- I am not a physicist, just a citizen scientist. I have read (mostly in popular publications like Scientific American and Sky and Telescope) about the theories of the origins of our universe for the last 40 years. A lot has happened, more will.
- I do not understand quantum mechanics or my wife though I believe that entanglement plays a part in both.
- In an infinite universe, anything…
The idea of an object so massive that light cannot escape from it actually goes back to the 18th century. It wasn’t until early in the 20th century that the modern concept of a black hole was put into a theoretical framework by Einstein, Schwarzschild, and Chandrasekhar (among others). (5) This has been built upon since by many notable physicists including Penrose and Hawking. A black hole has only three measurable properties, mass, electrical charge, and angular momentum or spin. (7) Black holes also have a non-zero temperature due to Hawking radiation. When an object falls into a black hole all information about these three properties becomes part of the event horizon. All other information such as size, shape, or the properties of the particles that it was composed of is supposedly lost.Continue reading “Black Holes, the Instant of Creation”
I’m not going to go into too much depth on what black holes are or how they come into being. The concept itself is pretty basic. It’s a region of space in our universe that has so much mass that the escape velocity is greater than the speed of light. They are defined by the event horizon, the surface that surrounds them where the gravitational pull of what is inside the black hole equals the speed of light. In other words, if you are inside a black hole and shine a flashlight towards the inside surface of that event horizon the light will never escape out into the rest of the universe. Black holes, although they can not be observed directly, can be observed by the gravitational effect that they have on their surroundings. Astronomers have “observed” these effects, weighed their masses, and have generally proven that they exist. The radius of this event horizon (called the Schwarzschild radius) is defined by a simple formula that is a function of the mass and rotation. Most of the references for this article are to Wikipedia (5) where you can find lots of fascinating details.Continue reading “Black Holes”
Let’s spend a bit of time on the concept of what a multiverse is. Most people are familiar with the concept of our universe. It consists of everything around us including all of the stars and galaxies that we can see as well as what is beyond the visible horizon, that part of space and time that has not had time for the light emitted from it to reach us.
The theory of the Big Bang says that our universe began as a very hot and dense dimensionless point some 13.7 billion years ago (2). A very small fraction of time later it went through a tremendous expansion or inflationary phase which smoothed it out. This inflation spread the tiny variations of density that were on sub atomic scales out to the size of what eventually became galactic super-cluster size. The universe literally expanded faster than the speed of light leaving most of it so far away that we can not see it. As time goes by light from an ever increasing sphere around us has time to reach us. This visible bubble is estimated to have a radius of about 46 billion light years (3). What lies beyond that can not be seen and can have no effect on us (perhaps not true – see note).Continue reading “The Infinite Multiverse”
Philosophers have discussed and theorized for ages about the origin of our universe. It is such an important question that every culture on our planet has a story or mythology about how they and the world around them came to be. These frameworks were constructed on what they knew of their surroundings or of their recent history. The Ojibwa first nation in Canada believed the world was found by a muskrat and is carried on the back of a turtle. In the last couple of hundred years our framework has changed and is based on scientific experiment and theory. Instead of inventing our origin we build theories based on scientific experiment and then test them with new experiments. One of the most significant contributions to this framework came from Albert Einstein when he developed his theories of special and general relativity. Most of what we hold to be true about our universe is based on relativity and quantum mechanics. (As an aside, I do not understand quantum mechanics, I can grasp some of the effects, but I do not understand the fundamentals. By the same token, I don’t understand my wife, but I do comprehend how she modifies my universe.)Continue reading “Big Bangs and Black Holes”