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Physics Mysteries
150 questions answered by our physicists
Jaroslav Kores, Ph.D.
I'm not a doctor but I'll try to answer to the best of my knowledge and applications of physical phenomena. I will convert the term thought to the processing of information which is certainly a thought. Our body is (in m…
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Jaroslav Kores, Ph.D.
The very alternation of day and night is caused by the rotation of the Earth around its axis. But that's not the only movement the Earth makes, it also orbits the Sun. Orbiting around the Sun alone would not affect the l…
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Jaroslav Kores, Ph.D.
We probably intuitively know that there will be a difference when two small passenger cars collide and when a passenger car collides with a truck. It is obvious that the result of the collision is somehow related not onl…
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Jaroslav Kores, Ph.D.
Although it may seem that a pulley (or an inclined plane or a lever) are special machines, using some strange aspect of physics, the opposite is true — these machines (we call them collectively simple machines) prove tha…
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Jaroslav Kores, Ph.D.
Our eye has 2 types of light-sensitive cells — retinal rods and cones. While rods respond to less intense light but not to colours, cones are less sensitive to light intensity but respond to colours. That's why we see th…
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Jaroslav Kores, Ph.D.
The formation of a rainbow is one of the proofs that light is an (electromagnetic) wave. When the wave encounters an obstacle, it can bounce off or pass through the obstacle. In the case of passage into an obstacle (and…
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Jaroslav Kores, Ph.D.
Different drag forces act against the movement of bodies, this situation is described as rolling drag. The size of the rolling drag depends on several quantities — the force that pushes the wheel on in our case, the ridi…
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Jaroslav Kores, Ph.D.
A microwave oven uses electromagnetic waves of a specific frequency for heating — 2.45 GHz. This frequency is not chosen randomly, it is the resonance frequency of water molecules. Resonance is an action in which we supp…
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Jaroslav Kores, Ph.D.
I like questions that I can always get right (or always wrong but I'm an optimist).The correct answer to such a question is yes and no. If I wanted to have only one correct answer, I would have to add to the question whe…
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Jaroslav Kores, Ph.D.
Unfortunately, there is no simple answer to such a simple question. The rate of evaporation of any substance depends on many factors and only a few are listed. Specifically, the rate of evaporation depends on the materia…
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Jaroslav Kores, Ph.D.
The electromagnetic waves we use to make wireless calls are integral to our surroundings — and I'm not just talking about visible light. Electromagnetic waves of other frequencies, which we are unable to detect with our…
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Edita Bromova
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…
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Edita Bromova
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 f…
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Edita Bromova
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 i…
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Edita Bromova
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 rea…
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Edita Bromova
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 u…
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Edita Bromova
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 f…
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Edita Bromova
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 suc…
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Edita Bromova
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…
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Edita Bromova
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…
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