Tuesday, September 09, 2014
Thursday, August 21, 2014
Wednesday, August 13, 2014
یاسها منتظرند
باد و باران و گیاهی که تویی بر لب جوی
همه از کوچه ها مرا می خوانند
من از این باران ها می دانم خانه ویران خواهد شد
ویران
یاس ها ریخته اند
زیر باران ها در کوچه رها
مثل مرداب بزرگی که در آن نیمه ی شب ها تنها
غوک ها می خوانند
و تو تنها می مانی
تا بدانی که چه ها می گذرد
من از این پنجره واری که سیاهست و بلند
به صدای تو که جاری خواهی شد
که مرا تنها در کوچه رها خواهی کرد
به صدای تو رها می شوم از شاخه ی خویش
زیر باران ها در کوچه سنگی
ویران خواهم شد
زیر این پنجره واری که تماشا گه باد است و گیاهی تاریک
به جهان گذران می نگرم
بادها در گذرند
یاسها منتظرند
جوی گریانی و در بارانها می گذری
تا می مانی و باران غریبی که زمین را
ویران خواهد کرد
آسمانی که به ما می نگریست
ماهتابی که به مه میتابید
همه در تاریکی ها ماندند
همه در باران فریاد زنان می گفتند
یاسها منتظرند
و تو گریان می گفتی : یاسها ریخته اند
باد و باران و تماشای گیاهی که مرا می بیند
من ازین پنجره واری که سیاهست و بلند
به تو فریادزنان می گویم
یاس ها منتظرند
و تو گریانی و در باران ها می گذری
خانه ویران خواهد شد
ویران
و گیاهی که تویی بر لب جوی
ریشه در آب روان خواهد شست
یاسها منتظرند
من همینجا تنها خواهم ماند
همه از کوچه ها مرا می خوانند
من از این باران ها می دانم خانه ویران خواهد شد
ویران
یاس ها ریخته اند
زیر باران ها در کوچه رها
مثل مرداب بزرگی که در آن نیمه ی شب ها تنها
غوک ها می خوانند
و تو تنها می مانی
تا بدانی که چه ها می گذرد
من از این پنجره واری که سیاهست و بلند
به صدای تو که جاری خواهی شد
که مرا تنها در کوچه رها خواهی کرد
به صدای تو رها می شوم از شاخه ی خویش
زیر باران ها در کوچه سنگی
ویران خواهم شد
زیر این پنجره واری که تماشا گه باد است و گیاهی تاریک
به جهان گذران می نگرم
بادها در گذرند
یاسها منتظرند
جوی گریانی و در بارانها می گذری
تا می مانی و باران غریبی که زمین را
ویران خواهد کرد
آسمانی که به ما می نگریست
ماهتابی که به مه میتابید
همه در تاریکی ها ماندند
همه در باران فریاد زنان می گفتند
یاسها منتظرند
و تو گریان می گفتی : یاسها ریخته اند
باد و باران و تماشای گیاهی که مرا می بیند
من ازین پنجره واری که سیاهست و بلند
به تو فریادزنان می گویم
یاس ها منتظرند
و تو گریانی و در باران ها می گذری
خانه ویران خواهد شد
ویران
و گیاهی که تویی بر لب جوی
ریشه در آب روان خواهد شست
یاسها منتظرند
من همینجا تنها خواهم ماند
M.Azad
Friday, May 30, 2014
SpaceX unveils sleek, reusable Dragon crew capsule - space - 30 May 2014 - New Scientist
SpaceX unveils sleek, reusable Dragon crew capsule - space - 30 May 2014 - New Scientist
First cargo, now crew – the uber-modern "space taxi"
known as the Dragon V2 is ready for passengers. At an unveiling ceremony
yesterday, complete with smoke effects and coloured lights, SpaceX CEO
Elon Musk gave the world its first glimpse of the upgraded Dragon
spacecraft.
known as the Dragon V2 is ready for passengers. At an unveiling ceremony
yesterday, complete with smoke effects and coloured lights, SpaceX CEO
Elon Musk gave the world its first glimpse of the upgraded Dragon
spacecraft.
NASA is already using an unpiloted version of Dragon to send cargo to the International Space Station and return valuable gear and scientific experiments. But Musk has always wanted Dragon to become a reusable ride for astronauts.
The new vehicle has simple silvery walls,
seats for up to seven passengers and a set of flatscreen control panels.
The spacecraft can dock itself to the ISS without help from the space station's robotic arm. But the most radical aspect of the redesign is the landing gear, which will allow astronauts to set the spacecraft down on solid ground.
seats for up to seven passengers and a set of flatscreen control panels.
