Meta & Fysikken: Afsnit 74: Fusion, supernovaer og meget andet
Godt Nytår! Vi er igang med 2023! Vores 5-års jubilæum står for døren!
Vi lægger ud med et afsnit om fusionsenergi, supernovaer og så taler vi lidt om solcellefarme, klima og meget mere.
1: FUSION
Earlier this month, researchers at the government-backed Lawrence Livermore National Laboratory used the "world's largest and highest energy laser system" to blast light at small capsules of deuterium-tritium fuel — and were able to get more energy out of it than they had to put in, an apparent world first in the long-delayed road of fusion power.
More energy out than in. For 7 decades, fusion scientists have chased this elusive goal, known as energy gain. At 1 a.m. on 5 December, researchers at the National Ignition Facility (NIF) in California finally did it, focusing 2.05 megajoules of laser light onto a tiny capsule of fusion fuel and sparking an explosion that produced 3.15 MJ of energy—the equivalent of about three sticks of dynamite.
Hvordan:
Lawrence Livermore National Laboratory is home to the National Ignition Facility (NIF), which began full operations in March 2009. NIF’s 192 powerful laser beams, housed in a 10-story building the size of 3 football fields, can deliver nearly 2 million joules of ultraviolet laser energy in billionth-of-a-second pulses to the target chamber center. When NIF’s laser beams focus all of their energy on a target the size of a pencil eraser, they briefly produce extraordinary temperature and pressure conditions within the target.The chief goal of NIF is to use its laser energy to create pressures and temperatures so intense that the nuclei of hydrogen atoms within a target fuse—a process that mimics on a small scale what occurs constantly within our Sun. A successful fusion reaction within a NIF target will release many times NIF is the world’s largest and most energetic laser.more energy than the laser energy required to initiate the reaction; this reaction is referred to as ignition.The powerful laser energy that bombards a target at NIF begins as an initial laser beam that is far too weak to power a single light bulb. The energy must be amplified a quadrillion times as it journeys to the target chamber. The diagram illustrates the components that create, guide, amplify, and interact with the laser energy as it travels through NIF.
The fuel pellets contain "heavy" versions of hydrogen—deuterium and tritium—that are easier to fuse and produce more energy. However, the fuel pellets need to be heated and pressurized to conditions found at the center of the sun, which is a natural fusion reactor.
Once these conditions are achieved, fusion reactions release several particles, including alpha particles, which interact with the surrounding plasma and heat it up further. The heated plasma then releases more alpha particles and so on, in a self-sustaining reaction—a process referred to as ignition.
NIF was never designed to produce power commercially. Its primary function is to create miniature thermonuclear explosions and provide data to ensure the U.S. arsenal of nuclear weapons is safe and reliable. Many researchers believe furnacelike tokamaks are a better design for commercial power because they can sustain longer fusion “burns.” In a tokamak, microwaves and particle beams heat the fuel and magnetic fields trap it. “The challenge is to make it robust and simple,” White says.
However, the leading tokamak device, the ITER reactor under construction in France, is anything but simple. It is vastly over budget, long overdue, and will not reach breakeven until the late 2030s at the earliest. With NIF’s new success, proponents of such laser-based “inertial fusion energy” will be pushing for funding to see whether they can compete with the tokamaks.
DOE Funding og fremtidens kraftværker:
The goal is "hopefully to enable a fusion pilot to operate in the early 2030s," a senior DOE official told the publication.
It's the first pilot of its kind and could push US companies to invest in developing technologies that could realize the dream of having fusion reactors powering the grid.
At least 15 companies are seeking the grant, but it's unclear how many of them will be awarded funds.
Despite the most recent breakthrough, scientists still have a lot of work ahead of them. For one, they will have to figure out the feasibility and scalability of systems like the one being used at Livermore.
Kilder:
https://www.science.org/content/article/historic-explosion-long-sought-fusion-breakthrough
https://futurism.com/the-byte/scientists-now-plotting-first-fusion-power-plant
2: Robots to build solar farms:
https://www.freethink.com/energy/utility-scale-solar
Stoettet af Bill Gates.
Gates’ Breakthrough Energy Ventures, a venture capital firm that focuses on climate change solutions.
“It took fifty years for the world to build the first Terawatt (one million Megawatts) of solar, but we need at least 50 additional Terawatts built as quickly as possible to meet global decarbonization targets,” Campbell described the challenge.
3 COP27 og Klimaet:
Hvad skete der denne gang?
Fond for Klima Retfaerdighed
After years of resistance from rich governments, nations for the first time agreed to set up a fund to provide payouts to developing countries that suffer "loss and damage" from climate-driven storms, floods, droughts and wildfires.
Despite being the standout success of the talks, it will likely take several years to hammer out the details over how the fund will be run, including how the money will be dispersed and which countries are likely to be eligible.
The final COP27 deal drew criticism from some quarters for not doing more to rein in climate damaging emissions, both by setting more ambitious national targets and by scaling back use of fossil fuels such as coal, oil and natural gas.
ESA maaler en Top-Down evaluering af CO2. Landene selv melder hvad deres CO2 forbrug er. Det er en Bottom up vurdering.
4: Under iskappen paa Antarkis loeber der en 460 kilometer lang flod.
The researchers behind the discovery used a combination of airborne radar surveys that can peer through the ice, plus water flow modeling. The large area under examination includes ice from both the east and west ice sheets in the Antarctic, with water running off into the Weddell Sea.
"The region where this study is based holds enough ice to raise the sea level globally by 4.3 meters," says glaciologist Martin Siegert from Imperial College London in the UK.
"How much of this ice melts, and how quickly, is linked to how slippery the base of the ice is. The newly discovered river system could strongly influence this process."
"When we first discovered lakes beneath the Antarctic ice a couple of decades ago, we thought they were isolated from each other," says Siegert.
"Now we are starting to understand there are whole systems down there, interconnected by vast river networks, just as they might be if there weren't thousands of meters of ice on top of them."
https://www.sciencealert.com/scientists-just-discovered-a-huge-river-hidden-under-antarctica
5: 5000 milliarder ton er forsvundet i Grønland.
https://www.tjekdet.dk/faktatjek/5000-milliarder-ton-er-forsvundet-i-groenland-paa-20-aar?
6: Hawaii's Mauna Loa i udbrud
7: RFif / Wireless card reader - how it works
Wireless card reader bbc (facebook)
Et Creditcard bliver taget fra hinanden: