Examples of time dilation in the following topics:
-
- Time dilation is an actual difference of elapsed time between two events as measured by observers moving relative to each other.
- Time dilation is an actual difference of elapsed time between two events as measured by observers either moving relative to each other.
- For instance, two rocket ships (A and B) speeding past one another in space would experience time dilation.
- The formula for determining time dilation is: $\Delta t' = \gamma \Delta t = \frac{\Delta t}{\sqrt{1 - v^{2}/c^{2}}}$
- Thus, time dilation effects and extremely small and can be safely ignored in a daily life.
-
- According to the time dilation, in the unprimed frame it oscillates more slowly at a time interval $\bigtriangleup t=2\pi \gamma / \omega$.
- The time between the arrival for two crests of the wave in the unprimed frame is given by,
-
- This occurs because special relativity shows that the faster one travels, the slower time moves for them.
- This result appears puzzling because each twin sees the other twin as traveling, and so, according to a naive application of time dilation, each should paradoxically find the other to have aged more slowly.
- In the spacetime diagram , drawn for the reference frame of the Earth-based twin, that twin's world line coincides with the vertical axis (his position is constant in space, moving only in time).
- Time is relative, but both twins are not equivalent (the ship experiences additional acceleration to changes the direction of travel).
-
- Time could not affect space and space could not affect time.
- This can be expressed in the time dilation equation:
- One of the more radical results of time dilation is the so-called "twin paradox. " The twin paradox is a thought experiment in special relativity that involves identical twins.
- The square root factor in the time dilation equation is very important and we denote it as:
- Thus in every day life $\gamma \approx 1$ and we do not experience significant time dilation or length contraction.
-
- The speed of light is generally a point of comparison to express that something is fast. shows a scale representation of the time it takes a beam of light to reach the moon from Earth.
- This is known as the mass-energy equivalence, and it uses the speed of light to interrelate space and time.
- For example, length contracts and time dilates (runs slower) for objects in motion.
- The Lorentz factor (γ) is the factor by which length shortens and time dilates as a function of velocity (v):
- A beam of light is depicted travelling between the Earth and the Moon in the time it takes a light pulse to move between them: 1.255 seconds at their mean orbital (surface-to-surface) distance.
-
- Labor and birth are divided into three stages: the dilation of the cervix, the delivery of the baby, and the expulsion of the placenta.
- At this time, the baby reorients, facing forward and down with the back or crown of the head engaging the cervix (uterine opening).
- At the same time, the placenta releases prostaglandins into the uterus, increasing the contractions.
- During stage one, the cervix thins and dilates.
- A cervix is considered fully dilated at 10 centimeters.
-
- Vaginal delivery childbirth has three distinct phases: dilation of the cervix, delivery of the infant, and delivery of the placenta.
- The onset of actual labor is defined when the cervix begins to progressively dilate.
- Full dilation is reached when the cervix has widened enough to allow passage of the baby's head, around 10 cm dilation for a term baby.
- The second stage begins when the cervix is fully dilated and ends when the baby is born.
- The average time from delivery of the baby until complete expulsion of the placenta is estimated to be 10–12 minutes.
-
- As contractions become closer and stronger, the cervix will gradually start to dilate.
- During this phase, the cervix dilates from 1-4 centimeters.
- During this phase, the cervix dilates on average 1 cm per hour, dilating from 4-7 centimeters, indicating a rapid dilation and contractions are longer, stronger and closer togther.
- Dilation from 8-10 centimeters occurs during transition.
- There are times when a mother may need outside aid in the delivery of the baby, some of these methods include: Forceps, an instrument used to cradle the fetus' head and manipulate the head under the pubic bone so it can more easily pass through the birth canal.
-
- These techniques differ in the mechanism used to apply suction, in how early in pregnancy they can be used, and in whether cervical dilation is necessary.
- Manual vaccum aspiration (MVA), also known as "mini-suction" and "menstrual extraction", can be used in very early pregnancy, and does not require cervical dilation.
- Dilation and evacuation (D&E) consists of opening the cervix of the uterus and emptying it using surgical instruments and suction.
- In the U.S., the risk of maternal death from abortion from 1998 to 2005 was 0.6 per 100,000 procedures, making abortion about 14 times safer than childbirth (8.8 deaths per 100,000 live births).
- The use of abortion procedures is dictated primarily by gestational time period.
-
- Physiological changes induced by the sympathetic nervous system include accelerating the heart rate, widening bronchial passages, decreasing motility of the large intestine, dilating the pupils, and causing perspiration.
- For example, the sympathetic nervous system can accelerate heart rate, widen bronchial passages, decrease motility of the large intestine, constrict blood vessels, increase peristalsis in the esophagus, cause pupillary dilation, piloerection (goose bumps) and perspiration (sweating), and raise blood pressure.
- In the human fight or flight response in prehistoric times, fight was manifested in aggressive, combative behavior and flight was manifested by fleeing potentially threatening situations, such as being confronted by a predator.
- In current times, these responses persist, but fight and flight responses have assumed a wider range of behaviors.
- During stressful times, a mother is especially likely to show protective responses toward her offspring and affiliate with others for shared social responses to threat.