Tuesday, April 23, 2024

Quote of the Day April 23, 2024

“We shall never know all the good that a simple smile can do.”
Saint Teresa

“हम कभी नहीं जान पाएंगे कि एक छोटी सी मुस्कान कितना भला कर सकती है।”
संत तरेसा

What is Hubble Tension?

Scientists from Germany and the U.K. have proposed a radical explanation for the discrepancy in measurements of the universe’s expansion rate, known as the Hubble tension. The Hubble Constant, denoted as H0, is a fundamental parameter in cosmology that describes the current expansion rate of the Universe. It is named after the renowned astronomer Edwin Hubble, who first observed the relationship between a galaxy’s distance and its apparent velocity. The Hubble Constant is expressed in units of kilometers per second per megaparsec (km/s/Mpc), which represents the speed at which galaxies move away from each other over a given distance.

The Emergence of Hubble Tension

The Hubble Tension arises from the fact that different methods of measuring the Hubble Constant have yielded inconsistent results. This implies that two equally valid ways to measure how fast the universe is expanding have yielded two different estimates. The two primary approaches used to determine H0 are:

The Cosmic Microwave Background (CMB) method: This approach relies on observations of the oldest light in the Universe, the CMB radiation, and uses the standard cosmological model to infer the value of H0.
The cosmic distance ladder method: This technique involves measuring distances to nearby galaxies using various astronomical objects, such as Cepheid variable stars and Type Ia supernovae, and then using these distances to calculate H0.

The problem lies in the fact that these two methods have produced significantly different values for the Hubble Constant, with the CMB method yielding a value of around 67 km/s/Mpc, while the cosmic distance ladder method suggests a higher value of approximately 74 km/s/Mpc.

Implications and Possible Explanations

The discrepancy between the two measurements of the Hubble Constant has far-reaching implications for our understanding of the Universe. If the tension persists, it could indicate that our current cosmological models are incomplete or that there are unknown physical phenomena at play. Some possible explanations for the Hubble Tension include:

Systematic errors: There might be unaccounted-for systematic errors in one or both of the measurement methods, leading to the discrepancy.
New physics: The Hubble Tension could hint at the existence of new physical processes or particles that are not accounted for in the standard cosmological model, such as dark energy or neutrinos with unexpected properties.
Modified gravity: Some scientists propose that the tension could be resolved by modifying Einstein’s theory of general relativity, which underpins our understanding of gravity and the Universe’s expansion.

Ongoing Efforts and Future Prospects

Resolving the Hubble Tension is a top priority for cosmologists worldwide. Numerous research teams are working on refining the measurement techniques, searching for potential sources of error, and exploring alternative theoretical models. Modern astronomical facilities, such as the James Webb Space Telescope and the Vera C. Rubin Observatory, are expected to provide more precise data that could help shed light on this cosmic puzzle.

Recent Studies and Current Status

A study published in Monthly Notices of The Royal Astronomical Society (MNRAS), where scientists suggest that the current model used to understand the Universe, called Λ cold dark matter (ΛCDM), might be wrong and could be the reason behind the Hubble Tension. However, this is presented as a radical explanation and not a definitive solution.

Space Debris Threat to Earth’s Defenses

As the number of satellites in Earth’s orbit continues to grow at an unprecedented rate, experts are raising concerns about the potential impact of space debris on the planet’s magnetic field and atmosphere.

The Growing Problem of Space Debris

Current estimates suggest that there are nearly 10,000 active satellites in orbit, with companies working to deploy tens of thousands more in the coming decades.
Jonathan McDowell from the Harvard-Smithsonian Center for Astrophysics projects that the number of satellites could reach 100,000 within the next 10 to 15 years.
The rapid increase in satellite launches is resulting in a significant amount of space debris, including defunct rockets and satellites that are no longer operational.

Potential Impact on Earth’s Magnetic Field and Ionosphere

The influx of metallic debris from defunct rockets and satellites could disrupt the ionosphere and magnetosphere, which are essential systems that protect Earth’s atmosphere and sustain life on the planet.
The ionosphere, located roughly 48 to 965 kilometers above the Earth’s surface, is a region where atoms and molecules become ionized by solar radiation, creating a layer of charged particles that reflects radio waves and enables long-distance communication.
The ionosphere also helps protect life on Earth by absorbing harmful ultraviolet radiation from the Sun.
The magnetosphere is a plasma cocoon that surrounds the Earth, interacting with the solar wind and cosmic radiation to create a shield against harmful particles and radiation from space.

