A- A A+
Log in

Login form

You need to sign in to those awesome features
or use your account
Remember me
Power by Joomla Templates - BowThemes

Create an account

Fields marked with an asterisk (*) are required.
Name (*)
Username (*)
Password (*)
Confirm password (*)
Email (*)
Confirm email (*)

NHA Banner

Natural History Assoc

Notices on Our Content (hover on each phrase): Member Protected Content  Walk Access Restrictions May Apply   

detective2up We collected weblinks for our Custom Google Search above to help you target searches to nature websites we like. Submit your favourite nature website - contact us. Internet Explorer users need to be on Version 10+.

Around the world the arrival of the New Year is celebrated by massive displays of fireworks which seem to become more extravagant and spectacular with every passing year.

The basic design of aerial fireworks is a shell or casing with a timed fuse and bursting charge, within the shell is black powder which surrounds small pellets or packets of colourants known as pyrotechnic stars. When the shell is launched the fuse burns, ignites the bursting charge and explodes the shell scattering the pyrotechnic stars. How do these stars produce light and colour?

Visible light can be described as electromagnetic radiation that can be perceived by the human eye. The colours of the visible spectrum are red, orange, yellow, green, blue, indigo and violet (in order of longer to shorter wavelengths)

There are two basic types of light sources.

Incandescence is the release of electromagnetic radiation from an object as a result of heat and occurs when atoms are heated and release some of their thermal vibration as electromagnetic radiation.

The colour of the light released, the photon, depends upon the temperature. Because red is the lowest energy and longest wavelength of visible light it is the colour we first see when objects are heated, then orange, yellows until if
enough heat is applied a substance will glow white-hot. White light is not a colour but is a combination of all of the colours of the visible spectrum.

In fireworks incandescent light of gold, white and silver are produced by burning metals such as iron, magnesium, aluminium and titanium.

In nature sunlight, starlight and fire are examples of incandescent light.

Luminescence is the release of electromagnetic radiation from an object as a result of chemical, biochemical, or crystallographic changes, the motions of subatomic particles, or radiation-induced excitation of an atomic system. The effect of the cool energy source alters the orbital pattern of electrons in atoms.

When energy is absorbed by an electron of an atom or molecule, it moves into a high-energy state and orbits farther away from the atomic nucleus. When the electron falls back into its ground state it releases energy in the form of light. This is known as a photon and it produces light of a certain colour.

In fireworks luminescent light of red, orange, yellow, green, blue and purple is produced by chemical reactions between a range of compounds including strontium salts, lithium salts, calcium salts, sodium compounds, barium compounds, copper compounds and strontium compounds,

In nature luminescent light may be produced by a number of processes. Bioluminescent light is produced by chemical reactions in the cells of species such as glowworms, fireflies, fungi and marine creatures. Some gemstones, minerals and compounds exhibit phosphorescence.

Another example of natural luminescent light is the natural polar light display of Aurora Borealis and Aurora Australis. Unfortunately few people have the opportunity to witness what must be the most spectacular aerial fireworks display on Earth.

Share this post

Submit to DeliciousSubmit to DiggSubmit to FacebookSubmit to Google PlusSubmit to StumbleuponSubmit to TechnoratiSubmit to TwitterSubmit to LinkedIn
Real time web analytics, Heat map tracking

okoaraInjured Wildlife

Wildcare SEQ (07) 5527 2444

RSPCA / DEHP Brisbane - Gold Coast

1300 ANIMAL (1300264625)

Elsewhere in Australia

Feral Animal Control

Gallery Tree

Random Images - NHA

  • 2016-11-25 NW Clagiraba Ck Track _119
  • 2015-10-02 NHA NW PalmGrove_148
  • 2010-05-22 White Rock
  • Description: Bushwalking in SE Qld
  • 2011-02-12 Fingal Head
  • Description: Bushwalking in SE Qld
  • 2016-02-26 TMNHA NW Ohia Ct - Shallow roots on fallen tree
  • Description: Nature Walk
  • 2014-05-30 Esme Lahey Park - Tall Original Trees
  • Description:

    Esme Lahey Park - Tall Original Trees

Why does attentiveness to nature matter? In a very fundamental sense, we are what we pay attention to. Paying heed to beauty, grace, and everyday miracles promotes a sense of possibility and coherence that runs deeper and truer than the often illusory commercial, social "realities" advanced by mainstream contemporary culture. ... Our attention is precious, and what we choose to focus it on has enormous consequences. What we choose to look at, and to listen to--these choices change the world. As Thich Nhat Hanh has pointed out, we become the bad television programs that we watch. A society that expends its energies tracking the latest doings of the celebrity couple is fundamentally distinct from one that watches for the first arriving spring migrant birds, or takes a weekend to check out insects in a mountain stream, or looks inside flowers to admire the marvelous ingenuities involved in pollination. The former tends to drag culture down to its lowest commonalities; the latter can lift us up in a sense of unity with all life. The Way of Natural History, edited by Thomas Lowe Fleischner and published by Trinity University Press (Texas)