First, it’s important to know that the big bang wasn’t an explosion of matter into empty space—it was the rapid expansion of space itself. This means that every single point in the universe appears to be at the center. Think of the universe as an empty balloon with dots on it. Those dots represent clusters of galaxies. As the balloon inflates, every dot moves farther away from every other dot.
Yes, the universe itself will eventually outpace the speed of light. Just how this will happen is a bit complicated, so let’s begin at the very beginning: the big bang. Around 14 billion years ago, all matter in the universe was thrown in every direction. That first explosion is still pushing galaxies outward. Scientists know this because of the Doppler effect, among other reasons. The wavelengths of light from other galaxies shift as they move away from us, just as the pitch of an ambulance siren changes as it moves past.
Mapping the universe and its billions of galaxies is a tedious business, but a project spanning more than a decade and mashing up near-infrared sky surveys with painstaking redshift analysis has produced the wold’s most detailed 3-D map of the local universe. Reaching out to a distance some 380 million light-years from our own solar system, the 2MASS Redshift Survey (2MRS) was presented today at the 218th meeting of the American Astronomical Society.
After a five-year study of 200,000 galaxies, scientists are more certain than ever that dark energy acts as a repulsive force, tearing the universe apart at an accelerating rate. The research confirms the idea that dark energy dominates gravity throughout the cosmos. But no one has any idea what dark energy actually is or how it works.
Every December since 2004, engineers have flown to the South Pole to drill 8,000-foot-deep holes in the ice. The team lowers cables, each strung with 60 disco-ball-size light sensors, into the holes and let them freeze over. So far they have completed 79 such holes, set in a grid half a mile on each side, and plan to drill the final seven this month. The result will be the IceCube Neutrino Observatory, a cube of ice packed with 5,320 sensors looking for cosmic particles.
The Wilkinson Microwave Anisotropy Probe, or WMAP, has been gathering information about the Big Bang, dark matter, and the nature of the universe for nine years now, and it's finally being put to rest (rest being a "parking orbit" around the sun).
A particularly mind-bending (and controversial) physics paper surfaced in the past week that should make you feel pretty special. It seems the laws of physics can change after all, and it just so happens they're uniquely suited for us right here, right now.
Results from the largest and most ambitious survey of the cosmos ever undertaken by the Hubble Space Telescope are in, and the findings are commensurately big, suggesting dark energy is indeed real, and the general theory of relativity holds up even under larger intergalactic scrutiny.
First came dark matter, the gravitational source from within our galaxy that astronomers couldn't see. Then came dark energy, the undetectable force pushing the expansion of the universe. Now, NASA scientists believe they have confirmed a new player, dubbed "dark flow," that is dragging hundreds of galaxies along the same path. Even stranger, the researchers believe that dark flow is actually the gravitational pull from matter beyond the edge of the known universe.
Everyone loves a good road movie, whether it's Hope and Crosby or Fonda and Hopper. But the scope of those films pales in comparison to the ground covered by the Hayden Planetarium's new video, The Known Universe. The video starts in Tibet and zooms out through time and space until it shows well, the entire known universe.
Dark Energy Hunter:Europe's Euclid space telescope could pick up on distorted light from distant galaxies, and pick up clues on the existence of dark energy. S. Colombi (IAP), CFHT Team
Dark energy may not have much in common with aliens, unless there's a flotilla of freaky monoliths out there with really weird physical properties. But astrophysicists hope to build a two-in-one space telescope that can search for signs of dark energy along with exoplanets.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.