Femtotechnology
Encyclopedia
Femtotechnology is a hypothetical term used in reference to structuring of matter on a femtometer, which is 10-15 m. This is a smaller scale in comparison to nanotechnology
and picotechnology
which are 10-9 m and 10-12 m respectively. Work in the femtometer range involves manipulation of excited energy states within atomic nuclei
(see nuclear isomer
) to produce metastable (or otherwise stabilized) states with unusual properties. In the extreme case, excited states of the individual nucleon
s that make up the atomic nucleus (proton
s and neutron
s) are considered, ostensibly to tailor the behavioral properties of these particles (though this is in practice unlikely to work as intended).
The most advanced form of molecular nanotechnology
is often imagined to involve self-replicating
molecular machines, and there have been some speculations suggesting something similar might be possible with "molecules" composed of nucleons rather than atoms. For example, the astrophysicist Frank Drake
once speculated about the possibility of self-replicating organisms composed of such nuclear molecules living on the surface of a neutron star
, a suggestion taken up in the science fiction
novel Dragon's Egg
by the physicist
Robert Forward
. It is thought by physicists that nuclear molecules may be possible, but they would be very short-lived, and whether they could actually be made to perform complex tasks such as self-replication, or what type of technology could be used to manipulate them, is unknown.
Practical applications of femtotechnology are currently considered to be unlikely. The spacings between nuclear energy levels require equipment capable of efficiently generating and processing gamma rays, without equipment degradation. The nature of the strong interaction
is such that excited nuclear states tend to be very unstable (unlike the excited electron states in Rydberg atom
s), and there are a finite number of excited states below the nuclear binding energy, unlike the (in principle) infinite number of bound states available to an atom's electrons. Similarly, what is known about the excited states of individual nucleons seems to indicate that these do not produce behavior that in any way makes nucleons easier to use or manipulate, and indicates instead that these excited states are even less stable and fewer in number than the excited states of atomic nuclei.
The hypothetical hafnium bomb can be considered a crude application of femtotechnology.
Nanotechnology
Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres...
and picotechnology
Picotechnology
The term picotechnology is a neologism intended to parallel the term nanotechnology. It is a hypothetical future level of technological manipulation of matter, on the scale of trillionths of a meter...
which are 10-9 m and 10-12 m respectively. Work in the femtometer range involves manipulation of excited energy states within atomic nuclei
Atomic nucleus
The nucleus is the very dense region consisting of protons and neutrons at the center of an atom. It was discovered in 1911, as a result of Ernest Rutherford's interpretation of the famous 1909 Rutherford experiment performed by Hans Geiger and Ernest Marsden, under the direction of Rutherford. The...
(see nuclear isomer
Nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus caused by the excitation of one or more of its nucleons . "Metastable" refers to the fact that these excited states have half-lives more than 100 to 1000 times the half-lives of the other possible excited nuclear states...
) to produce metastable (or otherwise stabilized) states with unusual properties. In the extreme case, excited states of the individual nucleon
Nucleon
In physics, a nucleon is a collective name for two particles: the neutron and the proton. These are the two constituents of the atomic nucleus. Until the 1960s, the nucleons were thought to be elementary particles...
s that make up the atomic nucleus (proton
Proton
The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....
s and neutron
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
s) are considered, ostensibly to tailor the behavioral properties of these particles (though this is in practice unlikely to work as intended).
The most advanced form of molecular nanotechnology
Molecular nanotechnology
Molecular nanotechnology is a technology based on the ability to build structures to complex, atomic specifications by means of mechanosynthesis. This is distinct from nanoscale materials...
is often imagined to involve self-replicating
Self-replicating machine
A self-replicating machine is an artificial construct that is theoretically capable of autonomously manufacturing a copy of itself using raw materials taken from its environment, thus exhibiting self-replication in a way analogous to that found in nature. The concept of self-replicating machines...
molecular machines, and there have been some speculations suggesting something similar might be possible with "molecules" composed of nucleons rather than atoms. For example, the astrophysicist Frank Drake
Frank Drake
Frank Donald Drake PhD is an American astronomer and astrophysicist. He is most notable as one of the pioneers in the search for extraterrestrial intelligence, including the founding of SETI, mounting the first observational attempts at detecting extraterrestrial communications in 1961 in Project...
once speculated about the possibility of self-replicating organisms composed of such nuclear molecules living on the surface of a neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
, a suggestion taken up in the science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
novel Dragon's Egg
Dragon's Egg
Dragon's Egg is a hard science fiction novel written by Robert L. Forward and published in 1980. In the story, Dragon's Egg is a neutron star with a surface gravity 67 billion times that of Earth, and inhabited by cheela, intelligent creatures that have the volume of sesame seeds and live a...
by the physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
Robert Forward
Robert Forward
Robert Lull Forward — known as Robert L. Forward — was an American physicist and science fiction writer...
. It is thought by physicists that nuclear molecules may be possible, but they would be very short-lived, and whether they could actually be made to perform complex tasks such as self-replication, or what type of technology could be used to manipulate them, is unknown.
Practical applications of femtotechnology are currently considered to be unlikely. The spacings between nuclear energy levels require equipment capable of efficiently generating and processing gamma rays, without equipment degradation. The nature of the strong interaction
Strong interaction
In particle physics, the strong interaction is one of the four fundamental interactions of nature, the others being electromagnetism, the weak interaction and gravitation. As with the other fundamental interactions, it is a non-contact force...
is such that excited nuclear states tend to be very unstable (unlike the excited electron states in Rydberg atom
Rydberg atom
thumb|right|300px|Figure 1: Energy levels in atomic [[lithium]] showing the Rydberg series of the lowest 3 values of [[Angular momentum#Angular momentum in quantum mechanics|orbital angular momentum]] converging on the first ionization energy....
s), and there are a finite number of excited states below the nuclear binding energy, unlike the (in principle) infinite number of bound states available to an atom's electrons. Similarly, what is known about the excited states of individual nucleons seems to indicate that these do not produce behavior that in any way makes nucleons easier to use or manipulate, and indicates instead that these excited states are even less stable and fewer in number than the excited states of atomic nuclei.
The hypothetical hafnium bomb can be considered a crude application of femtotechnology.