Variants of this question are; What existed before the big bang? Can something come from nothing? Where did the universe come from? A new theory of the multiverse may hold all the answers! A theory that may answer the impossible questions At long last, we may be on the verge of having answers to these most fundamental questions, thanks to cosmologist Laura Mersini-Houghton. She has developed predictions based on the theory of the multiverse, which could one day be verified,

This image was generated for this article by AI This article will look at Einstein's alternative view of gravity and follows on from “Part 1 of What is Gravity?” in which we looked at Newton's theory. Phase 1 - Development of Special Relativity Two hundred years after Newton, Albert Einstein (1879 to 1955) embarked on the development of special relativity, which shows how particles behave traveling at velocities close to the speed of light. To do this he used a mathematical c

This is an image generated for this article by AI This is the first of a two part article that asks the question, what is gravity? The first part will look at Newton's version of gravity and the second will delve into Einstein's alternative theory. The Facts Gravity is the force that keeps you glued to the ground. Without it, we would all just drift away into space. Gravity is what keeps the international space station going round the earth, locked into an orbit, just like th

A Journey into Modern Physics website Our web-site's pages and frames are rendered to device screens as intended using a CHROME browser on computers and mobile devices. We are aware that other browsers have been failing to render some pages correctly , usually resulting in text strings being wrapped inappropriately and messing up carefully formatted layouts. The problem is that different browsers render fonts slightly differently to CHROME, which can affect spacing between l

Graph showing how relativistic mass increases with speed Mass and Light-speed How often have you heard someone say that as an object approaches the speed of light, its mass increases? Historically, physicists used a quantity called relativistic mass, which does increase with speed and would approach infinity as the speed of light is approached. However, modern physics has largely abandoned this idea because it causes so much confusion. Today, physicists use the term rest-mass

This image is reproduced under licence. See details at end of article. What is the physics of water? In part 1 of this article, we looked at how water molecules have six unique properties that make it very special and vital to the evolution of life. In this article, we're going to look at how water molecules interact with other water molecules to create a dynamic and chaotic structure when in liquid form to a highly organised and static structure when in solid form (ice). Thi

The Development of Quantum Physics & Relativity Modern physics developed in response to phenomena that classical physics could not explain. Through necessity, the evolution of modern physics started to explain the unexplainable and in so doing led to a fascinating picture of reality that has endured decades of testing. Predictions have been made from the theories of quantum physics and Einstein's relativity that have been proved right time-after-time, with remarkable precisio

Water - The Astonishing Liquid Water is something we all take for granted, but in fact it is the most astonishing liquid. Without it, none of us would be here, for reasons far beyond simply needing to drink it, as you'll see. Its physical properties make it quite unique and totally fascinating. Many of the things it can do, chemistry tells us it shouldn’t be able to do! To understand what it does, you have to delve into the physics of how the enigmatic H₂O molecule behaves. T

Even more new features this month, designed to help you continue your journey after reading the series A Journey into Modern Physics . Alternatively, if you haven't read any of the series, the video links, images and external references, all taken from the book series, might encourage you to down-load one or more of the E-books, or even buy a paperback version! These new features act as extensions to the book series, making it easier to access videos and external reading refe

Electron population of atomic orbital lobes In Part 1 of A Journey into Modern Physics, chapter 4 describes how electrons populate atoms in terms of a sequential order. Diagrams were used, like the one above, to indicate how atoms are made up with a maximum of 2 electrons (one spin-UP and one spin-DOWN) in orbital lobes that are full. Only outermost orbitals exist in an empty state or a partially populated state (one electron). There may even be empty orbitals in between popu

© 2026 Kieron Conway In Part 2 of A Journey into Modern Physics, chapter 7 has a flow diagram that shows the birth and death of stars of all sizes. This was figure 7.8 in Part 2 of the main series but was not included in the LIGHT adaptation of Part 2 for size reasons. To compensate for the omission, we have included the diagram in this article an also on the web site. If you want to see how all stars enter the main sequence and what happens to them after the red-giant phase,

Inside hadrons As discussed in Part 1 of a Journey into Modern Physics, the strong-nuclear interaction is the force that keeps the quarks of protons confined to the tiny volume of the proton. The same applies to the neutron: in fact, it applies to the quarks in all hadrons, the proton being the only stable hadron when on its own. Outside hadrons – the nucleus of an atom So, how do all the protons and neutrons stay locked inside an atom's nucleus? All the protons are positivel

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We've now published over a dozen articles on physics topics on this blog, so that you can continue your Journey into Modern Physics, even when you've read all three parts of the main series, or the LIGHT adaptations. We've built an index of the titles of the published articles in date order, for you to scan and go directly to an article of interest, rather than you having to sequentially search the list of articles on the blog. The index is accessed from the web site of the b

By accelerating charged particles (electrons, protons, or other ions), the LINAC (linear accelerator), invented in the 1930s, became one of the key machines that advanced nuclear physics well into the second half of the twentieth century. One of the main uses of LINACs today is as the primary source of particle beams at high-energy laboratories around the world. High-energy particle colliders are usually ring-based, such as the LHC (Large Hadron Collider). Ring-based accelera

A Cosmic Mystery for the Next Generation of Scientists Recent research from South Korea (2025), has raised new questions about one of the biggest mysteries in modern physics: dark energy. Understanding what dark energy is, and what it might do in the future, could determine the ultimate fate of our universe and there may be new evidence that we might have got it wrong! The Expanding Universe: A Quick History Before the 1990s Modern cosmology tells us that the universe began a

When writing about noble gases in a Journey into Modern Physics, the expression ' react with nothing, under normal conditions' was always used. This article explores noble gas chemistry, which may come as a surprise. Under certain conditions, some of the noble gasses do react with other atoms, in particular the more massive gasses are more reactive than the lighter ones as their outermost orbitals are not as strongly attached to the nucleus. However, we are not talking about

There are two fundamental problems in modern physics, which are; Problem 1: Spiral galaxies don't have enough gravity to stop their arms from spinning off into space. Something is clearly producing the additional gravitational attraction that keeps spiral galaxies from spinning apart. Whatever it is, it can't be detected, so it's called 'dark-matter'. Problem 2: The expansion of the universe is not slowing down as expected, it's actually speeding up. Something is clearly caus

In modern physics, we know that empty space isn’t really empty. Even in a perfect vacuum, tiny bursts of energy are constantly being created and disappearing. These are called quantum fluctuations, and they give space a kind of fizzy, restless background. Many scientists use the nickname “quantum foam” to describe this ever-changing activity. If you recall, there is energy at every point in the vacuum of space and Heisenberg's uncertainty principle allows quantum fluctuations

There are two things that can help us answer this question, although you may not be happy about the outcome. But the conclusion might cheer you up! The ΛCDM Model The current theory describing the history of the universe from time = 0 to the present is known as the ΛCDM (Lambda–Cold Dark Matter) model. Λ (Lambda) refers to Einstein’s cosmological constant. It has had a checkered history (Einstein once called it his “biggest mistake” ) but it’s now back in favour, representin