In space, no one can hear you fart (but they can smell it). They can! Zero gravity could even help them to travel, if the aroma was spreading through a virtual vacuum. Smells travel by the movement of individual aroma molecules.

You apply one force to the rope by flicking it upward and an opposite force when you snap it back down. This sends a wave through the rope. Both forces—the one that moves the rope up and the one that moves the rope down—are required to start a wave.

Types and features of waves Waves come in two kinds, longitudinal and transverse. Transverse waves are like those on water, with the surface going up and down, and longitudinal waves are like of those of sound, consisting of alternating compressions and rarefactions in a medium.

When you make a wave on a rope, the wave moves from one end of the rope to the other. But the rope itself moves up and down or from side to side, at right angles to the direction in which the wave travels. Waves that move the medium at right angles to the direction in which the waves travel are called transverse waves.

Vocabulary

• crest. Noun. the top of a wave.
• wave. Noun. moving swell on the surface of water.
• wave height. Noun. the distance between a wave’s trough and crest.
• wavelength. Noun. the distance between the crests of two waves.
• wave trough. Noun. the lowest part of a wave.

Space Environment On Earth, sound travels to your ears by vibrating air molecules. In deep space, the large empty areas between stars and planets, there are no molecules to vibrate. There is no sound there.

Krakatoa is believed to be the loudest sound produced on the surface of the planet — in human history, that is. It circled the Earth four times in every direction and shattered the ears of sailors 40 miles away. The Krakatoa volcano erupted with ungodly strength, sending ripples of sound heard thousands of miles away.

The most dangerous frequency is at the median alpha-rhythm frequencies of the brain: 7 hz. This is also the resonant frequency of the body’s organs.

Binaural beats in the alpha frequencies (8 to 13 Hz) are thought to encourage relaxation, promote positivity, and decrease anxiety. Binaural beats in the lower beta frequencies (14 to 30 Hz) have been linked to increased concentration and alertness, problem solving, and improved memory.

Healthy adults listened to gamma-frequency (40 Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340 Hz (control condition) for 3 min before and during a global–local task.

Neuroscientists may have a solution for you: Turn down your alpha brain waves. In a new study, the researchers found that people can enhance their attention by controlling their own alpha brain waves based on neurofeedback they receive as they perform a particular task.

Music therapy can reduce stress and promote relaxation. It’s been shown to be more effective than prescription drugs in reducing anxiety levels before surgery. A study published in 2017 found that a 30-minute music therapy session combined with traditional care after spinal surgery reduced pain.

2.1. 1 Brain Waves

Measurement of frequency band energy by spectral analysis The power spectral density was estimated in each segment (baseline and postspike) in 4 frequency bands: subgamma (0–40Hz), gamma (40–100 Hz), high frequency (HF, 100–200 Hz), and very high frequency (VHF, 250–500 Hz).

In the human context, the signals carried by the large-diameter, myelinated neurons that link the spinal cord to the muscles can travel at speeds ranging from 70-120 meters per second (m/s) (156-270 miles per hour[mph]), while signals traveling along the same paths carried by the small-diameter, unmyelinated fibers of …