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| .”Hubble Ultra Deep Field Infrared. Credit: NASA, ESA, G. Illingworth |
Lunchtime is a great moment to unravel the universal mysteries.
Having an astronomer by your side, at some point the conversation turns to scientific topics. Of course, my understanding of astrophysics is light-years behind of his. As the saying goes, jack of all trades master of none.
We order drinks and I try to get him to explain what is this thing the astronomers call “dark matter”, which is not the same as dark energy. I've heard it described as that which does not emit light. Is that it? Definitely not. It is more complex.
Due to the interruptions of our waitress - a charming freckled blonde that asks tirelessly whether we're doing fine or if we needed anything else, her earnest joy and enthusiasm deserving a malevolent sarcasm Chuck Palanyuk style - and the complexity of the issue, I'm not sure if I fully understand.
“You see”, he explains, “we know that, in the Universe, there is radiation and matter that we can see. But measurements made on the rotation of galaxies show results that cannot be explained when considering only the observable matter. At least twice the mass we see in them would be necessary to explain those results. This is only one among other phenomena of the Universe that suggest the existence of an invisible form of matter, which we call 'dark matter' and we don't know what it is made of.
There is also another thing, we call 'dark energy', that we don't know what it is either, but it is responsible of the movement of the galaxies getting away from each other, that is, the expansion of the Universe.
From the data we have gathered so far, it is believed that dark matter and dark energy comprise approximately 95% of all that exists. Which means that all the astronomical knowledge only explains the 5% of what's out there. The other 95% we do not even know what it is.
“Why don't we make a greater effort to research this?” I ask.
“It's being done, but it's not very well known by the public. The branch of astronomy that focuses on these issues is cosmology. Exciting, but difficult to explain in a simple way. It seeks to understand the structure of the universe on a large scale. And although on a different level, it shares this goal with some branches of physics like quantum optics and nuclear physics: trying to unravel the workings of the universe at its most fundamental level.
“It is important to know how the universe works. Only by getting to know these mechanisms will we be able to, for instance, create means of transportation that can take us to distant planets outside the solar system. Currently we can't even approach the speed of light; even if we could, that speed os entirely insufficient for such purposes. Unimaginable possibilities would open up to us if we manage to find a fast and viable way of travel through space. Unfortunately, it is not something that we will see in our lifetime”
The conversation dies out after this. It is, in part, its because the succulent fifteen dollar burger I've ordered is getting cold as we speak, and there is much to chew. But also because those words, “this we will not see in our lifetime” always manage to leave me speechless.
Jesus Martinez-Manso is working on his PhD at the Department of Astronomy of the University of Florida. Today he is dedicated to the study of the dynamics and stellar populations of spheroidal galaxies in the early universe to understand its evolution to this day. His research interests include observational cosmology, the evolution of galaxies and cosmological parameters. Jesus graduated in physics in 2009 at the University of Sevilla, Spain, and it is his second year at the Department of Astronomy at the UF.
Ps. He had fish fillet and salad.
Javier Barbuzano.
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