Lifeboat Foundation

In this Big Think interview, theoretical physicist Sean Carroll discusses the concept of time and the mysteries surrounding its properties. He notes that while we use the word “time” frequently in everyday language, the real puzzles arise when we consider the properties of time, such as the past, present, and future, and the fact that we can affect the future but not the past.

Carroll also discusses the concept of entropy, which is a measure of how disorganized or random a system is, and the second law of thermodynamics, which states that there is a natural tendency for things in the Universe to go from a state of low entropy to high entropy — in other words, from less disorganized to more disorganized. He explains that the arrow of time, or the perceived difference between the past and the future, arises due to the influence of the Big Bang and the fact that the Universe began in a state of low entropy.

In 1949 physicist Chien-Shiung Wu devised an experiment that documented evidence of entanglement. Her findings have been hidden in plain sight for more than 70 years.

Astrophysicists in Australia have shed new light on the state of the universe 13 billion years ago by measuring the density of carbon in the gases surrounding ancient galaxies.

The study, published in Monthly Notices of the Royal Astronomical Society, adds another piece to the puzzle of the history of the universe.

“We found that the fraction of carbon in warm gas increased rapidly about 13 billion years ago, which may be linked to large-scale heating of gas associated with the phenomenon known as the Epoch of Reionization,” says Dr. Rebecca Davies, ASTRO 3D Postdoctoral Research Associate at Swinburne University of Technology, Australia and lead author of the paper describing the discovery.

There’s a mystery happening in some satellites facing the sun, and scientists from the National Institute of Standards and Technology (NIST) and the Laboratory for Atmospheric and Space Physics (LASP) are on the case. The team has been trying to figure out what is clouding up and compromising the performance of tiny, thin metal membranes that filter sunlight as it enters detectors that monitor the sun’s ultraviolet (UV) rays.

These detectors can warn us about impending solar storms—bursts of radiation from the surface of the sun—that could reach Earth and temporarily disrupt communications or interfere with GPS readings.

Last year, the team disproved the prevailing theory: that this clouding was a buildup of carbon on the surface of the filters from organic sources stowing away on the satellite.

A team of physicists and material scientists at the University of Colorado has developed a way to better insulate double-paned glass used for windows by adding a transparent aerogel. In their paper published in the journal Nature Energy the group describes how their aerogel is made and how much of a boost in energy efficiency can be expected from windows using the material. Nature Energy has also published a Research Briefing in the same journal issue that outlines the work done by the team.

Since most homeowners prefer to have windows that allow them to see outside, heat loss is inevitable. Over the past several decades, heat loss from windows has been improved by adding a second pane of glass —the two panes are typically separated by a gap of insulating air. Still, such windows do not provide nearly the same degree of insulation as insulated walls. In this new approach, the team in Colorado has come up with a way to improve the insulation properties of double-paned glass.

To make the aerogel (a gel with pockets of air in it), the research team soaked nanofibers of cellulose extracted from wood in water. Next, the wood nanofibers were removed and were then dunked in an ethanol solution. Once saturated, the nanofibers were heated in a pressurized oven—this forced the ethanol pockets to be replaced with air. Next, the nanofibers, which were transparent, were coated with a water-repellent material to prevent condensation when situated between panes of glass.

“Our instincts of time and causation are our deepest, strongest instincts that physicists and philosophers—and humans—are loath to give up,” said one scientist.

Retraction undermines the bold claim by physicists who said their material conducted electricity without resistance at 15 ˚C.

No, it’s not hypermodern art. This image, generated by NASA

Established in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is “To discover and expand knowledge for the benefit of humanity.” Its core values are “safety, integrity, teamwork, excellence, and inclusion.” NASA conducts research, develops technology and launches missions to explore and study Earth, the solar system, and the universe beyond. It also works to advance the state of knowledge in a wide range of scientific fields, including Earth and space science, planetary science, astrophysics, and heliophysics, and it collaborates with private companies and international partners to achieve its goals.

It’s easy to envisage other universes, governed by slightly different laws of physics, in which no intelligent life, nor indeed any kind of organized complex systems, could arise. Should we therefore be surprised that a universe exists in which we were able to emerge?

That’s a question physicists including me have tried to answer for decades. But it is proving difficult. Although we can confidently trace cosmic history back to one second after the Big Bang, what happened before is harder to gauge. Our accelerators simply can’t produce enough energy to replicate the extreme conditions that prevailed in the first nanosecond.

Continue reading “The multiverse: Our universe is suspiciously unlikely to exist—unless it is one of many, says physicist” »