🕷️ Crawler Inspector

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Raw Queries and Responses

1. Shard Calculation

Query:

Response:

Calculated Shard: 159 (from laksa023)

2. Crawled Status Check

Query:

curl -X POST \
  'http://laksa159.int.ahrefs:8124/' \
  -H 'Content-Type: text/plain' \
  -H 'X-ClickHouse-Database: crawler3' \
  -H 'Authorization: Basic YXBpOg==' \
  -d 'SELECT getAhrefsURLFromUnparsed(src_unparsed) AS found_url, ifNull(toUnixTimestamp(download_stamp), 0) AS crawl_time, ifNull(toUnixTimestamp(props_url_first_seen), 0) AS first_indexed_time, download_http_code AS http_code, src_unparsed AS src_unparsed, src_root_hash AS src_root_hash, history_drop_reason AS history_drop_reason, meta_title AS meta_title, meta_descriptions AS meta_descriptions, attrs_boilerpipe_text AS attrs_boilerpipe_text, attrs_markdown AS attrs_markdown, attrs_readable_markdown AS attrs_readable_markdown, meta_canonical AS meta_canonical FROM crawler3.page_info_local FINAL PREWHERE (src_root_hash, src_unparsed) IN ((getAhrefsRootHashFromUnparsed(getAhrefsUnparsedNoserviceFromURL(\'https://www.thoughtco.com/brownian-motion-definition-and-explanation-4134272\')), getAhrefsUnparsedNoserviceFromURL(\'https://www.thoughtco.com/brownian-motion-definition-and-explanation-4134272\'))) FORMAT JSONEachRow'

Response:

{"found_url":"https:\/\/www.thoughtco.com\/brownian-motion-definition-and-explanation-4134272","crawl_time":1776288253,"first_indexed_time":1538983425,"http_code":200,"src_unparsed":"com,thoughtco!www,\/brownian-motion-definition-and-explanation-4134272 s443","src_root_hash":"15523395622417081559","history_drop_reason":null,"meta_title":"An Introduction to Brownian Motion","meta_descriptions":["Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules."],"attrs_boilerpipe_text":"Key Takeaways\nBrownian motion is the random movement of particles in a fluid due to collisions.\nAlbert Einstein explained Brownian motion, supporting the existence of atoms with indirect evidence.\nBrownian motion helps explain the movement of particles from areas of high to low concentration.\nBrownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. Brownian motion is also known as\npedesis\n, which comes from the Greek word for \"leaping.\" Even though a particle may be large compared to the size of atoms and molecules in the surrounding medium, it can be moved by the impact with many tiny, fast-moving masses. Brownian motion may be considered a macroscopic (visible) picture of a particle influenced by many microscopic random effects.\nBrownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. He described the motion in 1827 but was unable to explain it. While pedesis takes its name from Brown, he was not the first person to describe it. The Roman poet Lucretius describes the motion of dust particles around the year 60 B.C., which he used as evidence of atoms.\nThe transport phenomenon remained unexplained until 1905 when\nAlbert Einstein\npublished a paper that explained the pollen was being moved by the water molecules in the liquid. As with Lucretius, Einstein's explanation served as indirect evidence of the existence of atoms and molecules. At the turn of the 20th century, the existence of such tiny units of matter was only a theory. In 1908, Jean Perrin experimentally verified Einstein's hypothesis, which earned Perrin the 1926 Nobel Prize in Physics \"for his work on the discontinuous structure of matter.\"\nThe mathematical description of Brownian motion is a relatively simple probability calculation, of importance not just in physics and chemistry, but also to describe other statistical phenomena. The first person to propose a mathematical model for Brownian motion was Thorvald N. Thiele in a paper on the\nleast squares method\nthat was published in 1880. A modern model is the Wiener process, named in honor of Norbert Wiener, who described the function of a continuous-time stochastic process. Brownian motion is considered a Gaussian process and a Markov process with continuous path occurring over continuous time.\nBecause the movements of atoms and molecules in a liquid and gas is random, over time, larger particles will disperse evenly throughout the medium. If there are two adjacent regions of matter and region A contains twice as many particles as region B, the probability that a particle will leave region A to enter region B is twice as high as the probability a particle will leave region B to enter A.\nDiffusion\n, the movement of particles from a region of higher to lower concentration, can be considered a macroscopic example of Brownian motion.\nAny factor that affects the movement of particles in a fluid impacts the rate of Brownian motion. For example, increased temperature, increased number of particles, small particle size, and low\nviscosity\nincrease the rate of motion.\nBrownian Motion Examples\nMost examples of Brownian motion are transport processes that are affected by larger currents, yet also exhibit pedesis.\nExamples include:\nThe motion of pollen grains on still water\nMovement of dust motes in a room (although largely affected by air currents)\nDiffusion of pollutants in the air\nDiffusion of calcium through bones\nMovement of \"holes\" of electrical charge in semiconductors\nImportance of Brownian Motion\nThe initial importance of defining and describing Brownian motion was that it supported the modern atomic theory.\nToday, the mathematical models that describe Brownian motion are used in math, economics, engineering, physics, biology, chemistry, and a host of other disciplines.