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 tract collects and stores urine and provides a passage for urine to be expelled from the body. The ureters are about 25-30 cm long and carry urine from the kidneys to the bladder. Although the ureters are thin tubes they have muscle within their walls. This helps to push urine towards the bladder.