By Thiago Gonçalves
Promises from the telescopes that get around
We are on the verge of a revolution in our understanding of the universe. Over the next 10 years, telescopes and observatories will be inaugurated that will allow us to see further and in greater detail. But even with new eyes, science not only works with data, but also uses models and theories. And from studies, instruments are built that confirm the proposed models.
To understand how this process works, take the example of the James Webb telescope that was promised for the middle of the last decade. With new cameras and a mirror 6.5 meters in diameter, 4 meters larger than that of the revolutionary Hubble, it was designed to observe the first galaxies in the universe. If we remember that light has a finite speed, we can conclude that the further away an object is, the longer it will take to reach us and the older the observed object. Hubble, who rewritten astronomy for the past 30 years, was instrumental in breaking records, but did not reach the first stars, the first galaxies. Several models predict the properties of these cosmic fossils, but without data there is no way to tell which one is correct.
It’s up to James Webb who not only allows us to see the first generation of stars in the universe, but also to find our cosmic origins and try to understand how it all began. But not only. It will also be able to study the atmosphere of planets around stars other than the sun. In the past few years, we have discovered thousands of planets, many of which are similar to Earth, simply by measuring the star’s decrease in brightness as the planet passes in front of us.
Discovering life is much more difficult. One of the main strategies would be to measure the change in the star’s light as it passes through the planet’s atmosphere. That would require a telescope with tremendous sensitivity – and James Webb once again has the potential to guide this discovery.
And he won’t come alone. Three colossal telescopes will be inaugurated by 2029: the Magalhães Gigante with a diameter of 24 meters; the 30 meters (self-explanatory name) and the European Extremely Large with an impressive diameter of 39 meters. (Today the tallest in the world is 10 meters.)
Together, these terrestrial observatories can track space discoveries and provide clues such as the movement of stars or the chemical composition of the first galaxies to understand the physical processes that culminated in the first generation of structures in the cosmos. However, in creating new instruments, we have to be open to what we do not expect – it is such a coincidence.
Alexandre Fleming and Henry Becquerel, who are responsible for the discovery of penicillin and radioactivity, respectively, illustrate the positive surprise of the unexpected. For both, advances were fortuitous, though they resulted from techniques they had already worked with – and both were pervious to evidence that was beyond understanding at the time.
The same applies to Fritz Zwicky, who discovered dark matter in the 1930s. However, his studies were discredited by his colleagues, and dark matter was not taken seriously until the 1970s with Vera Rubin.
Other astronomers have had better luck. Arnold Penzias and Robert Wilson first observed cosmic background radiation (an observation confirmation of the Big Bang); Jocelyn Bell and her superior Anthony Hewitt discovered the pulsars, energetic remnants of dead stars; The teams led by Adam Riess, Brian Schmidt and Saul Perlmutter saw the first evidence of dark energy. All of this work achieved unpredictable results and was awarded the Nobel Prize.
The most important thing in the technological revolution is to stay open. The new telescopes will be able to observe unprecedented phenomena, and scientists should expect the unexpected.
Thiago Gonçalves is an astronomer at the Observatório do Valongo / UFRJ and a scientific sponsor.
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