\nBrownian Motion Versus Motility\nIt can be difficult to distinguish between a movement due to Brownian motion and movement due to other effects. In\nbiology\n, for example, an observer needs to be able to tell whether a specimen is moving because it is motile (capable of movement on its own, perhaps due to cilia or flagella) or because it is subject to Brownian motion. Usually, it's possible to differentiate between the processes because Brownian motion appears jerky, random, or like a vibration. True motility appears often as a path, or else the motion is twisting or turning in a specific direction. In microbiology, motility can be confirmed if a sample inoculated in a semisolid medium migrates away from a stab line.\nSource\n\"Jean Baptiste Perrin — Facts.\" NobelPrize.org, Nobel Media AB 2019, July 6, 2019.","attrs_markdown":"\n\n[Skip to content](https:\/\/www.thoughtco.com\/brownian-motion-definition-and-explanation-4134272#skip-to-content)\n\nMenu\n\n[Home](https:\/\/www.thoughtco.com\/)\n\n- [Science, Tech, Math](https:\/\/www.thoughtco.com\/sciences-math-4132465)\n  - [Science](https:\/\/www.thoughtco.com\/science-4132464)\n  - [Math](https:\/\/www.thoughtco.com\/math-4133545)\n  - [Social Sciences](https:\/\/www.thoughtco.com\/social-sciences-4133522)\n  - [Computer Science](https:\/\/www.thoughtco.com\/computer-science-4133486)\n  - [Animals & Nature](https:\/\/www.thoughtco.com\/animals-and-nature-4133421)\n- [Humanities](https:\/\/www.thoughtco.com\/humanities-4133358)\n  - [History & Culture](https:\/\/www.thoughtco.com\/history-and-culture-4133356)\n  - [Visual Arts](https:\/\/www.thoughtco.com\/visual-arts-4132957)\n  - 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[Privacy Policy](https:\/\/www.people.inc\/brands-privacy)\n\n- [Science, Tech, Math](https:\/\/www.thoughtco.com\/sciences-math-4132465) ›\n- [Science](https:\/\/www.thoughtco.com\/science-4132464) ›\n- [Physics](https:\/\/www.thoughtco.com\/physics-4133571) ›\n# An Introduction to Brownian Motion\n\n![Close up of moving water.](https:\/\/www.thoughtco.com\/thmb\/gxHibSaK4gLipTLaIfet-3VSc7I=\/1500x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/water-droplet-4284014_1920-dd16b193daed45589dd3f6925acf2b6f.jpg)\n\n![Close up of moving water.](https:\/\/www.thoughtco.com\/thmb\/gxHibSaK4gLipTLaIfet-3VSc7I=\/1500x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/water-droplet-4284014_1920-dd16b193daed45589dd3f6925acf2b6f.jpg)\n\nMYuenS\/Pixabay\n\n[![Science](https:\/\/www.thoughtco.com\/thmb\/GlGRAYLjgFbTQlbxhxfdvvPh9L8=\/150x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/left_rail_image_science-58a22da268a0972917bfb5cc.png)](https:\/\/www.thoughtco.com\/science-4132464)\n\n[Science](https:\/\/www.thoughtco.com\/science-4132464)\n\n- [Physics](https:\/\/www.thoughtco.com\/physics-4133571)\n  - [Physics Laws, Concepts, and Principles](https:\/\/www.thoughtco.com\/physics-core-theories-4133569)\n  - [Quantum Physics](https:\/\/www.thoughtco.com\/quantum-physics-4133568)\n  - [Important Physicists](https:\/\/www.thoughtco.com\/important-physicists-4133567)\n  - [Thermodynamics](https:\/\/www.thoughtco.com\/thermodynamics-4133566)\n  - [Cosmology & Astrophysics](https:\/\/www.thoughtco.com\/cosmology-and-astrophysics-4133565)\n- [Chemistry](https:\/\/www.thoughtco.com\/chemistry-4133594)\n- [Biology](https:\/\/www.thoughtco.com\/biology-4133580)\n- [Geology](https:\/\/www.thoughtco.com\/geology-4133564)\n- [Astronomy](https:\/\/www.thoughtco.com\/astronomy-4133558)\n- [Weather & Climate](https:\/\/www.thoughtco.com\/weather-and-climate-4133550)\n\nBy\n\n[Anne Marie Helmenstine, Ph.D.](https:\/\/www.thoughtco.com\/anne-marie-helmenstine-ph-d-601916)\n\n[Anne Marie Helmenstine, Ph.D.](https:\/\/www.thoughtco.com\/anne-marie-helmenstine-ph-d-601916)\n\nChemistry Expert\n\n- Ph.D., Biomedical Sciences, University of Tennessee at Knoxville\n- B.A., Physics and Mathematics, Hastings College\n\nDr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.\n\nLearn about our [Editorial Process](https:\/\/www.thoughtco.com\/about-us-4779650#toc-editorial-guidelines)\n\nUpdated on July 06, 2019\n\nClose\n\n### Key Takeaways\n- Brownian motion is the random movement of particles in a fluid due to collisions.\n- Albert Einstein explained Brownian motion, supporting the existence of atoms with indirect evidence.\n- Brownian motion helps explain the movement of particles from areas of high to low concentration.\n\nBrownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. Brownian motion is also known as *pedesis*, which comes from the Greek word for \"leaping.\" Even though a particle may be large compared to the size of atoms and molecules in the surrounding medium, it can be moved by the impact with many tiny, fast-moving masses. Brownian motion may be considered a macroscopic (visible) picture of a particle influenced by many microscopic random effects.\n\nBrownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. He described the motion in 1827 but was unable to explain it. While pedesis takes its name from Brown, he was not the first person to describe it. The Roman poet Lucretius describes the motion of dust particles around the year 60 B.C., which he used as evidence of atoms.\n\nThe transport phenomenon remained unexplained until 1905 when [Albert Einstein](https:\/\/www.thoughtco.com\/who-was-albert-einstein-2698845) published a paper that explained the pollen was being moved by the water molecules in the liquid. As with Lucretius, Einstein's explanation served as indirect evidence of the existence of atoms and molecules. At the turn of the 20th century, the existence of such tiny units of matter was only a theory. In 1908, Jean Perrin experimentally verified Einstein's hypothesis, which earned Perrin the 1926 Nobel Prize in Physics \"for his work on the discontinuous structure of matter.