The farther away they get, the smaller distant galaxies look. But only up to a point, and then they get magnified. Here’s how.
Nuclear physics usually involves high energies, as illustrated by experiments to master controlled nuclear fusion. One of the problems is how to overcome the strong electrical repulsion between atomic nuclei which requires high energies to make them fuse. But fusion could be initiated at lower energies with electromagnetic fields that are generated, for example, by state-of-the-art free electron lasers emitting X-ray light. Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) describe how this could be done in the journal Physical Review C.
During nuclear fusion two atomic nuclei fuse into one new nucleus. In the lab this can be done by particle accelerators, when researchers use fusion reactions to create fast free neutrons for other experiments. On a much larger scale, the idea is to implement controlled fusion of light nuclei to generate power – with the sun acting as the model: its energy is the product of a series of fusion reactions that take place in its interior.
For many years, scientists have been working on strategies for generating power from fusion energy. “On the one hand we are looking at a practically limitless source of power. On the other hand, there are all the many technological hurdles that we want to help surmount through our work,” says Professor Ralf Schützhold, Director of the Department of Theoretical Physics at HZDR, describing the motivation for his research.
How can physics on the smallest scales affect what the Universe does on its largest ones? Cosmic inflation holds the answer.
Dying stars sure are. ð
Their catastrophic explosions let out an intensely bright glow, often times rivaling the light of a whole galaxy. Can you spot the culprits in NASA’s Hubble Space Telescope image? https://go.nasa.gov/33Ylu5n
For hundreds of millions of years, the universe was nothing but darkness. One molecule holds the key to this forgotten epoch.
VR and Interstellar Travel
Crew members in route to a distant planet may best be accommodated by full immersion VR. The actual spaceship could be reduced to a relatively simple, small, well-shielded vehicle. Inside the crew’s biological material could be supported by a simplified nutrition, waste and maintenance system. Their minds could inhabit a fully immersive VR environment that would provide them with all the luxuries of vast, diverse spaces and experiences — complete with simulated gravity, simulated pleasant nature-like and artificial environments, and simulated meals.
They could also engage in simulating the type of society they intend to build once they arrive in their new physical environment, using similar constraints to the ones they will encounter. This could allow many years for actual human experiences to test and refine what they will build and how they will interact in their new home.
Continue reading “Scientists Are Contemplating a 1,000-Year Space Mission to Save Humanity” »
An international group of scientists, including Andrey Savelyev, associate professor of the Institute of Physical and Mathematical Sciences and Information Technologies of the IKBFU, has improved a computer program that helps simulate the behavior of photons when interacting with hydrogen spilled in intergalactic space. Results are published in the scientific journal Monthly Notices of the Royal Astronomical Society.
Andrey Saveliev states, “In the Universe there are extragalactic objects such as blazars, which very intensively generate a powerful gamma-ray flux, part of photons from this stream reaches the Earth, as they say, directly, and part are converted along the way into electrons, then again converted into photons and only then get to us. The problem here is that mathematical calculations say that a certain number of photons should reach the Earth, and in fact it is much less.”
Scientists, according to Andrey Savelyev, today have two versions of why this happens. The first is that a photon, after being converted into an electron (and this, as is known, in contrast to a neutral photon, a charged particle) falls into a magnetic field, deviates from its path and does not reach the Earth, even after being transformed again into the photon.
Robert Adams updated the work on a phase 2 Pulsed Fission-Fusion (PuFF) Propulsion Concept. Robert works at the NASA Marshall Space Flight Center. This system should be able to achieve 15 kW/kg and 30,000 seconds of ISP. This will be orders of magnitude improvement over competing systems such as nuclear electric, solar electric, and nuclear thermal propulsion that suffer from lower available power and inefficient thermodynamic cycles. Puff will meet an unfilled capability needed for manned missions to the outer planets and vastly faster travel throughout the solar system.
A tiny lithium deuteride and uranium 235 pellet will be fired into a shell of structure that will complete a circuit and generate high voltages and pressures that will compress the pellet and cause fission and fusion to occur.
CAPE CANAVERAL, Fla. (AP) — NASA’s sun-skimming spacecraft, the Parker Solar Probe, is surprising scientists with its unprecedented close views of our star.
Scientists released the first results from the mission Wednesday. They observed bursts of energetic particles never seen before on such a small scale as well as switchback-like reversals in the out-flowing solar magnetic field that seem to whip up the solar wind.
NASA’s Nicola Fox compared this unexpected switchback phenomenon to the cracking of a whip.
An instrument aboard NASA’s New Horizons is sending back data that could help scientists predict when the unmanned deep-space probe will reach interstellar space. Using the Solar Wind Around Pluto (SWAP) instrument aboard the spacecraft, a team of researchers led by Southwest Research Institute are learning more about how the solar winds change in the outer regions of the solar system.
Though the solar system may look like a big ball of nuclear fire at the center surrounded by a scattering of tiny, solid objects sitting in a lot of very hard vacuum, all that nothingness is permeated by the solar winds – an unceasing flow of ionized particles from the Sun that forms an uneven bubble around our family of planets called the heliosphere.
The outer limit of the heliosphere is where it encounters materials from interstellar space. This is the point where the solar wind slow down to subsonic speeds due to interacting and then is stopped altogether by the interstellar medium. These two points are called, respectively, the termination shock and the heliopause.
