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Physics Mysteries
150 questions answered by our physicists
Jaroslav Kores, Ph.D.
I believe that the content of radioactive substances in food depends mainly on where we get the food from. Radioactive materials enter food from its surroundings. Plants and mushrooms get radioactivity from the soil they…
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Jaroslav Kores, Ph.D.
Yes, mushrooms, like other plants, contain elements that they draw into themselves from the surrounding soil. Compared to other plants, however, mushrooms can absorb a greater number of different elements ...
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Jaroslav Kores, Ph.D.
The movements of bodies in the central gravitational field are described by Kepler's laws, of which only law 3 has the form of a formula. Isaac Newton used Kepler's laws to formulate (his) law of gravity ...
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Jaroslav Kores, Ph.D.
An earthquake is caused by a sudden release of mechanical stress between (or within) lithospheric plates. I'm not a geologist, but I believe this stress is caused by temperature differences and other phenomena that occur…
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Jaroslav Kores, Ph.D.
A tsunami wave, like other waves, spreads in all directions but the effects of a tsunami are observed only in certain places, so it may seem that the tsunami wave is moving in only one direction. Tsunami waves are caused…
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Jaroslav Kores, Ph.D.
The high tide and associated low tide are caused by the gravitational force acted by the Earth and the Moon on each other. Thanks to this force, the Moon orbits around us and does not fly away. This gravitational effect…
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Jaroslav Kores, Ph.D.
All photos are basically rotated, more precisely inverted. This is because the display system of the camera/mobile phone has to create an actual image on the sensor. If we want to use a lens/mirror to create a real image…
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Jaroslav Kores, Ph.D.
The mentioned "physics toys" represent an experimental verification of one of the basic laws of physics (and nature) — the law of conservation of energy. Energy is actually stored work and we can store this work in vario…
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Jaroslav Kores, Ph.D.
When we tap the glass, we can hear a sound. The pitch (frequency) of this sound depends on the material and shape of the glass. By tapping, we make the glass vibrate, this vibration is transferred due to impacts of the g…
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Jaroslav Kores, Ph.D.
The fact that the Moon orbits the Earth, does not fall on it and does not fly away, and in fact, the fact that it has become our companion, is due to a suitable combination of the speed of the Moon and its distance. Acco…
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Jaroslav Kores, Ph.D.
It can but it won't do us any good. I will not deal with hypothetical particles (tachyons), which in my opinion are more of a mathematical game resulting from the Theory of Relativity. It follows from the Theory of Relat…
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Jaroslav Kores, Ph.D.
Gravity is a property of all material bodies and cannot be directly "produced". Since the magnitude of the gravitational force depends on the mass and distance of the bodies acting on each other, we can make a smaller mo…
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Jaroslav Kores, Ph.D.
It certainly can, and in my opinion, it happens to a very limited extent. If we want anything to leave the Earth's gravitational field, we have to give it the so-called 2nd escape velocity (or Ve). Everything we throw/fl…
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Jaroslav Kores, Ph.D.
Atmospheric pressure varies mainly with weather and also with altitude. Because atmospheric pressure is the pressure caused by the weight of the air column, the higher we are, the smaller the height of the air above us a…
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Jaroslav Kores, Ph.D.
I don't think that there would always be a difference between the photos in the morning and in the evening, I would rather expect that we can observe something similar from time to time. And I would guess especially in t…
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Jaroslav Kores, Ph.D.
To be honest, I haven't experienced this but it's probably because I don't sunbathe much. I don't know if the winter tan is also related to the skiing/mountain activities. If this is indeed the case, I think it has two c…
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Jaroslav Kores, Ph.D.
I don't want to be a quibbler but with this question, it is clear that it is good to use the right terms for what we want to find out. Because I could easily answer yes or no, and in both cases I would be right ...
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Jaroslav Kores, Ph.D.
It is the same as why iron sinks to the bottom in water but wood rises. We probably all intuitively know that bodies with a high density in water sink to the bottom and bodies with a low density rise to the top. And perh…
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Jaroslav Kores, Ph.D.
Our eye perceives only a (very small) part of electromagnetic waves and we call this part light. This wave is described by its frequency (in visible light, the frequency corresponds to a certain colour). The colour of th…
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Jaroslav Kores, Ph.D.
It would certainly be possible but we would need either a better flashlight or a bigger magnifying glass. About 1,000 W/m2 of energy reaches the Earth from the Sun. If the Moon reflects roughly 20% of the falling sunligh…
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