Our Universe at Home Within a Larger Universe? So Suggests Physicist's Wormhole Research

Einstein-Rosen bridges like the one visualized above have never been observed in nature, but they provide theoretical physicists and cosmologists with solutions in general relativity by combining models of black holes and white holes. (Credit: Image courtesy of Indiana University)

 

Apr. 7, 2010 ---- SCIENCE DAILY — Could our universe be located within the interior of a wormhole which itself is part of a black hole that lies within a much larger universe?

 

Full Story @ ScienceDaily

Do Black Holes Have 'Hair'? New Hypothesis Challenges 'Clean' Model

Artist's illustration of a black hole. (Credit: iStockphoto)

Sep. 30, 2013 — A black hole. A simple and clear concept, at least according to the hypothesis by Roy Kerr, who in 1963 proposed a "clean" black hole model, which is the current theoretical paradigm. From theory to reality things may be quite different. According to a new research carried out by a group of scientists that includes Thomas Sotiriou, a physicist of the International School for Advanced Studies (SISSA) of Trieste, black holes may be much "dirtier" than what Kerr believed.

Full story @ ScienceDaily

Mount Sinabung volcano erupts in Indonesia

Indonesian farmers rush to harvest crops in the district of Karo as an ash cloud rises during a fresh eruption of the Mount Sinabung volcano. - Photo by AFP 

 

Thousands of villagers fled after Mount Sinabung's series of volcanic eruptions on Indonesia's Sumatra island, spewing rocks and red-hot ash onto surrounding villages, officials said.

A cloud of ash rises from the crater of the Mount Sinabung volcano (back C) during a fresh eruption. - Photo by AFP

Imran: talks only with those who renounce violence

Although he didn’t say it in so many words, the PTI chief implied that those unwilling to renounce violence should be taken head on and talks should be held only with who were willing to engage in dialogue. “Absolutely no reasoning could justify the killing of even one innocent human, let alone attacking a whole community.” — File Photo

Published 2013-09-24 06:40:36

 

 

ISLAMABAD: Pakistan Tehreek-i-Insaf Chairman Imran Khan appears to have adopted a less conciliatory attitude towards armed militants, although he does not single out any militant organisation currently attacking government forces in tribal areas.
Whether it is because of the killing of over 80 people in Sunday’s suicide blasts at the Peshawar church or of two senior military officers last week, Mr Khan is now somewhat toughening his stance against militancy.
A statement of Mr Khan issued by the PTI media wing on Monday said: “Those who carried out the attack against the Christian community and their church in Peshawar are to be condemned in the strongest terms possible.”
A strong proponent of talks with the militants fighting law-enforcement agencies in Fata and the PTI-ruled Khyber Pakhtunkhwa, Mr Khan said talks could be held only with those who were willing to renounce violence and accept the writ of the state.
“If peace is to be given a chance, then it is essential to isolate those who are dedicated to an agenda of violence and to carrying out terror attacks against innocent people, from those who are prepared to have a ceasefire and talk peace within the ambit of the Constitution of Pakistan.”
Although he didn’t say it in so many words, the PTI chief implied that those unwilling to renounce violence should be taken head on and talks should be held only with who were willing to engage in dialogue.
“Absolutely no reasoning could justify the killing of even one innocent human, let alone attacking a whole community.”

DAWN NEWS

Nawaz has no authority to hold peace talks: Pakistani Taliban

A spokesman for the Tehrik-i-Taliban Pakistan (TTP), while criticizing Nawaz Sharif, said his government was not serious about holding peace talks. – File Photo by Reuters

