|Posted on October 19, 2015 at 8:55 AM||comments (0)|
* This is a backup post from the main page
'by Clara Moskowitz | LiveScience.com
Nothing goes faster than the speed of light. At least, we didn't think so.
New results from the CERN laboratory in Switzerland seem to break this cardinal rule of physics, calling into question one of the most trusted laws discovered by Albert Einstein.
Physicists have found that tiny particles called neutrinos are making a 454-mile (730-kilometer) underground trip faster than they should — more quickly, in fact, than light could do. If the results are confirmed, they could throw much of modern physics into upheaval.
"The consequences would be absolutely revolutionary and very profound," said physicist Robert Plunkett of the Fermilab laboratory in Batavia, Ill., who was not involved in the new study. "That's why such a claim should be treated very carefully and validated as many ways as you can."
Rewriting the rules
The results come from the OPERA experiment, which sends sprays of neutrinos from CERN in Geneva to the INFN Gran Sasso Laboratory in Italy. Neutrinos don't interact with normal atoms, so they simply pass through the Earth as if it were a vacuum.
After analyzing the results from 15,000 particles, it seems the neutrinos are crossing the distance at a velocity 20 parts per million faster than the speed of light. By making use of advanced GPS systems and atomic clocks, the researchers were able to determine this speed to an accuracy of less than 10 nanoseconds (.00000001 seconds). [Countdown: The Coolest Little Particles in Nature]
"According to relativity, it takes an infinite amount of energy to make anything go faster than light," Plunkett told LiveScience. "If these things are going faster than light, then these rules would have to be rewritten."
Previous studies have found that certain materials can travel faster than light through a medium. For example, certain particles are able to move more swiftly than light when travelling through water or oil. However, nothing should be able to move faster than light through a vacuum.
"It's really thought to be an absolute speed limit," said Michael Peskin, a theoretical physicist at SLAC National Accelerator Laboratory in Menlo Park, Calif. "Quantum field theory, the mathematical theory on which basically all results in particle physics are based, has the property that signals cannot travel faster than the speed of light through a vacuum. It’s really an absolute prohibition."
Backbone of physics
This cosmic speed limit, 299,792,458 meters per second (about 700 million miles an hour), forms the backbone of Einstein's seminal Theory of Special Relativity, published in 1905. To rewrite this law would have broad-ranging implications, including even the possibility of time travel.
And the findings aren't just in conflict with existing theory, but other measurements as well. For example, a famous study from the Kamiokande II experiment in Japan of the supernova SN1987A, which lies about 168,000 light years from Earthin the Large Magellanic Cloud, found that light and neutrinos that departed this exploded star arrived at Earth within hours of each other. This measurement was used to prove that neutrinos travel within 1 part in 100,000,000 of the optical speed of light.
Yet the new OPERA discovery suggests that neutrinos actually surpass the speed of light by 60 nanoseconds over 730 kilometers, which corresponds to 2 parts in 100,000, "which exceeds the SN1987A limit by a factor of more than 2,000!" astronomer Derek Fox of Pennsylvania State University wrote in an email. "So the observation is in dramatic conflict with the SN1987A result (which is not in doubt)."
But this doesn't mean that the OPERA results are wrong, Fox said. He suggested some theoretical solution, perhaps even involving string theory, could reconcile the two measurements.
Realizing full well how scandalous the results will be if they are borne out, the scientists behind OPERA, led by Antonio Ereditato of the University of Bern, have decided to make their data public, in hopes of inviting scrutiny that could make sense of such radical findings. The scientists also intend to gather more data and further analyze their measurements in order to establish them more fully, or refute them. Their results will be published Friday (Sept. 23) on the physics preprint site ArXiv.
One of the best hopes to verify or disprove the findings comes from Fermilab's MINOS experiment, which also sends neutrinos flying underground over a similar distance to end up at the Soudan mine in Minnesota. In 2007, MINOS researchers found a trend in their data that suggested neutrinos might be arriving early, as they do in the new CERN data. However, the experiment at the time did not have enough precision to rule out the possibility that the results were a statistical fluke. [Gallery of Mysterious Lights]
"There was something that could have been a fluctuation in the direction of things arriving early, but it didn't have enough significance for us to make such a claim," said Plunkett, who is a co-spokesperson for MINOS. "Obviously, the hunt is on and we'll be upgrading that previous measurement and also implementing something we already had in the works, which is a plan to make improvements so we can reduce our errors. One of our next objectives is going to be trying to verify or disprove this result as hard as we can."
