What is Cremation?
(The details in the following come from Wikipedia.)
Cremation is the process of burning a human body after death. The box containing the body is placed in the retort (burning chamber of the crematorium) and incinerated at a temperature of 760 to 1150 °C (1400 to 2100 °F). During the cremation process, the greater portion of the body (especially the organs and other soft tissues) is vaporized and oxidized by the intense heat; gases released are discharged through the exhaust system. The process usually takes 90 minutes to two hours, with larger bodies taking a longer time.
Jewelry, such as necklaces, wrist-watches, and rings, are ordinarily removed before cremation, and returned to the family. Certain implanted devices are required to be removed. Pacemakers and other medical devices can cause surprisingly large, dangerous explosions.
Contrary to popular belief, the cremated remains are not ashes in the usual sense. After the incineration is completed, the dry bone fragments are swept out of the retort and pulverized by a machine called a Cremulator—essentially a high-capacity, high-speed blender—to process them into “cremated remains,” although pulverization may also be performed by hand. This leaves the bone with a fine sand-like texture and color, able to be scattered without need for mixing with any foreign matter, though the size of the grain varies depending on the Cremulator used. Not all that remains is bone. There may be melted metal lumps from items such as missed jewelry, casket hardware, dental fillings, and surgical implants.
After final grinding, the remains are placed in a container, which can be anything from a simple cardboard box to a decorative urn. The default container used by most crematoria, when nothing more expensive has been selected, is usually a zip-locked plastic bag placed inside a hinged, snap-locking plastic box.
An unavoidable consequence of cremation is that a tiny residue of bodily remains is left in the chamber after cremation. This residue then mixes with subsequent cremations.
Cremation and Jewish Observance
Traditional Judaism does not support cremation. In modern times, however, there are Jewish families who are choosing cremation for their loved ones. There are a few arguments to support such a choice, and many more for choosing ground burial. Most streams of Judaism today prefer ground burial as the most respectful way to honor the dead.
There are many articles that discuss this topic in detail. Some of these articles discuss the importance of ground burial from a Jewish perspective. Others discuss the negative aspects of cremation, exploring the entire process involved in burning a body, including the public health and environmental impacts. In addition, there are responsa from Orthodox, Conservative, and Reform Jewish perspectives, as well as articles on what other religions have to say about cremation versus ground burial.