How Helium makes our voice squeaky
Have you ever went to a birthday party and saw your friend sucking helium? Does his voice becomes squeaky afterwards?
Interesting right? But, why does helium cause your voice to become so squeaky?
The common misconception is that, because helium is a lighter element than the main components of air, your vocal chords will vibrate faster if immersed in it. This makes a certain amount of sense. People move faster through air than they do through heavier stuff like water. Less resistance should enable vocal chords to move faster as well.
As it turns out, though, vocal chords vibrate at pretty much the same frequency no matter what gas rushes over them – though chlorine would eventually pose a problem. That factor isn't what changes the sound of your voice.
When an audio speaker – or anything else – makes a sound, it vibrates at a certain frequency. That vibration compresses the air around the speaker. The compression moves through the air, hits a person's ear, and is interpreted as sound. The frequency of the compressions will determine the quality of the sound. A low frequency means a low note. When a high number of waves of compression hit the ear every second, the note will be high.
There are two major things that determine the sound of a person's voice. The first is the size and shape of the vocal chords themselves. The other is the shape of the throat that the air passes through. Vocal chords are not the precision instruments many people imagine them to be. They create not a single note, but a jumble of sound. Of that sound, certain notes are emphasized.
Specifically emphasized are the resonant notes. These are the notes which ‘fit' inside the throat.
Look at the figure to the right. Most people have idly played with a rope like this, whether that rope is a jump-rope, a shoe-lace, a gold necklace that their mother told them not to touch, or a particularly unfortunate snake. A number of different frequencies fit the rope. In the same way, a number of different frequencies fit a person's throat.
Frequencies that don't fit are choked off in much the same way as the waves in the picture above would be if someone were to hold the rope still just beyond point ‘A'.
How does helium change that? Sound travels faster in lighter gas. Because helium hangs out at the top of the periodic table, while nitrogen, oxygen and carbon dioxide, major components of the air we breathe, are heavier, sound will travel faster in a throat filled with helium than it will in a throat filled with air.
The faster speed of sound will allow more frequencies to resonate within a throat. Look again at the figure above. If the rope were made of ordinary twine, it would be relatively easy for two people with decent coordination to get all of those frequencies going. If the rope were made of inch-thick iron links, it would be a different story. Getting metal to move fast is hard, so a strong group would have a tough time getting even the top wave to work. They would, however, have the advantage later on when the inevitable fight broke out. But that's a different story.
When you breathe in helium, your regular voice is joined by a whole host of new, higher resonant frequencies. You'll still be able to sing or speak the same note as you do with regular air, but because the higher frequencies are included, your voice will sound high, odd, and hilariously funny to drunk people.
Speaking of drunk people inhaling things, this is the part of the article in which the dangers of this practice are explained in an earnest attempt to prevent injury and keep from getting sued. Helium inhalation is, as said before, hilarious to the intoxicated. It is also a painless, effective and relatively natural-feeling way to keep oxygen from getting to a person's brain. And yes, people do die from it. One shallow breath is all it takes to say something funny. Take one puff, and pass the balloon along. Any more than that — and it is very possible to die sounding like a gerbil.
Another common mistake is to try to inhale helium straight from the compressed air tank it often comes in. To understand what's wrong with that idea, it's probably best to picture an overfilled balloon popping. Now picture it filled with blood and connected to nerve-endings. Those are lungs. They are designed to take in air at a certain speed only, and everyone should respect that.
What's more, people, in their intrepid search to find more ignominious ways to kill themselves, have figured out that while helium makes a voice go up, heavier-than-air gases have the opposite effect. Heavier gases will limit the number of frequencies that resonate in a person's throat, and make their voices sound deeper. Great stuff, right?
Here's the problem. Even if a person could find a gas that won't kill them to inhale, lungs are very picky about what kind of physical conditions they can work under. They can push out air. They can't push out heavier things. One site, which under no circumstances will link to, recommends hanging upside-down after inhaling these gases, in order to clear the lungs. That technique is included in this article as a way of letting readers know what to do if they have had a heavy gas forced into their lungs by a super villain, killer robot, lab accident, or vicious-but-nerdy street gang. Do not, repeat, do not go to the park, inhale a bunch of xenon and try to climb onto the monkey bars. It won't end well. It didn't even begin well.
