33
votes
Accepted
Can one see flickering of a light bulb at 50 Hz?
Short answer
Yes, the flickering of a light bulb may be noticeable, and yes, that's directly related to the mains frequency. However, since the flickering of a bulb is about two times higher than the ...
- 51.8k
10
votes
Accepted
What is the smallest touch sensation that a human can feel?
Short answer
The detection threshold of static indentation stimuli on the palm of the hand is approximately 10 to 40 micrometers, dependent on the exact location under investigation.
Background
The ...
- 51.8k
8
votes
Can one see flickering of a light bulb at 50 Hz?
A lamp flickers at 2x the mains frequency, i.e. 100 or 120 Hz, and that is typically not noticeable to human eyes. It is visible to chicken and insects.
That being said, a low quality lamp or a lamp ...
- 181
6
votes
Accepted
What is the biological limit on hearing resolution?
Short answer
The main limitation to frequency discrimination is loudness.
Background
The cochlea is tonotopically organized - it basically acts as a Fourier transformer, where different frequencies ...
- 51.8k
5
votes
Accepted
What determines the perceived pitch (frequency) of tinnitus?
Short answer
Perceived tinnitus pitch tends to resemble the frequency content of the loud sound that induced the tinnitus.
Background
Solid, laboratory-controlled studies to the perceived pitch of ...
- 51.8k
4
votes
Accepted
Is there an absolute minimum intensity level to the stimuli we can perceive?
There are limits to what a sensory system can detect, which is called the detection threshold. To determine the detection threshold psychophysical methods can be used. A straightforward way to ...
- 51.8k
3
votes
Can one see flickering of a light bulb at 50 Hz?
Let's say there is a point source of light (it could be a lamp or a highly reflective object) that undergoes large, rapid intensity changes, say 50-100 times a second.
If you quickly move your eyes ...
- 191
3
votes
Accepted
What is 'noise'?
The term noise can mean a number of different (more or les related) things is used in a number of different fields such as signal processing, psychology and ...
- 67.8k
2
votes
How well do we notice asynchronicity?
Short answer
I can be 75% sure that the lights are synchronized within 0.02 - 0.2 seconds of one another.
Background
Interesting question, but hard to answer! Because it has been unanswered for quite ...
- 51.8k
2
votes
What is the smallest pressure differential that humans can detect?
Short answer
The sensitivity to pressure differences highly depends on the study setup used. A paper resembling the conditions in your kitchen experiment concludes that the just noticeable difference ...
- 51.8k
1
vote
Accepted
Consistency of consciouness
You trespass upon a question as old as antiquity: what properties constitute consciousness? The best means to respond to the question concerns a metaphysical answer and an answer in modern biology
We ...
- 439
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