Why is it almost impossible to produce blue LED light?

What does blue light do? Glowing blue, Rambo fans will say like a shot (if you didn't know: Here is an excerpt from the film). But this is not easy when the light source is one Light emitting diode (LED) Actions. These do not get their colors through colored coating. They directly emit a frequency of light that makes them appear colorful.

the Red LED It was developed in 1962, then in 1969 Green LED. However, blue was missing from the color palette. Firstly 1993 The Japanese succeeded Shoji Nakamurathe first Blue LED To produce. Only with this discovery began the triumph of LEDs. You can see why blue LED light is so difficult to produce here:

For his discovery, Nakamura received an equivalent reward from his employer 150 euros. In 2001, he sued for what he said was improper compensation and was awarded the equivalent amount 6 million euros. In 2014, he and two other researchers from Japan received an award Nobel Prize in Physics excellent.

This is how Apple imagined the future

Artificial intelligence in the home that communicates with residents via voice, miniature holograms, and a $20 billion company – the future at Apple was rosy. In one Video from 1987 Internal description of the company Apple User Group Connection, What will life be like in 10 years.

At the time, people probably wouldn't have imagined that Apple would be on the verge of bankruptcy in 1997. Apple made more than $1 trillion in 2019 – so… 1000 billion – It should be worth it, maybe not.

Can sand flow uphill?

Researchers at Lehigh University have found a way to make sand flow upward. To do this, molecules have to do this Coated with iron oxide It is controlled by magnets. Anyone who thinks that molecules are simply attracted to magnets and thus move is mistaken. Instead, a magnet is located underneath the particles and rotates. Grains of sand take this Torque It rotates so strongly that it moves against gravity.

Researchers have found bird species that have been lost since 1882

the The one with the black nap Ferguson pheasant pigeon It was last captured in 1882 and was considered extinct until it was caught on camera in September 2022. The discovery made international headlines. However, this is also interesting Researchers' reactionWho discovered the animal in the jungle of New Guinea. The enthusiasm they have for their work is evident in the video.

This drone is flapping its wings

in Bird-like dronesThe search is already underway. The inconspicuous drone can be used for spying and wildlife monitoring purposes. But until now, imitating the flapping of animal wings has been a challenge.

➤ Read more: Drones made from dead birds should fly more naturally using artificial intelligence

But there are already small drones that are very popular Fluttering in the air Can you catch me? You can see how these work here:

Black holes with a mass of tens of millions of solar masses are very small

not enough? When I went online last week, you could see, among other things, how small it was black holes In reality.