This article first appeared in Fermilab Today on July 25.
If you follow the news about physics, you might think that physicists don’t know what they are talking about when it comes to space.
I am not talking about the mysteries of outer space, or cataclysms like black holes. I mean ordinary space itself, the inner space between particles everywhere—what we used to call empty space or vacuum. What’s in it? Sometimes we hear that atoms are “mostly empty space.” Now we read in the papers that the newly discovered Higgs field “fills all of space” and “gives particles mass,” that it acts like a kind of space-filling “molasses,” or that it’s like a space-filling crowd of groupies hanging on as a celebrity’s posse.
On the other hand, astronomers tell us that space is expanding. Last year, the Nobel Prize in physics was awarded for the discovery that the cosmic expansion is speeding up. Scientists think that this acceleration is propelled by what they call “dark energy,” which fills and refills that ever-expanding void of intergalactic space. Cosmological space is said to be expanding in some places (between galaxies) and not expanding in others (such as Brooklyn, to choose Woody Allen’s example).
It gets even worse if you dig deeper. For example, the Higgs field is much weirder than the comparisons with molasses or crowds suggest, since it does not actually drag or impede particles, but still somehow shares its mass with them.
Stranger still, consider another space-filling field that also adds mass to everyday substances, in a way different from the Higgs field. The gluons of the strong nuclear force field create most of the mass of atoms through the energy of their incessant motion inside tiny bubbles of space that we call protons and neutrons. Since the mass-giving gluons are immune to the Higgs field, they have no mass themselves, but only add energy because of their motion. Moreover, they are held inside those bubbles by a gluon field that fills empty space everywhere between the bubbles…in just those places in space where the added mass isn’t.
Space is the first concept of physics we all learn as little kids, yet it is entangled with some of the deepest mysteries confronting physics. Confusing, koan-like paradoxes about space are not just pablum: They reflect a real and profound disparity of descriptions, at a deep level of mathematics, about what defines a vacuum, a position, a particle or a time.
It may be that all the space of the universe began, and may end, dominated by the energy of the vacuum, an expanding space devoid of particles. It may be that when examined over very short time intervals, space as we know it does not even exist, but dissolves into a cloud of quantum indeterminacy: It may never sit still, but constantly seethe in microscopic motion. It may be that space has many more than three dimensions on very small scales, while there may be only two truly independent dimensions on large scales. It may even be that all of these exotic possibilities actually apply in the real world.
At Fermilab, we are working on experiments including the Dark Energy Survey, the Holometer and the CMS experiment at the Large Hadron Collider that will probe these ideas in very different ways. If you want to find out more—watch this space!
—Craig Hogan, Director of Fermilab’s Center for Particle Astrophysics
Tags: accelerating universe, expansion of the universe, Fermilab, Higgs field, quantum physics
I have heard knowledgeable people (even astrophysicists) state that the expansion of the cosmos occurs because “space is constantly being created”, implying that additional Plank sized quantum foam is the sole source of expansion. To what extent do we know this to be true, as opposed to growth in size of space-time foam over time?
How has Plank dimensionality changed over the life of the universe?
“(…) while there may be only two truly independent dimensions on large scales” do you mean holographic theories by this or maybe some other interesting hypotheses?
The Higgs field acts as a vacuum refractive index toward matter. Refractive index sources interface impedence mismatch, anisotropy, refraction, dispersion, dichroism, and gyrotropy – the Barber Pole demonstration with plane-polarized light and corn syrup,
http://physicslearning.colorado.edu/Bib/PiraSubTOC.asp?STopic=6H30
Plane polarized light is the 1:1 sum of left- and right-handed circularly polarized light. Propagation through a net resolved chiral medium selectively retards propagation of one hand (higher refractive index), progressively rotating the plane of linear polarization.
The vacuum has observed parity-odd violations toward matter. The Equivalence Principle is then violated by locally vacuum free falling right-handed versus left-handed alpha-quartz single crystals in enantiomorphic space groups P3(1)21 versus P3(2)21, respectively. A benchtop Eotvos experiment is 5×10^(-14) difference/average sensitive in 90 days. Physics could look and know rather than hypothesize and curve fit. The worst a geometric Eotvos experiment can do is succeed – for it is not the solution sought, it has no precedent, and it seeks to falsify not validate orthodox theory and its hierarchies of manually-inserted patches.
I don’t understand most of what is being talked about here. I’ve heard of the Higgs field and the experiments in that huge atom smasher they are working on. Oddly enough my curiosity came out of drawing a line, then a square, then a box and I felt myself asking.. What is the next dimension? We have 1d, 2d, and 3d. I then started wondering “Maybe the 4d has something to do with the mass between matter”. So as I googled my way around I come across this which talks about the Higgs field.
What caught my attention were the comments “…since it does not actually drag or impede particles, but still somehow shares its mass with them.” and “The gluons of the strong nuclear force field create most of the mass of atoms through the energy of their incessant motion inside tiny bubbles of space that we call protons and neutrons. Since the mass-giving gluons are immune to the Higgs field, they have no mass themselves, but only add energy because of their motion.”
This immediatley made me think of a negative image. You’ve mentioned this space in the Gluons has no mass due to being unaffected by the higgs field, but they add energy and move. This made me think of 2 things. They are either a field themselves, pushing things away from them something like a magnet or something like the opposite of matter.
I don’t know enough to answer the questions I’m asking and probably wouldn’t understand the answer if given to me, but I thought I’d chime my silliness in.