Distances shorter than 1 pm

This page lists lengths shorter than 1 picometre (10⁻¹² m).

Femtometre scale

• 1 × 10⁻¹³ metres = 100 fm = 0.1 pm.
• ≈ 1 × 10⁻¹³ metres = 1 x unit
• 1 × 10⁻¹⁴ metres = 10 fm
• 7 fm - the radius of the effective scattering cross section for a gold nucleus scattering a 6 MeV alpha particle over 140 degrees^[1]
• 2.81794 fm — classical electron radius^[2]
• 1.5 fm — diameter of the Scattering Cross Section of an 11 MeV proton with a target proton^[1]
• 1 × 10⁻¹⁵ metres = 1 fm = 1 femtometre = 1,000 attometres

Attometre scale

• 850 am = 0.85 fm — approximate proton radius^[3]
• 1 × 10⁻¹⁶ metres = 100 am
• 1 × 10⁻¹⁷ metres = 10 am
• 1 × 10⁻¹⁸ metres = 1 am = 1 attometre = 1,000 zeptometres
• 1.0 am — sensitivity of the LIGO detector for gravitational waves.^[4]

Zeptometre scale

• 310 zm — de Broglie wavelength of protons at the Large Hadron Collider (4 TeV as of 2012)
• 1 × 10⁻¹⁹ metres = 100 zm
• 1 × 10⁻²⁰ metres = 10 zm
• 7 × 10⁻²¹ metres = radius of effective cross section for a 250 GeV neutrino scattering off a nucleon^[5]
• 2 × 10⁻²¹ metres = radius of effective cross section for a 20 GeV neutrino scattering off a nucleon^[5]
• 1 × 10⁻²¹ metres = 1 zm = 1 zeptometre = 1,000 yoctometres

Shorter than 1 zm (10⁻²¹ m)

• 1 × 10⁻²² metres = 100 ym
• 2 × 10⁻²³ metres = 20 ym, the effective cross-section radius of 1 MeV neutrinos as measured by Clyde Cowan and Frederick Reines^[6]
• 1 × 10⁻²³ metres = 10 ym
• 1 × 10⁻²⁴ metres = 1 ym = 1 yoctometre, the smallest named subdivision of the metre in the SI base unit of length.
• 1.62 × 10⁻³⁵ metres = the Planck length (lengths smaller than this do not make any physical sense, pending a working understanding of quantum gravity)

See also

• SI prefixed forms of metre (yoctometre, zeptometre, attometre, femtometre, picometre)
• Orders of magnitude (length)

References