The Electromagnetic Spectrum
Ανέβηκε στις 1 Αυγ 2010
http://www.facebook.com/ScienceReason ... Science@NASA: EMS (Episode 1) - An Introduction To The Electromagnetic Spectrum
---
Please SUBSCRIBE to Science & Reason:
• http://www.youtube.com/Best0fScience
• http://www.youtube.com/ScienceTV
• http://www.youtube.com/FFreeThinker
---
Measuring the electromagnetic spectrum
You
actually know more about it than you may think! The electromagnetic
(EM) spectrum is just a name that scientists give a bunch of types of
radiation when they want to talk about them as a group. Radiation is
energy that travels and spreads out as it goes-- visible light that
comes from a lamp in your house and radio waves that come from a radio
station are two types of electromagnetic radiation.
Other
examples of EM radiation are microwaves, infrared and ultraviolet light,
X-rays and gamma-rays. Hotter, more energetic objects and events create
higher energy radiation than cool objects. Only extremely hot objects
or particles moving at very high velocities can create high-energy
radiation like X-rays and gamma-rays.
The different types of radiation in the EM spectrum, in order from lowest energy to highest:
Radio:
Yes, this is the same kind of energy that radio stations emit into the
air for your boom box to capture and turn into your favorite Mozart,
Madonna, or Justin Timberlake tunes. But radio waves are also emitted by
other things ... such as stars and gases in space. You may not be able
to dance to what these objects emit, but you can use it to learn what
they are made of.
Microwaves: They will cook your popcorn in just
a few minutes! Microwaves in space are used by astronomers to learn
about the structure of nearby galaxies, and our own Milky Way!
Infrared:
Our skin emits infrared light, which is why we can be seen in the dark
by someone using night vision goggles. In space, IR light maps the dust
between stars.
Visible: Yes, this is the part that our eyes see.
Visible radiation is emitted by everything from fireflies to light bulbs
to stars ... also by fast-moving particles hitting other particles.
Ultraviolet:
We know that the Sun is a source of ultraviolet (or UV) radiation,
because it is the UV rays that cause our skin to burn! Stars and other
"hot" objects in space emit UV radiation.
X-rays: Your doctor
uses them to look at your bones and your dentist to look at your teeth.
Hot gases in the Universe also emit X-rays .
Gamma-rays:
Radioactive materials (some natural and others made by man in things
like nuclear power plants) can emit gamma-rays. Big particle
accelerators that scientists use to help them understand what matter is
made of can sometimes generate gamma-rays. But the biggest gamma-ray
generator of all is the Universe! It makes gamma radiation in all kinds
of ways.
• http://imagine.gsfc.nasa.gov/docs/sci...
.
---
Please SUBSCRIBE to Science & Reason:
• http://www.youtube.com/Best0fScience
• http://www.youtube.com/ScienceTV
• http://www.youtube.com/FFreeThinker
---
Measuring the electromagnetic spectrum
You
actually know more about it than you may think! The electromagnetic
(EM) spectrum is just a name that scientists give a bunch of types of
radiation when they want to talk about them as a group. Radiation is
energy that travels and spreads out as it goes-- visible light that
comes from a lamp in your house and radio waves that come from a radio
station are two types of electromagnetic radiation.
Other
examples of EM radiation are microwaves, infrared and ultraviolet light,
X-rays and gamma-rays. Hotter, more energetic objects and events create
higher energy radiation than cool objects. Only extremely hot objects
or particles moving at very high velocities can create high-energy
radiation like X-rays and gamma-rays.
The different types of radiation in the EM spectrum, in order from lowest energy to highest:
Radio:
Yes, this is the same kind of energy that radio stations emit into the
air for your boom box to capture and turn into your favorite Mozart,
Madonna, or Justin Timberlake tunes. But radio waves are also emitted by
other things ... such as stars and gases in space. You may not be able
to dance to what these objects emit, but you can use it to learn what
they are made of.
Microwaves: They will cook your popcorn in just
a few minutes! Microwaves in space are used by astronomers to learn
about the structure of nearby galaxies, and our own Milky Way!
Infrared:
Our skin emits infrared light, which is why we can be seen in the dark
by someone using night vision goggles. In space, IR light maps the dust
between stars.
Visible: Yes, this is the part that our eyes see.
Visible radiation is emitted by everything from fireflies to light bulbs
to stars ... also by fast-moving particles hitting other particles.
Ultraviolet:
We know that the Sun is a source of ultraviolet (or UV) radiation,
because it is the UV rays that cause our skin to burn! Stars and other
"hot" objects in space emit UV radiation.
X-rays: Your doctor
uses them to look at your bones and your dentist to look at your teeth.
Hot gases in the Universe also emit X-rays .
Gamma-rays:
Radioactive materials (some natural and others made by man in things
like nuclear power plants) can emit gamma-rays. Big particle
accelerators that scientists use to help them understand what matter is
made of can sometimes generate gamma-rays. But the biggest gamma-ray
generator of all is the Universe! It makes gamma radiation in all kinds
of ways.
• http://imagine.gsfc.nasa.gov/docs/sci...
.
Κατηγορία
Άδεια
- Τυπική άδεια YouTube
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου