What are Gravitational Waves?

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.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.


Startling new finding: 600 million years ago, a biological mishap changed everything

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 Going to Flip Soon!

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.



Carl Sagan, Stephen Hawking and Arthur C. Clarke – God, The Universe and Everything Else (1988)

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 ( • • )

A classic formula for pi has been discovered hidden in hydrogen atoms


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.


Dark matter: The matter we can’t see – James Gillies

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.

New Hubble views of earliest galaxies

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.


What we can learn from galaxies far, far away – Henry Lin

View full lesson: http://ed.ted.com/lessons/what-we-can…

In a fun, excited talk, teenager Henry Lin looks at something unexpected in the sky: galaxy clusters. By studying the properties of the universe’s largest pieces, says the Intel Science Fair winner, we can learn quite a lot about our own world and galaxy.

Talk by Henry Lin.

  • The Universe from Macro to Micro - A pet project by me