It’s been a long time since I’ve done it, but years ago I got scuba certified. As you might expect, there’s a lot more to it than just grabbing an air tank and jumping into the water. I found learning about some of the physics behind it to be very interesting. I know not everybody is a math person, so I’ll try to keep it pretty general.
Scuba diving is all about pressure. Before we get in the water we’re only dealing with the weight of air on us. If you’re standing on the shore at sea level, the weight of all the air above you equates to a little less than 15 pounds per square inch (psi). That’s not much, considering how many miles up that column of air extends. This level, 14.69 psi, is known as one atmosphere.
The water is a completely different story. Since water weighs so much more than air, a column of only about 34 feet of water exerts the same amount of pressure as one atmosphere. Standing at the ocean’s edge you have one atmosphere pressing down on you. Scuba diving 34 feet deep, you have two atmospheres pressing down on you (one air and one water).
Moving from sea level to 34 feet under the surface causes the pressure that’s exerted on your body to increase by 100%, to nearly 30 psi. It’s definitely noticeable. If you move another 34 feet deeper, you have a total of three atmospheres (almost 45 psi) pressing on your body. The same amount of air pressure in your tank offers differing amounts of breathable air at various depths because there needs to be enough “oomph” in your air tank(s) to overcome the water pressure to make it through the regulator, hoses, and into your lungs. That excess “oomph” is what determines how much air is available for you to breathe. The deeper you go, the less time you can stay there.
Here’s the kicker: as you’re descending deeper, you notice the biggest pressure difference early on, and even though you’re still descending, the rate of increase gets less noticeable the deeper you go. Ever dive deep into a pool or a lake? You probably had to plug your nose and equalize the pressure in your head/ears before you went 10-12 feet deep because it felt like there was a huge increase in pressure. Mathematically, moving from one to two atmospheres is a 100% increase. Moving from two to three atmospheres is an increase of only 50%. Moving from three to four atmospheres is an increase of only 33%. The further you go, going even further feels like less of a big deal.
Sin is like that too. When you first encounter something you know is wrong, it’s easy to identify as being wrong. Once you start accepting it, rationalizing it away, or getting comfortable with it, it becomes more difficult to think of as being “wrong.” You start to accept additional things you formerly would’ve rejected outright. Once you make the jump from “one atmosphere” to two, it becomes easier to move to the third, and from there to the fourth.
What’s the bottom line? If you know it’s wrong, don’t do it. Don’t compromise. The more you compromise on living a God-honoring life, the more you’ll be willing to make subsequent concessions. Stay in that area near the surface, where you’re still sensitive to small changes in pressure and where going only 10 feet down becomes painful.
Our world is changing. Things that were once considered unspeakable are now commonplace and even endorsed. God’s view of sin has not changed, so neither should ours. We’re all sinners, and we all need the salvation Christ offers. Everyone needs to hear about it (God loves each and every person He’s created, so we shouldn’t play favorites), and you may be the only way someone encounters the truth. The truth will be more evident in your life if you’re living the way God wants.
Lord Jesus, thank you for creating this wonderful world and even giving us examples from science! Help us all be sensitive about the things in our lives that we should not allow to be there. Also help us to avoid a “holier than thou” attitude and be willing to genuinely reach the “tax collectors and sinners” of the Bible. Praise You for what You’ve done for us! In Your name, Amen.