# Tagged Questions

for questions about design, process, data, or analysis of experiments and observations.

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### Interference or something beyond?

I have an experiment with He-Ne laser in my practical syllabus. In curiosity I took a photo of the incoming radiation directly from the laser with my mobile camera. Some strange pattern is observed. ...
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### Estimate heating wires temperature

Im design a power supply to work with heating wires and one of the task is to estimate the temperature of the bare wire for a given current or power consumption. I've tried to measure the ...
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### Why is it that the refrigerators (ice houses) from long ago can't be reconstructed in modern times? [closed]

A Long time ago (a couple of hundreds of years), people could make a refrigerator by applying a certain procedure with pieces of ice, harvested in winter, and other stuff. The ice hadn´t molten at the ...
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### Measuring potential

I apologize if the question below has been asked -- I could not find an answer. A charged conductor some distance above ground generates an electric field and corresponding potential profile. How ...
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### Why is the standard deviation the error on the singular measurement?

I'm a beginner with the study in data analysis in Physics. I'm trying to understand the meaning, in the field of experimental Physics, of the standard deviation $\sigma$ of a series of data. There ...
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### Why is the gravitational constant so difficult to measure?

The gravitational constant seems to be very low precision. For example, in the Wikipedia article recent measurements are given as having the significands of 6.67 and 6.69, a difference of 2 parts in ...
Actually, I have two related questions. The fist is the above question. The second is, what experiments confirmed that $\varepsilon_0\left(\frac{E^2}{2} + c^2 \frac{B^2}{2}\right)$ is the ...