Published 2013-09-29 01:11:54

KARACHI: The Pakistani Taliban militants Saturday assailed Prime Minister Nawaz Sharif for changing his mind and giving preconditions of weapon lay down for the APC-backed peace talks with them.
The comments appeared to have been sparked by an interview Sharif made with the Wall Street Journal during a trip to New York, in which he said militants must lay down their arms and follow the constitution. Previously the prime minister had not given preconditions for the talks.
The prime minister had also indicated during his meeting with US Secretary of State John Kerry that while seeking a dialogue with the Taliban, the government is also considering a more vigorous police and military action against them should the talks fail.
A spokesman for the Tehrik-i-Taliban Pakistan (TTP), while criticizing Sharif in an interview to a local news magazine, said his government was not serious about holding peace talks.
The spokesman, Shahidullah Shahid, did not explicitly reject the offer but his words gave little room for negotiations.
“By telling us that we will have to lay down arms and respect the constitution, the prime minister, Nawaz Sharif, showed that he is following the policy of America and its allies,” the spokesman said.
Declining to accept the writ and authority of the PML-N government, Shahid said: “He (Nawaz Sharif) is talking about laying down arms and accepting the Constitution. If we were willing to do that, there would be no need to have any kind of dialogue.”
“We will hold talks with (the government) only when it gets the authority to take decisions.”
Replying to a query about proof of Sharif’s ‘authority,’ he said there were three steps required for confidence-building; pull out the Army from FATA, release of Taliban prisoners, and end to US drone attacks in Pakistan.
“We will present our terms and conditions when we sit down for dialogue. What we have already mentioned are not conditions or preconditions, they are steps the government must take to build confidence and prove they have authority,” he added.
Answering a question regarding repercussions of a full-scale military operation against the militants, he said, “The operation against us has been going on for the last 10 years already. We have become used to it. We even welcome it.”

Source: DAWN NEWS

Twin blasts in Peshawar claim 31 lives

PESHAWAR: Twin blasts near the Qissa Khawani market in Peshawar on Sunday killed 31 people and wounded more than 70 others, DawnNews reported.
The blasts, which took place at 11am in the morning, set at least eight shops and surrounding vehicles aflame. The first blast was relatively smaller, and has been likened to a hand grenade. The second was much stronger and more destructive.
There was terror amongst the people in the area, who were helping each other out.
Police suspect that the second blast was a car bomb.
The wounded were initially being shifted to the hospital by the people in the area. They also include women and children.
According to a correspondent, five to six women who had been in the market with their children were completely burned as a result. He also added that no security had been present in the area at the time of the blast.
Minister of Health Shaukat Yusufzai stated that the Peshawar Police Station was the main target of the two blasts.
Prime Minister Nawaz Sharif has also condemned the blast as an act of terror.
An emergency was declared in Lady Reading Hospital after the blast.
A heavy infiltration of security forces and rescue teams was dispatched to the area.
The people in the area were terror-struck, which caused hinderance in the security forces' efforts to get them to evacuate.
The blasts took place exactly a week after twin sucide attacks in a church in Peshawar claimed 80 lives. This is the third attack in Peshawar in a week.

Source: Dawn News

4 killed in U.S. drone strike in NW Pakistan

ISLAMABAD, Sept. 29 (Xinhua) -- At least four people were killed in a U.S. drone strike launched in Pakistan's northwest tribal area of North Waziristan on Sunday morning, reported local media.
Local Urdu TV channel Geo said that the strike came at about 10: 50 a.m. local time when U.S. unmanned aircraft fired two missiles at a house suspected of being a militant hideout in the Dargah Mandi area of Miranshah in North Waziristan.
Identities of the killed are not immediately known.
Sunday's U.S. drone strike in North Waziristan is the 21st of its kind in Pakistan in 2013. According to Xinhua's tally, at least 117 people have reportedly been killed in such strikes since the start of the year.

Source:  http://news.xinhuanet.com/english/world/2013-09/29/c_132761197.htm

Many dead in new Pakistan quake

Updated: 09:49, Sunday September 29, 2013

Pakistani officials say they have already recovered 22 bodies following a powerful 6.8-magnitude earthquake that hit a region already devastated by an earlier tremor.
Officials fear the toll in yesterday's quake in the southwest province of Baluchistan, could still rise further. The quake is believed by the US Geological Survey to be an aftershock of Tuesday's 7.7-magnitude temblor which left more than 300 people dead.
However an official at the National Seismic Centre of Pakistan classified it as a new earthquake.

