10 science-backed life hacks you can teach yourself in under 5 minutes

The best way to tell if strawberries are ripe, according to Quora user Cyndi Perlman Fink, is to give them a sniff. "If they smell like strawberries, buy them; they will taste divine. If they look gorgeous but have no smell, they will have no taste."

Why? When a fruit ripens, chemical reactions take place that break down its complex carbohydrates into simpler sugars, and these are what we smell when we walk by the produce isle, food scientist Shirley O. Corriher told Fine Cooking.

You've just been introduced to someone, and you've already forgotten their name. Luckily, there are some strategies you can use remember names more easily:

When you first meet someone, take a mental picture of them. This will helps encode or store it in your brain as a longterm memory. Use creative associations — if a person named Joy looks happy all the time, think "Joy-ful person" when you see her, and you'll remember her name. Finally, and look up their name ahead of time, if possible — studies suggest it helps!

No one likes soggy pizza. But Quora user Wassim Ferose offers this tip for reheating a leftover slice: Microwave it alongside a glass of water.

Microwaves work by zapping your food with electromagnetic radiation, which is absorbed by water, fats, and sugars and converted into heat. But some waves get reflected and bounce around. Adding a glass of water to the microwave acts as a sink for all that extra energy, so it doesn't vaporize your pizza crust.

All you need for this simple trick is a walnut and a soft cloth. How? The natural oils in the nut act as a kind of natural furniture polish, repelling dust by static electricity.

As this YouTube video explains, just remove the nut from its shell and rub it diagonally across the scratch or ding you want to get rid of. Then, rub the area with your finger to warm it up, and wait a few minutes to let the nut's natural oils sink in. Finally, use the cloth to polish the spot. Pecans, almonds, and Brazil nuts also work.

Having trouble counting sheep? Arpit Pareek offers this tip: "Look for patterns in the random noise of your eyelids and try to 'follow' it. Once you start seeing complete images you're under way to dreamland." Don't worry if it doesn't work right away — "Try again, just relax, think about nothing and watch the pretty pictures."

If that doesn't work, you can also try avoiding using your phone or laptop right before bed, as the bright light can interfere with your brain's internal clock, keeping you wide awake. Or if you can't wean yourself completely, try an app like f.lux, which dims your screen to a warmer color that won't keep you up.

Lost while hiking without a GPS? If you have a watch, you easily can turn it into a compass, Quora user Amarnath Ganesh explains. Just position your watch horizontally so the hour hand is facing the sun, and imagine a line passing through the midpoint of the hour hand and the 12 — that's your North-South axis, with North pointing away from the sun. For example, if the hour hand is pointing at 4 o'clock, the 2 points toward South, and 8 points north.

Note: This trick only works in the northern hemisphere. And during daylight savings time, use the 1 instead of the 12.

You can thank physics for this one. If your shoelaces keep coming undone, never fear. Ian's secure shoelace knot, also known as a double slit knot, is here to the rescue. Here's how it works:

1. Tie a normal starting knot, then make both ends into loops.

2. Cross one loop in front of the other.

3. Wrap the first loop around the second and thread it through the hole.

4. At the same time, thread the second loop through the hole in the opposite direction.

5. Pull both loops through the hole.

6. Tighten!

Watch a YouTube video of how to tie the knot here.

The key to speed reading is simple: read with your eyes, not with the voice in your head, says Quora user Raj Rai. "Just work on eliminating the voice. Why? You cannot say words nearly as fast as you can comprehend them," he says.

Okay, this one's technically more than 5 minutes. But this workout app lets you squeeze in a full workout in just 7 minutes, less than the time it takes to get changed and go to the gym.

The workout includes 12 different exercises, such as jumping jacks, situps, and planks. The science behind the app rests on the idea that short bouts of intense exercise have many of the same benefits as longer exercise sessions.

This one might sound odd, but feminine hygiene products can make great wound dressings because they're 1) sterile and 2) very absorbent. They're great for plugging a bloody nose, as long as you don't mind the strange looks. They can also apparently be used to fill a bullet wound, but only as a last resort, because the blood can clot around the tampon and make it hard to remove.