Question: The most common symptom of LED (and diode laser) failure is the gradual lowering of light output and loss of efficiency. Sudden failures, although rare, can also occur. Early red LEDs were notable for their short service life. With the development of high-power LEDs the devices are subjected to higher junction temperatures and higher current densities than traditional devices. This causes stress on the material and may cause early light-output degradation. To quantitatively classify useful lifetime in a standardized manner it has been suggested to use L70 or L50, which are the runtimes (typically given in thousands of hours) at which a given LED reaches 70% and 50% of initial light output, respectively.
Is there an answer to this question: What is a symptom of non-LED failure?

Answer: unanswerable

Question: With the advent of quantum physics, some scientists believed the concept of matter had merely changed, while others believed the conventional position could no longer be maintained. For instance Werner Heisenberg said "The ontology of materialism rested upon the illusion that the kind of existence, the direct 'actuality' of the world around us, can be extrapolated into the atomic range. This extrapolation, however, is impossible... atoms are not things." Likewise, some philosophers[which?] feel that these dichotomies necessitate a switch from materialism to physicalism. Others use the terms "materialism" and "physicalism" interchangeably.
Is there an answer to this question: Who said "This extrapolation, however, is impossible... atoms are lots of things"

Answer: unanswerable

Question: Tiberius' brother Gaius was elected tribune in 123 BC. Gaius Gracchus' ultimate goal was to weaken the senate and to strengthen the democratic forces. In the past, for example, the senate would eliminate political rivals either by establishing special judicial commissions or by passing a senatus consultum ultimum ("ultimate decree of the senate"). Both devices would allow the Senate to bypass the ordinary due process rights that all citizens had. Gaius outlawed the judicial commissions, and declared the senatus consultum ultimum to be unconstitutional. Gaius then proposed a law which would grant citizenship rights to Rome's Italian allies. This last proposal was not popular with the plebeians and he lost much of his support. He stood for election to a third term in 121 BC, but was defeated and then murdered by representatives of the senate with 3,000 of his supporters on Capitoline Hill in Rome. Though the senate retained control, the Gracchi had strengthened the political influence of the plebeians.
Is there an answer to this question: Which elected official lost the election in 121 BC?

Answer: Gaius

Question: Each sensory system begins with specialized receptor cells, such as light-receptive neurons in the retina of the eye, vibration-sensitive neurons in the cochlea of the ear, or pressure-sensitive neurons in the skin. The axons of sensory receptor cells travel into the spinal cord or brain, where they transmit their signals to a first-order sensory nucleus dedicated to one specific sensory modality. This primary sensory nucleus sends information to higher-order sensory areas that are dedicated to the same modality. Eventually, via a way-station in the thalamus, the signals are sent to the cerebral cortex, where they are processed to extract biologically relevant features, and integrated with signals coming from other sensory systems.
Is there an answer to this question: Signals are sent from the thalamus to what part of the brain?

Answer:
cerebral cortex