- Beta Ophiuchi or β Ophiuchi, also named Cebalrai /ˌsɛbəlˈreɪ.iː/, is a star in the equatorial constellation of Ophiuchus. The apparent visual magnitude of this star is 2.7, which is readily visible to the naked eye even from urban skies. The distance to this star can be estimated using parallax measurements, yielding a value of 83.4 light-years (25.6 parsecs) from the Sun.
- Cogito, ergo sum (Wikipedia)
The Latin cogito, ergo sum, usually translated into English as “I think, therefore I am”, is the “first principle” of René Descartes’s philosophy. He originally published it in French as je pense, donc je suis in his 1637 Discourse on the Method, so as to reach a wider audience than Latin would have allowed. It later appeared in Latin in his Principles of Philosophy, and a similar phrase also featured prominently in his Meditations on First Philosophy. The dictum is also sometimes referred to as the cogito. As Descartes explained in a margin note, “we cannot doubt of our existence while we doubt.” In the posthumously published The Search for Truth by Natural Light, he expressed this insight as dubito, ergo sum, vel, quod idem est, cogito, ergo sum (“I doubt, therefore I am — or what is the same — I think, therefore I am”). Antoine Léonard Thomas, in a 1765 essay in honor of Descartes presented it as dubito, ergo cogito, ergo sum (“I doubt, therefore I think, therefore I am”).