 Source: http://www.skynews.com.au/world/article.aspx?id=910357

Google I/O 2011: HTML5 versus Android: Apps or Web for Mobile Development?

HTML and CSS: Design and Build Websites [Book @ Amazon]

This book is really targeted at beginners without a technical background, and it does an exceptional job in serving this audience. The approach is perhaps the gentlest introduction to the concept of web programming that I've ever encountered. So gentle, in fact, I think that almost anyone could pick up this book and start to make a simple web page relatively quickly. It takes you right from creating your HTML file with a text editor, through learning HTML and CSS, all the way to deploying your file and adding Google Analytics.

Buy @ Amazon

Edward Lear's Nonsense Botany

A selection of Edward Lear’s drawings from the Houghton Library’s collections

Anna Lena Phillips

In a January–February Science Observer, we considered the resurgence of interest in Edward Lear’s scientific illustration—and the possibility that his nonsense drawings and verse might have practical use as well. Lear (1812–1888) made his name with a monograph on parrots, published in 1832. As he labored over his exacting illustrations, he also made whimsical poetry and drawings for children. Concerned that the latter would cause people to take his scientific work less seriously, he published them pseudonymously at first. Later he became well known for these limericks, nonsense alphabets and other poems.

Full Article @ AmericanScientist

Accelerator On a Chip: Technology Could Spawn New Generations of Smaller, Less Expensive Devices for Science, Medicine

Sep. 27, 2013 — In an advance that could dramatically shrink particle accelerators for science and medicine, researchers used a laser to accelerate electrons at a rate 10 times higher than conventional technology in a nanostructured glass chip smaller than a grain of rice.

Full Story @ ScienceDaily

MATLAB Window Environment and the Base Program (Lesson 2)

Starting MATLAB

On the Windows desktop, the installer usually creates a shortcut icon for starting MATLAB; double-clicking on this icon opens MATLAB desktop.

The MATLAB desktop is an integrated development environment for working with MATLAB suite of toolboxes, directories, and programs. We see in Fig. M1.1 that there are four panels, which represent:

1. Command Window
2. Current Directory
3. Workspace
4. Command History

A particular window can be activated by clicking anywhere inside its borders.

Fig. M1.1 MATLAB Desktop (version 7.0, release 14)

Desktop layout can be changed by following Desktop --> Desktop Layout from the main menu as shown in Fig. M1.2 (Default option gives Fig. M1.1).

 

Fig. M1.2 Changing Desktop Layout to History and Command Window option

Command Window

We type all our commands in this window at the prompt ( >> ) and press return   to see the results of our operations. Type the command ver on the command prompt to get information about MATLAB version, license number, operating system on which MATLAB is running, JAVA support version, and all installed toolboxes. If MATLAB don't regard to your speed of reading and flush the entire output at once, just type more on before supplying command to see one screen of output at a time. Clicking the What's New button located on the desktop shortcuts toolbar, opens the release notes for release 14 of MATLAB in Help window. These general release notes give you a quick overview of what products have been updated for Release 14.

Working with Command Window allows the user to use MATLAB as a versatile scientific calculator for doing online quick computing. Input information to be processed by the MATLAB commands can be entered in the form of numbers and arrays.

As an example of a simple interactive calculation, suppose that you want to calculate the torque ( T ) acting on 0.1 kg mass ( m ) at   swing of the pendulum of length ( l ) 0.2 m. For small values of swing, T is given by the formula . This can be done in the MATLAB command window by typing:

>>   torque = 0.1*9.8*0.2*pi/6

MATLAB responds to this command by:

torque =

  0.1026

MATLAB calculates and stores the answer in a variable torque (in fact, a   array) as soon as the Enter key is pressed. The variable torque can be used in further calculations.   is predefined in MATLAB; so we can just use pi without declaring it to be 3.14….Command window indicating these operations is shown in Fig. M1.3.

Fig. M1.3 Command Window for quick scientific calculations ( text in colored boxes corresponds to explanatory notes ).

