I was reading a article on very distinguished website on the topic "Has progress in cosmology stalled ? ". I became very convinced that I should write on this topic and to tell the people who are not heavily concered with physics tell what has been done in the study of marriage of space-time.
The Stuff in Common Imagintion
While maybe the majority of population of planet earth are not conerned heavily with cosmology , there is always a distinctive attention towards an idea which chaneges our understnding of the cosmos.Whether it was a the time of Copernicus first predicted that the Earth centred Universe is wrong to the time of Galileo from his observations proving that the Earth revolves around the Sun to the time of Newton revealing the everpreset and universal force of gravity to when Einstein described Space-time and unravalled the most radical ideas of cosmology , there has always been a factor of popular public attention. Because in the mind of every human being lies the key question about "what we are ? " .If we roll back the years topics such as the big bang & black holes have been in the popular imagination now for years . They have not only been a popular talking topic but have also been n integral part in hollywood Sciene-fiction films and topics of long debates in news channel debate programmes . Also stuff like wormholes , the predicted shortcuts in the universe , have also been in popular imagintion for a long time . The concept of time travel , which is also heavilly related to cosmology , has been the most talked about science topic in the 21st century .
The Unsung heroes and marvels
Undoubtedly cosmology is having an unprecedented public attention but there are still much ideas and brilliant people who have contribued so much but have been remained virtually unknown . For example Eistein's General theory of Relativity beautifully describes space-time but is virtually not much known to the normal public because of the complex mathematical model of this idea is so radical that some physics techers even suggest students not heavily concered with cosmology not to even have a look at that theory! Stephen Hawking is widely considered as one of the most brilliant minds to have walked on planet Earth , but if you ask normal person what are Hawking's scientific achievemets he'd probably be silent. His greatest ahievement was to prove that the universwe had came from a singularity whih is called the big bang singularity.Hawking reversed Sir Roger Penrose's equatios which showed that the singularity is so powerful it can destroy a universe and he(Hawking) found out tht the universe had come into being from a singularity itself. Hawking also found out that Black Holes emit a form of black body radiation through whcih they loose their mss and eventually evaporate . The radiation in his honour was named "Hawking Radiation" .These quintessential ideas changed the way we understand blak holes , Then in 1981 a spectacular discovery was made about the big bang by Alan Guth. Guth had discovered that the early Universe expanded exponentially fast for a fraction of a second after the Big Bang.This idea is called "Inflation". It explains the origin of the Large scale structure of the cosmos , Quantum fluctutions in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe .Soon after this ecstatic discovery , 2 Russin Physicists named Alex Vilekin and Andrei Linde studied Inflation in pretty detail . They though that this idea could solve the question "Are there more universes". Suprisigly , one day while bathing Vilekin realized that inflation would stop in some regions of space but continue in some other regions of space and immediately he worked out the equatios .Then he went to Guth to explain his realization and to his astonishment Guth was not convinced and not paid much attention. The idea of Vilekin was that inflation would cause oher universes to burst up in different regions of space and so there were multiple big bangs before ours and many more after ours. The problem was that this idea could not be tested experimentally. Linde and Vileken throw up their idea as they considered it worthless. But theories after that have supported the idea of "Multiverse". And so from that we see another great marvel in our modern era in cosmology in the "String Theory". The string theory actually comes from quantum mechanics and strig theory says that all matter is made up of vibrating forms of energy which make our atoms and particles. Each string will have different type of shape.When we actually solve the equations of string theory to find out the amount of shapes or the amount of dimensions in cosmological sense we find that there are 10^500 possible dimenions or even more , each being equally valid as the other . This idea suggests that each of those dimensions (which are not actually be dimensions) are describing a possible universes and this supports the idea of Multiverse . Maybe 4-5 years someone will explain this idea in totally different way! Another great discovery in modern cosmology which has not been much talked about are Dark energy and dark matter . Edwin Hubble had shown us in 1930's that the Universe was expanding. But phyicists thought what caused the expansion? the answer has been found in the start of 21st century. Physicists have deemed that there is an unkown kind of energy which is causing the expansion known as "Dark Energy". But suprisingly when measured the magniude of dark energy is 10^-221.That seems insane but turns out to be the reality.By fitting a theoretical model of the composition of the Universe to the combined set of cosmological observations, Physicists have come up with the composition that we described above, ~68% dark energy, ~27% dark matter, ~5% normal matter. What is dark matter?Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe.
So, what can we make out of all the stuff above ?we can only say that never in the history of any field of science ,let alone be physics , has progress stalled and will never be atleast until curiosity in every human being survives