Radiation pressure is the mechanical pressure exerted upon any surface due to the exchange of momentum between the object and the electromagnetic field. This includes the momentum of light or electromagnetic radiation of any wavelength that is absorbed, reflected, or otherwise emitted (e.g. black-body radiation) by matter on any scale (from macroscopic objects to dust particles to gas molecules). The associated force is called the radiation pressure force, or sometimes just the force of light.
The forces generated by radiation pressure are generally too small to be noticed under everyday circumstances; however, they are important in some physical processes and technologies. This particularly includes objects in outer space, where it is usually the main force acting on objects besides gravity, and where the net effect of a tiny force may have a large cumulative effect over long periods of time. For example, had the effects of the Sun's radiation pressure on the spacecraft of the Viking program been ignored, the spacecraft would have missed Mars' orbit by about 15,000 km (9,300 mi). Radiation pressure from starlight is crucial in a number of astrophysical processes as well. The significance of radiation pressure increases rapidly at extremely high temperatures and can sometimes dwarf the usual gas pressure, for instance, in stellar interiors and thermonuclear weapons. Furthermore, large lasers operating in space have been suggested as a means of propelling sail craft in beam-powered propulsion.
Radiation pressure forces are the bedrock of laser technology and the branches of science that rely heavily on lasers and other optical technologies. That includes, but is not limited to, biomicroscopy (where light is used to irradiate and observe microbes, cells, and molecules), quantum optics, and optomechanics (where light is used to probe and control objects like atoms, qubits and macroscopic quantum objects). Direct applications of the radiation pressure force in these fields are, for example, laser cooling (the subject of the 1997 Nobel Prize in Physics), quantum control of macroscopic objects and atoms (2013 Nobel Prize in Physics), interferometry (2017 Nobel Prize in Physics) and optical tweezers (2018 Nobel Prize in Physics).Radiation pressure can equally well be accounted for by considering the momentum of a classical electromagnetic field or in terms of the momenta of photons, particles of light. The interaction of electromagnetic waves or photons with matter may involve an exchange of momentum. Due to the law of conservation of momentum, any change in the total momentum of the waves or photons must involve an equal and opposite change in the momentum of the matter it interacted with (Newton's third law of motion), as is illustrated in the accompanying figure for the case of light being perfectly reflected by a surface. This transfer of momentum is the general explanation for what we term radiation pressure.
Hi folks, first time poster. I'm a math undergrad taking my final physics3 requirement. I'm doing ok in the class, but about 2 out of 8 of the homework problems confound me. I removed the numbers below and replaced them with variables (does that matter on this site?). Mostly I'm interested...
b]1. Homework Statement [/b]
Estimate the radiation pressure due to a 75 Watt bulb at a distance of 8 cm from the center of the bulb.
Homework Equations
S=(E x B) , P = S/c
The Attempt at a Solution
I'm not sure were to start. How can I determine the value of E from a 75 Watt bulb.
Hi,
When radiation pressure exerts a force on an object causing it to move, where does the object's kinetic energy come from, and how?
E.g. consider a perfectly reflecting solid block in vacuum. Its face is illuminated by light. From conservation of momentum, the reflection of the light...
Hey!
When a photon is reflected off an interface doesn't it deliver some of it's momentum to the object that it hits due to radiation pressure? If so, shouldn't the reflected light have a longer wavelength (smaller wavenumber) than the incident light? Is this effect present, but just so small...
Pressure = energy flux / speed of light
Taking an energy flux of 1000 watts per meter sq (typical flux of sunlight on Earth's surface)
We gain, pressure = 1,000/300,000,000 = 1/300,000 Pascals.
If it is reflected, we gain twice that = 2/300,000 pascals
Now my question, if I had two...
Q: Near the Earth the flux of the EM energy from the sun is ~ 1.4 kW/m2. If an interplanetary sailplane has a sail of mass 1g/m2 and negligible other weight, what would be its acceleration due to solar radiation pressure?
Help! I am a stuck on this. However, I have a few thoughts:
We know...
Hello! First time on this site, so I hope I do this right. I have a homework question that I could use some help on:
(From Physics for Scientists and Engineers, Third Ed. Fishbane, Gasiorowicz, Thornton)
Chapter 34 #39.
Suppose that you want to use the radiation pressure from a beam of...
How do scientists counteract the radiation pressure of sunlight falling on artifical satellites for e.g. on solar panels? Do they use rockets or is the orbit self-correcting?
Ok, i got a problem that reads as followed.
Suppose that a perfectly reflecting circular mirror is initially at rest a distance R away from the sun and is oriented so that the solar radiation is incident upon, and perpendicular to, the plane of the mirror. What is the critical value of...
Knowing that a 10 watt light source is used to illuminate a 1m(squared) area of glass surface with n=1.5 orthogonal to it's surface, how can i find the radiation pressure?
Formula for solar radiation pressure
I'm looking for a formula that gives the amount of force in Newtons that is produced from the pressure of solar radiation.
I've googled it and found:
F_R = C_R \frac{I}{c}S
where I is the radiation intensity, c is the speed of light, and S is the...
A plane electromagnetic wave of intensity 6.00 W/m2 strikes a small pocket mirror, of area 30.0 cm2, held perpendicular to the approaching wave.
(a) What momentum does the wave transfer to the mirror each second?
kg · m/s
Ok, well for a perfect reflector, the formula is given as total...
I'm working on a project that involves 'acoustic radiation pressure'.. This means that an acoustic wave can exert a net force on some object, along it's propagation-direction.. if the object was a plate, it would look somewhat like this:
...... |
----||--wave--> |->Force...