Scientific Inquiry Process Finds More Evidence Supporting Einstein’s Theory
Posted on May 29, 2012 Comments (0)
As scientists have been able to see farther and deeper into the universe, the laws that govern its expansion have been revealed to be under the influence of an unexplained force.
In a paper on the arXiv, Astrophysical Tests of Modified Gravity: Constraints from Distance Indicators in the Nearby Universe, are a vindication of Einstein’s theory of gravity. Having survived several decades of tests in the solar system, it has passed this new test in galaxies beyond our own as well.
In 1998, astrophysicists made an observation that turned gravity on its ear: the universe’s rate of expansion is speeding up. If gravity acts the same everywhere, stars and galaxies propelled outward by the Big Bang should continuously slow down, like objects thrown from an explosion do here on Earth.
This observation used distant supernovae to show that the expansion of the universe was speeding up rather than slowing down. This indicated that something was missing from physicists’ understanding of how the universe responds to gravity, which is described by Einstein’s theory of general relativity. Two branches of theories have sprung up, each trying to fill its gaps in a different way.
One branch — dark energy — suggests that the vacuum of space has an energy associated with it and that energy causes the observed acceleration. The other falls under the umbrella of “scalar-tensor” gravity theories, which effectively posits a fifth force (beyond gravity, electromagnetism and the strong and weak nuclear forces) that alters gravity on cosmologically large scales.
“These two possibilities are both radical in their own way,” University of Pennsylvania astrophysicist Bhuvnesh Jain said. “One is saying that general relativity is correct, but we have this strange new form of energy. The other is saying we don’t have a new form of energy, but gravity is not described by general relativity everywhere.”
Jain’s research is focused on the latter possibility; he is attempting to characterize the properties of this fifth force that disrupts the predictions general relativity makes outside our own galaxy, on cosmic length scales. Jain’s recent breakthrough came about when he and his colleagues realized they could use the troves of data on a special property of a common type of star as an exquisite test of gravity.
Teen Solves Puzzle That Has Stumped Mathematicians for 300 Years
Posted on May 27, 2012 Comments (0)
The solution devised by Shouryya Ray, 16, makes it possible to calculate exactly the path of a projectile under gravity and subject to air resistance. Shouryya, who lives in Dresden, eastern Germany, came up with the solutions to this and a second mathematical riddle while working on a school project.
Only partial solutions had been discovered up to now, requiring simplified assumptions or calculations by computer. Shouryya’s elegant solutions could contribute to greater precision in fields such as ballistics.
Elephant Underpass in Kenya
Posted on May 21, 2012 Comments (3)
Without the underpass, animals that try to move between isolated areas often destroy fences and crops—leading to conflicts with people.
Since its completion in late 2010, the underpass has been a “tremendous success”—hundreds of elephants have been spotted walking through the corridor, according to the conservancy.
It is great to see such solutions put into place. Animals that come into conflict with people (whether it is farmers in Africa, ranchers in the USA or villagers in India) often lose. There is a reason humans dominate the globe. We might be easy to beat in a one on one battle when we can prepare. But when we get frustrated and decide it is time to take action, that is bad news for most mammals (bacteria are only in trouble with our scientists and manufacturers get together and even then the bacteria might not lose).
What we need to do is find ways for the animals to live without too severely impacting people. Because if we don’t eventually the people will take action.
I have been to the game parks in Kenya twice, it is amazing.
Related: Monkey Bridge in Kenya – Insightful Problem Solving in an Asian Elephant – underwater highway bridge – A Group of Wild Mountain Gorillas Strolling Through Camp Observing Humans Observe the Gorillas
Modeling Weight Loss Over the Long Term
Posted on May 17, 2012 Comments (1)
Researchers at the National Institutes of Health have created a mathematical model of what happens when people of varying weights, diets and exercise habits try to change their weight. The findings challenge the commonly held belief that eating 3,500 fewer calories, or burning them off exercising, will result in a pound of weight loss.
Instead, the researchers’ computer simulations indicate that this assumption overestimates weight loss because it fails to account for how metabolism changes. The computer simulations show how these metabolic changes can significantly differ among people.
However, the computer simulation of metabolism is meant as a research tool and not as a weight-loss guide for the public. The computer program can run simulations for changes in calories or exercise that would never be recommended for healthy weight loss. The researchers hope to use the knowledge gained from developing the model and from clinical trials in people to refine the tool for everyone.
“This research helps us understand why one person may lose weight faster or slower than another, even when they eat the same diet and do the same exercise,” said Kevin Hall, Ph.D., an obesity researcher and physicist at the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases. “Our computer simulations can then be used to help design personalized weight management programs to address individual needs and goals.”
The online simulation tool based on the model enables researchers to accurately predict how body weight will change and how long it will likely take to reach weight goals based on a starting weight and estimated physical activity. The tool simulates how factors such as diet and exercise can alter metabolism over time and thereby lead to changes of weight and body fat.
The team found that people’s bodies adapt slowly to changes in dietary intake. They also found heavier people can expect greater weight change with the same change in diet, though reaching a stable body weight will take them longer than people with less fat.
The model also points to a potential simplified method to approximate weight loss in an average overweight person. An adult who has a body mass index (a measure of a person’s weight in relation to his or her height) between 25 and 29.9 is considered overweight. One example: For every pound you want to lose, permanently cut 10 calories from your current intake per day. At that rate, it will take about one year to achieve half of the total weight loss, and almost all of the weight loss will have occurred by three years. This calculation shows how long it takes to achieve a weight-loss goal for a single permanent change of diet or exercise.
