I think my favorite super power is probably the ability to walk through walls. I've always wanted to be able to break into any building, escape any pursuer, or drop through the floor instead of taking the stairs. It's one of my main regrets that I'll never be able to do it.
The next best thing to being able to do something is knowing as much as you can about it. In elementary school I'd learned that atoms were mostly empty space. You have the electrons and the nucleus, but it seemed to me that if you managed to squish two atoms into the same space then they might be able to pass through each other.
I was pretty excited to learn, when I got to middle school, why exactly objects couldn't do that. For one thing, if you got the atoms occupying roughly the same space, then the electromagnetic forces would interfere with each other and the electrons of both atoms would be disrupted. This would severely mess up any chemistry that was going on with those atoms, and probably do very bad things to a person walking through a wall (and the wall itself).
Luckily, my youthful attempts to pass through my bedroom wall were doomed to fail for a reason that didn't involve all of my molecules coming apart. Originally, I thought this was due to electron repulsion. According to my high school physics teachers, atoms can't get that close together because the electrons of the atoms repell each other. Just like magnets of the same pole, two electrons will stay as far apart as they can. You can't make use of all that empty space within an atoms because the electrons form a kind of force field to keep other atoms out of their own territory.
It turns out that electron repulsion isn't actually what prevents objects from passing through each other. It's actually a quantum effect called electron degeneracy pressure, Basically, two electrons can't possibly be in the same place at once (that's part of the Pauli exclusion principle). When electrons get too close to each other, they must assume different energy levels. This means that to bring electrons close together, you need to add enough energy to put most of them into very high energy states. The closer objects come, the more energy you need. On the macro-level, that manifests as degeneracy pressure. That's why objects feel solid.
Understanding this almost makes up for not being able to walk through walls.
Einstein's theory of general relativity has dramatically changed life on our planet. It's used in a lot of different technologies, but perhaps the most surprising place to find the theory of relativity is in your smartphone. Smartphones account for general relativity in two different ways.
The place that it's most commonly pointed out is in GPS. Your phone figures out where it is by calculating the distance to a number of satellites. It does this by measuring the time of flight of a signal broadcast by each satellite. Once the phone knows how far away different satellites are, it can do triangulation on the known positions of the satellites to figure out where you are. This location measurement can be pretty precise (on the order of a meter).
The precision of GPS is possible because your phone takes into account special relativity in the form of time dilation. Satellites are travelling very fast with respect to a stationary smartphone. That high speed means that time goes slower for the satellite, and the clock it uses to calculate time of flight is off. Your phone takes that into account when calculating how long it took the signal broadcast by the satellite to get to wherever you are.
General relativity comes into play because satellites are so much higher than your phone, which means that they experience less of Earth's gravity than you do (note that this is different from microgravity). Since satellites experience less gravity than you do, time travels faster for them. So there are really two relativistic effects that need to be taken into account to actually figure out how fast time is travelling for the satellite, which can help tell how long it takes for a radio signal to travel from the satellite to your phone.
The second way that a smartphone takes general relativity into account is far simpler. Your phone has an accelerometer in it that measures acceleration on the phone. This is how your phone knows which way you're holding it. It's also how it makes those cool light-saber sounds when you swing your phone around.
When you're having a light-saber duel, your phone is measuring the acceleration applied by your wild jabs and lunges. No relativity there. However, when the phone is stationary and it detects which way it's oriented, it's measuring gravity. Gravity isn't acceleration, but it is indistinguishable under the theory of general relativity. It's only through the effects described by general relativity that your phone works the way that it does.
Science! It's closer than you think!
There's a concept in economics called the externality that my environmentalist friends like to talk a lot about. An externality is a cost that exists for some enterprise, but it's a cost on somebody other than the enterprise itself. The classic environmentalist example is that environmental damage is an externality for oil companies. Oil companies get a lot of money for extracting oil, and they sometimes don't bother to take care of the environment as they do that. This is because environmental damage affects the local community, but not the oil company's profits.
In many ways, it seems to me that an externality in economics is similar to entropy in physics. Entropy in a closed system never decreases, it's only by ignoring some part of the system that you can say that you're increasing order. So too with externalities. Those costs created by the enterprise still exist and still need to be paid for. The only reason that a company (or person, or government) can console themselves about not paying for those costs is that they're not a part of the closed system that is the company and its customers and suppliers.
As the concept of externalities has come to be better understood by governments, there have been attempts to make destructive companies take responsibility for their actions. This seems like what I used to do in my physics classes by redrawing system boundaries to account for entropy. Redrawing system boundaries for economic externalities is usually done by creating laws that require companies to pay for any damage that they may create. One good example of this is Montana, where mining companies have been required to create trusts that are responsible for cleaning up after them.
What's interesting to me is that the owners and CEOs of possibly damaging companies sometimes realize that they live inside the wider system that encompasses whatever damage is caused by their company. One example of that is Sunoco, which is the only oil company to sign on to the Ceres Principle.
I wonder if a better understanding of physics would cause people to realize the impact of such externalities to other parts of their lives. Even companies that work to mitigate externalities don't do all that they could. Perhaps CEOs of potentially harmful companies should be required to take a course in thermodynamics to get a good understanding of entropy and system boundaries.