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Comment by Dr. Krishna Kumari Challa on May 6, 2025 at 11:05am

Technically, it is currently impossible to accelerate rockets to a speed at which this effect could be seen in a photograph. However, physicists found another solution inspired by art: they used extremely short laser pulses and a high-speed camera to recreate the effect in the laboratory.
They moved a cube and a sphere around the lab and used the high-speed camera to record the laser flashes reflected from different points on these objects at different times.
It is easy to combine images of different parts of a landscape into one large image. What has been done here for the first time is to include the time factor: the object is photographed at many different times. Then the areas illuminated by the laser flash at the moment when the light would have been emitted from that point if the speed of light was only 2 m/s are combined into one still image. This makes the Terrell-Penrose effect visible.
They combined the still images into short video clips of the ultra-fast objects. The result was exactly what they expected.
The demonstration of the Terrell-Penrose effect is not only a scientific success—it is also the result of an extraordinary symbiosis between art and science.

Dominik Hornof et al, A snapshot of relativistic motion: visualizing the Terrell-Penrose effect, Communications Physics (2025). DOI: 10.1038/s42005-025-02003-6

Part 2

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Comment by Dr. Krishna Kumari Challa on May 6, 2025 at 11:02am

Special relativity made visible

When an object moves extremely fast—close to the speed of light—certain basic assumptions that we take for granted no longer apply. This is the central consequence of Albert Einstein's special theory of relativity. The object then has a different length than when it is at rest, and time passes differently for the object than it does in the laboratory. All this has been repeatedly confirmed in experiments.

However, one interesting consequence of relativity has not yet been observed—the so-called Terrell-Penrose effect. In 1959, physicists James Terrell and Roger Penrose (Nobel laureate in 2020) independently concluded that fast-moving objects should appear rotated. 

Now, a collaboration study has succeeded for the first time in reproducing the effect using laser pulses and precision cameras—at an effective speed of light of 2 meters per second. The research is published in the journal Communications Physics.

Suppose a rocket whizzes past us at 90% of the speed of light. For us, it no longer has the same length as before it took off, but is 2.3 times shorter. This is the relativistic length contraction, also known as the Lorentz contraction.

However, this contraction cannot be photographed. If you want to take a picture of the rocket as it flew past, you will have to take into account that the light from different points take different lengths of time to reach the camera. 

The light coming from different parts of the object and arriving at the lens or our eye at the same time is not emitted at the same time—and this results in complicated optical effects.

Let's imagine that the super-fast object is a cube. Then the side facing away from us is further away than the side facing towards us. If two photons reach our eye at the same time, one from the front corner of the cube and one from the back corner, the photon from the back corner has traveled further. So it must have been emitted at an earlier time. And at that time, the cube was not at the same position as when the light was emitted from the front corner. This makes it look to us as if the cube has been rotated.

This is a combination of relativistic length contraction and the different travel times of light from different points. Together, this leads to an apparent rotation, as predicted by Terrell and Penrose.

Of course, this is irrelevant in everyday life, even when photographing an extremely fast car. Even the fastest Formula One car will only move a tiny fraction of the distance in the time difference between the light emitted by the side of the car facing away from us and the side facing towards us. But with a rocket traveling close to the speed of light, this effect would be clearly visible.

Part 1

Comment by Dr. Krishna Kumari Challa on May 5, 2025 at 9:33am

Home washing machines fail to remove important pathogens from textiles

Health care workers who wash their uniforms at home may be unknowingly contributing to the spread of antibiotic-resistant infections in hospitals, according to a new study published in PLOS One.

Hospital-acquired infections are a major public health concern, in part because they frequently involve antibiotic-resistant bacteria. Many nurses and health care workers clean their uniforms at home in standard washing machines, but some studies have found that bacteria can be transmitted through clothing, raising the question of whether these machines can sufficiently prevent the spread of dangerous microbes.

In the new study, researchers evaluated whether six models of home washing machine successfully decontaminated health care worker uniforms, by washing contaminated fabric swatches in hot water, using a rapid or normal cycle. Half of the machines did not disinfect the clothing during a rapid cycle, while one-third failed to clean sufficiently during the standard cycle.

The team also sampled biofilms from inside 12 washing machines. DNA sequencing revealed the presence of potentially pathogenic bacteria and antibiotic resistance genes. Investigations also showed that bacteria can develop resistance to domestic detergent, which also increases their resistance to certain antibiotics.

This research shows that domestic washing machines often fail to disinfect textiles, allowing antibiotic-resistant bacteria to survive. If we're serious about the transmission of infectious disease via textiles and tackling antimicrobial resistance, we must rethink how we launder what we wear.  