The spacecraft can dock itself to the ISS without help from the space station's robotic arm. But the most radical aspect of the redesign is the landing gear, which will allow astronauts to set the spacecraft down on solid ground.
Space chopper
The current version of Dragon deploys a
parachute as it descends and splashes down in the ocean. Dragon V2
instead comes with a set of incredibly powerful SuperDraco engines,
each capable of producing more than 70,000 newtons of thrust. The
engines will allow astronauts to better manoeuvre in space as well as
control their trajectory for re-entry.
parachute as it descends and splashes down in the ocean. Dragon V2
instead comes with a set of incredibly powerful SuperDraco engines,
each capable of producing more than 70,000 newtons of thrust. The
engines will allow astronauts to better manoeuvre in space as well as
control their trajectory for re-entry.
"You'll be able to land anywhere on Earth with the
accuracy of a helicopter," Musk said during the event at SpaceX
headquarters in Hawthorne, California. The engines are encased in
protective shells, and they are set up in pairs so that if one fails,
the other can give a boost of power to compensate.
accuracy of a helicopter," Musk said during the event at SpaceX
headquarters in Hawthorne, California. The engines are encased in
protective shells, and they are set up in pairs so that if one fails,
the other can give a boost of power to compensate.
Friday, April 04, 2014
Buried 'Lake Superior' seen on Saturn's moon Enceladus - space - 03 April 2014 - New Scientist
Buried 'Lake Superior' seen on Saturn's moon Enceladus - space - 03 April 2014 - New Scientist
They found that Enceladus has a rocky core and an icy
crust. "Before, we knew almost nothing about the core beyond its likely
existence. Now we know roughly how big it is, and also that it has a
surprisingly low density," says team member Francis Nimmo
at the University of California, Santa Cruz. "That might be due to open
fractures, or low-density hydrated minerals like clays. Either answer
suggests that the rock has been in substantial contact with water, for
instance allowing minerals to dissolve, and explaining the salty ice
grains we see coming out of the surface."
crust. "Before, we knew almost nothing about the core beyond its likely
existence. Now we know roughly how big it is, and also that it has a
surprisingly low density," says team member Francis Nimmo
at the University of California, Santa Cruz. "That might be due to open
fractures, or low-density hydrated minerals like clays. Either answer
suggests that the rock has been in substantial contact with water, for
instance allowing minerals to dissolve, and explaining the salty ice
grains we see coming out of the surface."
The team also found that the southern
hemisphere has a stronger gravitational pull than its topography would
suggest. That could be explained by a localised sea, sitting beneath 35
kilometres of ice and up to 8 kilometres deep. It would contain about as
much water as Lake Superior in North America.
hemisphere has a stronger gravitational pull than its topography would
suggest. That could be explained by a localised sea, sitting beneath 35
kilometres of ice and up to 8 kilometres deep. It would contain about as
much water as Lake Superior in North America.
Destination, Enceladus?
If there might be life there, when can we go?
Cassini winds down in three years and there are no firm plans for
future craft to return to Saturn. However, Cassini team member Carolyn Porco at the Space Science Institute in Boulder, Colorado, has written a paper (soon to appear in the journal Astrobiology)
arguing for a mission to collect samples from Enceladus and return them
to Earth. She says the new results bode well for such an effort. "The
next mission there can immediately get down to the business of searching
for signs of life or its precursor chemistry. It's a big juncture!"
Cassini winds down in three years and there are no firm plans for
future craft to return to Saturn. However, Cassini team member Carolyn Porco at the Space Science Institute in Boulder, Colorado, has written a paper (soon to appear in the journal Astrobiology)
arguing for a mission to collect samples from Enceladus and return them
to Earth. She says the new results bode well for such an effort. "The
next mission there can immediately get down to the business of searching
for signs of life or its precursor chemistry. It's a big juncture!"
The subsurface-sea idea is just the simplest possible interpretation of the gravity data, cautions William McKinnon
at Washington University in St Louis, who was not involved in the work.
If the sea exists, there is the question of how long it has been liquid
and whether it might eventually freeze – or spray itself away. The
former is important as life would require the sustained presence of
water to gain a toehold.
at Washington University in St Louis, who was not involved in the work.
If the sea exists, there is the question of how long it has been liquid
and whether it might eventually freeze – or spray itself away. The
former is important as life would require the sustained presence of
water to gain a toehold.
As for the possibility of the sea freezing
completely, it is true that Enceladus is losing a lot of heat to space,
but astronomers suspect that this is an unusual episode. "We are
looking at Enceladus at a wonderful special time, where it's very active
and there's a lot of heat," McKinnon says.
completely, it is true that Enceladus is losing a lot of heat to space,
but astronomers suspect that this is an unusual episode. "We are
looking at Enceladus at a wonderful special time, where it's very active
and there's a lot of heat," McKinnon says.