CERN plans to discuss the findings Friday during a public seminar that will be broadcast at http://webcast.cern.ch/.
|Posted on May 9, 2011 at 8:21 PM||comments (0)|
Why are oceans salty? by Fr. Victor Badillo
If we are in a lifeboat in the middle of the ocean, there will be water all around us, but not a drop to drink. The ocean is salty. The concentration of salt in seawater is about 35 parts per thousand. The most common salt is sodium chloride. Why is the ocean salty?
Salt in the ocean comes from the continents. What rain dissolves is carried in the runoff to streams and rivers to the ocean. What are dissolved are salts. The water leaves the ocean by evaporation but the salt cannot and remains in the ocean. The runoff from the land is slightly salty. The oceans get saltier with time.
Salts also come from below the ocean, from underwater volcanoes and from salts dissolved out from the earth’s crust.
This process can be seen in a small scale in the case of the Dead Sea. Slightly salty water from the Jordan River flows into the Dead Sea which has no outlet. The low input of fresh water plus the large evaporation rates make the Dead Sea saltier than the oceans. Because of its density, it is easy for men to float.
A similar process is seen in the salt making in the Philippines. Sea water is fed to the salt bed. When the water has evaporated, a new supply of sea water is fed, etc. until the salt maker thinks it is time to totally remove the water. Then he just rakes in the salt crystals into containers. They are for sale in wet markets and sought by makers of bagong and patis. I find this tastier and more nutritious than the salt from salt mines.
This can be done in regions with pronounced dry seasons, namely several months without rain. The regions are in the western part of Luzon and Mindoro. In the Metro Manila area, one place is Las Pinas. The word for salt is asin. The name Pangasinan may be understood as where salt is made, pangasin an, just as we have pala isda an,or place for raising fish or isda.This has been done as a small family affair. Now there are corporations making salt. But the Philippines still has to import salt.
Not to be neglected are the roles of the sun, gravity, dust particles and cosmic rays. The sun is needed to evaporate the water that becomes rain. In evaporation, the vapor-laden air immediately above the ocean surface is warmed and gravity makes it rise to cooler upper air where they can condense. Still needed are dust particles to serve as nuclei for the vapor to condense on. Serving also as nuclei are ions caused by the passage of cosmic rays. Then gravity makes the water drops fall to the ground and makes the water flow down to the ocean.
The Amazon River in Brazil contributes so much river water to the Atlantic Ocean that miles from the mouth of the river, water is still fresh and can be drunk. The small amount of salt in the river water from the Amazon and other rivers added to the ocean continuously for centuries cumulates to the present salinity. If a poor man patiently sets aside savings, he can rise above poverty.
|Posted on September 3, 2010 at 12:11 PM||comments (0)|
From Sharon Fangonon
I thought someone ought to make a computation of how much closer Mars would have to move away from its current orbit in order to be as large as the Moon.
Let's see if I can figure it out with some back-of- the-envelope computations. The moon is around 27% the size of Earth and it's around 30 times as far as the Earth's diameter. Mars is 53% the size of Earth.
On the average, the Moon is 384,400 km from the Earth. At Mars' closest approach in 2003 (perihelic opposition), it was 55,758,006 km from Earth. At that distance it wasn't even a tiny disc to the naked eye. If it's a simple ratio and proportion, then Mars ought to be 750,553 kms away from Earth to be the size of the Moon.
The average distance of Mars from the sun is 227,700,000 km. Earth's is 149,500,000 km. That's a difference of 78,200,00 km. This means Mars' new orbit should have a radius of around 150,250,000 km. That's only 59 Earth diameters away instead of the normal perihelic distance of 4,370 Earth diameters away.
I don't know what sort of catastrophic event would push Mars closer to the sun. Maybe a huge meteor strike? It would probably be catastrophic for the solar system and Earth, too. Even if Earth doesn't get struck, I wonder what sort of havoc the gravitational pull of a very close planet would mean.