Caroline Cayrou et al, Domestic laundering of healthcare textiles: Disinfection efficacy and risks of antibiotic resistance transmission, PLOS One (2025). DOI: 10.1371/journal.pone.0321467. journals.plos.org/plosone/arti … journal.pone.0321467

Comment by Dr. Krishna Kumari Challa on May 3, 2025 at 6:59am

In extreme conditions, heat does not flow between materials—it bounces off

A new study published in Nature Communications shows, for the first time, how heat moves—or rather, doesn't—between materials in a high-energy-density plasma state.

The work is expected to provide a better understanding of inertial confinement fusion experiments, which aim to reliably achieve fusion ignition on Earth using lasers. How heat flows between a hot plasma and a material's surface is also important in other technologies, including semiconductor etching and vehicles that fly at hypersonic speeds.

High-energy-density plasmas are produced only at extreme pressures and temperatures. The study shows that interfacial thermal resistance, a phenomenon known to impede heat transfer in less extreme conditions, also prevents heat flow between different materials in a dense, super-hot plasma state.

Researchers focused on how heat moves between metal and plastic heated to extreme temperatures and pressures. 

In their experiment, the tungsten wire was heated to about 180,000 degrees Fahrenheit while its plastic coating remained relatively cool at "only" 20,000 degrees Fahrenheit. Using a series of laser shots with progressively delayed timing, the researchers were able to see if the heat was moving between the tungsten and plastic.

When they looked at the data, they were totally shocked because the heat was not flowing between these materials. It was getting stuck at the interface between the materials. 

The reason was interfacial thermal resistance. The electrons in the hotter material arrive at the interface between the materials carrying thermal energy but then scatter off and move back into the hotter material.

Cameron H. Allen et al, Measurement of interfacial thermal resistance in high-energy-density matter, Nature Communications (2025). DOI: 10.1038/s41467-025-56051-1

https://vimeo.com/1065285809

Comment by Dr. Krishna Kumari Challa on May 3, 2025 at 6:52am

Next, researchers isolated target antibodies from the donor's blood that reacted with neurotoxins found within the snake species tested. One by one, the antibodies were tested in mice envenomated from each species included in the panel. In this way, scientists could systematically build a cocktail comprising a minimum but sufficient number of components to render all the venoms ineffective.

The team formulated a mixture comprising three major components: two antibodies isolated from the donor and a small molecule. The first donor antibody, called LNX-D09, protected mice from a lethal dose of whole venom from six of the snake species present in the panel.

To strengthen the antiserum further, the team added the small molecule varespladib, a known toxin inhibitor, which granted protection against an additional three species. Finally, they added a second antibody isolated from the donor, called SNX-B03, which extended protection across the full panel.

Moreover, their results suggest that the three-part cocktail could be effective against many other, if not most, elapid snakes not tested in this study.

Snake-venom protection by a cocktail of varespladib and broadly neutralizing human antibodies, Cell (2025). DOI: 10.1016/j.cell.2025.03.050. www.cell.com/cell/fulltext/S0092-8674(25)00402-7

Part 2

Comment by Dr. Krishna Kumari Challa on May 3, 2025 at 6:46am

Scientists develop antivenom that neutralizes the neurotoxins of 19 of the world's deadliest snakes

By using antibodies from a human donor with a self-induced hyper-immunity to snake venom, scientists have developed the most broadly effective antivenom to date, which is protective against the likes of the black mamba, king cobra, and tiger snakes in mouse trials. Described in the journal Cell, the antivenom combines protective antibodies and a small molecule inhibitor and opens a path toward a universal antiserum.

How we make antivenom has not changed much over the past century. Typically, it involves immunizing horses or sheep with venom from a single snake species and collecting the antibodies produced. While effective, this process could result in adverse reactions to the non-human antibodies, and treatments tend to be species and region-specific.

While exploring ways to improve this process, scientists stumbled upon someone hyper-immune to the effects of snake neurotoxins. The donor, for a period of nearly 18 years, had undertaken hundreds of bites and self-immunizations with escalating doses from 16 species of very lethal snakes that would normally kill a horse.

After the donor, Tim Friede, agreed to participate in the study, researchers found that by exposing himself to the venom of various snakes over several years, he had generated antibodies that were effective against several snake neurotoxins at once.

What 's exciting about the donor 's his once-in-a-lifetime unique immune history. Not only did he potentially create these broadly neutralizing antibodies, in this case, it could give rise to a broad-spectrum or universal antivenom.

To build the antivenom, the team first created a testing panel with 19 of the World Health Organization's category 1 and 2 deadliest snakes across the elapid family, a group which contains roughly half of all venomous species, including coral snakes, mambas, cobras, taipans, and kraits.

Part 1

Comment by Dr. Krishna Kumari Challa on May 3, 2025 at 6:18am

Breath-hold diving not only limits the body's oxygen supply but also raises divers' blood pressure during a dive, the researchers say. Holding one's breath in other contexts, such as sleep apnea, is associated with pregnancy-related blood pressure disorders, although it's unknown whether diving causes the same effect.

