Think Science .

In this post, I’ve tried to cover most of the frequently asked questions regarding the black holes. If you’ve more questions or if you think anything in this is missing or needs correction then do let me know in the comments.

What are black holes?
Black hole is region is from which nothing escapes, not even light. Black holes are simple objects as seen from outside their event horizon.

Who coined the term “Black hole” first?
John wheeler in 1967, coined the term “black hole” in his public lecture of : Universe- Known and the Unknown. Same term was also cited by anie Ewing to AAAS.

What are properties of black hole?
Black hole has three properties: Mass, angular momentum and electric charge.

What makes it impossible to any object not to escape from black hole?
Point of event horizon makes any object unable to move from the mass hence the object can’t pass through this point.

What are types of black holes?
Simplest type of black holes is called as Schwarzschild black holes. Other classified types are “Super massive black holes”, “Intermediate mass black holes”, “Stellar-mass black holes”, “Micro black holes”

How the size of black hole is determined?
The size of black hole is determined by the “radius of event horizon” or Schwarzschild radius.
Any references for black holes at the center of galaxy?
You can take a look at these:

1. “ASCA View of Our Galactic Center: Remains of Past Activities in X-Rays?” Publications of the Astronomical Society of Japan, v.48, p.249-255.

2. Sky and Telescope, June 1996, p.28.

Any nearest black hole & how far is it?

It is believed that “Cygnus X-1”, located about 8000 light years away” is the nearest one.

Is there any chance all the stars in universe will turn into black holes?
Nope. Not all the stars have enough mass become black holes at the end of their lives.

What is event horizon?
Event horizon is a surface in space-time that marks point of no return.

What is singularity?
According to general relativity, there is a space time singularity at the center of a spherical t the center of a spherical black hole, which means there exist an infinite space-time curvature.

What is an ergosphere?
Rotating black holes are surrounded by a region of space-time in which it’s not possible to stand still, so it is called an ergosphere.

What is a hawking radiation?
Sir Stephen Hawkins showed that the black holes are not entirely black but they do emit some thermal radiation, this effect is known as Hawkins radiation.

What are “Warp gates” in black holes?
Warp gates as shown in science fiction films are purely work of fiction and it has nothing to do with the actual black hole concept. Some folks assume if any matter goes into black hole it gets teleported to another universe side. Such theories are purely fictional and people churn those subjects for the pleasure.

What about black holes from LHC experiment? Are they going to destroy the earth?
Not at all. TV and media are showing this with excessive footage and featuring pseudo-science people claiming such things. Black holes which are being created at LHC are tiny and last for fractions of seconds. And they’ve no time for merging with additional matter. All that is shown on TV & newspaper/blogs is complete hoax and manipulated by retarded reporters by giving links to Mayan calendar and with interviews of average wannabe famous pseudo-science people.

I hope the information above helped. I’ll update this post in future with more questions and answers.

Few weeks ago a student in astrophysics was asking this question and was furious to get answer. He was confused with the mathematics behind most of these theories. So he asked that “Why we need M-theory”? He thinks that not everything we do in real life can be justified by maths and science so why we need such theory? So in response to question i’ve decided to make a blog post so that if any other student ask this type of question then i can forward him/her to this post.

M-theory?
Yes, we need M-theory. Theories seldom “change” drastically. They evolve over time as our understanding and tools for mathematical analysis improve. The initial approach in physics focused on the particle theory and thus we needed different kinds of particles to explain different kind of properties of matter as well as the different kinds of interactions. Like the EM force is carried by electrons, the strong force by Gluons and so forth. Thus it was proposed that Gravity must also have a particle (Graviton) associated with it. Mass could not be explained in anyway at that point of time. All these led to the evolution of String theory ( which by the way would have been impossible had computers not been around). These theories relied on the assumption that matter was comprised of loops of strings and that the properties of the matter could be explained by the modes of vibration in different dimensions. It is difficult to see the beauty of these equations if you are not a hard core mathematician but the concept itself is pretty straight forward.

