Being the fan of Stephen Hawking that I am, it’s quite surprising that I have not devoted even a single blogpost to his works. Let me do that today, with the adding of a new category to this blog: Science & Technology.
One of the most interesting of his thoughts is about the arrow of time. We take ‘time’ for granted as a fixed entity universal for everyone. However, as Theory of Relativity tells us: time is personal. Everyone carries his own clock, and they may not necessarily agree. Now, the problem is, how do we define time? I will let the master speak in his own words:
The increase of disorder or entropy with time is one example of what is called an arrow of time, something that distinguishes the past from the future, giving a direction to time. There are at least three different arrows of time. First, there is the thermodynamic arrow of time, the direction of time in which disorder or entropy increases. Then, there is the psychological arrow of time. This is the direction in which we feel time passes, the direction in which we remember the past but not the future. Finally, there is the cosmological arrow of time. This is the direction of time in which the universe is expanding rather than contracting.
He goes on to explain why all three arrows point in the same direction, and why its impossible for intelligent beings such as us to exist in conditions where the three arrows do not point in the same direction.