On today's #Daily-Dose-On-Curiosity with 
Why is salt used to melt ice on roads in winter?
Let's find out together 👇👇👇
Image by Jonthan Toole from Pixabay
Ice forms when the water temperature reaches 0 degrees Celsius, and that includes ice on roads. Road salt works by lowering the freezing point of water through a process called freezing point depression. The freezing point of water drops as soon as the salt is added, so the salt makes it difficult for the water to freeze. A 10 percent salt solution freezes at 20 degrees Fahrenheit (-6 degrees Celsius) and a 20 percent solution freezes at 2 degrees Fahrenheit (-16 degrees Celsius).
The key is that there must be at least some water on the road for freezing point depression to work. Therefore, trucks often pre-treat the roads with a brine solution (a mixture of salt and water). when ice and snow are forecast. If the roads are dry and the DOT is just salting the roads, it probably won't make much of a difference. However, pre-treating with a brine solution can help ensure ice never forms and reduce the amount of road salt trucks need to spread later to de-ice.
Why do pilots wear headphones?
Flight headsets fall into two broad categories: passive noise reduction and active noise reduction (ANR). Passive noise canceling headphones rely on a good seal around the ear and high clamping force. Headphones must be powered to function properly, but all ANR headphones will function as passive noise canceling headphones without power.
To power the aircraft, a dedicated branded headphone plug must be installed in the control panel (a single jack provides power, headphone, and microphone connections). The headphone cable has 2 plugs (for airplanes) or one plug (for helicopters). These two connector types are electronically equivalent, and the helicopter cable has an extra conductor to accommodate the microphone and headphones in the same connector. The variant with two plugs has a headphone connection and a microphone connection.
These differ from gaming headsets in that the headphone plug is .25" (the kind that a good stereo receiver uses) and the microphone plug is .206". This difference in size is to avoid confusing the plug with the port. The headset is connected to the aircraft audio panel.
Audio panels vary in complexity, but their basic role is to provide intercom for communication between aircraft occupants and access to the communication radio for communication with ATC. The audio panel can also monitor (listen) to certain navigation radios. Beacon Types. On transport aircraft, the audio panel is also connected to the passenger address system and cabin crew phones. The microphone is the usual method, and the audio panel offers a mute switch so you don't transmit cabin noise when you're not speaking.
ATC transmissions are via a push-to-talk (PTT) switch.
So there you have it for today's
#Daily-Dose-On-Curiosity, Tomorrow is another section, stay tuned!