\"\n\nThe mathematical description of Brownian motion is a relatively simple probability calculation, of importance not just in physics and chemistry, but also to describe other statistical phenomena. The first person to propose a mathematical model for Brownian motion was Thorvald N. Thiele in a paper on the [least squares method](https:\/\/www.thoughtco.com\/what-is-a-least-squares-line-3126250) that was published in 1880. A modern model is the Wiener process, named in honor of Norbert Wiener, who described the function of a continuous-time stochastic process. Brownian motion is considered a Gaussian process and a Markov process with continuous path occurring over continuous time.\n\n## What Is Brownian Motion?\nBecause the movements of atoms and molecules in a liquid and gas is random, over time, larger particles will disperse evenly throughout the medium. If there are two adjacent regions of matter and region A contains twice as many particles as region B, the probability that a particle will leave region A to enter region B is twice as high as the probability a particle will leave region B to enter A. [Diffusion](https:\/\/www.thoughtco.com\/definition-of-diffusion-604430), the movement of particles from a region of higher to lower concentration, can be considered a macroscopic example of Brownian motion.\n\nAny factor that affects the movement of particles in a fluid impacts the rate of Brownian motion. For example, increased temperature, increased number of particles, small particle size, and low [viscosity](https:\/\/www.thoughtco.com\/viscosity-2699336) increase the rate of motion.\n\n## Brownian Motion Examples\nMost examples of Brownian motion are transport processes that are affected by larger currents, yet also exhibit pedesis.\n\nExamples include:\n\n- The motion of pollen grains on still water\n- Movement of dust motes in a room (although largely affected by air currents)\n- Diffusion of pollutants in the air\n- Diffusion of calcium through bones\n- Movement of \"holes\" of electrical charge in semiconductors\n## Importance of Brownian Motion\nThe initial importance of defining and describing Brownian motion was that it supported the modern atomic theory.\n\nToday, the mathematical models that describe Brownian motion are used in math, economics, engineering, physics, biology, chemistry, and a host of other disciplines.\n\n## Brownian Motion Versus Motility\nIt can be difficult to distinguish between a movement due to Brownian motion and movement due to other effects. In [biology](https:\/\/www.thoughtco.com\/biology-meaning-373266), for example, an observer needs to be able to tell whether a specimen is moving because it is motile (capable of movement on its own, perhaps due to cilia or flagella) or because it is subject to Brownian motion. Usually, it's possible to differentiate between the processes because Brownian motion appears jerky, random, or like a vibration. True motility appears often as a path, or else the motion is twisting or turning in a specific direction. In microbiology, motility can be confirmed if a sample inoculated in a semisolid medium migrates away from a stab line.\n\n## Source\n\"Jean Baptiste Perrin — Facts.\" NobelPrize.org, Nobel Media AB 2019, July 6, 2019.\n\nCite this Article\n\nFormat\n\n[mla](https:\/\/www.thoughtco.com\/brownian-motion-definition-and-explanation-4134272) [apa](https:\/\/www.thoughtco.com\/brownian-motion-definition-and-explanation-4134272) [chicago](https:\/\/www.thoughtco.com\/brownian-motion-definition-and-explanation-4134272)\n\nYour Citation\n\nHelmenstine, Anne Marie, Ph.D. \"An Introduction to Brownian Motion.\" ThoughtCo, Apr. 1, 2025, thoughtco.com\/brownian-motion-definition-and-explanation-4134272. Helmenstine, Anne Marie, Ph.D. (2025, April 1). An Introduction to Brownian Motion. Retrieved from https:\/\/www.thoughtco.com\/brownian-motion-definition-and-explanation-4134272 Helmenstine, Anne Marie, Ph.D. \"An Introduction to Brownian Motion.\" ThoughtCo. https:\/\/www.thoughtco.com\/brownian-motion-definition-and-explanation-4134272 (accessed April 15, 2026).\n\ncopy citation\n\n- [![The kinetic molecular theory of gases assumes gas particles act as hard, completely elastic spheres.](https:\/\/www.thoughtco.com\/thmb\/s_5_Tb1L6EeKqbwRk28Nvi4_KCM=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-589092779-58192bf73df78cc2e82eeebd.jpg) ![The kinetic molecular theory of gases assumes gas particles act as hard, completely elastic spheres.](https:\/\/www.thoughtco.com\/thmb\/s_5_Tb1L6EeKqbwRk28Nvi4_KCM=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-589092779-58192bf73df78cc2e82eeebd.jpg) Kinetic Molecular Theory of Gases](https:\/\/www.thoughtco.com\/kinetic-theory-of-gases-2699426)\n- [![A nuclear isomer occurs when protons or neutrons in an atomic nucleus become excited, but don't decay immediately](https:\/\/www.thoughtco.com\/thmb\/NA9obPf4YGwAg4IM48JP80QJh1Y=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/technology-and-energy-background-508089172-58b331a65f9b586046c4831a.jpg) ![A nuclear isomer occurs when protons or neutrons in an atomic nucleus become excited, but don't decay immediately](https:\/\/www.thoughtco.com\/thmb\/NA9obPf4YGwAg4IM48JP80QJh1Y=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/technology-and-energy-background-508089172-58b331a65f9b586046c4831a.jpg) Nuclear Isomer Definition and Examples](https:\/\/www.thoughtco.com\/nuclear-isomer-definition-4129399)\n- [![A simple electromagnet shows how electricity and magnetism are connected.](https:\/\/www.thoughtco.com\/thmb\/EOG8fJRYF-Brc3hXpDWGbAD620Y=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/close-up-of-cropped-hands-during-an-experiment-667745107-5b4b71a746e0fb00377d34b3.jpg) ![A simple electromagnet shows how electricity