We live in a pretty strange universe. While we rely on scientists to provide us with the information that we need to understand what’s going on around us, even they have trouble with some of the harder questions. So, what are 5 of the most interesting unanswered questions in physics?
5. What is dark matter?
Ordinary matter accounts for only about 4% of the universe. Scientists can determine this by determining how much mass is needed to hold galaxies together. They also look at how gravity bends light from distant objects – these measurements can tell astronomers how much of the universe is actually comprised of dark matter.
Dark matter makes up most of the universe – and it’s not the stuff that we’re made up of. In fact, the search to understand it has brought physicists and cosmologists together. The leading theory is that neutrinos or two other kinds of particles, neutralinos and axions, are the culprits. They’ve never been detected, and are thought to be electrically neutral – unable to absorb or reflect light, but stable enough to have made it through since the earliest moments after the Big Bang.
4. Do neutrinos have mass?
Following on from the questions surrounding dark matter, is the question of whether or not neutrinos have mass. Neutrinos hardly interact with ordinary matter, so they can allow us to look directly into the heart of a star.
Until recently, physicists thought that neutrinos were massless, but recent studies show that they may actually have a small amount of mass. Any evidence of this would also help validate theories that attempt to find a common description for three of the four natural forces – weak force, strong force, and electromagnetism.
3. Where do ultrahigh-energy particles come from?
Neutrinos and gamma-ray photons, are two of the most energetic particles that hit us from space. They’re called cosmic rays, and they bombard our planet constantly. Sometimes, they’re so energetic that scientists have determined that they must have been created in cosmic accelerators fueled by cataclysms of absolutely astonishing proportions.
Some scientists think that the source is actually the Big Bang itself, shock waves from supernovas forming into black holes, and matter accelerated as it’s sucked into the black holes at the center of various galaxies
2. Are protons unstable?
If you’re worried that the protons that make you up will suddenly disappear, don’t. Various observations and studies have shown that protons have been stable for at least a billion trillion trillion years. However, some physicists think that if the three atomic forces are just different versions of a single unified field, bosons will materialize out of quarks sometimes, causing quarks, and the protons they make up, to degenerate.
Sure this sounds unlikely, but scientists aren’t making it up. There’s something called the Heisenberg Uncertainty Principle, which says that you can never know both the momentum and position of a particle at once, so it’s possible for an enormous boson to form out of a tiny quark, causing the proton that it makes up to decay.
1. Are we living in a multiverse?
Last on the list of the 5 of the most interesting unanswered questions in physics is the multiverse theory. Researching the four dimensions that we can easily observe, will naturally lead us to wondering if there are dimensions that we can’t. String theory combines gravity with the other three forces into an 11-dimensional world. Seven of the dimensions are wrapped up in very small areas so that they escape our notice.
String theorists argue that we can’t see more dimensions, because we don’t have the tools powerful enough to resolve them. In fact, we may never see these dimensions directly, but could detect evidence of them with the instruments of astronomers and particle physicists.
Science is cool
While we’ve taken a look at 5 of the most interesting unanswered questions in physics, there are still so many more. If you take anything from this, think about the fact that we’ve really only just begun scientific exploration within the last few hundred years. Already, we’ve discovered so much – although it’s not even the tip of the iceberg. What will the next few hundred years change?