This new finding is well out of the ballpark in many ways. (Please read this link to see the scope of the research in detail.) Increased universal heat requires a whole range of phenomena to happen at all. You don’t just add a bar heater to the entire universe and expect the whole thing to heat up.
The study by Ohio State University Center for Cosmology and Astro Particle Physics was conducted to study light and temperatures over a multi-billion year time frame. The current theory is that the gravitational collapse of dark matter and galaxy formation is driving the temperature increase.
The research involved a lot of high-end data assessing “all the light in the universe”, measuring ancient light from billions of years ago and more recent light. The finding of this epic number crunching was that the ancient universe was much cooler.
The current theory is that this is a natural process, driven by the formation of galaxy structures. This includes the drag by gravity on dark matter and gases to heat up the universe. According to research fellow Yi-Kuan Chiang the gravity drag is “violent”, causing a shock effect. Gigantic amounts of materials can conduct a lot of heat, and generate a lot of heat.
Issues? Dark matter, for one, but there’s more to it than that.
The increase in temperature comes with some baggage and a need for further research to cover a few essential points. For example – If you were to conduct an “audit” of matter in the universe (for which this pioneering study hasn’t really had time) you’d expect to see correlative increases in temperature. When did space XYZ start to heat, how did it heat, how did heating progress?
Different spaces would/should have different initial temperatures, and the heat variance would qualify and explain the general temperature increase by locality, types of matter, etc.
The trouble with introducing dark matter into this equation is that the ever-growing definition of dark matter isn’t exactly definitive. It’s invisible or very hard to detect; it includes multiple exotic types of matter, perhaps, but how do you translate that semi-definition into heat conductivity and transfer? Tricky, and very demanding.
The definition of dark matter as non-regular matter may seem like a copout in some ways, but it’s necessary. I’m no admirer of the definition, but it does cover a lot of possible types of matter and their properties. There is a necessary interaction between dark matter and normal matter, to make the matter/dark matter relationship work, too. This may explain quite a few observed but not-well-understood things, like too many positrons in cosmic ray analyses. (Readers note this is also a meaningful step forward from “We have no idea what 80% of the universe is made of”, the previous rather inadequate definition.)
The defining issues with increased universal heat
Not long ago, increasing heat in the universe would have been totally counterintuitive. The expected Big Cool Down was the theory. Now we know the exact opposite is what’s happening.
A few points:
• The huge increase in heat can’t “just happen”. There must be a working mechanism in place to drive such a massive increase.
• In terms of space relative to volume, a general increase in heat is a real universally-applied principle in process. Why wouldn’t heat dissipate, in such a gigantic area?
• How does the heat increase become universal? How is this cockamamie universe retaining heat?
• 2 million degrees is a lot of heat. Why that specific degree of heating?
• It may be possible from the data used for this research to map local heat in gradients, seeing how it heated in particular places. This would help to predict the progression of temperature rises.
• How is this heating affecting surrounding spaces like voids, spaces between galactic clusters, etc.?
• If the heating isn’t affecting surrounding spaces, why not?
• How does heating affect the “web” structure of the universe? If heat follows conductivity, it should follow the heat trails of the universe, heating the space(s)and space around the trails.
• Are the galactic streams conduits for the heat? Looks like they’re the default conductors of heating.
• What about expansion? Does it generate a gravitational force (it should exert some sort of force on the overall mass) which causes collapse, therefore heating?
Watch this space, literally, because this is some of the toughest astrophysics ever attempted. It’ll be worth the wait to see what they discover. This is one of the most difficult problems astrophysics has ever found for itself, and understanding it will take some doing. Every paradox IS its own answer. That may be the key to the sheer number of spanners this finding has thrown at a lot of sacred cows. (How to stuff up an analogy, simplified. )
