The thirteen scales that define our physical universe

The journey from macroscopic to subatomic scales spans many orders of magnitude, but going down small steps can make each new scale more accessible than the last. Humans are made up of organs, cells, organelles, molecules and atoms, then electrons and nuclei, then protons and neutrons, then quarks and gluons inside. This is the limit of how far we probe nature.

On the right, the measured bosons, which mediate the three fundamental quantum forces of our universe, are illustrated. There is only one photon that mediates the electromagnetic force, there are three bosons that mediate the weak force, and eight that mediate the strong force. This indicates that the Standard Model is a mixture of three groups: U(1), SU(2), and SU(3), whose interactions and particles combine to form all that is known to exist. The size of each of the known fundamental particles cannot be larger than about ~10^-19 μm.

When two protons, each made up of three quarks bound together by gluons, interact, it is possible for them to fuse together into a composite state depending on their properties. The most common and proven possibility is the production of a deuteron, made of a proton and a neutron, which would require the emission of a neutrino, a positron, and possibly a photon as well.

Even though you yourself are made of atoms, what you feel as a “touch” does not necessarily require another external atom to actually come into contact with the atoms in your body. Just getting close enough to exert force is not only not enough, it is the most common occurrence.

Molecules, examples of molecules of matter bound in complex formations, achieve the shapes and structures they do because of the electromagnetic forces that exist between their constituent atoms and electrons. The variety of structures that can be created is almost unlimited.

This tunneling electron microscope image shows a few samples of the cyanobacterium Prochlorococcus marinus. Each of these organisms is only about half a micron in size, but all cyanobacteria are largely responsible for the formation of oxygen on Earth: in the beginning and even through the present day. Like all bacteria, their life is much shorter than that of a person.

In warm, shallow bodies of water, pink flamingos can often be found wading, preening, and searching for food. A lack of carotenoid pigments in their food supply, which is seen in some (but not all) of the flamingos shown here, causes many of these flamingos to be closer to white than the stereotypical pink or red, but the behavior of standing on one foot rather than Two, he succeeded in reducing body heat loss almost in half.

This selection of asteroids and comets visited by spacecraft spans several scales in size, from objects less than a kilometer to objects more than 100 kilometers on one side. However, none of these objects have enough mass to pull them into a circular shape. Gravity can hold them together, but electromagnetic forces are mainly responsible for their shapes.

Now that Saturn has been imaged by the JWST, the first “family picture” of the gas giant worlds as seen by the JWST’s eyes can be formed. Here, each planet is shown at an angular size calibrated to how they appear relative to each other as seen by the JWST. Planets can be twice the size of Jupiter, but may be 1000 km or even less.

Illustration of the inner and outer Oort Cloud surrounding our Sun. While the inner Oort Cloud is ring-shaped, the outer Oort Cloud is spherical. The true extent of the outer Oort Cloud may be less than 1 light year, or more than 3 light years; There is a huge uncertainty here. Any massive object passing through the Oort Cloud has a high chance of disturbing objects in its vicinity.

While there are many examples of many galaxies in the same region of space, it usually occurs either between just two galaxies or in very dense regions of space, such as the centers of galaxy clusters. Seeing 5 galaxies interacting in a space less than a million light-years away is extremely rare, captured in fantastic detail by Hubble here. Because all of these galaxies are still forming new stars, they are all classified as “alive” by astronomers.

Between the great clusters and filaments of the universe are great cosmic voids, some of which can span hundreds of millions of light-years in diameter. While some voids are larger in extent than others, spanning a billion light-years or more, they all contain matter at some level. Even the void that includes MCG+01–02–015, the most isolated galaxy in the universe, likely contains small galaxies with low surface brightness that are below the current detection limit of telescopes such as Hubble.

On larger scales, the way galaxies cluster together in observations (blue and violet) cannot match simulations (red) unless dark matter is included. Although there are ways to reproduce this type of structure without specifically including dark matter, such as adding a specific type of field, these substitutions either appear suspiciously indistinguishable from dark matter or fail to reproduce one of the many observations the other to support dark matter.

In modern cosmology, the universe is punctuated by an extensive network of dark matter and ordinary matter. On individual and smaller galaxy scales, the structures formed by matter are highly nonlinear, with densities deviating from average densities by enormous amounts. However, at very large scales, the density of any region in space is very close to the average density: the accuracy is about 99.99%.

This vertically oriented logarithmic map of the universe spans nearly 20 orders of magnitude, taking us from planet Earth to the edge of the visible universe. Each large ‘mark’ on the right-hand side scale bar corresponds to an increase in the distance scales by a factor of 10.