Sunday, 22 February 2015

Indian scriptures mention gravity 1500 years before Isaac Newton: Former ISRO chief G Madhavan Nair

Former ISRO chairman G Madhavan Nair (Photo: PTI)

One of the country's leading scientists and former ISRO chairman G Madhavan Nair on Saturday propounded the theory that some shlokas in the Vedas mentioned about presence of water on the moon and astronomy experts like Aryabhatta knew about gravitational force much before Issac Newton.
The 71-year-old Padma Vibhushan awardee said the Indian vedas and ancient scriptures also had information on metallurgy, algebra, astronomy, maths, architecture and astrology way before the western world knew about them.
Speaking at an international conference on Vedas, he however, added that the information in vedas was in a "condensed format" which made it difficult for the modern science to accept it.
"Some sholkas in one of the Vedas say that there is water on the moon but no one believed it. Through our Chandrayaan mission, we could establish that and we were the first ones to find that out," Nair said, adding that everything in Vedas could not be understood as they were in chaste Sanskrit.
He also talked very highly about fifth century astronomer- mathematician Aryabhatta saying, "We are really proud that Aryabhatta and Bhaskara have done extensive work on planetary work and exploration of outer planets. It was one of the challenging fields.
"Even for Chandrayaan, the equation of Aryabhatta was used. Even the (knowledge of) gravitational field... Newton found it some 1500 years later... the knowledge existing (in our scriptures)," he said.
Nair, who was ISRO chairman from 2003-09, also claimed geometry was used to make calculations for building cities during the Harappan civilisation and the Pythagorean theorem also existed since the vedic period.
The comments by Nair came in the backdrop of many BJP leaders talking about ancient Indian scriptures having scientific information including on plastic surgery as well as aero-dynamics.

Wednesday, 11 February 2015

Popular Press Announces: The Big Bang Didn’t Happen!

Timeline of the Universe. Image credit: NASA
Timeline of the Universe. Image credit: NASA
Did the big bang really happen? Yes, despite recent claims to the contrary.  A new paper in Physical Letters B has the popular press wondering if there was no big bang, but the actual paper claims no such thing.
The big bang is often presented as some kind of explosion from an initial point, but actually the big bang model simply posits that the universe was extremely hot and dense when the universe was young. The model makes certain predictions, such as the existence of a thermal cosmic background, that the universe is expanding, the abundance of elements, etc. All of these have matched observation with great precision. The big bang is a robust scientific theory that isn’t going away, and this new paper does nothing to question its legitimacy.
That doesn’t mean there aren’t unanswered questions about the big bang. For example, simple big bang models show that if you go back in time far enough, there is time when the entire universe was an infinitely dense singularity. This singularity would mark time zero for the cosmos. As many of you know,singularities are problematic, and they tend to stir up lots of debate. That’s where this paper comes in.
The paper presents a big bang model without an initial singularity. It does this by looking at a result derived from general relativity known as the Raychaudhuri equation. Basically his equation describes how a volume of matter changes over time, so its a great way of finding where physical singularities exist in your model. But rather than using the classical Raychaudhuri equation, the authors use a variation with a few quantum tweaks. This approach is often called semi-classical, because it uses some aspects of quantum theory, but isn’t a complete quantum gravity model (which we don’t have).
big bangWhat the authors show is that their modified Raychaudhuri model eliminates the initial singularity of the big bang. It also predicts a cosmological constant, which is a proposed mechanism for dark energy. Their model is really basic, but this first result shows that this type of approach could work. The catch is that by eliminating the singularity, the model predicts that the universe had no beginning. It existed forever as a kind of quantum potential before “collapsing” into the hot dense state we call the big bang. Unfortunately many articles confuse “no singularity” with “no big bang.”
While this is an interesting model, it should be noted that it’s very basic. More of a proof of concept than anything else. It should also be noted that replacing the big bang singularity with an eternal history isn’t a new idea. Many inflation models, for example, make similar predictions. But none of these ideas eliminate the big bang, which is an established scientific fact.

