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Heavily pure brown dwarf has been discovered!

Researchers discovered a celestial body heavy brown dwarf, “SDSS J 0104 + 1535”, which is about 750 light years away from the earth.

If the brown dwarf is a celestial body larger than the planet, it could not cause nuclear fusion by light hydrogen. A new observation by the VLT at the European Southern Observatory in Chile revealed details of this object.

If SDSS J0104 + 1535 is predicted to be 10 billion years old, its mass is about 90 times that of Jupiter. However, the sun has a mass that is 1050 times that of Jupiter. SDSS J 0104 + 1535 is much lighter so it could not continue nuclear fusion.

Also, the constituent materials excluding hydrogen and helium is only 0.01%. This also makes it clear that SDSS J 0104 + 1535 is the most “pure” brown dwarf.

Zeng Hua Zhang, who is the Association of Astronomical Physics of the Canary Islands said, surprisingly commented that he discovered such pure brown dwarf. We may also find such a very heavy brown dwarf in near future.

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Complicated waves made from a simple equation

Speaking of waves, we come up with ocean. Wind creates complicated shapes of waves as you know.

Waves have an interesting property that is called principle of superposition. Each wave oscillates up and down. When an up-wave and a down-wave collide at a point, the both waves appear to be vanished if both waves have an equal amplitude.

Sounds and electromagnetic waves also have the same property.

The picture is expressed by the equation, sin(x^2)-cos(y^2)-sin(x*y).

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Gravity on Saturn: If you go there, how do you feel?

Question:

How strong is the gravity on the surface of Saturn?

a) About 0.5 times as strong as that on Earth
b) About 1 times as strong as that on Earth
c) About 2 times as strong as that on Earth
d) About 6 times as strong as that on Earth
e) About 10 times as strong as that on Earth

 

 

The answer is b). The gravitational acceleration is proportional to its mass, but inversely proportional to the square of the radius. Saturn is less dense than Earth.

Photo via Visual Hunt

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Georg Simon Ohm’s biography: How Ohm’s law was formulated

Georg Simon Ohm (1789 – 1854)

He was born in Bayern State in Germany. His father studied math, physics, and philosophy by himself and taught his children what he learned.

Because he learned enough from his father, Georg thought that he wouldn’t learn anything in school when he was eleven years old. After completing the college, he started working as a math teacher.

Although he was major in mathematics, he got a chance to teach physics in schools. He was gradually fascinated with electric phenomena discovered by Oersted. He got engaged in figuring out the mathematical aspect of electricity. Georg discovered that the magnitude of current in a metal wire is proportional to its cross-sectional area and inversely proportional to its length. In addition, he formulated that the resistance is equal to the voltage divided by the current in a circuit, which is called Ohm’s law nowadays.

His performance is based on the experiments and mathematical logic; however, he was not evaluated by German science society for a long time. Allegedly, the strong influence of idealism of philosophy might have prevented it from accepting Ohm’s way to analyze the whole.

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The gravitational wave, the way to understand it in terms of our daily lives

The gravitational waves were detected in February 2016, which was the very first time. After a few months, the scientists again detected another gravitational waves, and they found more details of how the waves were generated by spinning of black holes.

By the way, it sounds too far from our daily lives, doesn’t it? You may wonder about what those scientists are doing? What is the gravitational wave? Why is the black hole?

You can read the theoretical details in other “enthusiastic” websites or papers, but I would like to explain it in terms of what we have.

You know electromagnetic waves that are used for many of our technologies, such as cell phones, radios, wireless network, etc. In fact, the waves are created with electrically charged particles. More precisely, oscillation of the particles emit electromagnetic waves, which was experimentally proven a long time ago.

Now, we can get back to the gravitational wave. Gravity is induced by its mass. If we analogize this to the electromagnetic wave, oscillation of mass can generate the wave of gravity. That is also derived from what Einstein predicted.

Then, why was it really difficult to detect the gravitational wave? This is because the gravitational force is way too much weaker than the electromagnetic force. It depends on particles, but if the electromagnetic force is 1, the gravitational force is 0.0000000000 0000000000 0000000000 0000000001.

Therefore, in order to detect the gravitational wave, the mass to be oscillated must be very large. Black holes are actually very massive.

Let’s summarize it. The gravitational waves are similar to electromagnetic waves. However, the gravitational waves are very weak, so the massive black holes had to be used for the experiment and the technologies also had to be highly sophisticated.

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Manufacturing and engineering owe electricity and magnetism

Michael Faraday was a British physicist who contributed to many of important findings for electromagnetic phenomena.

His family was challenged economically, but his siblings and religious belief supported him. In his childhood, he was interested in doing experiments by reading science books.

The turning point of his life came when he audited Humphry Davy’s science lecture. Then, Michael Faraday became his assistant. After a while, Davy found that Faraday had a talent in performing experiments. Faraday was genuinely devoted to finding out electricity in his life.

Now, we are using electricity everyday in our lives, and it becomes indispensable. Without knowing the fundamental theory, we don’t even manufacture cars, airplanes, and a lot of other products.

On the other hand, if we apply such knowledge to what we make, we may be able to create innovative products.

History suggests that the combination between engineering and science changes our life styles and concepts.