Behind the Times: Viewing the Present from the Past

When astronomers estimate the distance between earth and another astronomical entity, they often talk in terms of light years. For example, the Alpha Centauri star (that actually comprises three separate stars) is the closest star to earth other than the sun and is estimated to be 4.37 light-years away. This means that if we were to view Alpha Centauri from earth, we would be looking at the star as it was some 4.37 years ago. In others words, it could be said that our view of Alpha Centauri is 4.37 years out of date.

On a much smaller scale, the exact same principle applies when we perceive objects that are much closer to us. We see an object because light from the sun (or another light source) is reflected by the object before travelling to the light-sensitive retina at the back of our eyes. As discussed in our recent post on ‘The World Through the Eyes of the Central Nervous System’, when sight receptors are stimulated, electrochemical impulses travel via a process of saltatory conduction and once received by the central nervous system, they are transformed into a coherent image that can be acted upon.

The speed of light is 299,792 kilometres per second but for the purposes of this post, we have rounded it up to 300,000 km/s. This means that if we look from the top of a mountain at a lake that is 30 kilometres away, it takes 0.00001 seconds for light from the lake to reach us. Therefore, our view of the lake is ever so slightly out of date. Likewise, if we look at a person standing just three meters in front of us, it takes approximately 0.000000001 seconds for the reflected light to reach us. In fact, it actually takes slightly longer than this because light travels slower through the earth’s atmosphere than it does through space, and it also takes a brief moment for electrochemical impulses to travel from the eyes and be processed by the brain.

In terms of how the average person goes about their daily business, we suspect that there are few (if any) implications of this observation. However, the fact of the matter is that when a person says that they are living in the present moment, this is not entirely true. They might be perceiving in the present, but what they are perceiving is the past. From this point of view, perhaps one could say that individuals following the fashionable trend of mindfulness are actually (slightly) behind the times!

 Ven Dr Edo Shonin and Ven William Van Gordon

 Further Reading

Mendelson, K. S. (2006). “The story of c”. American Journal of Physics, 74, 995-997.

Penrose, R. (2004). The Road to Reality: A Complete Guide to the Laws of the Universe. Vintage Books.

Schaefer, B. E. (1999). Severe limits on variations of the speed of light with frequency. Physical Review Letters, 82, 4964-4964.

Shonin, E., & Van Gordon, W. (2014). Dream or reality? Philosophy Now, 104, 54.

Shonin, E., & Van Gordon, W. (2013). Searching for the present moment, Mindfulness, 5, 105-107.

Torres, C. A. O., Quast, G. R., da Silva, L., de la Reza, R., Melo, C. H. F., & Sterzik, M. (2006). Search for associations containing young stars (SACY). Astronomy and Astrophysics 460(3): 695–708

Van Gordon, W., Shonin, E., & Griffiths, M. D. (2016). Buddhist emptiness theory: Implications for psychology. Psychology of Religion and Spirituality, DOI: 10.1037/rel0000079.

Wiegert, P. A., & Holman, M. J. (1997). The stability of planets in the Alpha Centauri system. The Astronomical Journal, 113, 1445-1450.