«Think of a neutron star like it's a huge nucleus, where you have ten times more
neutrons than protons.
Not exact matches
if you want hydrogen 1
proton, 1
neutron, 1 electron and you have 1 atom of hydrogen; the hard part is it would cost us more energy
than we can afford at this point in our technological stage to accomplish such a feat.
Pagels (1984) points out that if the relative masses of
protons and
neutrons were different by a small fraction of 1 per cent, making the
proton heavier
than the
neutron, hydrogen atoms would be unstable since the
protons that constitute their nuclei would spontaneously decay into
neutrons.
Protons and
neutrons cluster in a nucleus, 100,000 times smaller
than its atom, and are themselves composed of other stupendously small things: quarks and gluons.
Analysis of the water leaving Venus's atmosphere, however, shows that many of the hydrogen ions are actually a stable isotope of the element called deuterium, which consists of a
proton and a
neutron (rather
than just a
proton) in its nucleus.
Whereas «up» and «down» quarks instantly condense to form
protons and
neutrons, the addition of «strange» quarks makes a stable nugget that can grow far more massive
than the nuclei of ordinary atoms, Witten proposed in 1984.
But rather
than a knight getting «un-horsed,» this high - speed collision melts the
protons and
neutrons of the ions, freeing the quarks and other particles to disperse in an explosion very like that of the Big Bang.
The only way such a universe could create complex matter would be to have started out with fewer
neutrons and more free
protons than our universe did.
Because a
proton or a
neutron is on the order of a million times smaller
than an atom, nuclear fission and fusion typically require energies on the order of millions of electron volts (MeV).
When deuterium and helium - 3 fuse, they produce high - energy
protons rather
than neutrons.
Why is a
neutron, for example, more massive
than a
proton rather
than the other way around?
Because the strong force holding the
protons and
neutrons together is stronger
than the electromagnetic one, knocking the nucleus apart into pieces demands more energy
than removing the electrons.
At short distances (i.e. within the nucleus), a very strong force, more powerful
than electromagnetism, takes over and attracts the
protons and
neutrons.
Nucleons prefer pairing up with nucleons of a different type (
proton preferred
neutrons to other
protons) by 20 to 1, and nucleons involved in a short - range correlation carry higher momentum
than unpaired ones.
So the average
proton momentum is going to be higher
than the average
neutron momentum, because it's mostly the
neutrons that are sitting there, doing nothing, with nothing to pair up with, except themselves.»
The phenomenon also surprisingly allows a greater fraction of the
protons than neutrons to have high momentum in these relatively
neutron - rich nuclei, which is contrary to long - accepted theories of the nucleus and has implications for ultra-cold atomic gas systems and
neutron stars.
Photons with a billion times more energy
than photons of visible light exhibit properties once thought to belong solely to hadrons: the class of particles that includes the
proton and the
neutron
Baryons are particles of normal or «ordinary» matter (e.g., such as
protons and
neutrons) that make up more
than 99.9 percent of the mass of atoms found in the cosmos.
«As already mentioned, there is no stable nucleus with five or eight nuclear particles [nucleons], so it is not possible to build nuclei heavier
than helium by adding
neutrons or
protons to helium (4He) nuclei, or by fusing pairs of helium nuclei.
We've long known that the basic constituents of nature are far more numerous and varied
than the
protons,
neutrons and electrons that many people first learned about in high school.
All elements heavier
than iron were necessarily made by accretion of mostly
neutrons but sometimes
protons onto lighter nuclei.