Could the plumes deplete the sea
completely? Probably not. Even if they continue at the current rate, the
moon would only have lost 30 per cent of its water by mass when the sun
becomes a red giant in 6 billion years. "A lot of things can happen in 6
billion years, and it may shut off long before then, although the idea
of this thing blowing all of its ice away and becoming a little rocky
moon is kind of nice," Lunine says. "Some future extraterrestrials
visiting our solar system will be able to look at the naked rocky core
of what was once an ice moon."
completely? Probably not. Even if they continue at the current rate, the
moon would only have lost 30 per cent of its water by mass when the sun
becomes a red giant in 6 billion years. "A lot of things can happen in 6
billion years, and it may shut off long before then, although the idea
of this thing blowing all of its ice away and becoming a little rocky
moon is kind of nice," Lunine says. "Some future extraterrestrials
visiting our solar system will be able to look at the naked rocky core
of what was once an ice moon."
Gravitational Waves: The Big Bang's Smoking Gun | Space.com
Gravitational Waves: The Big Bang's Smoking Gun | Space.com
Direct evidence
In 2014, the Harvard-Smithsonian Center for Astrophysics found a faint signal in the cosmic microwave background
radiation (CMB) that signifies the first direct evidence of
gravitational waves ever discovered. Gravitational waves were the last
untested part of Einstein's general theory of relativity.
The Harvard-Smithsonian study spotted gravitational waves as ripples in
space-time possible left over from the rapid expansion of the universe
(called inflation) right after the Big Bang nearly 13.8 billion years ago.
Scientists working on the study found a distinct curling pattern
in the CMB — the comic fog that fills the universe and represents the
earliest detectable radiation — that further supports the idea that the
universe went through a huge period of inflation a fraction of a second
after the Big Bang.
"This work offers new insights into some of our most basic questions:
Why do we exist? How did the universe begin?," astrophysicist Avi Loeb,
who wasn't a member of the study team said in a statement about the
Harvard-Smithsonian research. "These results are not only a smoking gun
for inflation, they also tell us when inflation took place and how
powerful the process was."
Cosmic inflation
CMB radiation came into existence about 380,000 years after the Big
Bang. Scientists have mapped the CMB across the sky and found that it is
a uniform temperature, evidence that bolsters cosmic inflation theory.
"Why the cosmic microwave background temperature is the same at
different spots in the sky would be a mystery if it was not for
inflation saying, well, our whole sky came from this tiny region," Chuck
Bennett, principal investigator of NASA's Wilkinson Microwave
Anisotropy Probe (WMAP) mission, told Space.com in 2013. "So the idea of
inflation helps answer some of these mysteries, and it explains where
these fluctuations came from." ['Smoking Gun' of Universe's Inflation: Gravitational Waves (Infographic)]
Direct evidence
In 2014, the Harvard-Smithsonian Center for Astrophysics found a faint signal in the cosmic microwave background
radiation (CMB) that signifies the first direct evidence of
gravitational waves ever discovered. Gravitational waves were the last
untested part of Einstein's general theory of relativity.
The Harvard-Smithsonian study spotted gravitational waves as ripples in
space-time possible left over from the rapid expansion of the universe
(called inflation) right after the Big Bang nearly 13.8 billion years ago.
Scientists working on the study found a distinct curling pattern
in the CMB — the comic fog that fills the universe and represents the
earliest detectable radiation — that further supports the idea that the
universe went through a huge period of inflation a fraction of a second
after the Big Bang.
"This work offers new insights into some of our most basic questions:
Why do we exist? How did the universe begin?," astrophysicist Avi Loeb,
who wasn't a member of the study team said in a statement about the
Harvard-Smithsonian research. "These results are not only a smoking gun
for inflation, they also tell us when inflation took place and how
powerful the process was."
Cosmic inflation
CMB radiation came into existence about 380,000 years after the Big
Bang. Scientists have mapped the CMB across the sky and found that it is
a uniform temperature, evidence that bolsters cosmic inflation theory.
"Why the cosmic microwave background temperature is the same at
different spots in the sky would be a mystery if it was not for
inflation saying, well, our whole sky came from this tiny region," Chuck
Bennett, principal investigator of NASA's Wilkinson Microwave
Anisotropy Probe (WMAP) mission, told Space.com in 2013. "So the idea of
inflation helps answer some of these mysteries, and it explains where
these fluctuations came from." ['Smoking Gun' of Universe's Inflation: Gravitational Waves (Infographic)]
Monday, March 17, 2014
First glimpse of big bang ripples from universe's birth - physics-math - 17 March 2014 - New Scientist
First glimpse of big bang ripples from universe's birth - physics-math - 17 March 2014 - New Scientist
Waves in the very fabric of the cosmos are allowing us
to peer further back in time than anyone thought possible, showing us
what was happening in the first slivers of a second after the big bang.