and magnetism are connected.](https:\/\/www.thoughtco.com\/thmb\/EOG8fJRYF-Brc3hXpDWGbAD620Y=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/close-up-of-cropped-hands-during-an-experiment-667745107-5b4b71a746e0fb00377d34b3.jpg) The Relationship Between Electricity and Magnetism](https:\/\/www.thoughtco.com\/introduction-electricity-and-magnetism-4172372)\n- [![Iron filings sprinkled between two bar magnets](https:\/\/www.thoughtco.com\/thmb\/Tzuv6U9-lPrZI5Gcq91hVLOCjvg=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-452431879-f397518cb55749b2adf2c81756a2d3aa.jpg) ![Iron filings sprinkled between two bar magnets](https:\/\/www.thoughtco.com\/thmb\/Tzuv6U9-lPrZI5Gcq91hVLOCjvg=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-452431879-f397518cb55749b2adf2c81756a2d3aa.jpg) What Is Magnetism? Definition, Examples, Facts](https:\/\/www.thoughtco.com\/magnetism-definition-examples-4172452)\n- [![Albert Einstein](https:\/\/www.thoughtco.com\/thmb\/X199D2NYzNqd7n3xE3haZpZm0cc=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages_Einstein-3245599-58459dc93df78c0230ef6e3b.jpg) ![Albert Einstein](https:\/\/www.thoughtco.com\/thmb\/X199D2NYzNqd7n3xE3haZpZm0cc=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages_Einstein-3245599-58459dc93df78c0230ef6e3b.jpg) The Life and Work of Albert Einstein](https:\/\/www.thoughtco.com\/who-was-albert-einstein-2698845)\n- [![The visible light spectrum is the section of the electromagnetic radiation spectrum that is visible to the human eye.](https:\/\/www.thoughtco.com\/thmb\/6ziQfXenUgLxt4DhOlvxzIYSwtI=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/the-visible-light-spectrum-2699036_FINAL2-c0b0ee6f82764efdb62a1af9b9525050.png) ![The visible light spectrum is the section of the electromagnetic radiation spectrum that is visible to the human eye.](https:\/\/www.thoughtco.com\/thmb\/6ziQfXenUgLxt4DhOlvxzIYSwtI=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/the-visible-light-spectrum-2699036_FINAL2-c0b0ee6f82764efdb62a1af9b9525050.png) What Is the Visible Light Spectrum?](https:\/\/www.thoughtco.com\/the-visible-light-spectrum-2699036)\n- [![High frequency sine waves on oscilloscope screen](https:\/\/www.thoughtco.com\/thmb\/pzHcAtcFz0b0y97FmMMmWeks71c=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/high-frequency-sine-waves-on-oscilloscope-screen-85595482-59bf21669abed5001107911c.jpg) ![High frequency sine waves on oscilloscope screen](https:\/\/www.thoughtco.com\/thmb\/pzHcAtcFz0b0y97FmMMmWeks71c=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/high-frequency-sine-waves-on-oscilloscope-screen-85595482-59bf21669abed5001107911c.jpg) Oscillation and Periodic Motion in Physics](https:\/\/www.thoughtco.com\/oscillation-2698995)\n- [![Newton did think about gravity watching apples fall from trees, but he didn't have a \"eureka\" moment by having on fall on his head. That's just not true\\!](https:\/\/www.thoughtco.com\/thmb\/5k4jOAmCWnFWbHvxI_FnqRkDEdY=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-155382352-57a8e2e65f9b58974a5e7d62.jpg) ![Newton did think about gravity watching apples fall from trees, but he didn't have a \"eureka\" moment by having on fall on his head. That's just not true\\!](https:\/\/www.thoughtco.com\/thmb\/5k4jOAmCWnFWbHvxI_FnqRkDEdY=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-155382352-57a8e2e65f9b58974a5e7d62.jpg) Newton's Law of Gravity](https:\/\/www.thoughtco.com\/newtons-law-of-gravity-2698878)\n\n- [![Hand Operating Newton's Cradle](https:\/\/www.thoughtco.com\/thmb\/oqOfgNN1AVyLlilwGUQgrlZLri4=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/hand-operating-newton-s-cradle-522924194-5c4b8d2646e0fb00018de956.jpg) ![Hand Operating Newton's Cradle](https:\/\/www.thoughtco.com\/thmb\/oqOfgNN1AVyLlilwGUQgrlZLri4=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/hand-operating-newton-s-cradle-522924194-5c4b8d2646e0fb00018de956.jpg) Inertia and the Laws of Motion](https:\/\/www.thoughtco.com\/inertia-2698982)\n- [![](https:\/\/www.thoughtco.com\/thmb\/vv5Zkp8jV-WlykkJpC_QEM7GgNs=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/feynmancomic-56a72b385f9b58b7d0e7857e.jpg) ![](https:\/\/www.thoughtco.com\/thmb\/vv5Zkp8jV-WlykkJpC_QEM7GgNs=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/feynmancomic-56a72b385f9b58b7d0e7857e.jpg) Science Comic Books](https:\/\/www.thoughtco.com\/science-comic-books-2699172)\n- [![Torque](https:\/\/www.thoughtco.com\/thmb\/j46Cr6492qmyzsRJUOUu7HbOtak=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/3828658083_5054dd2798_b-59cee3c96f53ba00119a154d.jpg) ![Torque](https:\/\/www.thoughtco.com\/thmb\/j46Cr6492qmyzsRJUOUu7HbOtak=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/3828658083_5054dd2798_b-59cee3c96f53ba00119a154d.jpg) Definition of Torque in Physics](https:\/\/www.thoughtco.com\/torque-2699016)\n- [![Crashed car](https:\/\/www.thoughtco.com\/thmb\/xZ5xf17JWSxuDLFFRYaMHjIJ_jU=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/4231603374_3a2e67706f_o-598b9db8d088c000133db92a.jpg) ![Crashed car](https:\/\/www.thoughtco.com\/thmb\/xZ5xf17JWSxuDLFFRYaMHjIJ_jU=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/4231603374_3a2e67706f_o-598b9db8d088c000133db92a.jpg) Car Crash Physics: What Happens When Two Cars Collide?](https:\/\/www.thoughtco.com\/what-is-the-physics-of-a-car-collision-2698920)\n- [![Rider and horse jumping in competition.](https:\/\/www.thoughtco.com\/thmb\/6puJfbG2XAKw3uk-IQanAwX8wiU=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/person-riding-a-horse-1559388-9cbef2543ff0440d9410bb8012d1cc98.jpg) ![Rider and horse jumping in competition.](https:\/\/www.thoughtco.com\/thmb\/6puJfbG2XAKw3uk-IQanAwX8wiU=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/person-riding-a-horse-1559388-9cbef2543ff0440d9410bb8012d1cc98.jpg) Understanding