission control while they perform operations in space. In these recordings, you can hear the back-and-forth chatter, along with the astronaut's breathing and the background noise of their spacesuit pumping oxygen into their helmet to keep them alive. Yet, if they removed that helmet and broke the barrier of the suit shielding them from outer space, that conversation would be cut — and all sound would go radio silent. As astrophysicist Neil DeGrasse Tyson once explained on the podcast StarTalk, astronauts would be able to hear things from within the body itself — like their own heartbeat. 'The sound of silence is the sound of things that were always making noise that you never noticed before,' he said on the podcast. Sound waves are a vibration carried through some sort of medium, like air or water or in the case of the heartbeat, the body. When those vibrations reach our ears, they send a vibration through our eardrums, which is recognized in the brain as sound. Because sound needs something to travel through, it can't make its way through the vast majority of space, which is a vacuum containing essentially no particles. Interplanetary space contains just a few dozen particles in each cubic centimeter — in comparison, the air we breathe has tens of quintillions of molecules per cubic centimeter. (For scale, 10 quintillion seconds is longer than the age of the universe.) 'In the universe, an absolute vacuum is rare, and most of the universe is very low-density high-temperature plasma,' said Chris Impey, an astronomer at the University of Arizona. 'In principle, sound could travel through that, but it would have very different properties to what we are used to.' Gas clouds, dust clouds and solar winds for example, could all have sound waves pass through them, even if they are relatively low-density, said Phil Plait, an astronomer who runs The Bad Astronomy blog. The structures of many gas clouds, for example, can be formed by sound waves, or shock waves in the case that the material moves faster than the speed of sound, he explained. 'We see the effects of sound in these objects all the time,' Plait told Salon in an email. This would be nothing like the sound we are used to on Earth and wouldn't be detectable by the human ear, which can only hear a very narrow range of frequencies. You may remember the black hole in the Perseus galaxy cluster about 250 million light-years away, from which NASA detected emanating pressure waves in 2003. Although this was not a sound recording like you would hear from a microphone, NASA did convert these pressure waves into sound, albeit one that is far too low of a frequency for the human ear to detect. For what it's worth, though, they did find that the waves corresponded to the note of B-flat, about 57 octaves below the middle C note on a piano. Then, in 2022, NASA's Chandra X-ray Observatory sonified this wave data into a couple of sounds the human ear could hear at frequencies 144 quadrillion and 288 quadrillion times higher than the original. (To get a sense of just how astronomical this figure is, one study estimated that there are 20 quadrillion total ants on Earth.)"What's going on is that matter is surrounding the black hole, and when some stuff falls in it can create a powerful wind that compresses the material around it, making a sound wave,' Plait said. 'We don't detect the sound itself, but we can see the ripples in the gas and they can be converted into sound we hear.' There are entire projects dedicated to sonifying data from astronomical objects. In the Cassini mission, for example, NASA detected radio waves emitted from charged particles in magnetic fields, which were converted to sound. Still, these were plasma waves, and not sound waves. However, sound has been detected within our own solar system. During NASA's Perseverance mission on Mars in 2021, the rover's microphones detected the whir of the mission's helicopter and noises created by the rover. It also detected naturally occurring sounds on the planet itself — including Martian wind. Back in 1981, Russia also reported sounds on Venus during the Soviet Venera 13 mission, which sounds like waves hissing on a beach. Yet sounds on other planets sound different than they do on Earth because other planets have different