Material is composed of subatomic particles like neutrons, protons, and electrons, listed in order from highest to lowest weight. Electromagnetic rays are the tracks of energy particles called photons.
The weight and the energy of a photon are directly proportional to the rapidity of vibration of the rays.
Photons can produce particles if the equivalent mass of the photons is at least as great as the mass of the particles. Since c² is a large number, we need very energetic photons to make even low-mass particles.
X-rays have the most energetic photons scientists can produce with laboratory equipment. Low-energy gamma rays are identical to X-rays, but the term “gamma rays” refers to rays from natural sources. Some gamma rays have photons that are much more energetic than the most energetic X-ray photons we can produce. To materialize, rays must be at least as energetic as the energetic X-rays physicists make with cyclotrons or linear accelerators.
The weight and the energy of a photon are directly proportional to the rapidity of vibration of the rays.
Photons can produce particles if the equivalent mass of the photons is at least as great as the mass of the particles. Since c² is a large number, we need very energetic photons to make even low-mass particles.
X-rays have the most energetic photons scientists can produce with laboratory equipment. Low-energy gamma rays are identical to X-rays, but the term “gamma rays” refers to rays from natural sources. Some gamma rays have photons that are much more energetic than the most energetic X-ray photons we can produce. To materialize, rays must be at least as energetic as the energetic X-rays physicists make with cyclotrons or linear accelerators.
A single ray cannot materialize all by itself. Two rays, or a ray and a particle, must collide to materialize. If there is a particle present then the space is not empty, so let us describe first the collision of two rays in empty space. When gamma rays or energetic X-rays collide, they convert some or all of their energy into particles. The particles may be components of atoms, such as protons, neutrons, and electrons, or other, less well-known particles. We cannot see atoms because atoms are 5 000 times smaller than light waves. Subatomic particles are even smaller. During the collision, some of the original energy may become kinetic energy, the energy of moving objects. If so, the particles will depart from the scene of their materialization at high speed. If any of the original energy remains, it will travel on as one or more photons of lower energy. The photons continue to collide and fracture until they lack enough energy to materialize.
Sufficiently energetic rays become visible when they collide, fracture, and partially materialize as particles. The particles must form atoms, and the atoms must combine in great numbers before there is visible material. The remaining energy may be soft X-rays, ultraviolet rays, light, or heat. Only the light rays are visible.
An electron has the lowest mass of the three most common subatomic particles. Its mass is equivalent to the energy of the hard X-ray photons we use for treating cancer, much more than the energy of the softer X-ray photons we use for medical diagnosis. Visible light photons are far too weak to make electrons, let alone protons or neutrons. Photons of heat, light, ultraviolet rays, and soft X-rays are all too weak to materialize.
Sufficiently energetic rays become visible when they collide, fracture, and partially materialize as particles. The particles must form atoms, and the atoms must combine in great numbers before there is visible material. The remaining energy may be soft X-rays, ultraviolet rays, light, or heat. Only the light rays are visible.
An electron has the lowest mass of the three most common subatomic particles. Its mass is equivalent to the energy of the hard X-ray photons we use for treating cancer, much more than the energy of the softer X-ray photons we use for medical diagnosis. Visible light photons are far too weak to make electrons, let alone protons or neutrons. Photons of heat, light, ultraviolet rays, and soft X-rays are all too weak to materialize.
Light rays are visible and make other things visible. All other rays are invisible. They carry energy in darkness.
When doctors make an X-ray picture, they send a powerful pulse of energy through the patient’s body. The X-rays expose the film, but the patient sees nothing. To the patient X-rays are dark.
Since we can see the stars, we know that light can travel in space. We say that space is empty when it contains no matter, but empty space always contains the energy of heat and of any light or gamma rays in transit. We have never been able to make any space so cold and dark that it has no energy at all. Electromagnetic rays can exist in empty space, and there they can make material.
