Some of the numbers, both small and large, that are bandied around in modern physics are very difficult to grasp. Below is a table listing - from the infinitesimally small to the incomprehensibly large - some of the numbers which are relevant to the subject matter.

Obviously, the units used affects these numbers (e.g. meters, kilometers, miles, light years, etc), but I have tried to use consistent metric units throughout: meters for distance, seconds for time, meters/second for speed, degrees Kelvin for temperature, kilograms for mass, kilograms/meter3 for density, Joules for energy, Coulombs for electrical charge, kilopascals for pressure.



0.00000000000000000000000000000000000000000

00054

5.4 × 10-44

Planck Time (in seconds), the shortest meaningful interval of time, and the earliest time the known universe can be measured from.



0.000000000000000000000000000000000001616

1.616 × 10-35

Planck Length (in meters), the size of a hypothetical string. Lengths smaller than this are considered not make any physical sense in our current understanding of physics.



0.000000000000000000000000000000911

9.11 × 10-31

Approximate mass (in kilograms) of a stationary electron.



0.000000000000000000000000001

1 × 10-27

Approximate density (in kg/meter3) of the universe as a whole.



0.000000000000000000000000001673

1.673 × 10-27

Approximate mass (in kilograms) of a proton.



0.000000000000000000000000001675

1.675 × 10-27

Approximate mass (in kilograms) of a neutron.



0.000000000000000000000000005

5 × 10-27

Estimated critical density (in kg/meter3) of the universe, to allow a steady state between expansion and contraction (about 5 × 10-30 g/cm3).



0.00000000000000000000002

2 × 10-23

Effective radius (in meters) of a neutrino particle.



0.0000000000000000001602

1.602 × 10-19

Elementary charge (in Coulombs), i.e. the negative charge of a single electron, or the positive charge of a single proton.



0.00000000000000000052

5.2 × 10-19

Approximate energy (in Joules) of photons in visible light.



0.000000000000000001

1 × 10-18

Upper limit (in meters) on the size of the quark particles that make up protons and neutrons.



0.000000000000000001

1 × 10-18

Smallest object observable and measurable by current science.



0.00000000000000001

1 × 10-17

Approximate density (in kg/meter3) of the best vacuum achievable in a laboratory.



0.000000000000002818

2.818 × 10-15

Effective radius (in meters) of an electron according to classical theory.



0.00000000000001

1 × 10-14

Range (in meters) of the weak nuclear force within the nucleus.



0.00000000000008187

8.187 × 10-14

Rest mass-energy (in Joules) of an electron.



0.000000000001

1 × 10-12

Approximate mass (in kilograms) of the average human cell.



0.000000000005

5 × 10-12

Longest wavelength (in meters) of gamma rays.



0.000000000025

2.5 × 10-11

Radius (in meters) of a hydrogen atom.



0.0000000005972

5.972 × 10-10

Rest mass-energy (in Joules) of an alpha particle.



0.0000004

4 × 10-7

Approximate wavelength (in meters) of violet light, the shortest in the visible spectrum.



0.0000007

7 × 10-7

Approximate wavelength (in meters) of red light, the long in the visible spectrum.



0.007297

7.297 × 10-3

The fine-structure constant, α, measuring the electromagnetic interaction between elementary particles.



0.74

7.4 × 10-1

Proportion of all matter in the universe composed of hydrogen.



0

0 × 100

Temperature (in ° Kelvin) of absolute zero, the lowest possible temperature (equivalent to -273.15° Celsius).



1.48

1.48 × 100

Density (in kg/meter3) of Earth’s atmosphere at sea level.



2.725

2.725 × 100

Temperature (in ° Kelvin) of cosmic microwave background radiation.



3.14

3.14 × 100

Pi, the ratio of a circle's circumference to its diameter (more accurately 3.14159265358979323846...)



9.8

9.8 × 100

Strength of the gravitational field (in meters/second/second) at the Earth's surface.



92

9.2 × 101

Number of naturally occurring elements.



100

1 × 102

Wavelength (in meters) of the lowest shortwave radio frequency.



101

1.01 × 102

Standard atmospheric pressure (in kilopascals) for Earth at sea level.



331

3.31 × 102

Speed (in meters/second) of sound in air at sea level and 0°C.



464

4.64 × 102

Speed (in meters/second) of the Earth's rotation at the equator.



1,000

1 × 103

Density (in kg/meter3) of liquid water at 4°C.



1,366

1.366 × 103

Total solar radiation (in Joules) received from the Sun by one square meter of the Earth's surface per second.



5,780

5.78 × 103

Temperature (in ° Kelvin) of the surface of the Sun.



29,800

2.98 × 104

Speed (in meters/second) of the Earth in orbit around the Sun.



145,000

1.45 × 105

Ratio of the size of an atom of hydrogen to its nucleus (the ration of other more complex atoms is less).



150,000

1.5 × 105

Density (in kg/meter3) of the core of the Sun.



200,000

2 × 105

Speed (in meters/second) of the Solar System in orbit around the Milky Way galaxy.



552,000

5.52 × 105

Speed of the Milky Way galaxy, relative to the cosmic microwave background radiation.



3,474,000

3.474 × 106

Diameter (in meters) of the Moon.



12,756,000

1.2756 × 107

Equatorial diameter (in meters) of the Earth.



15,600,000

1.56 × 107

Temperature (in ° Kelvin) at the core of the Sun.