atmospheres. On Earth, the unique combination of oxygen, nitrogen and other gases, combined with the effects of gravity and solar heating, create a certain density of molecules that carries sound as we know it. In contrast, the atmosphere on Mars is roughly 2% as dense as Earth's, and its composition is dominated by carbon dioxide. Overall, sounds would be quieter and slightly muffled, and it would also take longer to reach you than it would on Earth. Some higher pitched sounds would be inaudible entirely. Interestingly, if you played a church organ on Mars, the set of flue pipes that create sound in a way similar to a flute would go up in pitch, but the reed pipes, which produce sound in a way similar to a saxophone, would go down in pitch, said Tim Leighton, an acoustics professor at University of Southampton, who created models to predict sound on other planets. Saturn's moon, Titan, is probably acoustically the closest to Earth. However, the pressure and density are a bit higher at ground level, and the speed at which sound travels through the atmosphere is lower than Earth. As a result, many sounds such as voices, flutes and organ pipes would play at a lower pitch, Leighton said. On Venus, sounds that are caused by solid objects vibrating, like harmonicas or reed organ pipes, would be pitched down because the atmosphere is dense and soupy. However, sounds from things like flue organ pipes or flutes, which are propagated through air, would be pitched higher than Earth. That's because the extremely hot temperatures on Venus make sound travel faster than on Earth. Additionally, if we theoretically heard a sound like a vocalization on Venus, our perception of the size of the creature it was coming from would be a little distorted. That's because humans evolutionarily developed a way of hearing vocalizations in which sound travels to the top of the nose of the speaker and back again in a form of echo, which we subconsciously use to estimate how large a creature is based on the tone they emit, Leighton said. On Venus, "this pulse quickly travels up to the top of the nose and back again much sooner than it would on Earth,' Leighton told Salon in a video call. 'Your brain hears that and imagines the person is about three feet tall.' As we continue exploring more distant planets, recording sound could help scientists better understand them. For example, measuring the sounds of wind on Mars could provide clues on how the planet's surface forms, Leighton explained. 'It can tell us a lot about the atmosphere and how it changes as the sun goes up and down, and how that, in turn generates winds to shape the surface of Mars,' Leighton said. 'That indicates the power of these microphones.' Sound could also help us explore planets like Jupiter and Saturn, which likely have plenty of sound to hear but have thick clouds and inhospitable conditions that make it difficult to access visually, Impey said. 'In fact, since the atmosphere is sort of opaque and you can't really see through it, it might be a way to sense what's happening better and more efficiently than you could with any sort of a camera, which wouldn't really work very well at all,' he told Salon in a phone interview. When looking for sound in the universe, astronomers have also looked back in time. Back in the early years of the universe, it was a hot plasma soup that was far more dense. That plasma carried acoustic oscillations, although still not at an audible range. However, in one research project, astronomer Mark Whittle compressed the first million years of the universe into 10 seconds, shifted up by 50 octaves so that the human ear could hear. It sounds like "a descending scream, a deep roar and a final growing hiss," he reported. About 400,000 years after the Big Bang, sound waves called Baryon acoustic oscillations rippled through the cosmos to influence how galaxies were distributed. As such, one could say that life on Earth as we know it in some way originated from a sound wave. It's not called the Big Bang for nothing, after all. 'Within that sea of brilliance, the seeds for all that we now know were already present, latent, waiting to unfold,' Whittle wrote in his report. 'Most remarkable of all, perhaps, these seeds were sounds – pressure waves coursing through the fluid.'