Momentum in Physics](https:\/\/www.thoughtco.com\/what-is-momentum-2698743)\n- [![Iron filings show magnetic field lines.](https:\/\/www.thoughtco.com\/thmb\/Sbm6bCGcAO5co2VMsnvZA2_TPS4=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/iron-filings-show-magnetic-fields-141196228-5b5477c646e0fb0037e0dd66.jpg) ![Iron filings show magnetic field lines.](https:\/\/www.thoughtco.com\/thmb\/Sbm6bCGcAO5co2VMsnvZA2_TPS4=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/iron-filings-show-magnetic-fields-141196228-5b5477c646e0fb0037e0dd66.jpg) The Science of Magnetic Field Lines](https:\/\/www.thoughtco.com\/magnetic-field-lines-4172630)\n- [![Sir Isaac Newton portrait.](https:\/\/www.thoughtco.com\/thmb\/a6GKvsb42wlXGa6I4yGoEdhNgTI=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-154320249-59443d2d5f9b58d58a2a2efe.jpg) ![Sir Isaac Newton portrait.](https:\/\/www.thoughtco.com\/thmb\/a6GKvsb42wlXGa6I4yGoEdhNgTI=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-154320249-59443d2d5f9b58d58a2a2efe.jpg) Introduction to Newton's Laws of Motion](https:\/\/www.thoughtco.com\/introduction-to-newtons-laws-of-motion-2698881)\n- [![Newton's cradle](https:\/\/www.thoughtco.com\/thmb\/NOeT-14MbnZiqMrexfXYCUkWoxw=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-713784033-5962f27b3df78cdc68bb2b6d.jpg) ![Newton's cradle](https:\/\/www.thoughtco.com\/thmb\/NOeT-14MbnZiqMrexfXYCUkWoxw=\/250x0\/filters:no_upscale\\(\\):max_bytes\\(150000\\):strip_icc\\(\\)\/GettyImages-713784033-5962f27b3df78cdc68bb2b6d.jpg) Definition of Force in Physics](https:\/\/www.thoughtco.com\/force-2698978)\n\n[ThoughtCo](https:\/\/www.thoughtco.com\/)\n\n## Follow Us\n\n- [Science, Tech, Math](https:\/\/www.thoughtco.com\/sciences-math-4132465)\n- [Humanities](https:\/\/www.thoughtco.com\/humanities-4133358)\n- [Languages](https:\/\/www.thoughtco.com\/languages-4133094)\n- [Resources](https:\/\/www.thoughtco.com\/resources-4132590)\n\n- [About Us](https:\/\/www.thoughtco.com\/about-us-4779650)\n- [Advertise](https:\/\/www.people.inc\/advertising)\n- [Careers](https:\/\/www.people.inc\/careers)\n- [Privacy Policy](https:\/\/www.people.inc\/brands-privacy)\n- [Editorial Guidelines](https:\/\/www.thoughtco.com\/about-us-4779650#toc-editorial-guidelines)\n- [Contact](https:\/\/www.thoughtco.com\/about-us-4779650#toc-contact-us)\n- [Terms of Service](https:\/\/www.people.inc\/brands-termsofservice)\n\nThoughtCo is part of the [People Inc.](https:\/\/www.people.inc\/) publishing family.","attrs_readable_markdown":"### Key Takeaways\n- Brownian motion is the random movement of particles in a fluid due to collisions.\n- Albert Einstein explained Brownian motion, supporting the existence of atoms with indirect evidence.\n- Brownian motion helps explain the movement of particles from areas of high to low concentration.\n\nBrownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. Brownian motion is also known as *pedesis*, which comes from the Greek word for \"leaping.\" Even though a particle may be large compared to the size of atoms and molecules in the surrounding medium, it can be moved by the impact with many tiny, fast-moving masses. Brownian motion may be considered a macroscopic (visible) picture of a particle influenced by many microscopic random effects.\n\nBrownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. He described the motion in 1827 but was unable to explain it. While pedesis takes its name from Brown, he was not the first person to describe it. The Roman poet Lucretius describes the motion of dust particles around the year 60 B.C., which he used as evidence of atoms.\n\nThe transport phenomenon remained unexplained until 1905 when [Albert Einstein](https:\/\/www.thoughtco.com\/who-was-albert-einstein-2698845) published a paper that explained the pollen was being moved by the water molecules in the liquid. As with Lucretius, Einstein's explanation served as indirect evidence of the existence of atoms and molecules. At the turn of the 20th century, the existence of such tiny units of matter was only a theory. In 1908, Jean Perrin experimentally verified Einstein's hypothesis, which earned Perrin the 1926 Nobel Prize in Physics \"for his work on the discontinuous structure of matter.\"\n\nThe mathematical description of Brownian motion is a relatively simple probability calculation, of importance not just in physics and chemistry, but also to describe other statistical phenomena. The first person to propose a mathematical model for Brownian motion was Thorvald N. Thiele in a paper on the [least squares method](https:\/\/www.thoughtco.com\/what-is-a-least-squares-line-3126250) that was published in 1880. A modern model is the Wiener process, named in honor of Norbert Wiener, who described the function of a continuous-time stochastic process. Brownian motion is considered a Gaussian process and a Markov process with continuous path occurring over continuous time.\n\nBecause the movements of atoms and molecules in a liquid and gas is random, over time, larger particles will disperse evenly throughout the medium. If there are two adjacent regions of matter and region A contains twice as many particles as region B, the probability that a particle will leave region A to enter region B is twice as high as the probability a particle will leave region B to enter A. [Diffusion](https:\/\/www.thoughtco.com\/definition-of-diffusion-604430), the movement of particles from a region of higher to lower concentration, can be considered a macroscopic example of Brownian motion.