Astronomy - Telescope & Time

I attended a talk on astronomy at Toa Payoh Library on Saturday 8 Feb 14 conducted by Gary Chee from Astro Sg. The talk gave a brief amatuer guide to buying and using a telescope. Generally telescope is classified into 3 types (1) Refractor - using lens to bring object closer (2) Reflector - using mirrors to concentrate the light and hence bring object closer (3) Schmidt Cassegrain - which is a hybrid mirror and lens telescope.

While there are various types of telescope, there are certain advantages and limitations to each type which buyers have to consider including portability, magnification, cost etc. Also, there are other factors which can influence the quality of image and they are light pollution, cloudy sky, earth atmosphere etc. I have this feeling that unless a high capital cost is spent on purchasing quality telescope, there will be insignificant impact on the image for amatuer grade telescopes.

I also watched a document (on youtube) on the concept of time and was given a brief understanding of the meaning enthropy. It is shown that the definition of event occuring "now" will be impacted by motion and gravity. Motion refers to whether the object is moving towards you or away from you. If the object is moving towards you, the impact of that event may be felt in the future. Even though both the object and you are feeling the same "now". It was also mentioned that since there was no evidence of future being coming into the current time, it could be inferred that time travelling, especially travelling back in time may be difficult practically. I was thinking that with the relationship between mass, gravity and speed (which has a component of time), it would be insurmountable for time travel as it would either involve mass to be infinetly big or that such attempt would require breaking down a living organism into particles that would not have a desirable outcome when those particles are put back together.

Nonethelesss, science is evolutionary. It is less than 500 years old that men are still proclaiming that earth is in the centre of universe (before Galileo discovery). However, science has always changed current theory and concept. There could be more game changing discovery that deviates from our current beliefs.