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Archive for the ‘physics’ category: Page 238

Jun 14, 2017

NASA-Funded Startup to Build Fusion-Powered Rockets

Posted by in categories: nuclear energy, physics, satellites

Nuclear fusion is the process that powers the sun, but closer to home scientists are trying to develop fusion reactors that could provide immense amounts of energy. These reactors are big and (currently) inefficient, but a NASA-funded startup called Princeton Satellite Systems is working on a small-scale fusion reactor that could power advanced fusion rockets. Suddenly, other planets and even other star systems could be in reach.

All the forms of rocket propulsion we currently have involve accelerating propellant out of a nozzle. Then, physics takes over and the vessel moves in the opposite direction. Most spacecraft use chemical propulsion, which provides a large amount of thrust over a relatively short period of time. Some missions have been equipped with ion drives, which use electrical currents to accelerate propellant. These engines are very efficient, but they have low thrust and require a lot of power. A fusion rocket might offer the best mix of capabilities.

Current nuclear reactors use fission to generate energy; large atomic nuclei are broken apart and some of that mass is transformed into energy. Fusion is the opposite. Small atomic nuclei are fused together, causing some mass to be converted into energy. This is what powers stars, but we’ve had trouble producing the necessary temperatures and pressure on Earth to get net positive energy generation.

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Jun 6, 2017

Solar System Map: Surprisingly deceptive

Posted by in categories: astronomy, cosmology, gravity, lifeboat, mapping, physics, space, space travel

What’s wrong with this illustration of the planets in our solar system? »

For one thing, it suggests that the planets line up for photos on the same solar ray, just like baby ducks in a row. That’s a pretty rare occurrence—perhaps once in several billion years. In fact, Pluto doesn’t even orbit on the same plane as the planets. Its orbit is tilted 17 degrees. So, forget it lining up with anything, except on rare occasions, when it crosses the equatorial plane. On that day, you might get it to line up with one or two planets.

But what about scale? Space is so vast. Perhaps our solar system looks like this ↓

No such luck! Stars and planets do not fill a significant volume of the void. They are lonely specs in the great enveloping cosmic dark.* Space is mostly filled with—well—space! Lots and lots of it. In fact, if Pluto and our own moon were represented by just a single pixel on your computer screen, you wouldn’t see anything around it. Even if you daisy chain a few hundred computer screens, you will not discern the outer planets. They are just too far away.

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Jun 2, 2017

Tomorrow’s Robots Will Train in Simulators, Just Like Today’s Troops

Posted by in categories: Elon Musk, physics, robotics/AI, transportation

Several firms are working on training environments like Star Trek’s Holodeck, but for machines.

When future robots enter the world, they won’t have a learning curve.

Artificial intelligence researchers are creating tools to help teach the robots that will assemble our gadgets in factories, or do chores around our home, before they ever step (or roll) into the real world. These simulators, most recently announced by Nvidia as a project called Isaac’s Lab but also pioneered by Alphabet’s DeepMind and Elon Musk’s OpenAI, are 3D spaces that have physics just like reality, with virtual objects that act the same way as their physical counterparts.

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Jun 2, 2017

Scientists detect Einstein gravitational waves for a third time

Posted by in categories: cosmology, physics

N” Scientists have for a third time detected ripples in space from black holes that crashed together billions of light years from Earth, a discovery that confirms a new technique for observing cataclysmic events in the universe, research published on Thursday shows.

Such vibrations, known as gravitational waves, were predicted by Albert Einstein more than 100 years ago and were detected for the first time in September 2015. They are triggered by massive celestial objects that crash and merge, setting off ripples through space and across time.

The latest detection occurred on Jan. 4, 2017. Twin lasers in Louisiana and Washington picked up the faint vibrations of two black holes that were 20 and 30 times more massive than the sun, respectively, before they spiraled toward each other and merged into a larger black hole.

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May 31, 2017

The “Door’ To Another Universe…Can We Find The Black Hole That Opens It…Physicists Say “Yes!”

Posted by in categories: cosmology, information science, mathematics, physics

According to a mind-bending new theory, a black hole could actually be a tunnel between universes, meaning our universe may be nested inside a black hole that is part of a larger universe. The theory explains that the matter doesn’t collapse into a single point, but rather gushes out a “white hole” at the other end of the black one.

The theory was published in the journal Physics Letters B, by Indiana University physicist Nikodem Poplawski. In his article, he presents new mathematical models of the spiraling motion of matter falling into the black hole. His equations suggest that wormholes are probable alternatives to the “space-time singularities” originally predicted by Albert Einstein.

Einstein’s equations for general relativity suggest singularities are created whenever matter in a given region gets too dense as would happen at the center of a black hole. Singularities are infinitely dense and hot, and take up no space. This idea has been supported by indirect evidence but has never been fully accepted into the scientific community.

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May 31, 2017

NASA announces historic mission to finally ‘touch the sun’

Posted by in categories: physics, space

CHICAGO — NASA is revealing new details Wednesday about its first-ever mission to fly into the sun’s atmosphere.

The Solar Probe Plus will be the first spacecraft to fly directly into the sun’s atmosphere.

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May 21, 2017

Gravitational Waves Are Permanently Warping The Fabric of Space-Time

Posted by in categories: cosmology, physics

Researchers have proposed a method for detecting exotic events in physics by looking for the scars they leave behind on the fabric of space.

By identifying how objects like cosmic strings or evaporating black holes leave behind memories of their existence on the Universe, it might be possible to move some rather strange phenomena from theoretical to empirical science.

It all comes down to an effect of general relativity called gravitational-wave memory, which is the distortion left behind as space is stretched and relaxed by a massive object.

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May 19, 2017

Scientists Found a Low-Cost Way to Produce the World’s Cleanest Energy Source

Posted by in categories: energy, physics

Scientists have discovered a low-cost, efficient catalyst for splitting water to create hydrogen. This means that the world’s cleanest form of energy, hydrogen, may be more easily and cheaply produced.

Physicists at the University of Houston have discovered a low-cost, efficient, and easily available catalyst that can split water into hydrogen and oxygen. The catalyst is far more efficient than other options that have previously been employed, and because it is grown from ferrous metaphosphate on a conductive nickel foam platform, it is both more durable and cheaper to produce.

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May 17, 2017

For The First Time, Physicists Have Observed a Giant Magnetic ‘Bridge’ Between Galaxies

Posted by in categories: physics, space

For the first time, scientists have detected evidence of a magnetic field that’s associated with the vast intergalactic ‘bridge’ that links our two nearest galactic neighbours.

Known as the Magellanic Bridge, the bridge is a huge stream of neutral gas that stretches some 75,000 light-years between our two neighbouring galaxies, the Large and Small Magellanic Clouds (LMC and SMC). Although researchers had predicted it was there, this is the first observation of its magnetic field, and it could help us understand how these vast bridges come to be.

“There were hints that this magnetic field might exist, but no one had observed it until now,” said lead researcher, Jane Kaczmarek from the University of Sydney.

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May 10, 2017

Stray Wi-Fi signals could let spies see inside closed rooms

Posted by in categories: holograms, internet, physics

Physicists use standard wireless transmitter to create hologram.

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