The animation below illustrates how gravitational waves are emitted by two neutron stars as they first orbit each other and then coalesce. Though gravitational waves were predicted to exist in 1916, actual proof of their existence wouldn't arrive until 1974, 20 years after Einstein's death.
Uroabdomen can result from various causes, but the most common is related to trauma. Damage to the kidney, ureter, bladder, or urethra may cause urine to leak into the abdomen. Some common forms of trauma that can result in a disruption of the urinary tract in cats include:
The urinary sphincter is a group of muscles around the bladder neck that keeps you from leaking urine. The bladder neck is where your bladder connects to your urethra. Your urine goes from your bladder through your bladder neck and into your urethra.