I witnessed something quite extraordinary a few years ago. The lamp post just in my street, which was not really tall, just about 2nd floor house height was vibrating, there was no wind, but the vibration was quite unusal, it was more like a sine wave that was passing through the post quite violently. The amount of vibration was as if it was made of rubber but was also vibrating not just from the base to the top, but at two points, like a secondary vibration. It looked unreal, because beause the post is sturdy, not very high, and I just could not figure what could be making it do that, nothing else was moving like it, only the post.
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Thank you - this was very formative and easy to follow
Excellent presentation. Thank you very much!
I witnessed something quite extraordinary a few years ago. The lamp post just in my street, which was not really tall, just about 2nd floor house height was vibrating, there was no wind, but the vibration was quite unusal, it was more like a sine wave that was passing through the post quite violently. The amount of vibration was as if it was made of rubber but was also vibrating not just from the base to the top, but at two points, like a secondary vibration. It looked unreal, because beause the post is sturdy, not very high, and I just could not figure what could be making it do that, nothing else was moving like it, only the post.