Besides, with any luck, the physics behind this will impress and amuse people much more than the trick itself. Sources: http://io9.com/5493257/why-does-helium-make-voices-sound-squeaky http://www.youtube.com/watch?v=N3bKgVEkKVQ&feature=related Google Images
My thoughts:
I feel that this is a very interesting thing, and many people might find it amusing. However, as stated in the article, the inhaling of such gases might lead to dire consequences. Inhaling helium can also result in serious lung injuries or even suffocation.The helium is harmless but it's the removing of oxygen from the lungs and the risk of damage to the the lungs. It is the depletion of oxygen that can cause brain damage. Helium does not contain enough oxygen and can also be poisonous. Therefore, inhaling helium is extremely dangerous, especially for people with weaker lungs. And, I would discourage everyone from sucking helium. Although we may find it humorous, it is no laughing matter and we should stop making a joke out of this.
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Amazonian Mushroom eats indestructible platics
We use polyurethane to make just about everything—garden hoses, furniture, the entirety of my local 99-cent store. It's easy to produce, durable, and dirt cheap. What it isn't is recyclable—there isn't a single natural process that breaks it down. That is until a newly-discovered Amazonian fungus takes a bite.
Pestalotiopsis microspora (not shown) is a resident of the Ecuadorian rainforest and was discovered by a group of student researchers led by molecular biochemistry professor Scott Strobel as part of Yale's annual Rainforest Expedition and Laboratory. It's the first fungus species to be able to survive exclusively on polyurethane and, more importantly, able to do so in anaerobic conditions—the same conditions found in the bottom of landfills. This makes the fungus a prime candidate for bioremediation projects that could finally provide an alternative to just burying the plastic and hoping for the best.
Source: http://gizmodo.com/5880768/amazonian-mushroom-eats-indestructible-plastics
My thoughts:
I feel that this might bring a threat to the human race. What if the species continues to multiply and gets loose? Think about it. Almost everything around you is made up of plastic. Your table, your files, literally everything would be decomposed by these species of mushrooms. I hope that experts would control the spreads of such dangerous species. However, this species of mushrooms should not be completely eradicated from earth. After all, we could still be able to use the genes from these mushrooms to develop further species.
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What happens when you pour water on oil fire?
During a trip to Yishun Fire Station during the Sabbaticals week, we were told how to put out oil fires safely. One of the DON'Ts include not pouring water onto oil fire as it would create a volcano-like eruption.
We were showed this video, but did not know what actually caused the fire. Curious, I decided to investigated. My Findings: Water and oil don’t mix and water is more dense than oil. When one pours water into a flaming pan of oil, it wants to sink to the bottom. When it does, it comes in contact with the very hot pan (and oil) and instantly vaporizes into steam. The instantaneous phase change, from a liquid to a gaseous state, is accompanied by a tremendous expansion. Because the water (now steam) is below the oil, it expands rapidly upward, explosively expelling the flaming oil. It atomizes the oil, in the process, oxygenating it and effectively creating a volcanic blow torch.
My thoughts:
This was a rather interesting encounter. Fortunately, I was introduced to this earlier and I now know that we can never attempt to put out an oil fire with water, as it might lead to a bigger and more serious explosion. This is because oil is less dense than water and thus water floats on oil, thus they cannot mix together. This results in an explosion due to the rapid expansion of oil. Thus, I have learnt the dangers of fire and we should never play around with it.
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Cracking your knuckles does not actually hurt your bones or cause arthritis
Ever cracked your knuckles before? Cracking your knuckles (or any of your joints) can have therapeutic benefits. When you crack one of your joints you are pulling the bones that are connected at the joint apart from each other. This process stimulates your tendons, relaxes your muscles, and loosens your joints. Chiropractors do this for spinal joints when your back is sore and stiff, but you can do this on your own for your knuckles, toes, knees, neck, etc. Unfortunately, there can be too much of a good thing. Cracking your knuckles will never lead to arthritis (despite what your mom keeps telling you), but scientists have discovered that it can cause tissue damage in the affected joints. Knuckle-cracking pulls your finger bones apart which stretches your ligaments. Too much stretching of your ligaments will cause damage to your fingers akin to the arm injuries sustained by a baseball pitcher who throws too many pitches. In addition to making your hand really sore, this ligament damage can also result in reduced grip strength.How does this work? Your joints, the places in your body where you can bend, are where your bones intersect and are held together by ligaments. These joints are surrounded by a liquid called synovial fluid. When you stretch your ligaments by pulling the bones apart to crack your knuckles a gas in the synovial fluid escapes and turns into a bubble. This process is called cavitation. Cavitation ends when the bubble eventually bursts, producing that popping sound we know and love. After that, your joints won't be able to crack for another 25-30 minutes while the gas gets reabsorbed into the synovial fluid.
Sources:
http://www.omg-facts.com/top
http://www.youtube.com/watch?v=zLbYI7S9MPA
