The letter by EM Izett in last week's Sun was interesting in the limitations it places on so-called aliens, in reality fellow dwellers in the universe. It also displays a lack of understanding of modern physics.
The distance to the nearest star, sun, is not 4.3 light years, as stated in the letter, but actually about 8 light minutes. This means that it takes about 8 minutes for the light to travel from the sun to Earth, not the 4.3 years that is inferred in the letter.
The letter also relies heavily on Newtonian physics, while modern physics recognises that quantum physics has produced many effects that cannot be explained by Newtonian physics. Some of these effects include the ability of a particle to appear to be in two places simultaneously, and the ability of paired particles separated by vast distances to apparently communicate with each other instantaneously.
Quite possibly our fellow universe dwellers have figured out how to use quantum physics to their advantage, and are therefore able to travel instantaneously between points in the universe and, as they can exist in two places at once, they can visit Earth and not even leave home.
Far more effective than travelling at the snail's pace EM Izett suggests.
It is highly unlikely that in the limitless universe we are the only living organisms that lay claim to intelligence. Just because no fellow universe dwellers happen to have been recognised as arriving from another planet does not mean that they do not exist (and maybe even live among us).
There is a theory that our existence on Earth is part of an experiment being carried out by fellow universe dwellers of vastly superior intelligence.
Looking at our current geopolitical situation, I wonder how these beings would see our progess so far.
Within the next 1000 years or so we will learn to use quantum physics to our advantage. But we will only do this if we are willing to accept the new paradigms and concepts that science is discovering. Remember that minds are like parachutes - they are most effective when they are open.
Alan Willoughby, Tauranga.