New York Post
11-05-2025
- Science
- New York Post
Astronomers detect ‘most promising signs yet' of life on other planets with shocking new discovery
Life. But how would we know it? The world of astronomy is abuzz with excitement. Have we discovered the first-ever evidence of off-world life? Advertisement Is the signal extracted from the interstellar noise a telltale of active biology? 'Astronomers have detected the most promising signs yet of a possible biosignature outside the solar system, although they remain cautious,' states a Cambridge University press release. What has them excited is the planet K2-18b. We only know it exists by the shadow it casts when it passes between its star and the Earth. But that shadow, like a stained-glass window, can tell a story. Advertisement 4 'Astronomers have detected the most promising signs yet of a possible biosignature outside the solar system, although they remain cautious,' states a Cambridge University press release. via REUTERS Across the gulf of space, the James Webb Space Telescope has managed to capture its light spectrum and atmospheric gases like methane, carbon dioxide, oxygen, and dimethyl sulphide also cast shadows when light strikes them. The challenge for astronomy is to catch enough of this distant light to dissect reliably and to interpret that data accurately. The Cambridge University astronomers have attempted to do just that. Scientists the world over have since been sciencing their results. Advertisement How was the data collected? What data was collected? How was it analysed? Does it support the conclusion? 'While this discovery is intriguing, most astronomers – including the paper's authors – aren't ready to claim that it means extraterrestrial life exists,' says University of Arizona distinguished professor of astronomy Chris Impey. There simply isn't enough data. Yet. Advertisement 'Searching for life beyond Earth is one of the great, profound pursuits of humankind. But any claim of life out there will require a thorough study by the scientific community as a whole before we have confidence in the results,' adds The Planetary Society's chief scientist, Dr Bruce Betts. In a post-truth world, that confidence is more important than ever. 'Just like the boy that cried wolf, no one wants a series of false claims to further diminish society's trust in scientists,' Johns Hopkins University astrophysicist Kevin Stevenson argues. 'Context is important when it comes to science communication, particularly for a hot-button topic like the search for life beyond Earth, and we need to be responsible stewards in that respect.' 4 We only know K2-18 b exists by the shadow it casts when it passes between its star and the Earth. But that shadow, like a stained-glass window, can tell a story. Cambridge University Brave new worlds 'It is in no one's interest to claim prematurely that we have detected life,' Professor Nikku Madhusudhan, a University of Cambridge astronomer and lead author of the study, told media. But he still called his study a 'revolutionary moment'. Advertisement 'It's the first time humanity has seen potential biosignatures on a habitable planet,' the professor explained. He added that the discovery was 'as big as it gets' for scientists. We don't know much about K2-18b. But we've guessed a lot. Advertisement It was found in 2015 by the Kepler Space Telescope. It has a radius about 2.4 times larger than that of Earth. Its year is just 32.9 days and it orbits within the habitable 'Goldilocks' Zone (warm enough for liquid water) of a cool red dwarf star about 120 light-years away in the direction of the constellation of Leo. University of Cambridge astronomers believe it may have a thin hydrogen atmosphere over an oceanic surface. Thus the term 'Hycean' (hydrogen-ocean) world. But the opposite could also fit the limited known facts: K2-18b could have a thick atmosphere over a magma sea. Advertisement One way to find out is to determine what that atmosphere is made o. That involves extracting a reliable spectrum from a shadow flickering within a pinprick of starlight. The cause of all the excitement is what the Cambridge University researchers believe is the presence of dimethyl sulphide. This molecule is only found on Earth as the by-product of plankton and bacterial life in our oceans. And that makes it a contender for the position of 'biomarker' – a chemical 'smoking gun' to the presence of life on other worlds. 4 The cause of all the excitement is what the Cambridge University researchers believe is the presence of dimethyl sulphide. Cambridge University Advertisement But has dimethyl sulphide really been found on K2-18b? 'Every detector has some noise from the random motion of electrons,' Professor Impey explained. 'The signal should be strong enough to have a low probability of arising by chance from this noise.' The planet was first photographed by the Hubble Space Telescope in 2016. Astrobiologists thought they saw indications of water vapor. Upon revision, this later turned out to be methane. The first look with the more powerful JWST was made by Professor Madhusudhan's team about two years ago. Analyzing a different set of wavelengths than the most recent study, this initially seemed to show the presence of methane and carbon dioxide – and a hint of dimethyl sulphide. But the raw data they drew their conclusions from has since been re-examined by different scientists using different methods. They have not confirmed the presence of CO2 or dimethyl sulphide. The data from the most recent survey was released for general review on April 28. Does this raw data show what the Cambridge University researchers believe it does? To be science, independent scientists must be able to draw the same conclusions using various methods, and the premise has to be proven correct. Otherworldly chemistry 'We didn't know for sure whether the signal we saw last time was due to DMS (dimethyl sulphide), but just the hint of it was exciting enough for us to have another look with JWST using a different instrument,' Professor Madhusudhan explained. 