The Universe is not empty. Scientists and astronomers are learning that there are immense flows of electricity like filaments of a gigantic web stretching all throughout the universe and these generate huge magnetic fields. These filaments are spread throughout the universe connecting stars, as far as our telescopes can see. In addition to this web of filaments, all space seems to be awash with particles, some speeding around at speeds faster than light! Other things we find are great clouds of dust particles; such a cloud is blocking our view of parts of our own galaxy and thus, prevents us from examining it. The dust cloud is huge! All radiation is made of particles. Scientific researchers are studying the many different types of particles and wave formations arriving on earth and at our space probes. Such waves and particles, when taken as a whole, is called radiation. There are two different sources of what we call space radiation arriving here. Firstly, there is Cosmic radiation arising from deep space – the Cosmos and secondly, there is the radiation which is emitted by our own sun. We also know about Radioactive decay of certain materials. Each of these types of radiation needs explanation.
The steady stream of radiation from the Cosmos has a whole mix of particles which are very dangerous for us and life on earth. Luckily, this Cosmic radiation is repulsed and blocked by the radiation from our sun. So the sun is our first line of defence from Cosmic radiation. But then, our sun, also sends out a steady stream of waves (sunlight) and particles called the solar wind, sent out in all directions including Earth. In day time, we on earth, are being continually bathed in the sun’s rays – of light, but also by speeding electrons and broken up parts of atoms, arising from the violent activities within the sun. This is the steady state of our sunlight.
Luckily, our planet has two further lines of defence against radiation. It is widely thought that our planet has a core of iron surrounded by liquid iron at the centre. This has created a protective magnetic field surrounding us like a bar magnet, called a magnetosphere, and this magnetic field protects us very well from most particles and waves. Secondly, our planet is blessed with a thick layer of atmosphere, much of which is of water molecules. This also forms a barrier and protects us. Incoming particles collide with molecules in the atmosphere and they fall to earth with little energy and are harmless to life on earth.
Unfortunately for us, the sun occasionally, blasts out trillions of tons of hot matter in what are called Coronal Mass Ejections. Our magnetosphere and thick atmosphere cannot shield us from such extreme events. These, too, are very dangerous for everything in its path because this material is of massive weight, very hot and traveling very fast. On one occasion a very large Coronal Mass Ejection has actually hit planet earth, in the event called the Carrington 1859 event. On that occasion transformers and transmission lines burnt out due to current overload. If it should occur in the present day, ATMs, cellphones, electric transformers would all be out of action for a month or two. Smaller flares and Coronal Mass Ejections are happening frequently but they shoot out at any angle of the 360 0 circumference, fortunately, usually missing Earth or affecting us very little.
Our magnetosphere has two toroid (doughnut) shaped magnetic rings which we name after the scientist who discovered them, called the Van Allen Belts. When Astronauts travel beyond the “Van Allen Belts” and out into space, they unavoidably experience radiation. At present, our ability to shield astronauts from this radiation is very limited. So, for their own safety, these men and women can only stay outside the Van Allen belts for a short time. If we want to escape our planet we have to overcome some very serious hazards, because strong radiation is emitted from both the sun and the outer Cosmos. This makes space travel most hostile to humans; we are spectacularly unsuited for anywhere other than our little cocoon found on Planet Earth.
TRANSFER OF ENERGY FROM THE SUN
The sun emits energy in the form of particles and also the whole spectrum of electro-magnetic waves. Both particles and short wave radiation transmit heat that warms the planet. The sun’s output is variable. The surface of the sun carries sunspots and coronal holes as it rotates, causing heating and cooling cycles, called the Glyssenburg Cycles, here on earth. Also, these surface variations affects the earth, creating different types of weather here.
Electro-Magnetic Waves
The earth is warm compared to space, so it also sends out heat in the form of long wave energy. Because it is much cooler than the sun it sends out only a little heat in comparison. The sun, because it is so hot, sends out the full spectrum of Electro-magnetic waves. Scientists have divided this frequency range into six major divisions: radio waves, infrared waves, visible light, ultra-violet light, x-rays and gamma rays. Radio waves are not strong so, not harmful; but gamma rays, or short frequency waves can only be created by hot objects, and so, transmit heat strongly. Even sound waves and dust particles such as olivine, arrive here as a form of radiation from the sun.
Types of Particle in Radiation
WE need to know some basics about the various particles of radiation. Has it been named – what is it? What is its energy? How many particles are involved? What do they do to the human body? – are all important questions.
Radiation can be transferred by elementary particles, (- having no sub-structure), small composite particles of the atom and electro-magnetic waves (as above). (We do not know how gravity is created or transmitted.)
Some particles are harmless. The sun produces enormous quantities of Neutrinos – electrically neutral, of small mass which have little interaction with other matter, so are harmless to us.
Electrons and muons as Beta radiation, deliver a negative charge to a body or surface. Protons are heavier and are positive. Alpha particles, which are parts of helium or hydrogen atoms are positively charged. Being large, they do much damage to our bodies. Neutrons create big damage but have no charge. Electro Magnetic Radiation delivers pure energy. Short waves, such as Gamma Rays are powerful and are called ionizing radiation because they break the structural bonds of atoms. All these particles and waves are very dangerous to the human body.
TRANSFER OF ENERGY FROM SPACE – COSMIC RADIATION
This radiation is mostly protons and/or ions (ions – broken up or parts of atoms). It is a shower of photons, electrons, muons, neutrons and ions. When these enter our atmosphere they collide and break up causing what we call, a cosmic ray shower of photons, electrons, muons and neutrinos.
RADIO ACTIVITY
Ionizing Radiation: Alpha, (helium nuclei), Beta (electrons, positrons), and Gamma (photons). These are found in many places on earth and is called background radiation and is found throughout our environment in small amounts. But certain metals, with unstable atoms are found to be strongly radioactive, and therefore, dangerous.
How many particles are there present arising from a source? Power is related to energy per time which is calculated in Watts.
Power of radiation is at maximum when measured close to the source of radiation. Because particles spread out in all directions in a space, so the further away you are, the fewer will hit you. Move away! The radiation which interacts with matter is the least likely to reach you.
How much radiation is absorbed by the body and what harm can it do? High amounts of energy pumped into the human body is harmful to us. Ionizing radiation breaks up the atoms in your body – it destroys them! Most countries set legal maximum levels of radiation their people should be exposed to. Alpha particles are the most dangerous to humans. Avoid!
DISTURBING TREND UNCOVERED
The number of sunspots per sunspot cycle has decreased over recent years. This tells us that the Sun’s Magnetosphere is weakening gradually and this will allow more Cosmic radiation to arrive at earth. That also means astronauts have less time in space before allowable limits of radiation dose are exceeded. For example in 1996 astronauts could operate for 1000 hours in space or the moon. Now, NASA has reduced the allowable time in space to 200 hours for safety reasons, due to the increased radiation entering from the Cosmos. And now we also know about lethal Coronal Mass Ejections occurring; astronauts have another serious problem to avoid.
Some of this information has been taken from Dr. Sabine Hossenfender’s talk on this subject found in the “GreatCoursesPlus.com”. You are invited to go to this address and learn more. PH. 12/2/21