Speaker 1: Welcome to Brainstuff the production of I Heart Radio, Hey,
Speaker 1: brain Stuff. Lauren vocal bomb here it's the operatic equivalent
Speaker 1: of the slip on the banana peal scene. The soprano
Speaker 1: on stage hits a high note so long in piercing
Speaker 1: that it cracks the opera glasses of the elegant Dowager
Speaker 1: in the box seat. Hollywood can do that with a
Speaker 1: trick of editing. But is it possible in real life? Well,
Speaker 1: yes it is, but so is being struck by lightning.
Speaker 1: Both require rare convergences of particular conditions and to understand
Speaker 1: these conditions and how they work together a crash course
Speaker 1: and acoustics is an order. Sound is acoustic energy, like electricity.
Speaker 1: Sound energy travels through substances in waves, which excites these
Speaker 1: substances particles and causes them to vibrate at a certain frequency.
Speaker 1: A frequency refers to the number of waves passing through
Speaker 1: a given point over a given period of time, and
Speaker 1: we measure frequent see and hurts. One hurts equals one
Speaker 1: wave per second. Meanwhile, every substance has a natural or
Speaker 1: resonant frequency, the frequency at which its own molecules vibrate.
Speaker 1: For example, suppose your bass guitar playing neighbor cracks the
Speaker 1: plaster on your walls when they play a low driving baseline.
Speaker 1: The quality of your neighbors speakers also affect the quality
Speaker 1: of the sound, but basically, the frequency of a bass
Speaker 1: guitar's lower deeper notes run from forty to fifty hurts,
Speaker 1: and thus the plasters resonant frequency must fall somewhere in
Speaker 1: that range. Because when a substance encounters a frequency it matches,
Speaker 1: it absorbs the energy rather than reflecting it. Glass shattering
Speaker 1: waves carry more energy they're shorter and choppier, thus more
Speaker 1: of them pass through per second at roughly five hundred
Speaker 1: and fifty six hurts. To shatter glass, the notes frequency
Speaker 1: must be the same as that of the glass. That's
Speaker 1: one condition. The note also has to be loud quality
Speaker 1: known as intensity. Intensity is measured in decibels, while conversational
Speaker 1: tones average fifty to sixty decibels. A trained vocalist might
Speaker 1: have the pipes to approach the approximately a hundred and
Speaker 1: five decibels needed to break glass. Even then they would
Speaker 1: have to be so close as to risk serious facial cuts.
Speaker 1: If the glass does explode, more likely a boost of
Speaker 1: electronic amplification would be needed. Finally, the glass must be
Speaker 1: strategically selected. A wine glass is a good choice. It's
Speaker 1: fine and thin, unlike say beer stein, which maximizes the
Speaker 1: amount of stress per particle. An empty glass cracks more readily,
Speaker 1: although less dramatically than one containing water or wine air,
Speaker 1: being less dense, the liquid carries the sound better, and
Speaker 1: if you can find a wine glass with a flaw
Speaker 1: in its structure, even an invisible one, that helps by
Speaker 1: providing a weak spot. Incidentally, real world tests involving resident
Speaker 1: frequencies offer more than an excuse to shatter glass. Resident
Speaker 1: frequency is the basis of ultrasonic testing, which is used
Speaker 1: to determine the safety of structures ranging from pipelines to airplanes.
Speaker 1: Ultrasonic testing is a type of non destructive testing which
Speaker 1: allows engineers to monitor the integrity of construction materials as
Speaker 1: where and while they're being used, which is preferable to
Speaker 1: otherwise dismantling a building or airplane for analysis in a laboratory.
Speaker 1: Today's episode is based on the article can You really
Speaker 1: Shatter a Glass? With a high note on how stuff
Speaker 1: works dot com, written by Christine Benzen. Brain Stuff is
Speaker 1: a production of by Heart Radio in partnership with how
Speaker 1: stuff Works dot Com, and it's produced by Tyler Clang.
Speaker 1: Four more podcasts my heart Radio, visit the i heart
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Speaker 1: favorite shows.