The Scale of the Problem

Current estimates suggest that the amount of metallic ash being dumped into the ionosphere annually is equivalent to multiple Eiffel Towers’ worth of debris.
Unlike meteorites, which are small and contain only trace amounts of aluminum, the wrecked spacecraft are large and consist entirely of aluminum and other highly conductive materials.
The accumulation of conductive materials in the magnetosphere could potentially trap or deflect parts of the Earth’s magnetic field, leading to regional perturbations and holes above the ozone layer.

Lack of Comprehensive Studies

Despite the potential risks posed by space pollution, there is a lack of comprehensive studies on its impact on the magnetosphere and ionosphere.
Plasma physicist Sierra Solter, who has been studying the issue, emphasizes the need for more research to understand the potential consequences of satellite debris on Earth’s plasma environment.

The rapid expansion of satellite constellations, driven by companies competing for dominance in the satellite internet market, is leading to an alarming accumulation of metallic debris that could disrupt the delicate balance of the magnetosphere and ionosphere, which play crucial roles in protecting life on Earth.

Doctors as Humans

A few years ago, I was on a return flight from New Delhi to Paris and New York, when the chief flight attendant suddenly broke up the humming silence and asked passengers to ring the call bell if anyone was a doctor. One physician, a tall and handsome young man, quietly rang the bell and was ushered to the front of the plane where another flight attendant was in physical distress due to a panic attack.

The doctor provided the treatment, and the patient was stabilized. Just a respectful and quiet thank you from the crew at the end of the flight along with a bottle of champagne and a cache of 75,000 frequent flier miles as a token of appreciation! A good doctor in the neighbourhood is a great blessing. “Wherever the art of medicine is loved,” thus spoke Hippocrates, “there is also a love of humanity.” The ancient Greek physician (460–370 BC), regarded as the father of medicine, also gave budding doctors the oath, “First Do No Harm.” But now when healthcare has become a most essential human right, much more is expected from doctors.

Today doctors, with and without borders, are in the killing fields of Ukraine and Gaza risking their lives to save lives. During the Covid-19 pandemic doctors and medical professionals played heroic roles, working endless days and nights, to save as many people as they could from an unprecedented massive global health crisis. Unbeknown to many of us, Artificial Intelligence played a crucial role in the development of Covid vaccines and the logistics of the vaccines global distribution. Early this month, Dr. Saeed Hassapour, Director of the Center for Precision Health and Artificial Intelligence at Dartmouth College, organized a symposium that drew some of the most brilliant AI experts, physicians, and researchers including, among others, Dr. Curtis Langlotz, a Stanford Professor and President of the Radiological Society of North America, known for his work in applying AI in medical imaging, and Dr. Faisal Mahmood, an Associate Professor at Harvard Medical School, credited for his contributions to digital pathology and AI in cancer diagnosis, prognosis, and biomarker discovery.

The interdisciplinary gathering of experts discussed how AI can provide valuable insights from vast amounts of digital health data, leading to more efficient and personalized care. There was a strong emphasis upon the importance of ethical integration of AI tools into healthcare practices and the need for medical professionals to be trained on how to use these technologies responsibly and effectively.

AI algorithms can assist radiologists at every step of the imaging process; for example, providing inputs to help decide which imaging tests to order; enhancing image quality; detecting imaging problems to ensure faulty images are retaken; conducting preliminary assessment; and serving as virtual assistants for reporting observations and following up with patients. The goal is to eliminate human errors. As President Sian Beilock of Dartmouth College pointed out in her opening remarks at the symposium, researchers are developing AI tools to help diagnose colorectal cancer and identify novel biomarkers for breast cancer, offering quicker and more accurate detection to facilitate timely treatment.

Digital mental health technologies, such as web-based and mobile tools, are being developed to transform mental health care. These tools can impact mental health outcomes of users by predicting behaviours, symptoms, and engaging in interventions and therapeutic approaches based on the predicted symptoms. With its capacity to sift through massive amounts of digital health data, AI can detect patterns that are hard for humans to see, thus helping radiologists to detect subtle signs of cancer with greater accuracy and informing which course of treatment is most likely to work for a patient with a certain medical history. That is the wonderful world of IA medicine dawning upon us. But it also raises important and complex questions about security, privacy, biases, ethics, and equity.

And that brings us back to the pivotal role of doctors, and how best to educate them in the age of AI high expectations with its emphasis upon diagnostic efficiencies, superb patient management (for brand reputation and to avoid lawsuits), and humanizing the increasing impersonal healthcare delivery systems. Under their white coats, habitual smiles and calm demeanours, let us not forget doctors are people too with the same human frailties as any of us ~ families under stress, fear and hopes about growing children, divorces, addictions, and most of all the pressure to keep up professionally with Joneses.