4 To be science, independent scientists must be able to draw the same conclusions using various methods, and the premise has to be proven correct. phonlamaiphoto – It's the second time the Cambridge University team has found the molecule. 'This is an independent line of evidence, using a different instrument than we did before and a different wavelength range of light, where there is no overlap with the previous observations. The signal came through strong and clear.' But K2-18b isn't Earth. Evidence has begun to emerge that dimethyl sulphide can be produced by non-biological means. Its signature spectrum has been spotted in the clouds of dust and gas that drift between stars. It may have been seen on an uninhabitable comet. Laboratory studies hint that it could be broken out of other molecules under UV light. Professor Madhusudhan concedes there could be previously unknown chemical processes at play. He and his team remain confident in the strength of their findings. 'Decades from now, we may look back at this point in time and recognise it was when the living universe came within reach,' Professor Madhusudhan said. 'This could be the tipping point, where suddenly the fundamental question of whether we're alone in the universe is one we're capable of answering.' But, given the rarity of dimethyl sulphide, the Oxford University measurements have raised eyebrows. Especially as they indicate K2-18 b's atmosphere is awash with it in concentrations thousands of times greater than Earth's. Start and end your day informed with our newsletters Morning Report and Evening Update: Your source for today's top stories Thanks for signing up! Enter your email address Please provide a valid email address. By clicking above you agree to the Terms of Use and Privacy Policy. Never miss a story. Check out more newsletters 'The claim is intriguing, as these gases can be associated with biological activity,' a statement released by the Search for Extraterrestrial Intelligence (SETI) reads. 'On the other hand, the signal is modest, ambiguous, and potentially explainable as the result of noise or systematic error.' But, like all research, this study is just one step in a winding journey, filled with obstacles and dead-ends. 'This study is not a confirmation of life; not even a hypothesis that life is present on K2-18b, but a demonstration of where our methodological strengths and limitations lie, and what must come next to an unambiguous claim of life beyond Earth,' the SETI statement concludes. In science's famous last words: More research is needed. 'It'll take time to figure all this out,' adds The Planetary Society. Different teams will do their own investigations, collect more data, learn more about how DMS might be produced, and better understand how it might show up in a planet's atmosphere. Only then will we have a chance at the full story.
News.com.au
11-05-2025
- Science
- News.com.au
New claim of ‘alien' life leaves space world in a bind
Life. But how would we know it? The world of astronomy is abuzz with excitement. Have we discovered the first-ever evidence of off-world life? Is the signal extracted from the interstellar noise a telltale of active biology? 'Astronomers have detected the most promising signs yet of a possible biosignature outside the solar system, although they remain cautious,' states a Cambridge University press release. What has them excited is the planet K2-18b. We only know it exists by the shadow it casts when it passes between its star and the Earth. But that shadow, like a stained-glass window, can tell a story. Across the gulf of space, the James Webb Space Telescope has managed to capture its light spectrum and atmospheric gases like methane, carbon dioxide, oxygen, and dimethyl sulphide also cast shadows when light strikes them. The challenge for astronomy is to catch enough of this distant light to dissect reliably and to interpret that data accurately. The Cambridge University astronomers have attempted to do just that. Scientists the world over have since been sciencing their results. How was the data collected? What data was collected? How was it analysed? Does it support the conclusion? 'While this discovery is intriguing, most astronomers – including the paper's authors – aren't ready to claim that it means extraterrestrial life exists,' says University of Arizona distinguished professor of astronomy Chris Impey. There simply isn't enough data. Yet. 'Searching for life beyond Earth is one of the great, profound pursuits of humankind. But any claim of life out there will require a thorough study by the scientific community as a whole before we have confidence in the results,' adds The Planetary Society 's chief scientist, Dr Bruce Betts. In a post-truth world, that confidence is more important than ever. 'Just like the boy that cried wolf, no one wants a series of false claims to further diminish society's trust in scientists,' Johns Hopkins University astrophysicist Kevin Stevenson argues. 