To learn more about our planet and the universe, we need to ask questions about everything. There are many things we do not know. We have not documented every plant or animal species on Earth. The far reaches of our universe, and the space beyond, contain mysteries that cannot yet be explained.
Even if something cannot be directly observed, we can collect indirect evidence by observing what is visible to us.
Dinosaurs:
Many of us can picture a dinosaur; it probably has scaly skin, threatening jaws, and a huge tail. This picture has probably been informed by both paleontology and pop culture, like the Jurassic Park franchise.
In the 1800’s, many people pictured dinosaurs as larger versions of crocodiles and other reptiles. At that time, scientists could only compare fossils to living animals to form an idea of what dinosaurs looked like. Scientists still compare fossils to present-day animals. But more advanced technology like CT scanners allows paleontologists to examine the internal anatomy of animals like crocodiles, and connect the results to prehistoric animals. Data evaluated with computers can reveal connections between many different dinosaur species. Virtual reality and computer imaging can build models of the asteroid crash, and the mass extinction that followed.
A particle accelerator in France called the European Synchrotron Radiation Facility creates super strong x-rays by moving electrons, almost at the speed of light, around a huge ring, and bending them with magnets. These x-rays can detect things as small as human red blood cells, and provide an amazingly detailed picture of fossils.
Subatomic particles:
Studying subatomic particles may reveal answers to the forces of the universe. A new piece of technology called LArPix has successfully photographed the path of charged particles. LArPix stands for liquid argon pixels. The detector works when charged subatomic particles transfer energy to electrons in liquid argon. An electric field then moves the electrons to a field of wires, which can form an image based on the electric signals.
Scientists need to detect neutrinos, which are subatomic particles with a very small mass. They are not electrically charged, so they are not impacted by electromagnetic forces. A project called DUNE, or Deep Underground Neutrino Experiment, is trying to use the LArPix to detect neutrinos by slightly changing the technology. This research would explore questions about matter and anti-matter in the universe.
Dark matter and dark energy:
The idea of dark energy comes from the process of the universe expanding. Over time, gravity should slow down the expansion of the universe. But the universe is expanding more rapidly right now than it was many, many years ago. This means that there must be something influencing the expansion, something that has not yet been discovered. It is estimated that about 68% of the universe is dark energy, 27% is dark matter, and 5% is ‘normal matter’, or the type of matter that is on Earth. The question is, what is dark matter, and does it even exist?
There are a few possible explanations for the speed of expansion; it could have something to do with Einstein’s theory of relativity, or maybe it is a new type of energy that behaves differently to normal energy. Most recently, a study was published in the Astrophysical Journal providing evidence that ‘dark matter’ might actually be an effect of gravity. The study observed that the speed of some star orbits are irregular. To explain this, the laws and theories of Newton and Einstein can be modified, according to physicist Mordehai Milgrom’s MOND hypothesis, to allow for a small amount of acceleration caused by gravity. Studying visible objects like stars and galaxies gives scientists more information about the effects of dark matter and the force of gravity.
Scientists have been able to research how dinosaurs lived and evolved, how neutrinos and charged particles move, and what the universe is made of, using new technology and methods of observation. As technology changes and we gather more information, our questions will change too. What do you think we will be able to study in the future?
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Resources
Greshko, M. (2021, May 18). See how we’re reimagining dinosaurs in today’s ‘golden age’ of paleontology. Magazine. https://www.nationalgeographic.com/magazine/article/reimagining-dinosaurs-prehistoric-icons-get-a-modern-reboot-interactive-feature
Staff, S. X. (2021, May 14). Detector technology yields unprecedented 3D images, heralding far larger applications to study neutrinos. Phys Org. https://phys.org/news/2021-05-detector-technology-yields-unprecedented-3d.html
Metcalfe, T. (2021, January 6). Maybe “dark matter” doesn’t exist after all, new research suggests. NBC News. https://www.nbcnews.com/science/space/maybe-dark-matter-doesn-t-exist-after-all-new-research-n1252995