The researchers speculate that if the genetic change helps lower blood pressure, it could be especially vital for the Haenyeo. These women dive throughout pregnancy and must avoid blood pressure conditions such as preeclampsia, which can be fatal.

This is not something that every human or every woman is able to do. It's kind of like they have a superpower, courtesy, their genes and practice.

A second genetic difference is related to pain tolerance—specifically, cold-based pain. Air temperatures off Jeju Island drop to around freezing in the winter, but the Haenyeo don't stop diving. 

The genetic differences that could boost diving ability are found throughout the population of Jeju Island. But much of what makes the Haenyeo women special comes from a lifetime of practice.

Researchers have long known that when anyone dives—trained or untrained, Haenyeo or not—their heart rate reflexively drops to conserve oxygen for longer. For an average untrained person from Jeju Island, heartbeat slows down by about 20 beats per minute over the course of a simulated dive. For Haenyeo with a lifetime of diving experience, heart rate drops by up to twice that.

The researchers hope that their discovery of a genetic difference linked to blood pressure will ultimately advance care for health conditions, like stroke, that are related to high blood pressure.

Genetic and Training Adaptations in the Haenyeo Divers of Jeju, Korea, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.115577. www.cell.com/cell-reports/full … 2211-1247(25)00348-1

Part 2

Comment by Dr. Krishna Kumari Challa on May 3, 2025 at 6:14am

Genetic analysis of all-women extreme divers finds changes linked to blood pressure and cold tolerance

A new analysis of a group of all-women extreme divers off the coast of Korea has uncovered genetic differences that could help them survive the intense physiological stresses of free-diving—and could ultimately lead to better treatments for blood pressure disorders.

The researchers worked with the Haenyeo: women who have spent their whole lives diving in the waters off Jeju Island, 50 miles south of mainland South Korea. They free-dive up to 60 feet below the surface to harvest seaweed, abalone, and other food items from the seafloor, spending hours a day in the water all year round.

For hundreds of years, Haenyeo diving was a staple of Jeju's economy and culture, although the practice is now waning.

They're absolutely extraordinary women, say the researchers. Every day, they head out and get in the water, and that's where they work all day. Surprisingly women over 80 dive off a boat before it even stopped moving.

To figure out if the Haenyeo's diving abilities are aided by differences in genetics, the researchers measured physiological variables related to diving ability, such as blood pressure and heart rate. They then sequenced participants' DNA—and found two changes related to diving physiology that could give the Haenyeo advantages underwater.

Haenyeo divers are more than four times more likely than mainland Koreans to have a genetic change associated with lower blood pressure while diving. The researchers think this difference could keep divers and their unborn children safe when diving during pregnancy.

Part 1

Comment by Dr. Krishna Kumari Challa on May 2, 2025 at 3:02pm

The findings could have far-reaching implications on our understanding of the role of cell division in disease. For example, in the context of cancer cells, this type of "non-round," asymmetric division could generate different cell behaviors known to promote cancer progression through metastasis.

Harnessing this information could also impact regenerative medicine, enabling us to better manufacture the cell types needed to regenerate damaged tissues and organs. Scientists may one day be able to influence the function of daughter cells by simply manipulating their parental cell shape.

Holly E. Lovegrove et al, Interphase cell morphology defines the mode, symmetry, and outcome of mitosis, Science (2025). DOI: 10.1126/science.adu9628. www.science.org/doi/10.1126/science.adu9628

Part 2

Comment by Dr. Krishna Kumari Challa on May 2, 2025 at 3:01pm

Re-writing textbooks: New insights into cell division

Scientists  have changed our understanding of how cells in living organisms divide, which could revise what students are taught at school. In a study published this week in Science, the researchers challenge conventional wisdom taught in schools for over 100 years.

Students are currently taught that during cell division, a parent cell will become spherical before splitting into two daughter cells of equal size and shape. However, the study reveals that cell rounding is not a universal feature of cell division and is not how it often works in the body.

Dividing cells, the researchers show, often don't round up into sphere-like shapes. This lack of rounding breaks the symmetry of division to generate two daughter cells that differ from each other in both size and function, known as asymmetric division.

Asymmetric divisions are an important way that the different types of cells in the body are generated, to make different tissues and organs. Until now, asymmetric cell division has predominantly only been associated with highly specialized cells, known as stem cells.

The scientists found that it is the shape of a parent cell before it even divides that can determine if they will round or not in division and determines how symmetric—or not—its daughter cells will be. Cells that are shorter and wider in shape tend to round up and divide into two cells which are similar to each other. However, cells that are longer and thinner don't round up and divide asymmetrically, so that one daughter is different from the other.

Part 1

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