Featured Research

from universities, journals, and other organizations

Out Of Pure Light, Physicists Create Particles Of Matter

Date:
September 18, 1997
Source:
University Of Rochester
Summary:
A team of 20 physicists from four institutions has literally made something from nothing, creating particles of matter from ordinary light for the first time.

A team of 20 physicists from four institutions has literally made something from nothing, creating particles of matter from ordinary light for the first time. The experiment was carried out at the Stanford Linear Accelerator Center (SLAC) by scientists and students from the University of Rochester, Princeton University, the University of Tennessee, and Stanford. The team reported the work in the Sept. 1 issue of Physical Review Letters.

Scientists have long been able to convert matter to energy; the most spectacular example is a nuclear explosion, where a small amount of matter creates tremendous energy. Now physicists have succeeded in doing the opposite: converting energy in the form of light into matter -- in this experiment, electrons and their anti-matter equivalent, positrons.

Converting energy into matter isn't completely new to physicists. When they smash together particles like protons and anti-protons in high-energy accelerator experiments, the initial particles are destroyed and release a fleeting burst of energy. Sometimes this energy burst contains very short-lived packets of light known as "virtual photons" which go on to form new particles. In this experiment scientists observed for the first time the creation of particles from real photons, packets of light that scientists can observe directly in the laboratory.

Physicists accomplished the feat by dumping an incredible amount of power -- nearly as much as it takes to run the entire nation but lasting only for a tiny fraction of a second -- into an area less than one billionth of a square centimeter, which is far smaller than the period at the end of this sentence. They used high-energy electrons traveling near the speed of light, produced by SLAC's two-mile-long accelerator, and photons from a powerful, "tabletop terawatt" glass laser developed at Rochester's Laboratory for Laser Energetics. The laser unleashed a tiny but powerful sliver of light lasting about one trillionth of a second (one picosecond) -- just half a millimeter long. Packed into this sliver were more than two billion billion photons.

The team synchronized the two beams and sent the electrons head-on into the photons. Occasionally an electron barreled into a photon with immense energy, "like a speeding Mack truck colliding with a ping pong ball," says physicist Adrian Melissinos of the University of Rochester. That knocked the photon backward with such tremendous energy that it collided with several of the densely packed photons behind it and combined with them, creating an electron and a positron. In a series of experiments lasting several months the team studied thousands of collisions, leading to the production of more than 100 positrons.

The energy-to-matter conversion was made possible by the incredibly strong electromagnetic fields that the photon-photon collisions produced. Similar conditions are found only rarely in the universe; neutron stars, for instance, have incredibly strong magnetic fields, and some scientists believe that their surfaces are home to the same kind of light-to-matter interactions the team observed. This experiment marks the first time scientists have been able to create such strong fields using laser beams.

By conducting experiments like this scientists test the principles of quantum electrodynamics (QED) in fields so strong that the vacuum "boils" into pairs of electrons and positrons. The scientists say the work could also have applications in designing new particle accelerators.

Spokesmen for the experiment, funded by the U.S. Department of Energy, are Kirk McDonald, professor of physics at Princeton, and Melissinos, professor of physics at Rochester. Also taking part in the experiment were William Bugg, Steve Berridge, Konstantin Shmakov and Achim Weidemann at Tennessee; David Burke, Clive Field, Glenn Horton-Smith, James Spencer and Dieter Walz at SLAC; Christian Bula and Eric Prebys at Princeton; and seven other physicists from Rochester, including Associate Professor David Meyerhofer; graduate students Thomas Koffas, David Reis, Stephen Boege, and Theofilos Kotseroglou; research associate Charles Bamber; and engineer Wolfram Ragg.


Story Source:

The above story is based on materials provided by University Of Rochester. Note: Materials may be edited for content and length.


Cite This Page:

University Of Rochester. "Out Of Pure Light, Physicists Create Particles Of Matter." ScienceDaily. ScienceDaily, 18 September 1997. <www.sciencedaily.com/releases/1997/09/970918045841.htm>.
University Of Rochester. (1997, September 18). Out Of Pure Light, Physicists Create Particles Of Matter. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/1997/09/970918045841.htm
University Of Rochester. "Out Of Pure Light, Physicists Create Particles Of Matter." ScienceDaily. www.sciencedaily.com/releases/1997/09/970918045841.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins