Two people diagnosed with the same type of cancer may not respond to the same treatment in the same way. A chemotherapy drug that works well for one patient may be less effective for another. This happens partly because tumours differ in their genetic makeup, growth patterns and response to medicines. Understanding these differences is vital for developing cancer research and treatments that work better for individual patients.

By sending miniature models of cancer tumours into space, scientists at Wake Forest Institute for Regenerative Medicines in the United States are exploring an unusual way to explore the problem. They are investigating whether the absence of normal gravity changes how colorectal cancer cells respond to chemotherapy. The project, called Tumor Avatars in Space (TAVIS), uses the International Space Station (ISS) as a laboratory to study how cancer cells behave in microgravity.

The experiment uses organoids, which are small, three-dimensional models of human tissues grown in laboratories. For this project, researchers developed tumour organoids using cancer cells collected from patients with colorectal cancer. These miniature models retain some of the biological features of the original tumours, allowing scientists to study how they respond to medicines.

The researchers will compare how these tumour models respond to chemotherapy in space and on Earth. By studying the differences, they hope to understand whether microgravity changes the way cancer cells react to treatment.

Why Study Cancer Cells in Space?

Gravity influences how cells grow and arrange themselves. On Earth, cells are affected by gravitational forces and the way they settle within their surroundings. In microgravity, these conditions change, allowing cells to form three-dimensional structures in different ways. This makes space an interesting environment for studying how cells behave. Researchers want to know whether changes in these conditions can affect tumour growth, cell activity and responses to cancer drugs.

Cancer tumours are made up of more than just cancer cells. They contain different types of cells that interact with one another and their surroundings. These interactions can influence how a tumour grows and responds to treatment. Studying three-dimensional tumour models can help scientists understand some of these processes better.

In the TAVIS experiment, researchers will examine whether colorectal cancer cells become more sensitive to chemotherapy under microgravity conditions. If they find differences, they will investigate the genetic and cellular changes responsible for them. One area of interest is how cancer cells use energy. This process, known as metabolism, helps cells grow, survive and carry out their functions. Changes in metabolism could influence how effectively chemotherapy destroys cancer cells.

The researchers hope to identify the biological processes behind any changes in treatment response. They will then investigate whether similar effects can be reproduced on Earth, potentially by targeting particular genes or cellular processes.

What are Tumour Organoids?

Organoids are miniature, three-dimensional structures grown in laboratories using stem cells or cells taken from human tissues. Depending on the cells used, scientists can grow models that reproduce certain features of organs such as the intestine, liver, brain and lungs. In cancer research, scientists can use cells collected from a patient’s tumour to grow patient-derived tumour organoids. These models retain some of the characteristics of the original cancer and allow researchers to test how different medicines affect it.

This approach provides more information than experiments using cancer cells grown in a flat layer in laboratory dishes. Since organoids have a three-dimensional structure, they can better represent some of the conditions in which cells grow and interact inside the body.

Researchers are also studying whether patient-derived organoids could help doctors identify treatments that are more likely to work for individual patients. However, this approach still requires further research and is not yet a replacement for established clinical treatment decisions.

Can it Help Cancer Treatment?

The TAVIS project is part of a wider effort to use space-based research to understand human biology and develop medical applications on Earth. After the experiment, researchers will compare the space-grown tumour models with those maintained on Earth. They will examine whether microgravity caused changes in the cancer cells and whether those changes affected their response to chemotherapy.

“If microgravity makes these tumors more responsive, we can look for the genetic changes behind that and try to induce the same changes here on Earth,” said Shay Soker, Ph.D., WFIRM professor and principal investigator of the study. “It’s similar in spirit to immunotherapy, which makes tumors more visible to the immune system. The tumor can run, but it can’t hide.”

If the space-grown models respond differently, scientists will investigate whether the same effects can be produced under normal conditions on Earth. This could help identify new ways to make cancer cells more responsive to existing treatments.

The experiment does not mean that cancer can be treated more effectively in space. Instead, it uses the unusual conditions aboard the ISS to investigate biological changes that are difficult to study in conventional laboratories. By understanding how cancer cells respond to different conditions, researchers hope to gain new insights into tumour behaviour, drug development and the possibility of more personalised cancer treatment.

