19.22 Light years away


Research that identifies other planets that may be capable of sustaining life sometimes leads to the suggestion that we may soon be communicating with alien life forms. Recently such a planet was identified that is 111 light years away from earth (https://www.bbc.com/news/science-environment-49648746).

What is a light year? It is the distance that light travels in 1 year. So light would take 111 years to travel from this planet to us. According to Einstein’s theory of relativity, nothing can move faster than the speed of light. Of course, like all scientific theories, this may in future be superseded by a better one, but, at present, it forms the only basis we have for thinking about things that move so quickly (post 16.2).

So, if we tried to visit aliens on their planet (or they tried to visit us) it would take 111 years. In Japan, the average life expectancy of a woman is 87 years (the longest average life expectancy in the world). This suggests that our interplanetary explorers would probably be dead on arrival!

And there is another problem – if matter were to move at the speed of light it would disappear and be converted into energy (post 17.41). So our speed-of-light space travellers would cease to exist! They would have to move more slowly and, as a result, their journey would take much longer than 111 years.

What about sending them signals, using radio, or other waves? The waves that we could transmit across empty space are all forms of electromagnetic waves that travel at the speed of light (post 19.9). So it would take the aliens 111 years to receive our signal, and 111 years for them to send a reply. Add to this that they have to receive the signal, understand what it is and decode it (remember, they probably won’t speak English or Chinese or Spanish despite one of these languages being spoken by very many people on Earth), so the total time is likely to be much greater than 222 years.

Even if alien life forms do exist and have the technology to receive our signals, communication with them would take many generations.

I assume that any means of communication with aliens would be based on scientific principles. Then, as with all scientific predictions, we shouldn’t simply accept what other people tell us – we need to think about what we are told. Once again, science is not about absorbing facts or the opinions of others – it provides a way of thinking about things, like communication with aliens, for ourselves.

Discovering a planet that could support life is a long way from communicating with aliens.


Related posts

19.4 Dietary information
18.18 Who benefits from scientific research
17.46 Peeing contests
17.33 Lord Kelvin and flying machines
17.14 Confusion
17.9 Scientists believe that
17.1 It’s obvious
16.36 Good and bad
16.32 Faith in science
16.22 Science can’t explain everything
16.15 Science education
16.3 Scientific proof
16.2 Scientific laws can be broken
16.1 Drug safety testing



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