This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

Share this

Free weekly newswire

Sign up to receive all our latest news direct to your inbox.

Physics on film

100 Second Science Your scientific questions answered simply by specialists in less than 100 seconds.

Watch now

Bright Recruits

At all stages of your career – whether you're an undergraduate, graduate, researcher or industry professional – brightrecruits.com can help find the job for you.

Find your perfect job

Physics connect

Are you looking for a supplier? Physics Connect lists thousands of scientific companies, businesses, non-profit organizations, institutions and experts worldwide.

Start your search today

Blog

Is your hair dusty?

chair.jpg
Rising plumes

By Hamish Johnston in Portland, Oregon

Any guesses as to what you are looking at?

The red shape is a “person” sitting in a small room. The temperature at the surface of the person is 25 degrees – the temperature of your clothes, apparently – and the temperature of the room is 20 degrees.

The image is from a huge simulation of how air circulates in a room with floor and ceiling vents that was done by John McLaughlin and colleagues at Clarkson University.

The yellow plumes are warm air rising from the sitting person – and McLaughlin looked at how tiny particles comparable to viruses or pollen behaved in the room. He found that the plumes tend to concentrate the particles over the person’s head – and then they fall down onto the poor person!

This could be bad news in a hospital, for example, where there could be lots of nasty bugs floating around.

So if your head is getting dusty, perhaps it’s because you are sitting perfectly still in a small room.

This entry was posted in APS March Meeting 2010. Bookmark the permalink.
View all posts by this author  | View this author's profile

2 comments

  1. HenkZw

    Wouldn’t the rising warm air prevent the dust from settling on you ?

  2. Sum Kin, Tsang

    A similar photo, a schlieren image of a standing person, taken by the MRC Clinical Research Centre, shows similar result. The photo appeared in the book “Physical Fluid Dynamics”, written by D. J. Tritton (page 458).

Leave a comment

Your e-mail address will not be published. Required fields are marked *

Guidelines

  • Comments should be relevant to the article and not be used to promote your own work, products or services.
  • Please keep your comments brief (we recommend a maximum of 250 words).
  • We reserve the right to remove excessively long, inappropriate or offensive entries.

Show/hide formatting guidelines

Tag Description Example Output
<a> Hyperlink <a href="http://www.google.com">google</a> google
<abbr> Abbreviation <abbr title="World Health Organisation" >WHO</abbr> WHO
<acronym> Acronym <acronym title="as soon as possible">ASAP</acronym> ASAP
<b> Bold <b>Some text</b> Some text
<blockquote> Quoted from another source <blockquote cite="http://iop.org/">IOP</blockquote>
IOP
<cite> Cite <cite>Diagram 1</cite> Diagram 1
<del> Deleted text From this line<del datetime="2012-12-17"> this text was deleted</del> From this line this text was deleted
<em> Emphasized text In this line<em> this text was emphasised</em> In this line this text was emphasised
<i> Italic <i>Some text</i> Some text
<q> Quotation WWF goal is to build a future <q cite="http://www.worldwildlife.org/who/index.html">
where people live in harmony with nature and animals</q>
WWF goal is to build a future
where people live in harmony with nature and animals
<strike> Strike text <strike>Some text</strike> Some text
<strong> Stronger emphasis of text <strong>Some text</strong> Some text
WordPress Appliance - Powered by TurnKey Linux