How do you quantify curvature?

The definition of gravity in relativity theory is a curvature of space time, while quantum physicists are constantly trying to quantify gravity as the force and find graviton. Then the question is how do you quantify curvature?

What is π

π is the ratio of the circumference of a circle to its diameter. In other words, pi equals the circumference divided by the diameter (π = c/d). Yep, that’s it. It’s just a relation between diameter and circumference. However it’s been used a lot in math and physics and you probably have heard about it dozen amount of times, but why ? Because there are plenty of circles and spheres around us! Planet’s circumference is a circle, approximate electron’s orbit is a circle, circles and spheres are everywhere at every scale.

π is not a constant in all areas of time-space, it was discovered 4k years ago in ancient Greece. There are a lot of representations of π, you can get it without any geometry but that’s the hard way to explain it.  So if the question is: “What is π and why it’s so important?”, then brief answer is it helps to describe shapes of the universe.

Oh by the way, here is π itself, enjoy.

Pluto and Beyond!

The party begins !

Do you remember where you were on January 19th, 2006 at 14:00 EST? Unless you have an extremely detailed journaling addiction, I’m guessing you don’t. If you have a fondness for a certain celestial object, however, you just might. You see, on that fateful day the New Horizons probe launched on a journey to Pluto and the mysterious Kuiper Belt. If you have been following New Horizon’s progress through the solar system, complete with a gravity assist from Jupiter, you are in for a treat. In an epic case of delayed gratification, New Horizons is finally going to make its close encounter with Pluto, plus its five moons, in just a few days on July 14th.

Why is this exciting you ask? Well beyond satisfying the innate human desire to explore strange new worlds, the encounter with Pluto is epic because we know so little…

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Is it stuped to start a web search startup?

Who gonna make a web search service when there is Google? This likely to be a stuped idea which is doomed to failure, however there are some brave folks who tryed. And after this article you will not think they are just adrenaline maniacs.

Firstly direct google competitiors, fairly i don’t love them, they’re boaring but still show some success.

• Blekko. Nothing really special, some features like slashtags for custom searches and categorized results. But things become interesting when you discover that company received \$60.2 Million in 9 rounds of investment and was acquired by IBM on March 27, 2015.
• Duck Duck Go – private web search…private…and private. As you get main feature is privacy. Founded in 2008 they got \$3 Million Venture on October 13, 2011. Apple and Firefox included them as a search option. Okay.

The second will be social searchers, blogs searchers and so on. Search engines which search in a particular place. And it is plenty of them, i will cover few because they copy each other and sometimes difference is so small that can be neglected.

•  BuzzSumo. This one is for contens search and analysis. It shows number of shares in social networks have alot of adjustments and cool features. They started in 2014 and their funding info is closed. But they have future for sure!
• Topsy! Great for analyzing twitter, you can search influencers, photos, videos and so on. It’s good for researching your competitors because service keeps tweets from 2006. Founded in 2007 Topsy recived \$35.2 Million in 6 Rounds and was Acquired by Apple on December 2, 2013.

Third Is Wolframalpha. Scientific search! Here you can easily find data about specific scientific stuff. And it delivers free HD porn solves equations! You tipe them in search box and wolframalpha will give you the roots + graphics. Founded in 2009 and never took dilutive funding, it was financed by it’s creator Stephen Wolfram. Wolframalpha is used by Siri in iphones and offers paid pro version, which is it’s monetization. And it’s my favorite because it helped me to pass university exams, and it is a truly new idea.

So google is a no doubts monopoly in search services market, but there are also pirates who no matter what get their prey! The prey is small but it depends of what is small for you. I wanted to write something inspirational here but…my first thoughts when i accidently found one of this services were “why the fuck heck it exists?”, but it exists and makes money, enjoy.

Feel the mind warp

Smoke some, play Hans Zimmer and look at the Universe) Wasn’t these awesome ?

How do they calculate stellar masses?

How do scientists determine masses of stars? Is it an assumption? Let’s figure out! Now we can calculate an approximate mass of any star via it’s luminosity. It’s called mass – luminosity relation. In other words there is a relation between star’s light intensiveness and it’s mass. And how did we come up with this relation? – Empirically, it means that we made a lot of observations, measuring luminosity of stars which mass was known, that was stars in binary systems ( two stars rotating around each other ) to which the distance is known via standard parallax measurements or other techniques, and masses can be calculated. You want to know how exactly? Be ready to meet a couple of formulas 😉

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

So This is how. Firstly, let’s figure out how to calculate masses in binary system.  This are two equations we will need:

1.( m1 + m2 ) P2 = ( d1 + d2 ) 3 = R3

2.m1d1 = m2d2                                                                                                                                                                    d1+d2 = R

Where P is orbital period, m1 and m2 are respective masses, R = d1 + d2. From these equation, if the period P and the average separation R are known, we can solve for the total mass M = m1 + m2 of the binary system. Then, if we know enough about the orbits to determine the distances d1 and d2 separately, the second equation can be used to determine the individual masses m1 and m2.

So now you know how to determine masses in binary systems, just make enough observations to see a clear relation between luminosity and mass. But wait some guys already did it, here it is:

where L and M are the luminosity and mass of the Sun and 1 < a < 6. The value a = 3.5 is commonly used for main-sequence stars  ( there are spetial relations for extreamly small and large ones).

More precise determining requires some calculations, in brief you should imagine star as a black body made of an ideal gas a couple of manipulations with formulas and you will have your desired stellar mass. If you wish to go even more precise it will require building of a detailed thermodynamic star model and making a lot of sophisticated calculations and measurements.

If you wish to deepen in this go here or have some fun with this binary system simulator, or calculate the mass of our sun with guide from NASA ( it’s quite simple ). Hope you enjoyed this article.

Humanity is entering a space age

This note is inspired by that accident with Falcon, it made me think a little about the whole topic. I suddenly discovered that it’s it! Human has finally made first really solid steps on the road of space exploration. Just take a look around and you will smell it, its in the air. Cosmic blogs become more and more popular, 5 years ago i saw really few people interested in them, NASA clips on Vine gain million loops. Films about the space become blockbusters and so on. People become more aware of the topic, people look at the sky they support the idea. And this is awesome because people are the key.

The first steps are always hard, remember how we tried to build planes for example, but they always worth it, now you can cross a half of the globe in 20 hours. Let’s wish good luck to Elon Musk with his SpaceX, because guys like this will bring us to the future we all have dreamed about. To the future we have only seen in Sci Fi books and films, to the future where you will fly to Mars for a vacation.

New iphone with force touch

TNW is reposting that Bloomberg is reporting Apple has started production of new iphones with force touch. 😉
This technology allows your device detect different levels of pressure. It means your iphone screen will feel like a giant button with 5 levels of push. Also force touch can detect if you are trying to push with your nail or finger and will auto adjust it’s sensitivity level. Force touch is already integrated in 12inch MacBook, MacBook pro and AppleWatch.

Just imagine how many new features will apps develop using this technology: light push to copy – hard push to edit – harder push to delete, touch to jump – push to activate boost…and so on. It is really a new way to communicate with user.

– Hey CEO! – Startup which lets you learn from the dead startups!

Right here you can see 115 fail stories which may help you to avoid mistakes which killed startups described in them. Enjoy 😉