'Context is important when it comes to science communication, particularly for a hot-button topic like the search for life beyond Earth, and we need to be responsible stewards in that respect.' Brave new worlds 'It is in no one's interest to claim prematurely that we have detected life,' Professor Nikku Madhusudhan, a University of Cambridge astronomer and lead author of the study, told media. But he still called his study a 'revolutionary moment'. 'It's the first time humanity has seen potential biosignatures on a habitable planet,' the professor explained. He added that the discovery was 'as big as it gets' for scientists. We don't know much about K2-18b. But we've guessed a lot. It was found in 2015 by the Kepler Space Telescope. It has a radius about 2.4 times larger than that of Earth. Its year is just 32.9 days and it orbits within the habitable 'Goldilocks' Zone (warm enough for liquid water) of a cool red dwarf star about 120 light-years away in the direction of the constellation of Leo. University of Cambridge astronomers believe it may have a thin hydrogen atmosphere over an oceanic surface. Thus the term 'Hycean' (hydrogen-ocean) world. But the opposite could also fit the limited known facts: K2-18b could have a thick atmosphere over a magma sea. One way to find out is to determine what that atmosphere is made o. That involves extracting a reliable spectrum from a shadow flickering within a pinprick of starlight. The cause of all the excitement is what the Cambridge University researchers believe is the presence of dimethyl sulphide. This molecule is only found on Earth as the by-product of plankton and bacterial life in our oceans. And that makes it a contender for the position of 'biomarker' – a chemical 'smoking gun' to the presence of life on other worlds. But has dimethyl sulphide really been found on K2-18b? 'Every detector has some noise from the random motion of electrons,' Professor Impey explained. 'The signal should be strong enough to have a low probability of arising by chance from this noise.' The planet was first photographed by the Hubble Space Telescope in 2016. Astrobiologists thought they saw indications of water vapour. Upon revision, this later turned out to be methane. The first look with the more powerful JWST was made by Professor Madhusudhan's team about two years ago. Analysing a different set of wavelengths than the most recent study, this initially seemed to show the presence of methane and carbon dioxide – and a hint of dimethyl sulphide. But the raw data they drew their conclusions from has since been re-examined by different scientists using different methods. They have not confirmed the presence of CO2 or dimethyl sulphide. The data from the most recent survey was released for general review on April 28. Does this raw data show what the Cambridge University researchers believe it does? To be science, independent scientists must be able to draw the same conclusions using various methods, and the premise has to be proven correct. Otherworldly chemistry 'We didn't know for sure whether the signal we saw last time was due to DMS (dimethyl sulphide), but just the hint of it was exciting enough for us to have another look with JWST using a different instrument,' Professor Madhusudhan explained. It's the second time the Cambridge University team has found the molecule. 'This is an independent line of evidence, using a different instrument than we did before and a different wavelength range of light, where there is no overlap with the previous observations. The signal came through strong and clear.' But K2-18b isn't Earth. Evidence has begun to emerge that dimethyl sulphide can be produced by non-biological means. Its signature spectrum has been spotted in the clouds of dust and gas that drift between stars. It may have been seen on an uninhabitable comet. Laboratory studies hint that it could be broken out of other molecules under UV light. Professor Madhusudhan concedes there could be previously unknown chemical processes at play. He and his team remain confident in the strength of their findings. 'Decades from now, we may look back at this point in time and recognise it was when the living universe came within reach,' Professor Madhusudhan said. 'This could be the tipping point, where suddenly the fundamental question of whether we're alone in the universe is one we're capable of answering.' But, given the rarity of dimethyl sulphide, the Oxford University measurements have raised eyebrows. Especially as they indicate K2-18 b's atmosphere is awash with it in concentrations thousands of times greater than Earth's. 'The claim is intriguing, as these gases can be associated with biological activity,' a statement released by the Search for Extraterrestrial Intelligence (SETI) reads. 'On the other hand, the signal is modest, ambiguous, and potentially explainable as the result of noise or systematic error.' But, like all research, this study is just one step in a winding journey, filled with obstacles and dead-ends. 'This study is not a confirmation of life; not even a hypothesis that life is present on K2-18b, but a demonstration of where our methodological strengths and limitations lie, and what must come next to an unambiguous claim of life beyond Earth,' the SETI statement concludes. In science's famous last words: More research is needed. 'It'll take time to figure all this out,' adds The Planetary Society. Different teams will do their own investigations, collect more data, learn more about how DMS might be produced, and better understand how it might show up in a planet's atmosphere. Only then will we have a chance at the full story.
