What Is History? belief in a hard core of historical facts existing objectively and independently of the interpretation of the historian is a preposterous fallacy, but one which it is very hard to eradicate. Carr maintained that there is such a vast quantity of information in the modern era that the historian always chooses the "facts" he or she decides to make use of. In Carr's famous example, he claimed that millions had crossed the Rubicon, but only Julius Caesar's crossing in 49 BC is declared noteworthy by historians. Carr divided facts into two categories: "facts of the past", that is historical information
Rule of thirds (diving) Rule of thirds (diving) In scuba diving, the rule of thirds is a rule of thumb used by divers to plan dives so they have enough breathing gas remaining in their diving cylinder at the end of the dive to be able to complete the dive safely. This rule generally only applies to diving in overhead environments, such as caves and wrecks, where a direct ascent to the surface is impossible and the divers must return the way they came. For divers following the rule, one third of the gas supply is planned for the outward journey, one third is