 All right, all right, you've drawn my ire. Okay, so maybe I'm just kidding, but there has been a contentious point over the past couple of months that's been growing during our live show, which is does dark matter exist? So this is your space pod all about dark matter for January 25th, 2017. So this is going to be quite an interesting pod. There's a lot of you convinced that I'm wrong about dark matter, as you can see all around me. Now, I'm not going to be getting into who's right or who's wrong in this space pod. I'm simply going to be talking about dark matter itself. We're going to talk about how and why it's important to cosmology. So we're going to get started with history first. You ready for an intellectual slobberknocker? Jacobus captain, Jan Ort and Fritz Wicke all hypothesized in the 1920s and 30s that dark matter may exist based upon data from the rotation of galaxies, but it was Fritz Wicke which did the math that showed dark matter could potentially exist. Finally, in the 1960s and 70s, instrumentation allowed the recently passed Vera Rubin and Kent Ford to make extremely precise measurements of the rotation of galaxies. To the astonishment of the astronomical community, the literal opposite of physics was found to be true. Expected rotation speeds would have been higher towards the cores of galaxies and slowed down towards the further out one moved from the core. But what was actually found was astonishing. The cores of galaxies rotated at a slower rate and the outer areas rotated faster and at a consistent speed to the very edge of the galaxies. As early as 1980s, scientists began to seriously incorporate the idea of a dark matter hypothesis into models of the universe and still do today. That's right, a dark matter hypothesis. Suddenly, my on air militancy insisting that dark matter is an absolutely 100% genuinely real thing seems well a little bit silly. So viewers, you're right, I'm wrong points to you. But if dark matter really is a thing, why is it so important in cosmology? Enter the lambda cold dark matter model or what many call the current standard model of cosmology. It's what we use when looking out at the universe and making models for supercomputers to generated simulated universes within. The current standard model is used because it is the simplest model that accounts for the properties of the universe like the structure of cosmic microwave background radiation, super clusters and distributions of galaxies, the development and abundances of hydrogen, helium and lithium and the accelerating expansion of the universe. The standard model calls for the universe to be made out of three things. Ordinary matter like what makes up you and me, dark matter and dark energy. For ordinary matter, the stuff that you and I are made out of, well that accounts for about 4.9% of the mass energy of the universe. Dark matter accounts for 26.8% and dark energy accounts for 68.3% of the mass energy of the universe. We know this simply by observing the universe itself. This may sound difficult because dark matter gets its name from the fact that when we look out into the universe, it does not appear to emit any sort of electromagnetic radiation, the big scientific word for light. But what dark matter does do is influence the ordinary matter around it via gravity. We can look at galaxy clusters and via gravitational lensing, see places where there's simply not enough regular matter to account for the mass. Scientists hypothesize that this could be because dark matter is a WIMP, literally, a weekly interacting massive particle, also known as a WIMP. WIMPs have no current definition, but they are hypothesized to be a new elementary particle and one of the great hunts currently underway in particle physics is to try and find WIMPs. They're thought to only interact with matter briefly, and all manner of detectors have been designed to try and find them, but so far, no luck. The standard model does happen to predict a particle like WIMPs, so it's no coincidence. But if they are the mass behind dark matter, well, we're going to have to find some WIMPs first. Thanks for watching this space pod. I'm Jared Heck. What do you think about dark matter and the hypothesis of its existence? Well, let us know in the comments below. I'm social media at r slash t m r o wherever you can chime in and let us know what you think. And we want to give a huge shout out to all of our patrons of space pods. Without these folks, we would not be able to make these space pods possible for everyone to enjoy. So if you would like to help crowdfund the space pods of tomorrow, head on over to patreon.com slash space pod. And until the next space pod, keep exploring.