If any statement is followed by a semicolon,

>> m = 0.1;

>> l = 0.2;

>> g = 9.8;

the display of the result is suppressed. The assignment of the variable has been carried out even though the display is suppressed by the semicolon. To view the assignment of a variable, simply type the variable name and hit Enter. For example:

>> torque=m*g*l*pi/6;

>> torque

torque =

   0.1026

It is often the case that your MATLAB sessions will include intermediate calculations whose display is of little interest. Output display management has the added benefit of increasing the execution speed of the calculations, since displaying screen output takes time.

Variable names begin with a letter and are followed by any number of letters or numbers (including underscore). Keep the name length to 31 characters, since MATLAB remembers only the first 31 characters. Generally we do not use extremely long variable names even though they may be legal MATLAB names. Since MATLAB is case sensitive, the variables A and a are different.

When a statement being entered is too long for one line, use three periods, … , followed by   to indicate that the statement continues on the next line. For example, the following statements are identical (see Fig. M1.4).

>> x=3-4*j+10/pi+5.678+7.890+2^2-1.89

>> x=3-4*j+10/pi+5.678...

+7.890+2^2-1.89

+ addition,   subtraction, * multiplication, / division, and ^ power are usual arithmetic operators.

The basic MATLAB trigonometric commands are sin, cos, tan, cot, sec and csc. The inverses , etc., are calculated by asin, acos, etc. The same is true for hyperbolic functions. Some of the trigonometric operations are shown in Fig M1.5.

Variables j = and i = are predefined in MATLAB and are used to represent complex numbers.

Fig. M1.4 Command Window with example operations

 Fig. M1.5 Example trigonometric calculations

MATLAB representation of complex number :

  or  

The later case is always interpreted as a complex number, whereas, the former case is a complex number in MATLAB only if j has not been assigned any prior local value.

MATLAB representation of complex number :

  or  

  or  

In Cartesian form, arithmetic additions on complex numbers are as simple as with real numbers. Consider two complex numbers   and . Their sum   is given by

For example, two complex numbers   and   can be added in MATLAB as:

>>   z1=3+4j;  

>>   z2=1.8+2j;

>>   z=z1+z2

z =

   4.8000 + 6.0000i

Multiplication of two or more complex numbers is easier in polar/complex exponential form. Two complex numbers with radial lengths   and   are given with angles   and   rad. We change   to radians to give   rad=   rad. The complex exponential form of their product   is given by

This can be done in MATLAB by:

>>   theta1=(35/180)*pi;

>>   z1=2*exp(theta1*j);

>>   z2=2.5*exp(0.25*pi*j);

>>   z=z1*z2

z =

  0.8682 - 4.9240j

Magnitude and phase of a complex number can be calculated in MATLAB by commands abs and angle. The following MATLAB session shows the magnitude and phase calculation of complex numbers   and .

>> abs(5*exp(0.19*pi*j))

ans =

     5

>>   angle(5*exp(0.19*pi*j))

ans =

    0.5969

>>   abs(1/(2+sqrt(3)*j))

ans =

    0.3780

>>   angle(1/(2+sqrt(3)*j))

ans =

   -0.7137

Some complex numbered calculations are shown in Fig. M1.6.

Fig. M1.6 Example complex numbered calculations  

The mathematical quantities and   are calculated with exp(x), log10(x), and log(x), respectively.

All computations in MATLAB are performed in double precision . The screen output can be displayed in several formats. The default output format contains four digits past the decimal point for nonintegers. This can be changed by using the format command. Remember that the format command affects only how numbers are displayed, not how MATLAB computes or saves them. See how MATLAB prints   in different formats.

Format command at MATLAB prompt	Display format
format short	31.4159
format short e	3.1416e+001
format long	31.41592653589793
format long e	3.141592653589793e+001
format short g	31.416
format long g	31.4159265358979
format bank	31.42

The following exercise will enable the readers to quickly write various mathematical formulas, interpreting error messages, and syntax related issues.

