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How do I know that I managed to achieve fusion at home in the garage?
If I have a brilliant idea and build a device in my garage that could achieve fusion, how will I know I’ve really succeeded?
It depends on what kind of fusion reaction you are trying to achieve in your garage device. If deuterium-tritium fusion is your goal, get a quality neutron detector and a long cable to run from the detector in the garage to your computer. Deuterium-tritium fusion generates very strong neutron fluxes. One successful fusion of deuterium with tritium produces one neutron ...
Is there cold fusion?
All the fusion reactions we know need extremely high temperatures to take place, which is why they are so difficult to achieve on the Earth ...
What the particles need for successful fusion is not so much temperature but speed. Only when they rush towards each other with sufficient speed can they overcome the electrostatic repulsive forces and get close enough for the nuclei of the atoms to fuse. But to have high speeds means to have high temperatures in the world of particles ...
Will we run out of water because of fusion power plants?
The fuel for a fusion power plant is hydrogen, which can be obtained from water. If we met all of civilization’s energy needs only from fusion power plants in the future, wouldn’t we ...
I don’t think we have to worry about that. It is true that the deuterium required for thermonuclear fusion is obtained from seawater, but its consumption is very low compared to the volume of all the world’s oceans. It is estimated that a 1,000 MW fusion power plant could consume around 250 kilograms of deuterium per year. That is less than a kilogram of deuterium per day ...
How long does it take for a new star to ignite thermonuclear reactions?
At the beginning of every star, there is only a cloud of hydrogen gas, which begins to roll up and shrink due to gravity until suddenly, fusion ignites in it and the hydrogen cloud becomes a real star ...
From a cosmic point of view, it happens quite quickly, only a few tens of millions of years are enough. A star begins its life as a large ball of hydrogen that has condensed from a hydrogen cloud. In order for fusion reactions to occur, the hydrogen sphere must shrink enough to increase the pressure in its centre sufficiently ...
The NIF announced that they had finally achieved fusion. Does this mean we will soon have a fusion power plant?
In December 2022, the National Ignition Facility, which is experimenting with laser-driven fusion, announced that they had finally achieved “ignition” and that it was a major breakthrough ...
The success of the National Ignition Facility in an experiment on December 5, 2022, which released 3.15 MJ of energy in a fusion reaction using only 2.05 MJ of energy for the lasers required to ignite this reaction, is undoubtedly huge and a significant milestone in thermonuclear fusion research ...
How big a bucket of water would you need to put out the Sun?
You can put out a campfire with a few buckets of water or put out a forest fire with a small lake dropped from helicopters and airplanes ...
No bucket of water will be big enough to extinguish the Sun. On the contrary, the more water you pour on the Sun, the more it will burn. The fire we normally encounter on the Earth, whether it is a campfire or a candle flame, is based on a chemical reaction ...
How is it that everything around the tokamak doesn’t immediately burn to ashes when it has a temperature of 150 million degrees inside?
The fusion reactor is supposed to have an absolutely incredible temperature of 150,000,000 degrees in its core ...
If matter was in direct contact with an object 150 million degrees hot, it would certainly not only melt, but also vaporize and immediately turn into plasma. But the extremely hot plasma core in the tokamak is not in such close contact with anything. The point is that it is effectively isolated from the tokamak chamber and the surrounding area by a layer of vacuum ...
Can an uncontrollable fusion reaction occur?
Can the fusion get out of control under some circumstances and burn uncontrollably? In fission, an uncontrolled reaction can occur under certain conditions, so the question is whether something like t ...
Under terrestrial conditions, a spontaneous fusion reaction can never occur. Keeping the fusing fuel in a state where fusion can occur requires constant outside intervention. In the case of magnetic confinement, a proper magnetic fields to hold the plasma in place and heat the plasma to keep it at a sufficiently high temperatures are essential ...
How would it look like to use a fusion reactor to power a spaceship?
One can read about what a fusion reactor power plant would look like but this amazing technology could power spaceships! We would finally explore our Solar System properly ...
The use of fusion reactions to power spacecraft is still pure speculation but in principle there would be two possibilities. The first option is that the electricity produced by the reactor would be used to operate some revolutionary, not yet discovered type of propulsion ...
Why do we want to try to ignite a completely different type of fusion than the one operated by the Sun?
On the Earth, scientists are trying to ignite a fusion reaction between deuterium and tritium at extremely high temperatures of around 150 million degrees ...