Why maths?
As for mathematics, well, lets just say that you have to pick your battles when it comes to mathematical concepts. Some of the ideas are really surprising and tie in beautifully to everyday life while some are pretty far fetched. Physicists do rely on mathematics a lot but what they use more is intuition. Mathematics is just a tool and its the one who uses it that matters. Example: Set theory led to concepts of Boolean algebra and everything from Computers to Satellites use Boolean logic now. Laplace/Fourier transforms are extensively used in communication theory and they lead to negative frequencies which obviously has no physical interpretation.

I’ m compiling list of books that all of us can use as reference for “cosmology”. I’m asking for recommendation and suggestion about these books on plenty of science forums and communities. So if you think there are more that can be added to the list or anything which should be taken off from the list then please post about it in comments.

In this post i’ll list some of the cosmology related books.

1. Kolb and Turner: The Early Universe.

2. “Principles of Cosmology and Gravitation”,Berry, M. V.

3. Dennis Overbye: Lonely Hearts of the Cosmos

4. Weinberg: First Three Minutes

5. Hawking: Brief History of Time

6. Introduction to Cosmology : J. V. Narlikar

7. Timothy Ferris: Coming of Age in the Milky Way

8. “Black Holes and Warped Spacetime”, by William J. Kaufmann, III.

9. Peebles: Principles of Physical Cosmology

10. The large-scale structure of the universe / by P. J. E. Peebles.

11. The big bang / Joseph Silk

12. Structure formation in the universe / T. Padmanabhan.

13. Bubbles, voids, and bumps in time: the new cosmology / editedby James Cornell.

14. Cosmology: Steven weinberg

15. Introduction to cosmology Matts Roos

This list will keep on expanding but for now I’ve tried my best come up with 15 good books for cosmology. If you think I missed something or you think any book shouldn’t be referred anymore then please let me know in the comments.

I decided to make few posts on topic of global warming. I’ll make more post related to the ways with which one can reduce global warming. This post lists simple 6 ways to reduce global warming.

1. Try to walk or use a bicycle, instead of using the car.

2.Turn off the lights of the rooms, when they are not in use.

3. Print on both side of the paper. Avoid printing if you can read or show things on computer. Or your clients/students can work with computer documents it is good to spread electronic copies of stuff instead of printing it out.

4. Avoid using air fresheners, or similar types of sprays.

5. Minimize waste.

6. Try your best to recycle all the paper and bottles.

7. Unplug your appliances after use, since they will still keep on taking energy even if you are not using them, this called as phantom load.

8. Plant trees.

There are definitely more ways to reduce global warming. You can submit your suggestion in the comments. I’ll post more information and tips on reducing global warming in future.

Fractals are structures with self-symmetry. Some of the popular fractals are Mandelbrot fractal and Julia fractal. With Fractal explorer software you can study these two fractals on your computer system.

Installation of Fractal explorerIn order to run fractal on your computer, you’ve to install “ruby” & “ruby-opengl gem” on your system. Download the ruby on-click installer from this site: http://rubyforge.org/projects/rubyinstaller/Just use this installer to install ruby and opengl-gem on your system.Then download the Fractal explorer zip archive from this link:http://tpreal.dcmembers.com/Fractals.zipThen unzip the archive and run MandelbrotExplorer.rb or JuliaExplorer.rb .

Mandelbrot explorerMandelbrot Explorer allows you to explore the Mandelbrot set. It allows you to zoom into any part of the set. Use arrow keys to move up and down. To use zoom: A and Z.

Julia ExplorerWhen you run Julia explorer it will display the tutorial on how to use it. The basics are: use Arrows and A, Z to see the fractal evolve, and use U, J, H and K, and zoom: S, X, to zoom into any part of the fractal. Julia Explorer allows you to explore Julia sets of quadratic polynomials of the form z^2+c.

If you’ve any issues with the Fractal explorer program then ask your questions and get program support at this site:http://www.donationcoder.com/Forums/bb/index.php?topic=15943.0