Related: full press release – Healthy Diet, Healthy Living, Healthy Weight – Study Shows Weight Loss From Calorie Reduction Not Low Fat or Low Carb – Obesity Epidemic Largely Explained – $500 Million to Reduce Childhood Obesity in USA
Video of Young Richard Feynman Talking About Scientific Thinking
Posted on May 15, 2012 Comments (2)
The enjoyable video above shows a young Richard Feynman discussing how scientific thinking can advance our understanding of the world.
Repair Cafes in The Netherlands
Posted on May 13, 2012 Comments (3)
I really like these efforts. We throw away too much stuff that has plenty of useful life left. Also it is a great way to build community. And it is an interesting way to learn about products we use everyday (both by fixing them and having your items fixed). The throw away culture is something we should aim to change. By these actions and also by engineers designing products to be fixed instead of thrown away. I donated to a similar fixer collective in Brooklyn via Kickstarter.
Video of Kittens Being Rescued by Their Mother
Posted on May 11, 2012 Comments (1)
Repost of this fun cat video and a reminder to thank your mother for all the times she saved you from your version of the slide. Have a happy friday. Maybe you should forward this video to your Mom with a note of thanks and make it a happy one for her too.
Largest Google Summer of Code Ever
Posted on May 8, 2012 Comments (0)
Google summer of code allows college students to work on open source software projects during the summer and get a $5,000 stipend from Google.
We also accepted more students this year: 1,212 from 69 countries. This year India supplied the largest number of students, 227.
USA has 172 students, Germany 72, Russia 56 and China 45. This year set the highest percentage of women (self identified) yet. Guess what percentage. If you guessed 8.3% you are right.
Projects from the following organizations/software projects are included this year: Apache Software Foundation, Debian Project, Electronic Frontier Foundation/The Tor Project, GIMP, haskell.org, The JRuby Project, OpenStreetMap, Python Software Foundation, R project for statistical computing, Twitter, Wikimedia Foundation.
Google provides a stipend of 5,000 USD to the student and $500 to the mentoring organization. That puts Google’s support at over $6,500,000 this year.
Using Nanocomposites to Improve Dental Filling Performance
Posted on May 6, 2012 Comments (0)
After a dentist drills out a decayed tooth, the cavity still contains residual bacteria. Professor Huakun (Hockin) Xu says it is not possible for a dentist to remove all the damaged tissue, so it’s important to neutralize the harmful effects of the bacteria, which is just what the new nanocomposites are able to do.
Rather than just limiting decay with conventional fillings, the new composite he has developed is a revolutionary dental weapon to control harmful bacteria, which co-exist in the natural colony of microorganisms in the mouth.
“Tooth decay means that the mineral content in the tooth has been dissolved by the organic acids secreted by bacteria residing in biofilms or plaques on the tooth surface. These organisms convert carbohydrates to acids that decrease the minerals in the tooth structure,” says Xu, director of the Division of Biomaterials and Tissue Engineering in the School’s Department of Endodontics, Prosthodontics and Operative Dentistry.
The researchers also have built antibacterial agents into primer used first by dentists to prepare a drilled-out cavity and into adhesives that dentists spread into the cavity to make a filling stick tight to the tissue of the tooth. “The reason we want to get the antibacterial agents also into primers and adhesives is that these are the first things that cover the internal surfaces of the tooth cavity and flow into tiny dental tubules inside the tooth,” says Xu.
The main reason for failures in tooth restorations, says Xu, is secondary caries or decay at the restoration margins. Applying the new primer and adhesive will kill the residual bacteria, he says.
Majority of Clinical Trials Don’t Provide Meaningful Evidence
Posted on May 3, 2012 Comments (2)
The largest comprehensive analysis of ClinicalTrials.gov finds that clinical trials are falling short of producing high-quality evidence needed to guide medical decision-making.
The analysis, published today in the Journal of the American Medical Association, found the majority of clinical trials is small, and there are significant differences among methodical approaches, including randomizing, blinding and the use of data monitoring committees.
This is a critical issue as medical studies continue to leave quite a bit to be desired. Even more importantly the failure to systemically study and share evidence of effectiveness once treatments are authorized leaves a great deal to be desired. On top of leaving quite a bit to be desired, the consequences are serious. If we make mistakes for example in how we date fossils it matters but it is unlikely to cause people their lives or health. Failure to adequately manage and analyze health care experiments may very well cost people their health or lives.
“Our analysis raises questions about the best methods for generating evidence, as well as the capacity of the clinical trials enterprise to supply sufficient amounts of high quality evidence to ensure confidence in guideline recommendations,” said Robert Califf, MD, first author of the paper, vice chancellor for clinical research at Duke University Medical Center, and director of the Duke Translational Medicine Institute.
The analysis was conducted by the Clinical Trials Transformation Initiative (CTTI), a public-private partnership founded by the Food and Drug Administration (FDA) and Duke. It extends the usability of the data in ClinicalTrials.gov for research by placing the data through September 27, 2010 into a database structured to facilitate aggregate analysis.
New Blog with Simple Demonstrations and Scientific Explanations
Posted on May 2, 2012 Comments (3)
Try this at home is a new blog by Dr Mark Lorch, a chemistry lecturer at the University of Hull, with instructions for the citizen scientist. This example shows how to move a can with a ballon without touching the can.
The posts include instructions on how to do these simple demonstrations and a nice explanation on the scientific reason for what is going on:
It is quite a nice site (especially if you have kids interested in science or are a kid interested in science – no matter how old you are), add it to your RSS reader. Here are some more science blogs you may enjoy.