If confirmed, the discovery of these primordial waves will have rippling
effects throughout science. It backs up key predictions for how the
universe began and operates, and offers a glimmer of hope for tying
together two foundational theories of modern physics. It might even net
the discoverers a Nobel prize.
to peer further back in time than anyone thought possible, showing us
what was happening in the first slivers of a second after the big bang.
If confirmed, the discovery of these primordial waves will have rippling
effects throughout science. It backs up key predictions for how the
universe began and operates, and offers a glimmer of hope for tying
together two foundational theories of modern physics. It might even net
the discoverers a Nobel prize.
The waves in question are called
gravitational waves and are produced when a massive object accelerates
through the fabric of space-time, causing ripples. They appear in
Einstein's highly successful theory of general relativity, although they have never been directly detected.
gravitational waves and are produced when a massive object accelerates
through the fabric of space-time, causing ripples. They appear in
Einstein's highly successful theory of general relativity, although they have never been directly detected.
Today, scientists working with the BICEP2
collaboration at the south pole announced the first clear sign of
gravitational waves, found in maps of the earliest light emitted after
the big bang. The distinctive swirls made by the waves are more
pronounced than the team expected, because models had suggested that
gravitational waves from this early era would be incredibly weak and
perhaps even undetectable.
collaboration at the south pole announced the first clear sign of
gravitational waves, found in maps of the earliest light emitted after
the big bang. The distinctive swirls made by the waves are more
pronounced than the team expected, because models had suggested that
gravitational waves from this early era would be incredibly weak and
perhaps even undetectable.
The team has spent three years ruling out
alternate explanations, such as dust in our own galaxy, distortions
caused by the gravity of more distant galaxies and errors introduced by
the telescope itself. In a pair of papers published online today,
they report a confidence level greater than 5 sigma. In other words,
the odds of seeing this signal by chance are less than 1 in 3.5 million.
alternate explanations, such as dust in our own galaxy, distortions
caused by the gravity of more distant galaxies and errors introduced by
the telescope itself. In a pair of papers published online today,
they report a confidence level greater than 5 sigma. In other words,
the odds of seeing this signal by chance are less than 1 in 3.5 million.
Sunday, February 16, 2014
"The Fabric of Space and Time is in Turmoil" --More on Stephen Hawking's Black Hole Update
"The Fabric of Space and Time is in Turmoil" --More on Stephen Hawking's Black Hole Update
"Following through with Hawking's argument, we conclude that if there
is evaporation there must be a boundary to the event horizon, a place
of transition between the inside and outside of the black hole," says
Lamontagne. "A high energy envelope, a firewall, which burns up matter,
is proposed."
However, this scenario poses a problem: if the firewall exists, we
should be able to see it. Furthermore, the existence of a firewall
around a black hole is inconsistent with the theory of general
relativity.
While the two major theories, that of general relativity (a theory of
gravity) and quantum mechanics (a description of the microscopic
world), work well in their respective fields, they are not universal:
neither can explain alone how black holes work.
"The Holy Grail would be to find THE theory that would unify the
other two. And Stephen Hawking has come back with a new proposal," says
Lamontagne. Roughly, Hawking suggests that if the firewall is not
visible, it is because its position fluctuates constantly and rapidly.
"Hawking says, and this is purely hypothetical, that the fabric of space
and time is in turmoil and we cannot define its whereabouts."
"Following through with Hawking's argument, we conclude that if there
is evaporation there must be a boundary to the event horizon, a place
of transition between the inside and outside of the black hole," says
Lamontagne. "A high energy envelope, a firewall, which burns up matter,
is proposed."
However, this scenario poses a problem: if the firewall exists, we
should be able to see it. Furthermore, the existence of a firewall
around a black hole is inconsistent with the theory of general
relativity.
While the two major theories, that of general relativity (a theory of
gravity) and quantum mechanics (a description of the microscopic
world), work well in their respective fields, they are not universal:
neither can explain alone how black holes work.
"The Holy Grail would be to find THE theory that would unify the
other two. And Stephen Hawking has come back with a new proposal," says
Lamontagne. Roughly, Hawking suggests that if the firewall is not
visible, it is because its position fluctuates constantly and rapidly.
"Hawking says, and this is purely hypothetical, that the fabric of space
and time is in turmoil and we cannot define its whereabouts."
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