Jan 22, 2020

There is No Dark Matter. Instead, Information Has Mass, Physicist Says


  • Researchers have been trying for over 60 years to detect dark matter.
  • There are many theories about it, but none are supported by evidence.
  • The mass-energy-information equivalence principle combines several theories to offer an alternative to dark matter.
  • The  “discovery” of dark matter

    We can tell how much matter is in the universe by the motions of the stars. In the1920s, physicists attempting to do so discovered a discrepancy and concluded that there must be more matter in the universe than is detectable. How can this be?
    In 1933, Swiss astronomer Fritz Zwicky, while observing the motion of galaxies in the Coma Cluster, began wondering what kept them together. There wasn't enough mass to keep the galaxies from flying apart. Zwicky proposed that some kind of dark matter provided cohesion. But since he had no evidence, his theory was quickly dismissed.
    Then, in 1968, astronomer Vera Rubin made a similar discovery. She was studying the Andromeda Galaxy at Kitt Peak Observatory in the mountains of southern Arizona when she came across something that puzzled her. Rubin was examining Andromeda's rotation curve, or the speed at which the stars around the center rotate, and realized that the stars on the outer edges moved at the exact same rate as those at the interior, violating Newton's laws of motion. This meant there was more matter in the galaxy than was detectable. Her punch card readouts are today considered the first evidence of the existence of dark matter.
    Many other galaxies were studied throughout the '70s. In each case, the same phenomenon was observed. Today, dark matter is thought to comprise up to 27% of the universe. "Normal" or baryonic matter makes up just 5%. That's the stuff we can detect. Dark energy, which we can't detect either, makes up 68%.
    Dark energy is what accounts for the Hubble Constant, or the rate at which the universe is expanding. Dark matter on the other hand, affects how "normal" matter clumps together. It stabilizes galaxy clusters. It also affects the shape of galaxies, their rotation curves, and how stars move within them. Dark matter even affects how galaxies influence one another.

    Leading theories on dark matter

    NASA writes: 'This graphic represents a slice of the spider-web-like structure of the universe, called the "cosmic web." These great filaments are made largely of dark matter located in the space between galaxies.'Credit: NASA, ESA, and E. Hallman (University of Colorado, Boulder)Since the '70s, astronomers and physicists have been unable to identify any evidence of dark matter. One theory is it's all tied up in space-bound objects called MACHOs (Massive Compact Halo Objects). These include black holes, supermassive black holes, brown dwarfs, and neutron stars.
    Another theory is that dark matter is made up of a type of non-baryonic matter, called WIMPS (Weakly Interacting Massive Particles). Baryonic matter is the kind made up of baryons, such as protons and neutrons and everything composed of them, which is anything with an atomic nucleus. Electrons, neutrinos, muons, and tau particles aren't baryons, however, but a class of particles called leptons. Even though the (hypothetical) WIMPS would have ten to a hundred times the mass of a proton, their interactions with normal matter would be weak, making them hard to detect.
    Then there are those aforementioned neutrinos. Did you know that giant streams of them pass from the Sun through the Earth each day, without us ever noticing? They're the focus of another theory that says that neutral neutrinos, that only interact with normal matter through gravity, are what dark matter is comprised of. Other candidates include two theoretical particles, the neutral axion and the uncharged photino.
    Now, one theoretical physicist posits an even more radical notion. What if dark matter didn't exist at all? Dr. Melvin Vopson of the University of Portsmouth, in the UK, has a hypothesis he calls the mass-energy-information equivalence. It states that information is the fundamental building block of the universe, and it has mass. This accounts for the missing mass within galaxies, thus eliminating the hypothesis of dark matter entirely.

    Information theory 

    To be clear, the idea that information is an essential building block of the universe isn't new. Classical Information Theory was first posited by Claude Elwood Shannon, the "father of the digital age" in the mid-20th century. The mathematician and engineer, well-known in scientific circles—but not so much outside of them, had a stroke of genius back in 1940. He realized that Boolean algebra coincided perfectly with telephone switching circuits. Soon, he proved that mathematics could be employed to design electrical systems.

No comments:

Post a Comment