Femtotechnology is a term used in reference to the hypothetical manipulation of matter on the scale of a
femtometer
The femtometre (American spelling femtometer), symbol fm, (derived from the Danish and Norwegian word 'fifteen', ) is a unit of length in the International System of Units (SI) equal to 10−15 metres, which means a quadrillionth of one metre. ...
, or 10
−15 m. This is three orders of magnitude lower than
picotechnology, at the scale of 10
−12 m, and six orders of magnitude lower than
nanotechnology
Nanotechnology is the manipulation of matter with at least one dimension sized from 1 to 100 nanometers (nm). At this scale, commonly known as the nanoscale, surface area and quantum mechanical effects become important in describing propertie ...
, at the scale of 10
−9 m.
Theory
Work in the femtometer range involves manipulation of excited energy states within
atomic nuclei
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford at the University of Manchester based on the 1909 Geiger–Marsden gold foil experiment. Aft ...
, specifically
nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state levels (higher energy levels). "Metastable" describes nuclei whose excited states have Half-life, half-lives of ...
s, to produce metastable (or otherwise stabilized) states with unusual properties. In the extreme case, excited states of the individual
nucleon
In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number.
Until the 1960s, nucleons were thought to be ele ...
s that make up the atomic nucleus (
proton
A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...
s and
neutron
The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...
s) are considered, ostensibly to tailor the behavioral properties of these particles.
The most advanced form of
molecular nanotechnology
Molecular nanotechnology (MNT) is a technology based on the ability to build structures to complex, atomic specifications by means of mechanosynthesis. This is distinct from nanoscale materials.
Based on Richard Feynman's vision of miniat ...
is often imagined to involve
self-replicating
Self-replication is any behavior of a dynamical system that yields construction of an identical or similar copy of itself. Cell (biology), Biological cells, given suitable environments, reproduce by cell division. During cell division, DNA repli ...
molecular machine
Molecular machines are a class of molecules typically described as an assembly of a discrete number of molecular components intended to produce mechanical movements in response to specific stimuli, mimicking macromolecular devices such as switch ...
s, and there have been some speculations suggesting something similar might be possible with analogues of molecules composed of
nucleons
In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number.
Until the 1960s, nucleons were thought to be ele ...
rather than atoms. For example, the
astrophysicist Frank Drake
Frank Donald Drake (May 28, 1930 – September 2, 2022) was an American astrophysicist and astrobiologist.
He began his career as a radio astronomer, studying the planets of the Solar System and later pulsars. Drake expanded his interests ...
once speculated about the possibility of self-replicating organisms composed of such nuclear molecules living on the surface of a
neutron star
A neutron star is the gravitationally collapsed Stellar core, core of a massive supergiant star. It results from the supernova explosion of a stellar evolution#Massive star, massive star—combined with gravitational collapse—that compresses ...
, a suggestion taken up in the
science fiction
Science fiction (often shortened to sci-fi or abbreviated SF) is a genre of speculative fiction that deals with imaginative and futuristic concepts. These concepts may include information technology and robotics, biological manipulations, space ...
novel ''
Dragon's Egg'' by the
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...
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.
Applications
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
In nuclear physics and particle physics, the strong interaction, also called the strong force or strong nuclear force, is one of the four known fundamental interaction, fundamental interactions. It confines Quark, quarks into proton, protons, n ...
is such that excited nuclear states tend to be very unstable (unlike the excited electron states in
Rydberg atoms), 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.
In fiction
Femtotechnology plays a critical role in the 2005 science-fiction novel ''
Pushing Ice''. It also features in various stories by
Greg Egan
Greg Egan (born 20 August 1961) is an Australian science fiction writer and mathematician, best known for his works of hard science fiction. Egan has won multiple awards including the John W. Campbell Memorial Award, the Hugo Award, and the Lo ...
such as ''
Riding the Crocodile,''
where he proposes the idea of a "strong bullet" which overcomes the instability of high atomic weight femto-structures by being accelerated to near light speed, letting it travel interstellar distances before impacting a target and constructing a stable nano-scale structure as it decays.
See also
*
Attophysics
*
Femtochemistry
*
Mode-locking, a laser technique producing pulses in the femtosecond range
*
Ultrashort pulse
In optics, an ultrashort pulse, also known as an ultrafast event, is an electromagnetic pulse whose time duration is of the order of a picosecond (10−12 second) or less. Such pulses have a broadband optical spectrum, and can be created by ...
References
External links
Femtotech? (Sub)Nuclear Scale Engineering and ComputationThere’s Plenty More Room at the Bottom: Beyond Nanotech to FemtotechFemtocomputing
{{Levels of technological manipulation of matter
Hypothetical technology
Nanotechnology