Sentences with phrase «in radioactive decay»

I read your article on apparent seasonal changes in radioactive decay rates (17 November, p 42).

This explains why it took researchers nearly 30 years to catch a first glimpse of neutrinos, although their existence had been first postulated in 1930 to explain an apparent violation of the conservation of energy in the radioactive decay of unstable atomic nuclei known as beta decay.

A sharp drop in the radioactive decay rate could alert the world to another Carrington Event.

The changes in radioactive decay rate tracked that pattern, rising and falling on cue over the course of the year.

«The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter nuclide in the radioactive decay sequence.»

Not exact matches

In the experiment, the scientists studied the radioactive decay of an isotope called beryllium 8.

Yes, there is error in radioactive dating and variability in decay rates.

In order for K - 40 to decay by electron capture, there has to be an electron (for the radioactive nucleus) to capture.

Analyses of thin mineral deposits partly covering painted cave areas provided minimum age estimates for the art, based on known decay rates of radioactive uranium in the rock.

The only previously known radioactive carbon isotope at the time was carbon - 11, which had a half - life of only 21 minutes (half the isotope's radioactivity will decay in that time).

«I have done a terrible thing,» wrote physicist Wolfgang Pauli in 1930 while investigating a type of radioactive decay.

But unlike a radioactive atom, which either decays or doesn't, the false vacuum can decay in some places but not in others.

Mysterious seasonal wobbles in the rate of radioactive decay may be caused by elusive particles from the sun

In the 1920s, for instance, radioactive beta decay perplexed many physicists because it seemed not to obey the law of conservation of energy.

Because Charon's modern - day surface is mostly water ice, it makes sense that the 1212 - km - diameter moon once had a subsurface ocean kept liquid by heat from the radioactive decay of elements in its core, as well as by the heat generated from collisions of smaller bits when the moon first accumulated.

«About 20 percent of the helium is coming from the moon itself, most likely as the result from the decay of radioactive thorium and uranium, also found in lunar rocks,» said Benna.

Reburning spent rods in an SFR also reduces their radioactive decay time; the resulting waste would have to be sequestered for only a few hundred years instead of several thousand.

Argon - 40 results from the decay of naturally occurring radioactive potassium - 40, found in the rocks of all the terrestrial planets as a leftover from their formation.

But also new elements are created in the hot ejecta of the explosion, among them radioactive species such as 44Ti (titanium with 22 protons and 22 neutrons in its atomic nuclei) and 56Ni (28/28 neutrons / protons), which decay to stable calcium and iron, respectively.

Age estimates relied on measures of the decay of radioactive forms of argon and uranium in volcanic ash layers framing tool - bearing sediment.

So his group acquired a sample of radioactive manganese - 54, which decays in just under a year, neither too slow nor too fast to study.

«The radionuclide ratios we measured in the sediments and the rates of decay and growth of radioactive elements in the impacted sediments allowed us to essentially age - date the contamination to after 2011,» she explained.

Members of a team led by paleoanthropologist Isaiah Nengo estimated the fossil's age by assessing radioactive forms of the element argon in surrounding rock, which decay at a known rate.

Also that day, Fischbach recalls, «when we looked at our data there was a sharp drop in the count rate [the rate of radioactive decay], exactly coincident with the flare.»

They then applied a precise dating technique based on natural radioactive decay of uranium, as Urs Schaltegger added: «In the sedimentary cross-sections, we found layers of volcanic ash containing the mineral zircon which incorporates uranium.

Those nuclei beef up by gobbling neutrons in rapid succession and then quickly change their chemical identities through radioactive decay.

Dating relied on measures of the decay of a radioactive form of uranium in the human fossil and a nearby hippo tooth.

Neutrinos were predicted in 1930 by Wolfgang Pauli, who said they were emitted during radioactive decay within atomic nuclei.

«The South African extremophile bacteria are powered by the radioactive decay of unstable atoms in the rocks.

Go for a morning jog over hilly terrain and the very landscape is likely to be the result of tectonic plate movements, powered deep under our feet in great part by radioactive decays like that of the humble americium writ large.