\n\nAny factor that affects the movement of particles in a fluid impacts the rate of Brownian motion. For example, increased temperature, increased number of particles, small particle size, and low [viscosity](https:\/\/www.thoughtco.com\/viscosity-2699336) increase the rate of motion.\n\n## Brownian Motion Examples\nMost examples of Brownian motion are transport processes that are affected by larger currents, yet also exhibit pedesis.\n\nExamples include:\n\n- The motion of pollen grains on still water\n- Movement of dust motes in a room (although largely affected by air currents)\n- Diffusion of pollutants in the air\n- Diffusion of calcium through bones\n- Movement of \"holes\" of electrical charge in semiconductors\n## Importance of Brownian Motion\nThe initial importance of defining and describing Brownian motion was that it supported the modern atomic theory.\n\nToday, the mathematical models that describe Brownian motion are used in math, economics, engineering, physics, biology, chemistry, and a host of other disciplines.\n\n## Brownian Motion Versus Motility\nIt can be difficult to distinguish between a movement due to Brownian motion and movement due to other effects. In [biology](https:\/\/www.thoughtco.com\/biology-meaning-373266), for example, an observer needs to be able to tell whether a specimen is moving because it is motile (capable of movement on its own, perhaps due to cilia or flagella) or because it is subject to Brownian motion. Usually, it's possible to differentiate between the processes because Brownian motion appears jerky, random, or like a vibration. True motility appears often as a path, or else the motion is twisting or turning in a specific direction. In microbiology, motility can be confirmed if a sample inoculated in a semisolid medium migrates away from a stab line.\n\n## Source\n\"Jean Baptiste Perrin — Facts.\" NobelPrize.org, Nobel Media AB 2019, July 6, 2019.","meta_canonical":null}

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Boilerpipe Text	Key Takeaways Brownian motion is the random movement of particles in a fluid due to collisions. Albert Einstein explained Brownian motion, supporting the existence of atoms with indirect evidence. Brownian motion helps explain the movement of particles from areas of high to low concentration. Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. Brownian motion is also known as pedesis , which comes from the Greek word for "leaping." Even though a particle may be large compared to the size of atoms and molecules in the surrounding medium, it can be moved by the impact with many tiny, fast-moving masses. Brownian motion may be considered a macroscopic (visible) picture of a particle influenced by many microscopic random effects. Brownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. He described the motion in 1827 but was unable to explain it. While pedesis takes its name from Brown, he was not the first person to describe it. The Roman poet Lucretius describes the motion of dust particles around the year 60 B.C., which he used as evidence of atoms. The transport phenomenon remained unexplained until 1905 when Albert Einstein published a paper that explained the pollen was being moved by the water molecules in the liquid. As with Lucretius, Einstein's explanation served as indirect evidence of the existence of atoms and molecules. At the turn of the 20th century, the existence of such tiny units of matter was only a theory. In 1908, Jean Perrin experimentally verified Einstein's hypothesis, which earned Perrin the 1926 Nobel Prize in Physics "for his work on the discontinuous structure of matter." The mathematical description of Brownian motion is a relatively simple probability calculation, of importance not just in physics and chemistry, but also to describe other statistical phenomena. The first person to propose a mathematical model for Brownian motion was Thorvald N. Thiele in a paper on the least squares method that was published in 1880. A modern model is the Wiener process, named in honor of Norbert Wiener, who described the function of a continuous-time stochastic process. Brownian motion is considered a Gaussian process and a Markov process with continuous path occurring over continuous time. Because the movements of atoms and molecules in a liquid and gas is random, over time, larger particles will disperse evenly throughout the medium. If there are two adjacent regions of matter and region A contains twice as many particles as region B, the probability that a particle will leave region A to enter region B is twice as high as the probability a particle will leave region B to enter A. Diffusion , the movement of particles from a region of higher to lower concentration, can be considered a macroscopic example of Brownian motion. Any factor that affects the movement of particles in a fluid impacts the rate of Brownian motion. For example, increased temperature, increased number of particles, small particle size, and low viscosity increase the rate of motion. Brownian Motion Examples Most examples of Brownian motion are transport processes that are affected by larger currents, yet also exhibit pedesis. Examples include: The motion of pollen grains on still water Movement of dust motes in a room (although largely affected by air currents) Diffusion of pollutants in the air Diffusion of calcium through bones Movement of "holes" of electrical charge in semiconductors Importance of Brownian Motion The initial importance of defining and describing Brownian motion was that it supported the modern atomic theory. Today, the mathematical models that describe Brownian motion are used in math, economics, engineering, physics, biology, chemistry, and a host of other disciplines. Brownian Motion Versus Motility It can be difficult to distinguish between a movement due to Brownian motion and movement due to other effects. In biology , for example, an observer needs to be able to tell whether a specimen is moving because it is motile (capable of movement on its own, perhaps due to cilia or flagella) or because it is subject to Brownian motion. Usually, it's possible to differentiate between the processes because Brownian motion appears jerky, random, or like a vibration. True motility appears often as a path, or else the motion is twisting or turning in a specific direction. In microbiology, motility can be confirmed if a sample inoculated in a semisolid medium migrates away from a stab line. Source "Jean Baptiste Perrin — Facts." NobelPrize.org, Nobel Media AB 2019, July 6, 2019.
