Aliens. Great for SciFi movies, but in real life, they can’t exist, can they? Well back in 1961 Dr Frank Drake came up with an equation, that would be known by the name “The Drake Equation”, to estimate the number of communicative civilisations within the Milky Way Galaxy.
What is a Galaxy?
Now if you’re like me, a Galaxy was a milk chocolate bar that I enjoyed during my childhood.
However, when we’re talking about space a Galaxy is defined as:-
A large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space
Source: Dictionary.com
What is the Drake equation?
It is expressed mathematically as:-
![\[ N = R_* \cdot f_p \cdot \eta_e \cdot f_1 \cdot f_i \cdot f_c \cdot L \]](https://greyhairgreymatter.blog/wp-content/ql-cache/quicklatex.com-6659c61aa2fe200bbf39864a93c072b3_l3.png "Rendered by QuickLaTeX.com")
Where:-
N = The number of civilasations within the Milky Way where communication may be possible
R* = the average rate of star formation
⨍p = = the fraction of those stars that have planets
ηe = the average number of planets that can potentially support life per star that has planets
⨍1 = the fraction of planets that could support life that actually develop life at some point
⨍i = the fraction of planets with life that actually go on to develop intelligent life
⨍c = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L = the length of time for which such civilizations release detectable signals into space
Now don’t get freaked out by the Maths of it all.
It is only an approximation, but once you start to consider the numbers behind each of the elements of the equation, you quickly come to the conclusion it would be very arrogant of us to think we were the only sentient beings in the Universe.
How big is the Universe?
In short, the Universe we know about so far, and the emphasis is on so far, is vast. The furthest places in the Universe we can observe are around 46 billion light years away according to the BBC. That’s 540 sextillion miles.
That’s 540,000,000,000,000,000,000,000 miles.
It’s so vast I can’t begin to fit it in to any sort of scale relative to measures I know. The only thing I can relate it to is the circumference of the Earth which is 24,901 miles
24,901 miles around the Earth compared to 540,000,000,000,000,000,000,000 miles.
It kind of makes you feel really small.
So with all that space available to others, by which I mean non-Earthbound life-forms, is it really conceivable there’s nobody else out there? That aliens really don’t exist?
It makes you think, doesn’t it?
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