Expansion microscopy helps chart the planktonic universe

Plankton are essential to life on Earth, producing a significant portion of the planet's oxygen and serving as the foundation of the oceanic food chain. They exhibit remarkable diversity, with tens of thousands of species described and many more yet to be discovered. Among these organisms, protists, which are tiny, single-celled entities, are particularly notable for their evolutionary significance. Historically, scientists have been limited in their ability to study protists due to a lack of reliable imaging methods, relying primarily on genomic data for research. Recent advancements in imaging techniques, specifically expansion microscopy, have enhanced the ability to visualize these microscopic organisms. This method allows researchers to gain a clearer understanding of the diverse planktonic universe, which has been challenging to explore due to the small size and complexity of these organisms. The development of such imaging techniques is crucial for advancing scientific knowledge about plankton and their roles in marine ecosystems. In a different field of research, gravitational lensing has provided significant insights into the expansion of the universe, particularly regarding the ongoing Hubble tension. Gravitational lensing is an optical phenomenon where massive objects, such as galaxies, bend the light from objects behind them, enabling astronomers to observe distant celestial bodies more clearly. This technique has confirmed discrepancies in the measurements of the universe's expansion rate, which challenge existing cosmological models. The Hubble tension refers to the disagreement between different methods of measuring the universe's expansion rate, with one method yielding a higher value than the other. Observations using gravitational lensing have provided additional evidence that there may be fundamental issues in our understanding of cosmology. While this method has offered new confirmations regarding the discrepancies in the universe's expansion, experts caution that it alone will not resolve the Hubble tension. The complexity of the universe's expansion and the potential need for new physics or modifications to existing theories remain areas of active research.