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B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Learn about our [Editorial Process](https://www.thoughtco.com/about-us-4779650#toc-editorial-guidelines) Updated on July 06, 2019 Close ### Key Takeaways - Brownian motion is the random movement of particles in a fluid due to collisions. - Albert Einstein explained Brownian motion, supporting the existence of atoms with indirect evidence. - Brownian motion helps explain the movement of particles from areas of high to low concentration. Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. Brownian motion is also known as pedesis, which comes from the Greek word for "leaping." Even though a particle may be large compared to the size of atoms and molecules in the surrounding medium, it can be moved by the impact with many tiny, fast-moving masses. Brownian motion may be considered a macroscopic (visible) picture of a particle influenced by many microscopic random effects. Brownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. He described the motion in 1827 but was unable to explain it. While pedesis takes its name from Brown, he was not the first person to describe it. The Roman poet Lucretius describes the motion of dust particles around the year 60 B.C., which he used as evidence of atoms. The transport phenomenon remained unexplained until 1905 when [Albert Einstein](https://www.thoughtco.com/who-was-albert-einstein-2698845) published a paper that explained the pollen was being moved by the water molecules in the liquid. As with Lucretius, Einstein's explanation served as indirect evidence of the existence of atoms and molecules. At the turn of the 20th century, the existence of such tiny units of matter was only a theory. In 1908, Jean Perrin experimentally verified Einstein's hypothesis, which earned Perrin the 1926 Nobel Prize in Physics "for his work on the discontinuous structure of matter." The mathematical description of Brownian motion is a relatively simple probability calculation, of importance not just in physics and chemistry, but also to describe other statistical phenomena. The first person to propose a mathematical model for Brownian motion was Thorvald N. Thiele in a paper on the [least squares method](https://www.thoughtco.com/what-is-a-least-squares-line-3126250) that was published in 1880. A modern model is the Wiener process, named in honor of Norbert Wiener, who described the function of a continuous-time stochastic process. Brownian motion is considered a Gaussian process and a Markov process with continuous path occurring over continuous time. ## What Is Brownian Motion? Because the movements of atoms and molecules in a liquid and gas is random, over time, larger particles will disperse evenly throughout the medium. If there are two adjacent regions of matter and region A contains twice as many particles as region B, the probability that a particle will leave region A to enter region B is twice as high as the probability a particle will leave region B to enter A. [Diffusion](https://www.thoughtco.com/definition-of-diffusion-604430), the movement of particles from a region of higher to lower concentration, can be considered a macroscopic example of Brownian motion. Any factor that affects the movement of particles in a fluid impacts the rate of Brownian motion. For example, increased temperature, increased number of particles, small particle size, and low [viscosity](https://www.thoughtco.com/viscosity-2699336) increase the rate of motion. ## Brownian Motion Examples Most examples of Brownian motion are transport processes that are affected by larger currents, yet also exhibit pedesis. Examples include: - The motion of pollen grains on still water - Movement of dust motes in a room (although largely affected by air currents) - Diffusion of pollutants in the air - Diffusion of calcium through bones - Movement of "holes" of electrical charge in semiconductors ## Importance of Brownian Motion The initial importance of defining and describing Brownian motion was that it supported the modern atomic theory. Today, the mathematical models that describe Brownian motion are used in math, economics, engineering, physics, biology, chemistry, and a host of other disciplines. ## Brownian Motion Versus Motility It can be difficult to distinguish between a movement due to Brownian motion and movement due to other effects. In [biology](https://www.thoughtco.com/biology-meaning-373266), for example, an observer needs to be able to tell whether a specimen is moving because it is motile (capable of movement on its own, perhaps due to cilia or flagella) or because it is subject to Brownian motion. Usually, it's possible to differentiate between the processes because Brownian motion appears jerky, random, or like a vibration. True motility appears often as a path, or else the motion is twisting or turning in a specific direction. In microbiology, motility can be confirmed if a sample inoculated in a semisolid medium migrates away from a stab line. ## Source "Jean Baptiste Perrin — Facts." NobelPrize.org, Nobel Media AB 2019, July 6, 2019. Cite this Article Format [mla](https://www.thoughtco.com/brownian-motion-definition-and-explanation-4134272) [apa](https://www.thoughtco.com/brownian-motion-definition-and-explanation-4134272) [chicago](https://www.thoughtco.com/brownian-motion-definition-and-explanation-4134272) Your Citation Helmenstine, Anne Marie, Ph.D. "An Introduction to Brownian Motion." ThoughtCo, Apr. 1, 2025, thoughtco.com/brownian-motion-definition-and-explanation-4134272. Helmenstine, Anne Marie, Ph.D. (2025, April 1). An Introduction to Brownian Motion. Retrieved from https://www.thoughtco.com/brownian-motion-definition-and-explanation-4134272 Helmenstine, Anne Marie, Ph.D. "An Introduction to Brownian Motion." 