299,792,458

2.998 × 108

Speed (in meters/second) of light (or any electromagnetic radiation) in a vacuum.



384,000,000

3.84 × 108

Orbital distance (in meters) of the Moon from the Earth.



1,000,000,000

1 × 109

Approximate density (in kg/meter3) of white dwarf, or dead, stars.



1,390,000,000

1.39 × 109

Diameter (in meters) of the Sun (1.39 million kilometers).



10,000,000,000

1 × 1010

Temperature (in ° Kelvin) in a supernova explosion.



80,000,000,000

8 × 1010

Rough estimate of the number of stars in the Milky Way galaxy (estimates vary up to 4 × 1011).



150,000,000,000

1.5 × 1011

Mean distance (in meters) between the Earth and the Sun (150 million kilometers, or 1 Astronomical Unit).



380,000,000,000

3.8 × 1011

Pressure (in kilopascals) inside the core of the Earth.



900,000,000,000

9 × 1011

Estimated optical diameter (in meters) of Betelgeuse, a red supergiant star.



3,000,000,000,000

3 × 1012

Estimated optical diameter (in meters) of VY Canis Majoris, a red hypergiant and the largest known star (about 2,000 times the size of our Sun).



10,000,000,000,000

1 × 1013

Approximate diameter (in meters) of the Solar System (10 billion kilometers).



20,000,000,000,000

2 × 1013

Approximate density (in kg/meter3) of the universe at the electroweak epoch, about 10–12 seconds after the Big Bang.



90,000,000,000,000

9 × 1013

Theoretical total mass-energy (in Joules) of one gram of matter.



100,000,000,000,000

1 × 1014

Estimated number of cells in the human body (9 out of every 10 being bacteria cells).



9,460,000,000,000,000

9.46 × 1015

Distance (in meters) traveled by light in one year (1 light year or 9.46 trillion kilometers).



25,000,000,000,000,000

2.5 × 1016

Pressure (in kilopascals) inside the core of the Sun.



40,000,000,000,000,000

4 × 1016

Distance (in meters) to Proxima Centauri, the nearest star after the Sun (about 4.23 light years).



141,000,000,000,000,000

1.41 × 1017

Half-life (in seconds) of uranium (4.468 billion years).



200,000,000,000,000,000

2 × 1017

Density (in kg/meter3) of atomic nuclei and neutron stars.



432,000,000,000,000,000

4.32 × 1017

Estimated age (in seconds) of the universe, assuming 13.7 billion years since the Big Bang.



1,000,000,000,000,000,000,000

1 × 1021

Approximate diameter (in meters) of galactic disk of Milky Way galaxy (100,000 light years).



70,000,000,000,000,000,000,000

7 × 1022

Rough estimate of the number of stars in the observable universe (estimates vary from 1022 to 1024).



22,300,000,000,000,000,000,000

2.23 × 1022

Distance (in meters) to the Andromeda Galaxy, the nearest galaxy to our own (2.36 million light years).



2,000,000,000,000,000,000,000,000

2 × 1024

Diameter (in meters) of the Virgo Supercluster, the cluster of galaxies which includes our own Local Group of galaxies (about 200 million light years).



6,000,000,000,000,000,000,000,000

6 × 1024

Mass (in kilograms) of the Earth.



386,000,000,000,000,000,000,000,000

3.86 × 1026

Total energy output (in Joules) of the Sun each second.



880,000,000,000,000,000,000,000,000

8.8 × 1026

Approximate diameter (in meters) of the visible universe (93 billion light years).



1,000,000,000,000,000,000,000,000,000

1 × 1027

Temperature (in ° Kelvin) of the universe 10-35 seconds after the Big Bang, at the start of the inflationary epoch.



2,000,000,000,000,000,000,000,000,000,000

2 × 1030

Mass (in kilograms) of the Sun (1 solar mass).



40,000,000,000,000,000,000,000,000,000,000

4 × 1031

Mass (in kilograms) of Betelgeuse, a red supergiant star (about 20 solar masses).



141,700,000,000,000,000,000,000,000,000,000

1.417 × 1032

Planck Temperature, the temperature (in ° Kelvin) of the universe at 1 Planck Time after the Big Bang.



10,000,000,000,000,000,000,000,000,000,000,000,

000,000

1 × 1040

Approximate ratio of the strength of the electromagnetic to the gravitational force between sub-atomic particles.



36,000,000,000,000,000,000,000,000,000,000,000,

000,000

3.6 × 1040

Mass (in kilograms) of OJ287, the largest measured supermassive black hole.



687,000,000,000,000,000,000,000,000,000,000,000,

000,000

6.87 × 1041

Gravitational binding energy (in Joules) of the Sun.



120,000,000,000,000,000,000,000,000,000,000,000,

000,000,000

1.2 × 1044

Estimated energy (in Joules) released in a supernova explosion.



30,000,000,000,000,000,000,000,000,000,000,000,

000,000,000,000,000,000

3 × 1052

Estimated mass (in kilograms) of the observable universe.



4,000,000,000,000,000,000,000,000,000,000,000,

000,000,000,000,000,000,000,000,000,000,000,

000

4 × 1069

Estimated total mass-energy (in Joules) of the observable universe.



100,000,000,000,000,000,000,000,000,000,000,000,

000,000,000,000,000,000,000,000,000,000,000,000,

000,000,000

1 × 1080

Estimate the total number of fundamental particles in the observable universe (other estimates go up to 1085).

