LIGO Detected Gravitational Waves from Black Holes
On September 14, 2015 at 5:51 a.m. Eastern Daylight Time (09:51 UTC), the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA both measured ripples in the fabric of spacetime – gravitational waves – arriving at the Earth from a cataclysmic event in the distant universe. The new Advanced LIGO detectors had just been brought into operation for their first observing run when the very clear and strong signal was captured.
On Thursday (Feb. 11) at 10:30 a.m. ET, the National Science Foundation will gather scientists from Caltech, MIT and the LIGO Scientific Collaboration in Washington D.C. to update the scientific community on the efforts being made by the Laser Interferometer Gravitational-wave Observatory (LIGO) to detect gravitational waves.
In the wake of some very specific rumors focused on the possible discovery of these elusive ripples in spacetime, hopes are high that the international LIGO collaboration of scientists will finally put an end to the fevered speculation and announce the discovery of gravitational waves.
Caltech’s Konstantin Batygin, an assistant professor of planetary science, and Mike Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy, discuss new research that provides evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system.
If life is effectively an endless series of photocopies, as DNA is transcribed and passed on from one being to the next, then evolution is the high-stakes game of waiting for the copier to get it wrong.
Too wrong, and you’ll live burdened by a maladaptive mutation or genetic disorder. Worse, you might never live at all.
But if the flaw is wrong in exactly the right way, the incredible can happen: disease resistance, sharper eyesight, swifter feet, big brains, better beaks for Darwin’s finches.
Earth’s magnetic field is our great protector, shielding us from dangerous incoming solar radiation that would otherwise make life on Earth almost impossible. However, the strength of the field has changed through geological time, with the poles of the planet’s magnet switching dramatically at somewhat random intervals – roughly between 200,000 and 5 million years. Although the field strength has been dropping for the past two centuries, a new study, published in the Proceedings of the National Academy of Sciences, suggests it is not in danger of flipping any time soon.
Our planet’s magnetic field appears to be quite chaotic: It undergoes not only reversals, but also excursions wherein the poles “wander,” changing their coordinates on the surface of the planet rapidly with respect to geological time, before suddenly switching back to “normal.” Although the most recent reversal occurred 780,000 years ago, the poles temporarily flipped during an excursion in the middle of the last ice age 41,000 years ago.
Stephen Hawking, Arthur C. Clarke and Carl Sagan (via satellite) discuss the Big Bang theory, God, our existence as well as the possibility of extraterrestrial life.
“Overture From Tannhauser” by London Symphony Orchestra With Wyn Morris ( • • )
For the first time, scientists have discovered a classic formula for pi in the world of quantum physics. Pi is the ratio between a circle’s circumference and its diameter, and is incredibly important in pure mathematics, but now scientists have also found it “lurking” in the world of physics, when using quantum mechanics to compare the energy levels of a hydrogen atom.
Why is that exciting? Well, it reveals an incredibly special and previously unknown connection between quantum physics and maths.
“I find it fascinating that a purely mathematical formula from the 17th century characterises a physical system that was discovered 300 years later,” said one of the lead researchers, Tamar Friedmann, a mathematician at the University of Rochester in the US. Seriously, wow.
View full lesson: http://ed.ted.com/lessons/dark-matter…
The Greeks had a simple and elegant formula for the universe: just earth, fire, wind, and water. Turns out there’s more to it than that — a lot more. Visible matter (and that goes beyond the four Greek elements) comprises only 4% of the universe. CERN scientist James Gillies tells us what accounts for the remaining 96% (dark matter and dark energy) and how we might go about detecting it.
Lesson by James Gillies, animation by TED-Ed.
The largest sample yet of the faintest and earliest known galaxies in the universe, revealed by Hubble. Some formed just 600 million years after the Big Bang.
This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MACS J0416.1–2403. This is one of six being studied by the Hubble Frontier Fields programme, which together have produced the deepest images of gravitational lensing ever made. Due to the huge mass of the cluster it is bending the light of background objects, acting as a magnifying lens. Astronomers used this and two other clusters to find galaxies which existed only 600 to 900 million years after the Big Bang.
View larger. | The galaxy cluster MACS J0416.1–2403. It’s being studied by the Hubble Frontier Fields program. Due to the huge mass of the cluster it is bending the light of background objects, acting as a gravitational lens. Astronomers used this and two other clusters to find galaxies which existed only 600 to 900 million years after the Big Bang.
If we could look far enough away in space – and therefore far enough back in time – could we see the beginnings of the universe? The answer is surely yes, and now the Hubble Space Telescope has looked over 12 billion light-years away, and thus that far back in time, to create the largest sample yet of the faintest and earliest known galaxies in our universe. A technique called gravitational lensing revealed these galaxies, which existed at a time when our universe was very young. A Hubble website said this week (October 22, 2015) that some of these galaxies formed just 600 million years after the Big Bang.