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Readable Markdown	### Key Takeaways - Brownian motion is the random movement of particles in a fluid due to collisions. - Albert Einstein explained Brownian motion, supporting the existence of atoms with indirect evidence. - Brownian motion helps explain the movement of particles from areas of high to low concentration. Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. Brownian motion is also known as pedesis, which comes from the Greek word for "leaping." Even though a particle may be large compared to the size of atoms and molecules in the surrounding medium, it can be moved by the impact with many tiny, fast-moving masses. Brownian motion may be considered a macroscopic (visible) picture of a particle influenced by many microscopic random effects. Brownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. He described the motion in 1827 but was unable to explain it. While pedesis takes its name from Brown, he was not the first person to describe it. The Roman poet Lucretius describes the motion of dust particles around the year 60 B.C., which he used as evidence of atoms. The transport phenomenon remained unexplained until 1905 when [Albert Einstein](https://www.thoughtco.com/who-was-albert-einstein-2698845) published a paper that explained the pollen was being moved by the water molecules in the liquid. As with Lucretius, Einstein's explanation served as indirect evidence of the existence of atoms and molecules. At the turn of the 20th century, the existence of such tiny units of matter was only a theory. In 1908, Jean Perrin experimentally verified Einstein's hypothesis, which earned Perrin the 1926 Nobel Prize in Physics "for his work on the discontinuous structure of matter." The mathematical description of Brownian motion is a relatively simple probability calculation, of importance not just in physics and chemistry, but also to describe other statistical phenomena. The first person to propose a mathematical model for Brownian motion was Thorvald N. Thiele in a paper on the [least squares method](https://www.thoughtco.com/what-is-a-least-squares-line-3126250) that was published in 1880. A modern model is the Wiener process, named in honor of Norbert Wiener, who described the function of a continuous-time stochastic process. Brownian motion is considered a Gaussian process and a Markov process with continuous path occurring over continuous time. Because the movements of atoms and molecules in a liquid and gas is random, over time, larger particles will disperse evenly throughout the medium. If there are two adjacent regions of matter and region A contains twice as many particles as region B, the probability that a particle will leave region A to enter region B is twice as high as the probability a particle will leave region B to enter A. [Diffusion](https://www.thoughtco.com/definition-of-diffusion-604430), the movement of particles from a region of higher to lower concentration, can be considered a macroscopic example of Brownian motion. Any factor that affects the movement of particles in a fluid impacts the rate of Brownian motion. For example, increased temperature, increased number of particles, small particle size, and low [viscosity](https://www.thoughtco.com/viscosity-2699336) increase the rate of motion. ## Brownian Motion Examples Most examples of Brownian motion are transport processes that are affected by larger currents, yet also exhibit pedesis. Examples include: - The motion of pollen grains on still water - Movement of dust motes in a room (although largely affected by air currents) - Diffusion of pollutants in the air - Diffusion of calcium through bones - Movement of "holes" of electrical charge in semiconductors ## Importance of Brownian Motion The initial importance of defining and describing Brownian motion was that it supported the modern atomic theory. Today, the mathematical models that describe Brownian motion are used in math, economics, engineering, physics, biology, chemistry, and a host of other disciplines. ## Brownian Motion Versus Motility It can be difficult to distinguish between a movement due to Brownian motion and movement due to other effects. In [biology](https://www.thoughtco.com/biology-meaning-373266), for example, an observer needs to be able to tell whether a specimen is moving because it is motile (capable of movement on its own, perhaps due to cilia or flagella) or because it is subject to Brownian motion. Usually, it's possible to differentiate between the processes because Brownian motion appears jerky, random, or like a vibration. True motility appears often as a path, or else the motion is twisting or turning in a specific direction. In microbiology, motility can be confirmed if a sample inoculated in a semisolid medium migrates away from a stab line. ## Source "Jean Baptiste Perrin — Facts." NobelPrize.org, Nobel Media AB 2019, July 6, 2019.
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