Questions tagged [radiation-pressure]
42 questions
78
votes
2 answers
Can an atom orbit the Sun?
Is it possible for a molecule or atom to orbit a star (e.g. the Sun)? Or is there always too much outward force imparted by solar radiation compared to the inward force of gravitational attraction?
Nicole Sharp
- 657
10
votes
1 answer
How efficient is the Crookes radiometer?
I remember many years ago, I think at 8th grade, seeing the teacher show us a Crookes radiometer. I remember it being very fascinating. Today I read the wiki article on it, after looking up what it was called, but the article wasn't very clear in my…
Valtteri
- 359
- 1
- 11
6
votes
4 answers
Accelerating Expansion of Universe - Why Not Caused by Radiation?
As I understand it, dark matter and dark energy are used as an 'explanation' for how universe expansion is accelerating; because without it gravity would be expected to cause a long term shrinking.
Why, when extremely distant objects have such tiny…
Claud
- 199
3
votes
3 answers
Conceptual Issue With Radiation Pressure
Consider a flat, thin, perfectly reflective square mirror of mass $m$ lying on edge on a frictionless, horizontal surface that is met by an electromagnetic wave with Poynting vector parallel to the normal to the square. Suppose the EM wave recoils…
Arjun Puri
- 75
3
votes
1 answer
How are solar sails maneuvered by sunlight? Are they pushed or pulled?
On 20 May, 2010, Japan launched IKAROS probe with primary propulsion by a solar sail. If the radiation pressure, that helps the sail to move, comes from the sun, then shouldn't it be pushed away from the sun? But the IKAROS probe actually passed by…
Manish
- 35
- 6
3
votes
1 answer
What the name of the evacuated glass gadget with black and white vanes that turn when a light is applied?
I remember a glass device my physics teacher had at high school which
Contained some vanes mounted somehow on a vertical axis, which were all black on one side and white on the other
Was in a vacuum (partial, at least)
Caused the vanes to spin…
Highly Irregular
- 131
3
votes
1 answer
Can we use radiation pressure to push/levitate a human?
I want to know, at least in theory, are there any safe em wavelength that could affect human body as net force and do no harm?
To put it bluntly I want to know is it possible for levitate a human on Earth with radiation pressure?
I just think maybe…
Thaina
- 948
2
votes
1 answer
Understanding radiation pressure
I've been told that the radiation pressure of light can be understood(?) by considering a charged particle as a damped driven harmonic oscillator where the forcing term is the electromagnetic field, not neglecting the magnetic field term. In fact, I…
qmstatmech
- 53
2
votes
3 answers
If all objects emit IR radiation, would it be sufficient to place an IR mirror behind an object to propel it forward?
I'm assuming objects don't move all the time because they emit IR radiation in all directions. If we have an IR mirror behind the object to focus their direction, would this propel the object forward?
bubakazouba
- 365
2
votes
1 answer
Optomechanical interaction
In cavity optomechanics, we see that if one of the mirrors is oscillatory and the other one is fixed,the photons are not able to shift the oscillating mirror continuously in one direction no matter how high the radiation pressure force. Why is that…
Physiker
- 1,469
2
votes
4 answers
Can radiation pressure do work, if so does the magnetic field participate?
I understand that the magnetic field cannot do work because the Lorentz force is always perpendicular to the displacement. In my optics book(Hecht Ch3) these equations appear:
Electromagnetic pressure, P, is equal to the energy density of a light…
J_7
- 23
2
votes
4 answers
Can light radiation pressure change its own path
Well i have seen that light creates radiation pressure
Can two light waves coming from two different direction change each others path?
Opartunity
- 51
2
votes
3 answers
why do hypergiants shed mass before death?
I'm reading on this website here and will be using lots of quotes from it.
Hypergiant Star Seen Shedding Mass Ahead Of Explosive Death As Supernova
Astronomers using a telescope in Chile have observed a hypergiant star shedding massive amounts of…
EasyPeasy
- 837
2
votes
0 answers
Angular distribution of scattered photons in laser cooling
I currently prepare for a magneto-optical trap undergrad lab. Radiation pressure comes from the photon's momentum, that is clear. The emission of the photon (some time later) will give another recoil to the atom. The manual states that when hitting…
Martin Ueding
- 8,559
1
vote
2 answers
How can I relate the temperature and pressure at the core of a star?
There are many ways to estimate the temperature of the core of a star, one of which is by radiation pressure and the gravitational force of the star on itself. I am unable to relate both of them correctly to get the temperature. Note that by…
B 2012 Arshad Khatib
- 11
- 3