Just think about Dr. House in the American television medical drama where Gregory House (Hugh Laurie), a brilliant and unconventional diagnostician but a person with compromised ethics and messed up life, and given to substance abuse, is unable to have steady family or friendly relationships. Although TV dramas entertain us, they do reflect social realities. The case of Dr. House may be emblematic of a larger social problem of the medical community. According to American Addiction Centers, “Few careers have such odd working hours and so many traumatic situations as those in the healthcare industry. The high levels of stress and physical pain that often come with this job open the door for numerous types of addiction,” adding that “approximately 5.5 per cent of medical professionals struggle with illicit drug abuse.”

Equally serious is the problem of the physician burnout despite radical advancement through Artificial Intelligence. In 2022, for example, 71,309 doctors gave up their profession in the USA. Medical schools and hospitals do not talk about it. Perhaps the next Dartmouth Dialogue or Symposium should be about doctors as humans. Along with the integration of Artificial Intelligence with healthcare, the foundation of medical education needs a reset. It should rest firmly on the Humanities, Medical Humanities, as someone suggested in a recent dinner conversation I had with some Dartmouth alumni and friends.

The art and science of medicine, the liberal arts, and the humanities ~ song and dance, musicals, theatre, comedy ~ go together to make a good doctor in the age of Artificial Intelligence. More than anyone else doctors need a good sidesplitting belly-laugh once in a while.

NARAIN BATRA

Source: The Staesman, 22/04/24

(The writer is the author of several books including the most recent India In A New Key: Nehru To Modi. Under the auspices of the Osher Institute at Dartmouth College, he is scheduled to deliver, on Friday 24 May, a public lecture, Superintelligence: Why We Need It. The lecture would be available in YouTube)

Manipur’s Dilemma

Today, as the first votes are cast in India’s general election, the spotlight naturally turns to the bustling political activities across the country.

Today, as the first votes are cast in India’s general election, the spotlight naturally turns to the bustling political activities across the country. Yet, in the remote north-eastern state of Manipur, a contrasting scene unfolds, marked not by fervent public rallies but by a conspicuous silence borne out of fear. Manipur, along with most other north-eastern states, step into the electoral process today alongside Tamil Nadu in the south.

Unlike the rest, though, Manipur carries the weight of on-going strife and the palpable fear of violence. Manipur’s quiet streets during this significant democratic exercise are a tell-tale sign of the deep-seated troubles that have plagued the state. Ethnic tensions between the majority Meitei community and the minority Kuki-Zo tribes have escalated into a violent conflict that the Centre and the BJP-ruled state seems unable to quell. The state, split into two hostile enclaves, is a stark representation of the failure to foster peace and unity. The situation in Manipur is not just a local issue but a test of India’s ability to manage its internal affairs.

The promise of democracy is to provide a voice to all its constituents, yet the people of Manipur feel forgotten, their grievances largely unaddressed. The Centre’s responses, including strategic changes to border policy and security measures, have thus far not mitigated the tensions, and in some cases, may even have exacerbated them. The general elections are a time of hope and change, yet for many in Manipur, the vote casts a shadow rather than light. Despite the despair, there is a reluctant drive among the people to participate in the voting process. This dichotomy underscores a critical aspect of democracy: the right to vote, which is both a privilege and a powerful tool for expressing an opinion. Whether this democratic change will bring about change though remains in question.

The local support for the BJP points to a complex interplay of resigned acceptance and hopeful expectation that the Union government will eventually intervene more constructively. The Congress party’s promises to bridge the community divisions if elected offer an alternative, but whether this can convert into electoral gain or meaningful change is uncertain. Manipur’s electoral significance may seem minor on the national scale with its two seats in the Lok Sabha. Yet, the state’s current turmoil is a significant indicator of the broader challenges facing India’s democracy.

It is a reminder that the strength of a nation’s democratic process is tested not at the height of its peaceful gatherings but in the quiet corners where fear and conflict overshadow the fundamental and democratic act of voting. As India votes, it must not forget Manipur. The true measure of this election’s success will lie in how it addresses the silent challenges unfolding in such neglected regions, ensuring that every part of the country can partake of the democratic promise of peace, security, and prosperity.

Source: The Statesman, 19/04/24

Tuesday, April 09, 2024

Quote of the Day April 9, 2024

“Your imagination is the preview to life's coming attractions.”
Albert Einstein

“आपकी कल्पनाशक्ति आपके जीवन के आने वाले आकर्षणों का पूर्वावलोकन है।”
एल्बर्ट आइन्स्टाइन

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