Big Bang

Dr Carol Wood of Wesleyan University (a student of Abraham Robinson who pioneered non-standard analysis 50+ years ago) has discussed the hyperreals in two Numberphile videos: First: Extended: Wenmackers may also be helpful: In effect, using Model Theory (thus a fair amount of protective hedging!) or other approaches, one may propose an “extension” of the Naturals and the Reals, often N* or R* — but we will use *N and *R as that is more conveniently “hyper-“. Such a new logic model world — the hyperreals — gives us a way to handle transfinites in a way that is intimately connected to the Reals (with Naturals as regular “mileposts”). As one effect, we here circumvent the question, are there infinitely Read More ›

The WIMP (Weakly Interacting Massive particles) model has just not worked out: We understand how the Standard Model particles behave. We have solid predictions for how they should interact through all of the fundamental forces, and experimental confirmation of those theories. We also have extraordinary constraints on how they’re permitted to interact in a beyond-the-Standard-Model fashion. Because of our constraints from accelerators, cosmic rays, decay experiments, nuclear reactors and more, we’ve been able to rule out many possible ideas that have been theorized. When it comes to what might make up the dark matter, however, all we have are the astrophysical observations and our theoretical work, in tandem, to guide us. The possible theories that we’ve come up with include Read More ›

We are told that the Standard Model just doesn’t work: Every night, astronomers post new ideas to arXiv, the open access publishing site. Cosmologists, in particular, use arXiv to engage in timely back-and-forths that formal journals don’t permit. “We’re just holding on for dear life, trying to keep up with what’s coming out,” says Scolnic. And trying to figure out why the Hubble constant calculations don’t match, where they’ve gone wrong, where they go from here, and how our conception of the universe might change from that new vantage point. Something big may be about to happen to cosmology. It’s easy to see where the cosmologists are coming from, in their glee at the possibility that they’ve been wrong about Read More ›

According to the Standard Model of our universe, beginning with the Big Bang, there is no difference between matter and antimatter (although they annihilate each other on contact). Why then do we see all matter, no antimatter? A group of physicists decided to test a new theory: From ScienceDaily: About ten picoseconds after the Big Bang — right about the time the Higgs boson was turning on — the universe was a hot plasma of particles. “The technique of dimensional reduction lets us replace the theory which describes this hot plasma with a simpler quantum theory with a set of rules that all the particles must follow,” explains Dr. David Weir, the corresponding author of the article. “It turns out Read More ›

Belgian priest Lemaitre apparently got the idea, which “underpins modern cosmology,” two years before Edwin Hubble: The International Astronomical Union (IAU) recommends that the law now be known as the Hubble–Lemaître law. In the 1920s, the Belgian described in French how the expansion of the Universe would cause galaxies to move away from Earth at speeds proportional to their distance. He did this two years earlier than US astronomer Edwin Hubble used his own data to establish the same relationship. Of the 4,060 astronomers who cast votes (out of around 11,072 eligible members) 78% were in favour of the change.Elizabeth GIbney, “Belgian priest recognized in Hubble law name change” at Nature These name changes, like the downgrading of Pluto to Read More ›

An “expert voice” astrophysicist explains that the Big Bang is now the “vanilla Big Bang,” which is unpopular because it doesn’t explain all observations: The Big Bang model is our most successful explanation for the history of the universe that we live in, and it’s ridiculously easy to encapsulate its core framework in a single, T-shirtable sentence… But But there’s no reason for our universe to be flat. At large scales it could’ve had any old curvature it wanted. Our cosmos could’ve been shaped like a giant, multidimensional beach ball, or a horse-riding saddle. But, no, it picked flat. And not just a little bit flat. For us to measure no curvature to a precision of a few percent in Read More ›

Recent cosmic ray activity in Antartica is  provoking question and speculation: Physicists don’t know what it is exactly. But they do know it’s some sort of cosmic ray — a high-energy particle that’s blasted its way through space, into the Earth, and back out again. But the particles physicists know about — the collection of particles that make up what scientists call the Standard Model (SM) of particle physics — shouldn’t be able to do that. Sure, there are low-energy neutrinos that can pierce through miles upon miles of rock unaffected. But high-energy neutrinos, as well as other high-energy particles, have “large cross-sections.” That means that they’ll almost always crash into something soon after zipping into the Earth and never make it Read More ›

They hope to be surer of that fact after a couple of years more data. From ScienceDaily: It all started with the measurements of the Planck satellite, which was launched by the European Space Agency (ESA) to measure the cosmic background radiation. This radiation is, to some extent, an afterglow of the big bang. It conveys crucial information on the matter distribution in the early universe; showing the distribution as it was only 380.000 years after the big bang. According to the Planck measurements, this initial distribution was such that, over cosmic time, more galaxy clusters should have formed than we observe today. “We have measured with an X-ray satellite the number of galaxy clusters at different distances from ourselves,” Read More ›