For a few microseconds after the Big Bang, the universe was filled with an unusual state of matter. At temperatures reaching trillions of degrees, quarks and gluons moved freely in a dense, hot fluid known as quark-gluon plasma. As the universe expanded and cooled, these particles began combining to form protons and neutrons, the building blocks of ordinary matter.

Physicists can recreate this extreme environment today by colliding heavy atomic nuclei at nearly the speed of light inside particle accelerators. The collisions produce tiny droplets of quark-gluon plasma, each lasting only an extraordinarily brief period before breaking apart. Studying what happens inside these droplets is difficult. They are too small and short-lived for scientists to examine directly. Instead, researchers look at how other particles behave as they pass through the plasma. Their movements can reveal details about the fluid’s internal properties.

A study by physicists at the Massachusetts Institute of Technology (MIT) and the University of California, Santa Barbara (UCSB), has developed a new theoretical approach to this problem. Published in Physical Review Letters, the research examines how heavy subatomic particles respond to the forces exerted by a fluid when travelling at speeds close to that of light. The work extends a principle that physicists have relied on for more than a century: Albert Einstein’s explanation of Brownian motion.

The Problem with Einstein’s Explanation

In 1827, botanist Robert Brown noticed that pollen grains suspended in water moved continuously, even when the water appeared undisturbed. The movement was random, with the particles changing direction as though they were being pushed by invisible forces. Einstein explained this phenomenon in a 1905 paper. He showed that the apparently random movement resulted from collisions with the atoms and molecules in the surrounding fluid. These microscopic particles constantly strike a larger suspended particle, producing small, unpredictable changes in its motion.

Two effects determine how the particle moves. The fluid exerts drag, slowing it down, while microscopic collisions keep pushing it in different directions. The relationship between these forces can reveal information about the fluid’s temperature and microscopic composition. Scientists later applied this framework to a range of fluids, including quark-gluon plasma. However, the original theory was developed for particles moving at relatively low speeds. Heavy quarks travelling through an extremely hot plasma can move close to the speed of light, where the familiar relationship between drag and random fluctuations becomes inadequate.

Physicists have been aware of this limitation for about 20 years. MIT graduate researcher Jean Du Plessis and Bruno Scheihing-Hitschfeld of UCSB have now worked out a framework that accounts for the unusual behaviour of particles under these conditions.

When a Particle Receives an Unusually Large Kick

The researchers calculated the forces a heavy quark would experience while travelling through a fluid at relativistic speeds. They began with a simplified model in which the particle moved through a gas of weakly interacting quarks and gluons. This made it possible to calculate how the strong nuclear force would affect its momentum.

The team then examined the probability of different changes in the quark’s momentum. In the conventional Brownian motion model, small changes are common, while extremely large ones are rare. The resulting probability distribution takes the shape of a bell curve, with the most extreme movements appearing at its two ends. The calculations for relativistic heavy quarks produced a different pattern.

For smaller changes in momentum, the distribution still resembled a bell curve. At the outer ends, however, it became uneven. Large changes occurred more frequently than the conventional model would predict. A particularly interesting finding was that a large kick slowing the quark down was more likely than an equally large kick pushing it in the opposite direction.

This imbalance is important because it suggests that the movement of heavy quarks carries information that conventional Brownian motion models miss. “How often those large changes occur depends on the microscopic nature of the plasma,” Du Plessis said. Such events could therefore offer researchers another way to investigate what happens inside quark-gluon plasma. The researchers repeated their calculations for plasmas made up of different particles. They found that the same tilted probability distribution appeared across these different conditions. They also identified the mathematical pattern in an earlier calculation involving a strongly interacting plasma, despite the differences in the underlying microscopic physics. The finding points to a potentially universal feature of how relativistic particles interact with fluids.

Reading the Properties of the Early Universe

Quark-gluon plasma is known to behave more like a liquid than an ordinary gas. Experiments have shown that it flows with remarkably little internal resistance, suggesting that its constituent quarks and gluons interact strongly.

