Lecture 6 Notes - Current Challenges and Frontiers in Astronomy

Lecture 6 Notes - Current Challenges and Frontiers in Astronomy 1. Technological Limitations Telescope Power: Another important problem relates to the potency of the telescopes we use or can afford to use. With the Hubble Space Telescope and ground based observing such as the Very Large Telescope (VLT), we can not observe everything. To this day, there remain numerous objects and phenomena that cannot be investigated by conventional means. Resolution: That is why the resolving power of telescopes is also restricted. ● This is an implication to the point that we cannot view objects that are small or those that are far away in an elaborate manner. ● Currently, ALMA has improved this; however, the James Webb Space Telescope (JWST) to be launched soon will at least alleviate this problem but not erase it completely. Interference: ● Telescopes on earth are hindered by the atmosphere around the earth, artificial light at nights, and also signals interfered by human-made technologies. ● Telescopes placed in space do not have this problem, but they have other issues that are just as problematic, for instance - if they get a hole, one has to fix it by spending a fortune. 2. Dark Matter and Dark Energy These are two of the biggest mysteries in astronomy. We can see their effects, but we don't know what they actually are. Dark Matter: ● Dark is used here because it does not emit, absorb or otherwise reflect light in any manner. ● It is unknown and can only be deduced from the influence that it has on other matter, which is visible. Some estimates place it at making up approximately 27 percent of the universe. ● But what is it? That's still a mystery. Dark Energy: ● But contrary to dark matter, dark energy is known to exist in the amount of about 68% of the Universe. ● It is causing the faster rate of expansion of the universe. 3. Black Holes Black holes are another frontier. We know they exist and have some understanding of their properties, but many questions remain. Event Horizon: - Event horizon is another term used in black hole; it is the border beyond which nothing can escape the black hole. What happens beyond it? ● It remains uncertain in terms of the following advice on how it may still be possible to speak with a real person, such as a doctor, and presumably, get a more definitive answer. ● There are the theories like the possibility of existence of other universes or the existence of other dimensions. Hawking Radiation: Stephen Hawking proposed that black holes could emit radiation and eventually evaporate. - This is still a theoretical concept and hasn't been observed directly. 5. Theoretical Challenges Finally, there are many theoretical challenges in astronomy. These include questions about the fundamental nature of the universe. a. - Big Bang and Beyond: Currently, we know a lot about the Big Bang but what preceded this event? As for what will take place in the far future ? These are still the kind of questions To clarify, the following questions are still open b. Multiverse: It is now becoming acceptable to remark that the universe we live in is but one of the many universes out there. But how can one be certain about the existence of other universes? This is one of the biggest theoretical issues. - astronomy is ever expanding science and new findings are made from time to time. Modern developments could reverse all of what individuals consider as facts.