A Macroscopic Calculator
In terms of human experience, it is very difficult to get any real appreciation of the scale of the cosmos as our perception of everyday distances does not really extend to the abstraction of astronomical units. For example, while the concept of a lightyear (LY) corresponding to the distance travelled by light in one year is readily understandable, the actual distance of 5.8*1012 miles or 9.4*1012 kilometres is not so easy to comprehend unless put into some comparative context. Another measure of distance is called an astronomical unit (AU) that corresponds to the distance between the Earth and the Sun, which approximates to 92,955,807 miles or 149,597,871 kilometres. The reason for quoting these distances in both the imperial and metric units is because is it possible to construct a comparative measure that links the size of an astronomical unit with that of a lightyear.
The default comparative model is based on the coincidence, within the imperial system, that the number of inches in a mile (63,360) is approximately equal to the number of astronomical units in one lightyear (63,294). As such, if the distance of the Earth to the Sun is 1 inch, then the distance to the nearest star would be ~4.3 miles away. However, while this coincidence only exists in the imperial system, the results are only displayed in the metric system for consistency, such that 1 inch is equivalent to 0.0254 metres and 4.3 miles is equvalent to 6.91 kilometres. However, the following macroscopic calculator allows you to devise alternative scales, which then show actual and scaled distances to objects within the wider cosmos. For example, another comparative model might be linked to the picture above, where the size of sun might be perceived to be comparable to a football, e.g. 30 centimetres. By using either 'Calculate-1' or 'Calculate-2' you can invoke either of these default models or alternatively devised your own.
No matter which scaled model is used or devised, it quickly becomes clear that the distances between the stars and galaxies within the cosmos are enormous, especially when seen in comparsion to the size of a star, e,g. our Sun, let alone in comparision to planet Earth.
Using the 1AU=1" model, we can see that the size of the Sun would be ~0.2mm in diameter, i.e. smaller than a grain of sand, while its nearest neighbour, another grain of sand, would be 6.91 kilometres away. Within this model, these grains of sand, i.e. stars, would be rotating within a scaled galaxy that is 161,000 kilometres in diameter and exist within a scaled visible universe some 22 billion kilometres in radius.
Obviously, switching to the comparative Sun model increases the size of the Sun from a grain of sand to the size of a football, but now the nearest star would be some 8770 kilometres away and exist within a scaled Milky Way some 204 million kilometres in diameter.
Recently it was announced that Voyager-I was on the edge of our solar system about to enter intersellar space on its onwards journey to the stars. However, examination of the table above would suggest that Voyager-I has cover less than 1/1000th of the distance to the nearest star in its 36 year journey since its launch in 1977. As such, it would take Voyager some +36,000 years to travel the distance of nearest star, assuming it survives the journey, which is far longer than the entire recorded history of humanity.
These scaled model may therefore give us some better insight to the fact that the universe is a 'very, very big place' that appears to consist of an awful lot of empty space, the nature of which is still debated. On any scale, it would seem that we are but small microscopic specks of life on another small speck called 'The Earth' orbiting a grain of sand called 'The Sun' within one of a 100 billion visible galaxies floating within a vast expanse of space that may have no definable boundaries - see 'Concept of Space-Time'. By way of one last example of the 'emptiness' of space, consider the volume of a star, which typically represents about 99% of the mass of a solar system, existing in a volume of space defined by the distance to the nearest star. The figures suggest that a star only occupies something like 10-20 of this volume. However, in turn, it might also be worth highlighting the atomic model suggests that the star itself is primarily 'empty' space. See microscopic calculator for comparative models. As the links above attempt to discuss, maybe we need to seriously consider the fundamental nature of 'empty space'
There is no guarantee that the universe will conform to our predispositions. Carl Sagan