 

Exercise M1.1 By using arbitrary values of , check that . Verify with a few arbitrary values of   that . Verify with a few arbitrary values of   that . For t =0, 2, 5, 7, 12 and 25, find the value of the function . Exercise M1.2 Try entering complex number   in MATLAB as 3+j4 and check the answer. Initialize   and then enter 3+4j, 3+j*4, and 3+4*j and check the various answers. Interpret messages given by MATLAB. Calculate magnitude and phase of the following complex numbers for   using MATLAB.    . Use MATLAB to calculate the magnitude and phase of   for Exercise M1.3 Calculate the quantity   for . Calculate   for . Note: Inf, and NaN are predefined in MATLAB. NaN stands for Not-a-Number and results from undefined operations like 0/0. Inf represents .

 

Current Directory Window

This window (Fig. M1.7) shows the directory, and files within the directory which are in use currently in MATLAB session to run or save our program or data. The default directory is ‘C:\MATLAB7\work'. We can change this directory to the desired one by clicking on the square browser button near the pull-down window.

 

Fig. M1.7 Current directory window

One can also use command line options to deal with directory and file related issues. Some useful commands are shown in Table M1.1.

 

Table M1.1

Command	Usage
cd, pwd	To see the current directory
cd ..	To go one directory back from the current directory
cd \	To go back to the root directory
cd dir_name	To change to the directory named dir_name
ls or dir	To see the list of files and subdirectories within the current directory
what	Lists MATLAB-specific files in the directory. MATLAB specific files are with the extensions .m, .mat, .mdl, .mex, and .p.
mkdir (parentdir,dir_name) mkdir dir_name	Makes new directory with the name dir_name in the parent directory specified by parentdir . When supplied with only dir_name, it creates new directory within the current directory
delete file_name delete *.m	Deletes file from the current directory. Deletes all m-files from the current directory.

 

MATLAB desktop snapshot showing selected commands from Table M1.1 are shown in Fig. M1.8.

 

Workspace

Workspace window shows the name, size, bytes occupied, and class of any variable defined in the MATLAB environment. For example in Fig.M1.9, ‘b' is 1 X 4   size array of data type double and thus occupies 32 bytes of memory. Double-clicking on the name of the variable opens the array editor (Fig. M1.10). We can change the format of the data (e.g., from integer to floating point), size of the array (for example,   for variable A, from 3 X 4 array to 4 X 4 array) and can also modify the contents of the array.

 

Fig. M1.8 Example directory related commands

If we right-click on the name of a variable, a menu pops up, which shows various operations for the selected variable, such as: open the array editor, save selected variable for future usage, copy, duplicate, and delete the variable, rename the variable, editing the variable, and various plotting options for the selected variable.

Fig. M1.9 Entries in the Workspace

Fig. M1.10 Array editor window

 

Workspace related commands are listed in Table M1.2.

Table M1.2

Command	Usage
who	Lists variables currently in the workspace
whos	Lists more information about each variable including size, bytes stored in the computer, and class type of the variables
clear	Clears the workspace. All variables are removed
clear all	Removes all variables and functions from the workspace. This can also be done by selecting Edit from the main menu bar and then clicking the option Clear Workspace .
clear var1 var2	Removes only var1 and var2 from the workspace.

For example, see the following MATLAB session for the use of who and whos commands.

>> who

Your variables are:

A b

>> whos

Name	Size	Bytes	Class
A	3x4	96	double array
b	1x4	32	double array

Grand total is 16 elements using 128 bytes

Command History Window

This window (Fig. M1.11) contains a record of all the commands that we type in the command window. By double-clicking on any command, we can execute it again. It stores commands from one MATLAB session to another, hierarchically arranged in date and time. Commands remain in the list until they are deleted.

Fig. M1.11 Command history window

Commands can also be recalled with the up-arrow   key. This helps in editing previous commands.

Selecting one or more commands and right-clicking them, pops up a menu, allowing users to perform various operations such as copy, evaluate, or delete, on the selected set of commands. For example, two commands are being deleted in Fig. M1.12. 

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