The new framework could help physicists investigate these interactions by examining how heavy quarks lose momentum as they travel through the plasma. Researchers can compare the theoretical predictions with measurements from particle accelerator experiments and use the differences to refine their understanding of the fluid. Du Plessis believes the primordial quark-gluon plasma was more strongly interacting than a simple Brownian motion model might suggest. Its behaviour, he says, was closer to that of a liquid than a gas.

The calculations do not directly tell scientists what the universe’s first fluid looked like. They offer a more precise way to interpret the behaviour of particles produced in laboratory collisions, bringing researchers closer to understanding the properties of matter during the universe’s earliest moments. The research received support from the US Department of Energy’s Office of Nuclear Physics, the US National Science Foundation and the Simons Foundation.

An international team of researchers from India and Belgium has developed portable particle detectors that could help scientists examine the interiors of mountains, tunnels and historical monuments without damaging them. The technology uses naturally occurring cosmic-ray particles to map variations in the density of objects, offering a potential approach to non-invasive imaging of large structures.

The detectors, developed using glass-based Resistive Plate Chambers (RPCs), achieved a particle-detection efficiency exceeding 95% during testing, according to a report published by Research Matters on October 24, 2026. The findings demonstrate the potential of compact detector systems to investigate dense materials and support future applications in geology, archaeology and infrastructure assessment.

The collaboration includes researchers from India’s National Institute of Science Education and Research (NISER), Bhubaneswar, and the Homi Bhabha National Institute (HBNI), alongside researchers from Belgian institutions, including Université catholique de Louvain and the Inter-University Institute for High Energies.

How cosmic rays reveal hidden structures

The technology uses muons, high-energy particles produced when cosmic rays interact with Earth’s atmosphere. These particles continuously reach the Earth’s surface and can penetrate substantial thicknesses of rock, concrete and other materials.

As muons travel through an object, some are absorbed or deflected depending on its density and thickness. By measuring the number and trajectories of particles passing through a structure, researchers can identify variations in internal density and reconstruct images of otherwise inaccessible areas.

The technique, known as muography, is comparable in principle to X-ray imaging, but uses naturally occurring particles instead of an artificial radiation source. It has previously been used to investigate geological formations, including volcanoes, and to explore archaeological structures.

However, conventional muon detectors can be bulky, difficult to transport and challenging to operate in remote locations. The new glass-based detectors aim to address some of these limitations through a compact design and sealed operation, reducing dependence on continuous gas supplies.

Testing the detector system

The researchers developed three glass RPC prototypes using thin glass electrodes separated by gas-filled gaps. When a muon passes through a chamber, it ionises the gas, generating an electrical signal that can be recorded to determine the particle’s position.

Electronic readout systems capture these signals and help reconstruct the trajectories of incoming particles. During testing, the detectors achieved an efficiency exceeding 95%, with a timing resolution of approximately 1.8 nanoseconds, according to the research report.

To examine the system’s ability to detect dense materials, the team conducted an absorption experiment using one prototype. During an open-sky measurement, researchers recorded nearly 55,000 muon tracks. After placing a lead block in the experimental setup, the recorded count fell to 30,894, demonstrating how dense material reduced the number of particles reaching the detector.

Representational image.Image credit:Pexels

The experiment provided proof of principle that the system could measure muon attenuation and support radiographic imaging. However, imaging complex structures such as mountains or monuments requires measurements from multiple directions and further computational reconstruction.

Applications and challenges ahead

Portable muon detectors could eventually help researchers investigate hidden cavities, examine geological formations, inspect tunnels and study the internal structures of historical monuments. Engineers could also explore their application in assessing infrastructure such as dams and bridges, although these uses would require additional testing and validation.

For cultural heritage conservation, muography could offer a valuable alternative where drilling or other invasive investigations risk damaging fragile structures. A 2025 review published in iScience highlighted the technique’s potential as a complementary, non-destructive method for studying cultural heritage objects, while noting that the relatively low flux of naturally occurring muons can require lengthy data-collection periods.

The technology is not yet a universal replacement for existing inspection methods. Its practical application will depend on factors such as spatial resolution, detector size, measurement duration and the complexity of the structure being examined.

The researchers have proposed further improvements, including lighter structural materials, larger detector areas and enhanced readout systems. These developments could make the detectors easier to deploy and improve the quality of reconstructed images.