How Burning Plants Signal Future Generations to Grow
Previous studies have reported that chemicals known as karrikins are created as trees and shrubs burn during a forest fire and remain in the soil after the fire, ensuring the forest will regenerate. In the April 23 early online edition of the Proceedings of the National Academy of Sciences (PNAS), scientists at the Salk Institute and the University of California, San Diego, sought to uncover exactly how karrikins stimulate new plant growth.
The researchers found that a plant protein know as KAI2 binds to karrikin in dormant seeds, changing its shape. This karrikin-induced shape change may send a new signal to other proteins in the seeds causing seed germination when the time is right, after a forest fire.
NASA’s Spacesuits Through the Years
Nothing says “astronaut” quite like a spacesuit. Whether it’s the shiny aluminized nylon flight suits worn by the original Mercury Seven astronauts or the pressurized bright orange “pumpkin suits” worn by space shuttle crews, the clothes do make the man or the woman. It’s much more than a look; the suits could be the only thing that separates an astronaut from life or death in case of an emergency. Here’s a look at some spacesuits in NASA’s storerooms.
Unfortunately, stars don’t have birth certificates. So, astronomers have a tough time figuring out their ages. Knowing a star’s age is critical for understanding how our Milky Way galaxy built itself up over billions of years from smaller galaxies. But Jason Kalirai of the Space Telescope Science Institute and The Johns Hopkins University’s Center for Astrophysical Sciences, both in Baltimore, Md., has found the next best thing to a star’s birth certificate.
Using a new technique, Kalirai probed the burned-out relics of Sun-like stars, called white dwarfs, in the inner region of our Milky Way galaxy’s halo. The halo is a spherical cloud of stars surrounding our galaxy’s disk. Those stars, his study reveals, are 11.5 billion years old, younger than the first generation of Milky Way stars. They formed more than 2 billion years after the birth of the universe 13.7 billion years ago. Previous age estimates, based on analyzing normal stars in the inner halo, ranged from 10 billion to 14 billion years. Kalirai’s study reinforces the emerging view that our galaxy’s halo is composed of a layer-cake structure that formed in stages over billions of years.
White dwarf stars have remarkable properties, yet they are very simple. These stripped cores of normal hydrogen-burning stars are about 1 million times denser than matter on Earth. This means that a tablespoon of material from a white dwarf’s surface would weigh as much as a school bus on Earth. White dwarfs also have no fuel to generate energy, and most of their atmospheres contain a single atom, hydrogen.
The second figure illustrates the spectral features of a white dwarf, in comparison to the Sun and a blue giant. The white dwarf spectrum is simple, containing only absorption lines from the hydrogen atom. But, unlike the same lines in the blue giant spectrum (a bloated star with a low density), the features in the white dwarf are broadened due to the intense pressure on the surface of the star (essentially, the energy levels of the atom are being perturbed). This broadening of the lines, as well as their depth, is directly related to the mass and temperature of the star. Unlike for most stars, astronomers can therefore reliably establish fundamental properties for white dwarfs from their spectra.
In an effort to provide abused children with a safe way to reach out for help, a Spanish organization called the Aid to Children and Adolescents at Risk Foundation, or ANAR for short, created an ad that displays a different message for adults and children at the same time.
THIS IS AMAZING OMG
Isotope Titanium Lume Ring
The Isotope is all about contrast. The brilliant glow of the lume, and the sharp lines of the titanium create a visual moment that refuses to be ignored.
The special lume material in the Isotope ring soaks up both natural and artificial light and will glow bright green as soon as it is in a low-light environment. Wear it to bed and it will still be glowing when you get up for that 3am visit to the bathroom!
Moonglow is a ultra-high output photoluminesent polycarbonate. It soaks up both natural and artificial light and will glow bright green for hours once it is in a low-light environment. It also a passive-lume material, meaning it absorbs light. It does not generate its own light as radioactive materials such as tritium do.
oh man tron rings
To get ready for Early Life Weekend, I took a trip up to the Royal Ontario Museum’s palaeontology department and hung out with Dave Rudkin.
Dave Rudkin is the Assistant Curator of Invertebrate Palaeontology at the ROM and a truly great guy. Dave’s been busy preparing for the Gallery of Early Life, a permanent gallery opening in 2014, but he still found time to show me around the invertebrate palaeontology collections.
What I like most about Dave is that he always has time to support children’s programming, whether it’s to lend a few objects for a weekend, or just chat about palaeontology. His energy is infectious and he loves trilobites SO MUCH.
As all y’all know, I LOVE dinosaurs, and have spent a ton of time up in vertebrate palaeontology collection (of which you can see a few photos of here), but I’ve have had merely a glimpse of the workings of the invertebrate side.
This photo set features all sorts of animals from BEFORE the dinosaurs, the time when life first evolved on Earth. The ROM is a world leader in research on first life, specifically from the Burgess Shale site, so we have an absolutely PACKED collections room full of prehistoric treasures.
A record-setting blast of gamma rays from a dying star in a distant galaxy has wowed astronomers around the world. The eruption, which is classified as a gamma-ray burst, or GRB, and designated GRB 130427A, produced the highest-energy light ever detected from such an event.
“We have waited a long time for a gamma-ray burst this shockingly, eye-wateringly bright,” said Julie McEnery, project scientist for the Fermi Gamma-ray Space Telescope at NASA’s Goddard Space Flight Center in Greenbelt, Md. “The GRB lasted so long that a record number of telescopes on the ground were able to catch it while space-based observations were still ongoing.”
The burst subsequently was detected in optical, infrared and radio wavelengths by ground-based observatories, based on the rapid accurate position from Swift. Astronomers quickly learned that the GRB was located about 3.6 billion light-years away, which for these events is relatively close.
Gamma-ray bursts are the universe’s most luminous explosions. Astronomers think most occur when massive stars run out of nuclear fuel and collapse under their own weight. As the core collapses into a black hole, jets of material shoot outward at nearly the speed of light.
The jets bore all the way through the collapsing star and continue into space, where they interact with gas previously shed by the star and generate bright afterglows that fade with time.
If the GRB is near enough, astronomers usually discover a supernova at the site a week or so after the outburst.
“This GRB is in the closest 5 percent of bursts, so the big push now is to find an emerging supernova, which accompanies nearly all long GRBs at this distance,” said Goddard’s Neil Gehrels, principal investigator for Swift.
Ground-based observatories are monitoring the location of GRB 130427A and expect to find an underlying supernova by midmonth.
The 1st animation: The maps in the animation show how the sky looks at gamma-ray energies above 100 million electron volts (MeV) with a view centered on the north galactic pole. The first frame shows the sky during a three-hour interval prior to GRB 130427A. The second frame shows a three-hour interval starting 2.5 hours before the burst, and ending 30 minutes into the event. The Fermi team chose this interval to demonstrate how bright the burst was relative to the rest of the gamma-ray sky. This burst was bright enough that Fermi autonomously left its normal surveying mode to give the LAT instrument a better view, so the three-hour exposure following the burst does not cover the whole sky in the usual way.
The 2nd animation: This animation shows a more detailed Fermi LAT view of GRB 130427A. The sequence shows high-energy (100 Mev to 100 GeV) gamma rays from a 20-degree-wide region of the sky starting three minutes before the burst to 14 hours after. Following an initial one-second spike, the LAT emission remained relatively quiet for the next 15 seconds while Fermi’s GBM instrument showed bright, variable lower-energy emission. Then the burst re-brightened in the LAT over the next few minutes and remained bright for nearly half a day.
Credit: NASA/Swift/Stefan Immler