Science & Technology
Satellite television provider DirecTV Group Inc. may test delivering high-speed Internet service through power lines in a major U.S. city in the next year, its chief executive said on Monday.
Archaeologists got a royal surprise last week when they stumbled upon the tomb of a powerful official of the Egyptian court from 4,000 years ago.
Scientists from Belgium's Leuven Catholic University discovered the intact tomb in the Deir Al-Barsha necropolis in Minya, about 150 miles (241 kilometers) south of Cairo, while excavating another burial site, Egypt's culture ministry reported Sunday.
The tomb is of Henu, a courtier and real estate manager during the tumultuous First Intermediate period (2181 to 2050 B.C.) of Egyptian history.
Scientists from Belgium's Leuven Catholic University discovered the intact tomb in the Deir Al-Barsha necropolis in Minya, about 150 miles (241 kilometers) south of Cairo, while excavating another burial site, Egypt's culture ministry reported Sunday.
The tomb is of Henu, a courtier and real estate manager during the tumultuous First Intermediate period (2181 to 2050 B.C.) of Egyptian history.
Mathematicians and number buffs have their records. And today, an international team has broken a long-standing one in an impressive feat of calculation.
On March 6, computer clusters from three institutions - the EPFL, the University of Bonn and NTT in Japan -- reached the end of eleven months of strenuous calculation, churning out the prime factors of a well-known, hard-to-factor number that is a whopping 307 digits long.
"This is the largest 'special' hard-to-factor number factored to date," explains EPFL cryptology professor Arjen Lenstra. (The number is 'special' because it has a special mathematical form -- it is close to a power of two.) The news of this feat will grab the attention of information security experts and may eventually lead to changes in encryption techniques.
Although it is relatively easy to identify huge prime numbers, factoring, or breaking a number down into its prime components, is extremely difficult. RSA encryption, named for the three individuals who devised the technique (Ronald Rivest, Adi Shamir and Leonard Adleman), takes advantage of this. Using the RSA method, information is encrypted using a large composite number, usually 1024 bits in size, created by multiplying together two 150-or-so digit prime numbers. Only someone who knows those two numbers, the "keys", can read the message. Because there is a vast supply of large prime numbers, it's easy to come up with unique keys. Information encrypted this way is secure, because no one has ever been able to factor these huge numbers. At least not yet.
On March 6, computer clusters from three institutions - the EPFL, the University of Bonn and NTT in Japan -- reached the end of eleven months of strenuous calculation, churning out the prime factors of a well-known, hard-to-factor number that is a whopping 307 digits long.
"This is the largest 'special' hard-to-factor number factored to date," explains EPFL cryptology professor Arjen Lenstra. (The number is 'special' because it has a special mathematical form -- it is close to a power of two.) The news of this feat will grab the attention of information security experts and may eventually lead to changes in encryption techniques.
Although it is relatively easy to identify huge prime numbers, factoring, or breaking a number down into its prime components, is extremely difficult. RSA encryption, named for the three individuals who devised the technique (Ronald Rivest, Adi Shamir and Leonard Adleman), takes advantage of this. Using the RSA method, information is encrypted using a large composite number, usually 1024 bits in size, created by multiplying together two 150-or-so digit prime numbers. Only someone who knows those two numbers, the "keys", can read the message. Because there is a vast supply of large prime numbers, it's easy to come up with unique keys. Information encrypted this way is secure, because no one has ever been able to factor these huge numbers. At least not yet.
The High Resolution Stereo Camera (HRSC) on board ESA's Mars Express has captured breathtaking images of the Deuteronilus Mensae region on Mars.
The images were taken on 14 March 2005 during orbit number 1483 of the Mars Express spacecraft with a ground resolution of approximately 29 metres per pixel.
They show the Deuteronilus Mensae region, located on the northern edge of Arabia Terra and bordering the southern highlands and the northern lowlands. Situated at approximately 39° North and 23° East, Deuteronilus Mensae are primarily characterised by glacial features. The scene is illuminated by the Sun from the south-west (from bottom left in the image).
The images were taken on 14 March 2005 during orbit number 1483 of the Mars Express spacecraft with a ground resolution of approximately 29 metres per pixel.
They show the Deuteronilus Mensae region, located on the northern edge of Arabia Terra and bordering the southern highlands and the northern lowlands. Situated at approximately 39° North and 23° East, Deuteronilus Mensae are primarily characterised by glacial features. The scene is illuminated by the Sun from the south-west (from bottom left in the image).