There are many types of fusion reactions that release energy when the nuclei of light atoms fuse. Except for the different temperatures required for their ignition, they have different cross-sections and yields which are parameters that are crucial for the energy use of fusion ...
Will there ever be a wristwatch with a fusion battery?
Nuclear fission reactors are getting smaller. There is talk about small modular reactors, nuclear boilers heating remote villages, small nuclear reactors powering ships and submarines — will the ...
So far, the trend is exactly the opposite, and the new fusion reactors are getting bigger and bigger. It turns out that a larger volume of plasma provides it with better stability and better parameters, thanks to which the fusion reaction can be better achieved ...
Real plasma in flame
Is plasma formed during the burning of a flame? And if so, can the flame react to an electromagnetic field?
Plasma refers to a gas consisting of charged particles. Due to the high temperature of the flame, a neutral gas molecule (e.g., O2) can rupture into a free electron and a positive O2 ion and a candle flame can contain plasma. Indeed, such plasma is very sparse — there are fewer charged particles in it than the recommended molecules ...
The unpredictable path of lightning
Why does lightning sometimes hit a car on the road during thunderstorms, even though there are taller, wet and therefore conductive trees on both sides of the road?
Yes, it can happen, just as it is possible that the lightning does not hit the tree, but rather next to it, or that it does not “choose” the shortest path towards the ground. It is necessary to realize that lightning moves in smaller sections and only when the individual parts of the lightning reach the ground will what we call lightning happen (it is well seen in slow motion videos, e ...
Why is a higher pressure at depth when the water is incompressible?
Water is an incompressible liquid. So how is it possible that there is a high pressure in the sea depths when the water cannot be compressed?
The fact that there is higher pressure in greater depth is not related to compressibility of the fluid but with its weight. Air, unlike water, is compressible and there is also higher pressure at sea level than in the mountains. The air pressure calculation is more complicated than water because for water, we assume that its density is still the same (because it is incompressible) ...
How would the atomic bomb explosion look like in outer space?
In movies, whether we kill aggressive aliens or smash giant asteroids, an explosion in space is always a spectacular affair. What would the explosion of an atomic bomb in a space really look like?
Whether we eliminate aggressive aliens or giant asteroids in movies, an explosion in space is always a spectacular thing. How would the explosion of an atomic bomb in space vacuum really look like?
I am not an expert on nuclear weapons so I apologize in advance for any inaccuracies ...
Is it possible to create two identical snowflakes?
There cannot be two identical snowflakes. But what if two flakes were allowed to crystallize in the laboratory, under exactly the same conditions. Would they be the same or not?
I wouldn’t say two identical snowflakes can’t exist — it’s rather unlikely. There are about 10,000,000,000,000,000,000 ice crystals in a snowflake that randomly coalesce when the snowflake is formed. That’s 100,000 times more than the stars in our galaxy or 10 times more than all people’s hair on our planet ...
How fast is gravity?
If the Sun disappeared out of nowhere, would the Earth leave its orbit sooner, later or at the same time that the Sun would disappear from the sky and darkness would come?
The special theory of relativity shows that it is not possible for any information to spread faster than the speed of light. Thus, the Earth would “learn” of the disappearance of the Sun at the same time that the light from the Sun would stop to fall on it. The speed of gravity spread is the same as the speed of light ...
Why does the pond freeze from the surface?
The warm water rises up, so it should be warmer on the surface of the pond than at the bottom. How is it then possible that a pond always freezes from the surface and not from the bottom?
Yes, that’s right — warmer water rises (that’s why there is, for example, a heating spiral at the bottom of a kettle). In addition, this phenomenon works with all fluids (i.e. liquids and gases) ...
How can a tall spruce pull water from the roots to the top; does it have a pump inside?
A tall giraffe pumps blood into its head by its heart. But what draws water to the top of tens of meters high spruce? Trees have no hearts or pumps…
Capillary elevation is responsible for the nutrition of trees (and other plants)…
You may think that you will not encounter this phenomenon anywhere else but (like all physics) this phenomenon has a wide use. You could ask in the same way why a cloth or a sponge absorbs water.
Liquid molecules (e.g ...
Could bacteria fly?
To move in a water environment, bacteria have various cilia and flagella that they move forward with but in the air, they are passive travellers depending on where the wind blows them ...
I am not a naturalist, so I would rather only physically speculate on this issue. I think it's simple — they don’t need to. Evolutionary theory (in my interpretation) shows that the evolution of animal species prefers those “modifications” of organisms that lead to their better development and survival ...
