What energy is

If you ask what is energy? some people will tell you that energy is an abstract thing. This was how Richard Feynman described it in the Feynman lectures, volume I chapter 4. He used the analogy of children’s blocks. He said these blocks were absolutely indestructible and could not be divided. But then he said there are no blocks. Only then he contradicted himself by saying energy has a number of different forms, such as gravitational energy, kinetic energy, and heat energy: Image from Assignment point…

Continue Reading

The fate of the universe

One of the things cosmologists like to talk about is the fate of the universe. Some say it all depends on the density parameter omega: Ω. This started life as the average matter density of the universe divided by a “critical” matter density for the Friedmann universe: Based on the Friedmann universes public domain image by BenRG, see Wikipedia Commons and Wikipedia Nowadays when we talk about omega we don’t restrict ourselves to matter alone. That’s because energy doesn’t necessarily take the form of matter, and…

Continue Reading

The edge of the universe

When you dig into the history of cosmology, some things catch your eye. Things like the “boundary conditions” in Einstein’s 1917 cosmological considerations in the general theory of relativity. Or something Willem de Sitter said in his 1917 paper On the relativity of inertia. Remarks concerning Einstein's latest hypothesis. He said this: “if the gμν at infinity are zero of a sufficiently high order, then the universe is finite in natural measure”. There’s also something Paul Steinhardt said in his 1982 Natural Inflation paper. He said this:…

Continue Reading

Dark matter

There’s plenty of evidence for dark matter, ranging from velocity dispersion, flat galactic rotation curves, and gravitational lensing. The evidence for dark matter is so good we can even map it out: Image credit NASA, ESA and R. Massey (California Institute of Technology), see spacetelescope.org There’s also plenty of papers and articles about dark matter candidates. Maxim Khlopov refers to WIMPs, axions, neutrinos, mirror-world particles, extra-dimensional particles, and black holes. Andreas Ringwald refers to neutralinos, gravitinos, sterile neutrinos, and axions. Kim Griest refers to MACHOs, molecular…

Continue Reading

Dark matter candidates

Everybody loves a mystery, and one of the best mysteries in physics is dark matter. As to where it starts, check out Brian Koberlain who said its origins can be traced to the 1600s. Or Alexis Bouvard who in 1821 said anomalies in the orbit of Uranus could be caused by dark matter. Or see the Ars Technica history of dark matter article by Stephanie Bucklin. She said in 1884 Lord Kelvin concluded that “many of our supposed thousand million stars, perhaps a great majority of…

Continue Reading

The mystery of the missing antimatter

There’s an awful lot of articles about antimatter and mystery. For example there’s a 2017 Symmetry magazine article matter-antimatter mystery remains unsolved. It’s about the BASE experiment at CERN where they’ve measured the antiproton magnetic moment. Surprise surprise, it’s the exact opposite of the proton magnetic moment. Then there’s the LiveScience article mystery deepens: matter and antimatter are mirror images. Of course they are, the positron has the opposite chirality to the electron. And then there’s the CERN courier article does antimatter fall up? No it…

Continue Reading

The mystery of mass is a myth

When you look around on the internet, you can find a whole host of articles about the mystery of mass. For example there’s a Guardian piece by Ian Sample, who says the origin of mass is “one of the most intriguing mysteries of nature”. Or there’s Concepts of Mass by Max Jammer, who says ”the notion of mass, although fundamental to physics, is still shrouded in mystery”. There’s also the ATLAS article by Michael Chanowitz, who talks about uncovering “the deep mystery of the origin of…

Continue Reading

How a magnet works

To understand how a magnet works, you need to understand that the electron doesn’t have an electric field or a magnetic field, it has an electromagnetic field. In fact it is electromagnetic field. We made it in gamma-gamma pair production, such that a 511keV electromagnetic wave is configured as a spin ½ standing wave. Hence the wave nature of matter. When you wrap a sinusoidal electro-magnetic field variation into a twisted double loop, the minimum and maximum field variation combine, along with all points in between,…

Continue Reading

A detective story

So why isn't the future what it used to be? I think it’s something of a detective story, one where you have to look back at the history. In 1831 Michael Faraday was doing his ground-breaking experiments, showing how electricity and magnetism were interrelated. Then in 1865 James Clerk Maxwell developed the theory, and in 1880 we had light bulbs courtesy of Joseph Swan and Thomas Edison. In 1905 Einstein gave us E=mc², saying there was an awful lot of energy in matter. Then in 1934…

Continue Reading
Close Menu