He believes the extra osmium probably came from the decay of radioactive rhenium - 187, which is thought to exist in high concentrations in the metallic core (Science, vol 269, p 819).

There are four fundamental forces in the universe: electromagnetism; the strong force, which binds atomic nuclei together; the weak force, which is responsible for radioactive decay; and gravity.

The waste, hot from radioactive decay, is held in deep pools of water or in «dry casks» of concrete and steel that sit on reinforced pads.

Antimatter flits into existence in a variety of ways: it is produced by black holes, supernovas, and some types of radioactive decay.

Running a fusion reactor creates a small amount of short - lived radioactive waste that decays away in around a century; high - level waste from traditional nuclear reactors can stick around for thousands of years.

The findings, in the July 28 Nature, suggest that the origin of the 30 trillion to 45 trillion watts of heat produced by the earth's interior is about evenly divided between radioactive decay and leftover heat from the planet's molten formation.

Deep underground, uranium atoms in rocks undergo radioactive decay, sending off alpha particles — two protons and two neutrons — that can bump into other molecules and change them.

But uranium - lead dating, in which researchers estimate the age of a rock by comparing its concentrations of radioactive uranium and the lead it decays into, tells a different story.

The machines handle the decaying element's radiation better than human miners and can tolerate the radon gas released by the ore; early Navajo miners of uranium in the U.S. — and their families exposed to residual radioactive dust and debris as well as contaminated water — developed lung cancer and other ailments by the 1970s and 1980s.

The Man Who Found Time James Hutton and the Discovery of Earth's Antiquity Jack Repcheck, Perseus, $ 26 In days of old — before scientists realized that radioactive decay could act as a gauge to Earth's age — scholars consulted the scriptures for clues to Earth's antiquity.

But even in the cold of space, these wayward worlds could stay warm, thanks to the decay of radioactive elements in their rocky cores.

They saw an afterglow in long - wavelength infrared light, a signature of radioactive decay (arxiv.org/abs/1306.3960).

In addition, if the melted nuclear fuel proves bad enough — like Chernobyl's lethal mass of molten core known as the «elephant's foot» — it will have to be entombed for a number of years rather than removed, because of radiation risk from what is essentially a cooled shell of ceramic armor surrounding a highly radioactive core that remains hot and is still undergoing radioactive decay.

Taking samples of such speleothems from six caves, the researchers then reconstructed the last roughly 500,000 years of climate via the decay of radioactive particles in the stone.

Formaggio and former postdoc Benjamin Monreal, now an assistant professor of physics at UCSB, reasoned that if they could tune into this baseline frequency, they could catch electrons as they shot out of a decaying radioactive gas, and measure their energy in a magnetic field.

Williams looked at the radioactive elements uranium and thorium trapped in these calcite crystals, using them as a kind of clock based on the rate at which uranium decays into thorium.

As Formaggio explains it, when a radioactive atom such as tritium decays, it turns into an isotope of helium and, in the process, also releases an electron and a neutrino.

In a radioactive metamorphosis called single beta decay, a neutron (a neutral particle) in the nucleus of an unstable atom spontaneously turns into a proton (a positive particle) and emits an electron and an antineutrino — the antimatter twin of a neutrinIn a radioactive metamorphosis called single beta decay, a neutron (a neutral particle) in the nucleus of an unstable atom spontaneously turns into a proton (a positive particle) and emits an electron and an antineutrino — the antimatter twin of a neutrinin the nucleus of an unstable atom spontaneously turns into a proton (a positive particle) and emits an electron and an antineutrino — the antimatter twin of a neutrino.

These measurements may also shed light on the proportion of radioactive elements like uranium and thorium inside the Moon, since their decay produces heat and should increase the amount of heat radiated by the Moon, says Paul Spudis of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, US, who is developing radar instruments to fly on LRO and Chandrayaan - 1.

It is a naturally occurring isotope produced by the radioactive decay of thorium in sediments.