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Explainer: Einstein's Theory of General Relativity. It’s the year 2100.

Explainer: Einstein's Theory of General Relativity

You wake up alone in a small, windowless room. The only other thing in the room is a small ball. Maybe the room is located in your city, but maybe it’s inside that new spaceship everyone’s talking about. How can you tell? You pick up the ball and drop it. But a spaceship in the middle of deep space can also accelerate by that much, producing the exact same results. In 1911, Einstein formally proposed that gravitational mass (that which produces a gravitational field) and inertial mass (that which resists acceleration) were one in the same, and this became known as the “equivalence principle”. Another example is the infamous “Vomit Comet”, officially the Weightless Wonder (see video below), used by NASA for training, and occasionally by Hollywood for filming. This principle led Einstein to consider incorporating gravity into the framework of his special theory of relativity, culminating in his General Theory of Relativity.

Space-time Now for the mind-bending part … One-Minute Physics archive. Sandrine Ceurstemont, editor, New Scientist TV What's part of the universe?

One-Minute Physics archive

You may think of it as incorporating everything that exists - both on Earth and in space - but could it also include the unknown? In this One-Minute Physics episode, film-maker Henry Reich delves into the notion of the universe as described by physics, distinguishing between the whole universe and what's observable. He looks at the three components of the universe that we are sure of and whether mathematics could be included or not. Then there is the concept of parallel universes that could extend our understanding of space. If you enjoyed this post, check out our previous animations, to find out, for example, if space is infinite or why mass has a split personality.

Alcubierre Warp Drive Time Travel. An Alcubierre Warp Drive stretches spacetime in a wave causing the fabric of space ahead of a spacecraft to contract and the space behind it to expand.

Alcubierre Warp Drive Time Travel

The ship can ride the wave to accelerate to high speeds and time travel. The Alcubierre drive, also known as the Alcubierre metric or Warp Drive, is a mathematical model of a spacetime exhibiting features reminiscent of the fictional "warp drive" from Star Trek, which can travel "faster than light" (although not in a local sense - see below). Time.

Time is a measured or measurable period, a continuum that lacks spatial dimensions. Time is of philosophical interest and is also the subject of mathematical and scientific investigation. It is a component of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify the motions of objects. Time has been a major subject of religion, philosophy, and science, but defining it in a non-controversial manner applicable to all fields of study has consistently eluded the greatest scholars. In physics as well as in other sciences, time is considered one of the few fundamental quantities. Time is used to define other quantities – such as velocity – so defining time in terms of such quantities would result in circularity of definition. Among prominent philosophers, there are two distinct viewpoints on time. Temporal measurement has occupied scientists and technologists, and was a prime motivation in navigation and astronomy.

What would happen if I drilled a tunnel through the center of th". Want to really get away from it all?

What would happen if I drilled a tunnel through the center of th"

The farthest you can travel from home (and still remain on Earth) is about 7,900 miles (12,700 kilometers) straight down, but you'll have to journey the long way round to get there: 12,450 miles (20,036 kilometers) over land and sea. Why not take a shortcut, straight down? You can get there in about 42 minutes -- that's short enough for a long lunch, assuming you can avoid Mole Men, prehistoric reptiles and underworld denizens en route. Granted, most Americans would end up in the Indian Ocean, but Chileans could dine out on authentic Chinese, and Kiwis could tuck into Spanish tapas for tea [sources: NOVA; Shegelski].

Scientists probe the idea of chronesthesia. Yes... much of remembering the past means reconstructing it, not just re-experiencing it, and contemplating the future requires similar "construction. " It's why people can easily confabulate details in their memory—"remembering" things differently to how they actually happened, particularly when they're asked leading questions. It's a potent tool, this ability to remember the past and the future; but prone to error. Not to mention, thinking of the past and the future often distracts us from the present in potentially destructive ways. When your mind is someplace else, you're missing what's really going on right now. And then, later, when you try to recall right now, you can't do it very well because you were never really here to begin with.

Meteor Shower Rained Gold On Ancient Earth. Scientists squeeze light past quantum limit › News in Science (ABC Science) News in Science Monday, 12 September 2011 Stuart GaryABC Tiny ripples The race to discover gravity waves may be getting closer to the finish line with scientists successfully squeezing light using quantum mechanics.

Scientists squeeze light past quantum limit › News in Science (ABC Science)

The detection of gravity waves is one of the Holy Grails of astronomy and astrophysics. It will allow researchers to study the inner workings of exploding stars and colliding black holes. Einstein's general theory of relativity predicts these massive astronomical events generate tiny fluctuations, causing the fabric of space-time to expand and contract - like ripples on the surface of a pond. These yet to be discovered waves require the most sensitive detectors ever built, but up until now they've not been sensitive enough. College Physics.