Contents Under Pressure

Have you ever thought about atmospheric pressure? Most people don't pay much attention to it and the only time they hear anything about it is when the weatherman mentions it on the evening news: "There's a high pressure system coming in, and we'll probably have a storm or two." I don't think most people really appreciate how much pressure the atmosphere actually exerts on us.

There's a very simple experiment to demonstrate the power of atmospheric pressure, and it's a pretty cool experiment as well. It's not dangerous and you won't kill thousands of people if you do it wrong, but I suppose I should probably put a disclaimer in here somewhere. If you try this at home and you manage to hurt yourself, it's not my fault. I've done it several times myself and I've never gotten hurt, but there was that one time with the other guy and the ambulance...

I'm kidding. It's a very safe thing to try and I'm sure you'll get a kick out of it.

Anyway, all you need for the experiment is an empty pop can, a pot of cold water, a stove, and a potholder. An empty Crush can works best, but other soda cans will work fine too. Here's what you have to do:

1. Fill an empty pop can about a third full with water.
2. Put the can on a stove and wait until the water starts to boil.
3. Let the water boil for a minute or so, then pick the can up with the potholder. This is the most dangerous part of the experiment---boiling water is hot (no kidding), so be careful!
4. Quickly flip the can over and stick the mouth of the can into the pot of cold water. Make sure the open part of the can is completely underwater.

If you do the experiment right, the pop can will implode on itself. That's why the Crush can makes the experiment better. A can of Crush crushing itself...funny, right? If you don't believe me, you can check out this YouTube video.

You can do this trick to impress your friends and you can call it magic, but there's really a very simple explanation. The can didn't really crush itself---atmospheric pressure crushed the can. But why didn't the atmosphere crush the can when it was empty?

When the can was empty, the atmosphere was indeed exerting pressure on the outside of it. But since there was air inside, the atmosphere was exerting pressure on the inside of the can as well. The inside pressure and outside pressure cancel each other out, so the can remains intact. When the water begins to boil, though, it produces steam, which starts to displace the air that was inside the can. When the hot steam comes into contact with the cold water in the pot, it condenses back into liquid water.

As the steam cools, a partial vacuum forms. Most of the air was forced out by the steam and all of the steam is condensed by the cold water. Since there's nothing inside the can to counter the atmospheric pressure, the can collapses under the weight of the air outside.

Ain't science swell?

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I think the main reason we don't think much about atmospheric pressure is because we don't have to worry about being crushed. Our lungs always contain air and our bodies are able to stand up to the weight of the atmosphere much better than the thin aluminum walls of a can of Crush. All in all, we're pretty well equipped to withstand the pressure of the atmosphere. What about peer pressure? How well do we withstand that kind of pressure?

Every day, we encounter peer pressure. Sometimes it's good---a friend encouraging another friend to get good grades, for example. There's nothing wrong with that. Most of the time, though, peer pressure is a bad thing. There are plenty of examples of negative peer pressure, and we all can think of several. Oftentimes, we find ourselves doing things we wouldn't normally do, just because our friends asked us to.

Sometimes, negative peer pressure is easy to spot. If a couple of guys with ski masks and AK-47s walked up to you on the street to try get you to join their bank robbing crew, it would be pretty obvious that you have some bad peer pressure to deal with. Other times, though, peer pressure can be invisible.

We don't notice the weight of the atmosphere because we're well acclimated with it. Sometimes, we won't notice peer pressure for the same reason---because we're used to it. If you hang around with friends who swear and tell dirty jokes, you'll eventually find yourself doing the same thing. Your friends never implicitly asked you to swear, but you do it just the same. Oftentimes, we succumb to peer pressure without even realizing it was there in the first place.

The reason that the can collapsed under the weight of the atmosphere was because there was nothing inside of it. It was empty, and there was nothing inside to cancel out the outside pressure. I think that we collapse under peer pressure for the same reason---we're empty, and we don't have anything inside to counter pressure outside.

Psalm 119:11 says, "I have hidden your word in my heart that I might not sin against you." If we fill ourselves with the Word of God, then we'll be better equipped to counter the pressures of the world around us. Prayer is another way we can equip ourselves to withstand peer pressure. In Matthew 26:41, Jesus tells His disciples, "Watch and pray so that you will not fall into temptation. "

Standing up to negative peer pressure is a tough thing to do and sometimes, it'll make you unpopular. Your friends might call you a stick in the mud or a goody two-shoes for doing the right thing, but doing the right thing is, well...the right thing to do. "Everyone else is doing it" isn't a good excuse. Romans 12:2 tells us that we shouldn't conform to the patterns of this world. Chances are that if everyone else is doing it, we as Christians probably shouldn't be!

Being different isn't easy, but here's some words of encouragement that Jesus offered His disciples before His death:

"If the world hates you, keep in mind that it hated me first. If you belonged to the world, it would love you as its own. As it is, you do not belong to the world, but I have chosen you out of the world. That is why the world hates you. Remember the words I spoke to you: 'No servant is greater than his master.' If they persecuted me, they will persecute you also. "

John 15:18-20a (ESV)

Jesus wasn't of this world and the world hated Him. As Christians, we're called to live like Jesus. We don't belong to this world, so let's not act like it.

When peer pressure comes, stand firm on the Word of God---don't end up like a can of Crush.