Axios
31-03-2025
- Politics
- Axios
American progress in peril
The U.S. is freezing research funding, canceling projects, firing thousands of federal scientists and creating an atmosphere of uncertainty that scientists warn could slam the brakes on progress. Why it matters: America has enjoyed decades of dominance in science and technology — plus the economic boom, medical advancements and global influence that come with it. Now, as the U.S.'s global lead is contested and competition for the world's top talent gets stiffer, the Trump administration is disrupting the system that has propelled the country. "There are some immediate effects. People will be laid off, talent will go elsewhere, some research groups will shut down," says Chris Impey, an astronomer at the University of Arizona. "But over the years it will have a profoundly negative impact. You're creating an opportunity for other countries to happily start moving in, poaching our talent and riding the escalator of scientific progress." Stunning stat: 40% of U.S.-affiliated Nobel Prize winners in the sciences — physics, chemistry and medicine — between 2000 and 2023 were immigrants. Funding resources, top-notch universities, research freedom and a diverse culture that supports innovation are among the factors that have made the U.S. a global magnet for scientists. Zoom in: Some of those factors are in flux. For example, in 2022, the NIH spent 25 times more on grants for health research than the next largest funder, a U.K. charity, according to Nature. But NIH funding has dropped by more than $3 billion since Inauguration Day, compared to the same period last year, as the Trump administration cancels research programs and halts funding, the Washington Post reports. Some universities are accepting fewer graduate students amid funding uncertainty, and some professors are performing their own risk calculus to be sure they can support students. Changes at the Department of Health and Human Services, including the centralization of peer review for grants funded by the National Institutes of Health, are raising concerns about political interference in federal science-funding decisions. The stakes: The U.S. could see a two-fold brain drain: fewer foreign scientists coming to America, and American talent heading to other countries. Three-quarters of the 1,600 scientists surveyed in a new poll from Nature said they are considering leaving the U.S. due to the disruptions to science caused by the Trump administration's early actions. "The developments in the U.S. are a huge opportunity for Germany and Europe. I know that a lot of people are considering leaving." Ulrike Malmendier, a German economist who is a professor at the University of California, Berkeley, told Germany's Funke media group. France's Aix Marseille University has earmarked millions of dollars to hire U.S. scientists. Université Paris Sciences et Lettres wants to recruit U.S. researchers who work in projects in areas targeted for cuts by the Trump administration, including climate science and gender studies, the N.Y. Times reports. The upheaval has also been an opportunity for China and Russia: Both are allegedly trying to recruit former federal scientists. The other side: White House and DOGE officials argue changes to the system will boost research, not stifle it. For example, they say funding switch-ups, like cutting the dollars NIH provides institutions for overhead costs, will free up more funds for science. But universities say these administrative costs are a critical piece of conducting research. "The Trump Administration is committed to achieving and maintaining unquestioned and unchallenged global technological dominance," a White House official said. "We need fresh approaches to redefine how discovery happens in America to ensure our ecosystem draws talent, celebrates merit, and enables our scientists to focus on meaningful work." The big picture: Years before the funding freezes and firings, there were indications the U.S. lead in science was shrinking — while China was advancing in AI, biotech, space and other fields. The U.S. share of global R&D spending decreased while total spending grew. The number of international patents filed from inventors in China surpassed applications from the U.S. in 2021. In 2019, China for the first time awarded more doctorate degrees in science and engineering than the U.S. What to watch: Scientists, CEOs, university leaders and policymakers earlier this year called for updating the U.S. scientific enterprise to compete in the 21st century. Recommendations from that group and others include immigration reform, changes in tax credit and code that could spur private sector R&D, reducing the administrative burden on scientists, and increased investment in AI, biotech and other fields. President Trump has also tasked the newly confirmed head of the White House's Office of Science and Technology Policy, Michael Kratsios, with revitalizing America's science and technology enterprise, referring to a similar task FDR gave to his science advisor Vannevar Bush.