Physicists may have solved a long-standing mystery about sand dunes on Mars. The dunes looks as if they should have been created by the action of wind, but the Martian atmosphere is so still and thin that it was thought impossible for wind to have played a part. New computer simulations suggest that the wind can indeed drive the sand dunes on Mars -- it's just that the dunes are formed far more slowly than back on Earth.
Astronomers have long been puzzled by the sand dunes on Mars, which were first discovered in 1971. The dunes look very much like those on Earth, which suggests they were created by the action of wind. The problem is that the Martian atmosphere is so thin and still -- so how could the wind have played a part?
Even more curious is the fact that successive missions to Mars have not detected any change in the positions of the dunes, whereas the dunes on Earth are shifting constantly. Some scientists have therefore suggested that the dunes were created long ago, when the Martian atmosphere could have been much denser than it is today.
Astronomers have long been puzzled by the sand dunes on Mars, which were first discovered in 1971. The dunes look very much like those on Earth, which suggests they were created by the action of wind. The problem is that the Martian atmosphere is so thin and still -- so how could the wind have played a part?
Even more curious is the fact that successive missions to Mars have not detected any change in the positions of the dunes, whereas the dunes on Earth are shifting constantly. Some scientists have therefore suggested that the dunes were created long ago, when the Martian atmosphere could have been much denser than it is today.
Tomita's team successfully inserted into a common bacterium Albert Einstein's famous "E equals MC squared" equation and "1905," the year the Nobel Prize-winning physicist published the special theory of relativity.
Charlie Callagan, park ranger and naturalist, knows the rocks well. "You see the rocks and you see the tracks they left behind and it's obvious they've moved," says Callagan.
And there are no footprints, no tire tracks, no sign of someone moving them.
And there are no footprints, no tire tracks, no sign of someone moving them.
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"This is not my day job." So begins Michel Barsoum as he recounts his foray into the mysteries of the Great Pyramids of Egypt. As a well respected researcher in the field of ceramics, Barsoum never expected his career to take him down a path of history, archaeology, and "political" science, with materials research mixed in.
As a distinguished professor in the Department of Materials Science and Engineering at Drexel University, his daily routine consists mainly of teaching students about ceramics, or performing research on a new class of materials, the so-called MAX Phases, that he and his colleagues discovered in the 1990s. These modern ceramics are machinable, thermal-shock resistant, and are better conductors of heat and electricity than many metals-making them potential candidates for use in nuclear power plants, the automotive industry, jet engines, and a range of other high-demand systems.
As a distinguished professor in the Department of Materials Science and Engineering at Drexel University, his daily routine consists mainly of teaching students about ceramics, or performing research on a new class of materials, the so-called MAX Phases, that he and his colleagues discovered in the 1990s. These modern ceramics are machinable, thermal-shock resistant, and are better conductors of heat and electricity than many metals-making them potential candidates for use in nuclear power plants, the automotive industry, jet engines, and a range of other high-demand systems.
Our natural daily 24-hour cycle could be stretched by an extra hour safely and simply by exposure to pulses of bright light, research suggests.
Experts say it could prove useful for astronauts adapting for long-term missions to Mars - where a day lasts an extra 40 minutes.
The team, from universities in the US and France, tested the light treatment successfully on 12 volunteers.
The study features in the Proceeding of the National Academy of Sciences.
Experts say it could prove useful for astronauts adapting for long-term missions to Mars - where a day lasts an extra 40 minutes.
The team, from universities in the US and France, tested the light treatment successfully on 12 volunteers.
The study features in the Proceeding of the National Academy of Sciences.
YouTube's co-founders on Thursday challenged the Pentagon's assertion that soldiers overseas were sapping too much bandwidth by watching online videos, the military's principal rationale for blocking popular Web sites from Defense Department computers.
"They said it might be a bandwidth issue, but they created the Internet, so I don't know what the problem is," Chief Executive Chad Hurley said with a hearty laugh during an interview with The Associated Press.
Hurley, Chief Technology Officer Steve Chen and YouTube spokeswoman Julie Supan emphasized that the online video company is trying to work with the Pentagon in hopes the military will reverse course or at least partially repeal the ban.
"We'd like to explore what's at issue here and talk about what we can do to sort out what's the issue here," Supan said.
"They said it might be a bandwidth issue, but they created the Internet, so I don't know what the problem is," Chief Executive Chad Hurley said with a hearty laugh during an interview with The Associated Press.
Hurley, Chief Technology Officer Steve Chen and YouTube spokeswoman Julie Supan emphasized that the online video company is trying to work with the Pentagon in hopes the military will reverse course or at least partially repeal the ban.
"We'd like to explore what's at issue here and talk about what we can do to sort out what's the issue here," Supan said.
