Leading Harvard physicist has a radical theory of why humans exist
Stephanie Mitchell/Harvard Staff PhotographerWhere do we come from?? There are many correct answers to this question and the one you get very often depends on who you ask.
For example an astrophysicist would say perhaps that the chemical components of our bodies developed for the first time in the nuclear fires of the stars.
On the other hand, an evolutionary biologist might look at the similarities between our DNA and that of other primates to determine that have common ancestors with apes.
Lisa Randall, a theoretical physicist at Harvard University has another, novel answer, which she describes in her book "Dark Matter and Dinosaurs" explains.
Randall has also written other well-known scientific books, including The New York Times Bestseller "Hidden Universes: A Journey into Extradimensional Space.“ She researches theoretical particle physics and cosmology for studies at Harvard University.
In her latest book, she explains that the extinction of the dinosaurs- necessary for the advent of mankind- Is associated with dark matter. Dark matter is the mysterious, invisible matter that astronomers estimate makes up 85 percent of all matter in our universe.
The extinction of one species is the advance of another
Thomson ReutersPaleontologists largely agree that about 66 million years ago, a giant, 14.5-kilometer-long supernatural body- probably a comet- hit the earth. The impact wiped out 75 percent of all species across the planet, including most dinosaurs.
Among the survivors were small primates. Over the next 66 million years, these primates evolved in different ways, growing larger, learning to walk, and developing large brains, which they eventually used to invent the pizza delivery system.
But what caused a huge space rock to collide with our planet in the first place? giving primates the chance to fully evolve?
It could be only coincidence- or luck, depending on which perspective you look at it- but Randall would contradict both theories.
Business InsiderIn her book, Randall describes a dark, pancake-shaped mass, densely packed with dark matter within our galaxy, that could be responsible for how we came to be as a species.
Dark matter has never been directly detected. However, there is enough evidence of their enormous gravitational influence on our universe. Therefore, the vast majority of the scientific community agrees that dark matter is a form of mysterious matter that we can neither see nor touch, but which must nonetheless permeate our cosmos.
In general, dark matter tends to be concentrated in a ring around galaxies, like in big bubbles. But Randall believes that among our stars, planets and gas clouds, there may also be a so-called dark disc in our galaxy.
Beware the dark disc
If there is dark matter in Randall’s hypothetical dark disc, then it stands to reason that the disc would have a powerful gravitational influence on the objects around it- this includes our solar system.
But our solar system is not always near the disc, that is the crux of Randall’s theory.
As the solar system revolves around the center of the Milky Way- in the same way that the earth revolves around the sun- it also moves up and down, or it wobbles through our galactic plane (the disk-shaped galactic plane is where most of the galaxy’s mass lies). And the relation of these fluctuations is fascinating.
Below is an illustration of the fluctuation of our solar system, where the orange dot in the box at the bottom left is our sun and the black line in the center is the dark disc.
A team of astronomers made a rough estimate of the swing rate near the recent millennium, calculating that our solar system passes through the galactic plane of the Milky Way every 32 million years, which means that if there is a dark disc, we pass through it at the same time interval.
Interestingly, there is evidence to suggest that mass extinctions on Earth in the past happened in roughly this time frame, or about once every 25 to 35 million years.
The similarity between the rate of mass extinction and the rate of oscillation of our solar system through the galaxy was the reason Randall and her Harvard colleague, Matthew Reece, began to study the matter in scientific papers published in Physical Review Letters and published in their book were able to make a connection.
Randall hypothesizes that as we traverse the dark disc, the outer region of our solar system, called the Oort Cloud, is affected by the gravitational pull of dark matter.
Oort’s Cloud is located in the illustration below on the right side, roughly between 1.000 and 100.000 astronomical units (145 billion to 14.5 trillion kilometers) away from the sun. It is believed to contain billions of icy objects at least 19 kilometers across.
Uploaded by WolfmanSF to Wikipedia
If something 19 kilometers wide hit the Earth today, life as we know it would be over. And Randall believes that’s exactly what happened 66 million years ago, which opened the door to extended primate evolution.
The proof is missing (yet)
dark matter dark matter NASA Goddard Spaceflight Center/Flickr
While it is impossible to turn back the clock, proving the existence of the Dark Disc would be a major advance in Randall’s theory.
She tried to do this by looking at the speed and direction of stars in our galaxy. If stars moved in ways that could not be explained by the amount of normal, visible mass, then that could point to the presence of the Dark Disc.
But that’s an extensive task. There are about 100 billion stars in the Milky Way and chasing dark matter is extremely tricky.
We have about a dozen working sensors under the ground, on the Earth’s surface, and in space- none of which has yet been able to detect even a particle of dark matter. If they do, that would be a huge step toward supporting Randall’s hypothesis.
In her summary remarks, Randall writes:
„In a global sense, we are all descendants of Chicxulub [the place where the dinosaur-killing meteor hit]. It is a part of our history that we should understand. If true, the added depth in this book could mean that dark matter is not only responsible for having irrevocably changed our world, but also that it played a crucial role in making our existence possible.“