Tuesday, 10 February 2015

The Armstrong Purse: Flown Apollo 11 Lunar Artifacts

At the National Air and Space Museum, as elsewhere around the world, we were enormously saddened when we learned that Neil Alden Armstrong, the first man to set foot on the Moon, had died of complications associated with heart surgery in August 2012. Not long afterwards his family contacted the Museum about artifacts he left in his home office in Ohio. In November, Museum curators Margaret Weitekamp (social and cultural history of space exploration), Alex Spencer (personal aeronautical equipment), and I (as Apollo curator) traveled to Cincinnati and were warmly greeted by his widow, Carol. We reviewed the items with the intention of listing those we felt appropriate for possible donation to the National Collection. The Armstrong family had already decided to donate Neil’s correspondence and paper files to his alma mater, Purdue University. The remaining collection of personal items and memorabilia was also extremely rich. Margaret and Alex may have the opportunity to write about these items in the near future.
This post is about something else however. A few weeks after we returned to Washington, D.C., I received an email from Carol Armstrong that she had located in one of Neil’s closets a white cloth bag filled with assorted small items that looked like they may have come from a spacecraft. She wanted to know if they were also of interest to the Museum. She provided the following photograph of the bag and the items spread out on her carpet.
Photograph provided by Carol Armstrong showing the objects found within the white cloth bag.
Needless to say, for a curator of a collection of space artifacts, it is hard to imagine anything more exciting. Realizing how important it would be to determine whether any or all of these items were actually flown in the Lunar Module Eagle during the historic Apollo 11 mission, I decided to enlist the expertise of Eric Jones, Ken Glover, and the team of experts who have put together the incredible Apollo Lunar Surface Journal (ALSJ) website, an indispensable site of detailed information about all aspects of the Apollo program.
The bag itself was immediately recognizable in that the ALSJ long has had a page devoted to what the astronauts referred to as a McDivitt Purse. The purse was a special container (officially called a Temporary Stowage Bag or TSB) stowed in the Lunar Module during launch but specially fitted with pins that fit into sockets in front of the Commander’s station to the left of the Lunar Module hatch. The TSB looks like a clutch purse in the way it opens and closes.
Apollo 11 Temporary Stowage Bag
The astronauts referred to it as a McDivitt purse, apparently because the need for a bag to temporarily stow items when there wasn’t time to return them to fixed stowage locations was first suggested by Apollo 9 Commander James McDivitt.
After a close examination of detailed photographs taken when the objects were in the Armstrong family’s possession and after they were shipped for cataloging and research to the National Air and Space Museum, the ALSJ experts were able to determine with almost complete certainty that all of the items were indeed from the Eagle, and that — although they were formally scheduled to be left behind — they were assembled in the Temporary Stowage Bag and saved from the fate that awaited Eagle’s ascent stage and all of its contents: crashing into the lunar surface.
Evidence that the items were intentionally preserved is found in the mission transcripts themselves. (The transcripts of voice communications are the documents around which the entire ALSJ is organized.) The rescued items are referenced by the Apollo 11 crew soon after Neil and Buzz Aldrin rejoined Michael Collins in lunar orbit. While still in the Lunar Module and after lunar orbit rendezvous with the Command Module, Neil and Buzz spent considerable time passing over to Mike the rock boxes and the contingency samples they had collected from the Moon. Less than an hour before they were ready to jettison Eagle, mission transcripts record Armstrong saying to Collins (Mission Elapsed Time (MET): 129:14:53): “You know, that — that one’s just a bunch of trash that we want to take back — LM parts, odds and ends, and it won’t stay closed by itself. We’ll have to figure something out for it.”
Later (MET 181:38:04) they would describe to mission control the container with the “odds and ends” as, “10 pounds of LM miscellaneous equipment.” It was important they account for the amount and distribution of any added weight so that the return trajectory and entry parameters could be calculated with precision.
As far as we know, Neil has never discussed the existence of these items and no one else has seen them in the 45 years since he returned from the Moon. (I asked James Hansen, Neil’s authorized biographer if he had mentioned the items, and he had not.) Each and every item has its own story and significance, and they are described with photographs in extraordinary detail in an addendum to the Apollo Lunar Surface Journal. But two of the items are especially timely. Both have been placed on display as part of the recently opened temporary exhibition Outside the Spacecraft: 50 Years of Extra-Vehicular Activity.
The first is the 16mm Data Acquisition Camera that was mounted in the window of the lunar module Eagle to record the historic landing and “one small step” made by Armstrong as humankind first set foot on another world.
Apollo 11 16mm Data Acquisition Camera. Below are a handful of images captured by this camera.
Neil Armstrong about to step on the Lunar surface as recorded by the 16mm Data Acquisition Camera.
Camera view of Neil and Buzz setting the American Flag.
The second is one of two waist tethers provided in the lunar module explicitly for securing astronauts should they have to spacewalk from the Lunar Module back to the Command Module had there been a problem reconnecting the two spacecraft in orbit around the Moon. We have determined that this tether was the one Neil Armstrong jerry-rigged to support his feet during the single rest period on the Moon, a story well told and documented in the new Journal entry.
Apollo 11 Waist Tether used by Neil Armstrong to suspend his legs as he attempted to get comfortable during the rest period inside the Lunar Module.
In the future, we hope to complete documenting and cataloging the entire collection of items and, as appropriate, to place them on public display. Seeing such things with one’s own eyes helps us to appreciate that these accomplishments are not just in history books or movies, but involved real people and real things, and that they involved an extraordinary amount of detailed engineering and planning.