<p><a href="https://spacephysics.msfc.nasa.gov/science/dusty/posters/rot_exp.pdf" rel="nofollow noreferrer">This poster</a> suggests an answer of <em>yes and no</em>. Essentially the poster reports a demonstration of some of the proposed mechanisms, but the rotation speeds produced are in the <span class="math-container">$kHz$</span> not <span class="math-container">$GHz$</span> range because the dust partcles are bigger, the vacuum less good and so on.</p>

<p>To quote the summary:</p>

<blockquote>
  <ul>
  <li>First laboratory measurements of rotation of the analogs of interstellar
  dust grains induced by radiative torques have been made</li>
  <li>The measurements were made on irregularly shaped SiC particles
  particles of ~ 0.17 to 8.2 <span class="math-container">$\mu m$</span> effective radii levitated in an electrodynamic
  balance and illuminated with laser light at a wavelength of 5320 Å, at
  pressures of <span class="math-container">$10^{-3}$</span> to <span class="math-container">$10^{-5}$</span> torr.</li>
  <li>The rotation rates with radiation intensities of ~ <span class="math-container">$4-30 Wcm^{-2}$</span> were
  observed in the range of 1,000-22,000 rot/sec.</li>
  <li>The grain rotation rates were observed to follow the expected functional
  relationships, being directly proportional to the incident radiation
  intensities and inversely proportional to the drag represented by the
  ambient pressure.</li>
  </ul>
</blockquote>

CC BY-SA 4.0
2018-12-18T01:19:45.900Z
Bingo! This is exactly the kind of thing I was looking for, thank you.
uhoh
CC BY-SA 4.0
2022-08-30T17:07:07.210Z
unfortunately without an author name, year, or name of the event, the broken link will be difficult to put back together again, so unaccepting for now at least.
uhoh
CC BY-SA 4.0
2018-12-17T23:05:45.697Z
2018-12-17T23:05:45.697Z
Steve Linton
<p>This <a href="https://astronomy.stackexchange.com/a/22996/7982">excellent answer</a> to the question <em>What is the physics of the “spinning dust” contribution to Cosmic Microwave Background measurements?</em> includes the figure below which helps show what it was the triggered the existence-hypothesizing of cosmic spinning dust.</p>

<p><a href="https://i.sstatic.net/eHR9q.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/eHR9q.png" alt="enter image description here"></a></p>

<p>The question <a href="https://astronomy.stackexchange.com/q/28637/7982">Why doesn't the equipartition theorem disallow spinning dust?</a> is my way of starting to wonder if spinning dust is real, or if it really happens.</p>

<p>One thing that would make me more comfortable than an <s>argument</s> gedankenexperiment involving a modified Crookes radiometer with the gas removed would be some kind of experiment showing that simply being exposed to some very low pressure hydrogen, or photons, can make dust spin at anything close to 20 GHz!</p>

<p>These days optical trapping of particles in very high vacuum is readily accessible for example, so I think if someone wanted to try to make GHz-spinning-dust they could certainly have a go. </p>

<p><strong>Question:</strong> Has this been tried? Has "GHz-spinning dust" ever been demonstrated in the laboratory? </p>

<astrophysics><interstellar-medium><dust>
Has "GHz-spinning dust" ever been demonstrated in the laboratory?
uhoh
# Has "GHz-spinning dust" ever been demonstrated in the laboratory?

(Asked by: username_0 on 2018-12-17)

This [excellent answer](https://astronomy.stackexchange.com/a/22996/7982) to the question *What is the physics of the “spinning dust” contribution to Cosmic Microwave Background measurements?* includes the figure below which helps show what it was the triggered the existence-hypothesizing of cosmic spinning dust.

[![enter image description here](https://i.sstatic.net/eHR9q.png)](https://i.sstatic.net/eHR9q.png)

The question [Why doesn't the equipartition theorem disallow spinning dust?](https://astronomy.stackexchange.com/q/28637/7982) is my way of starting to wonder if spinning dust is real, or if it really happens.

One thing that would make me more comfortable than an ~~argument~~ gedankenexperiment involving a modified Crookes radiometer with the gas removed would be some kind of experiment showing that simply being exposed to some very low pressure hydrogen, or photons, can make dust spin at anything close to 20 GHz!

These days optical trapping of particles in very high vacuum is readily accessible for example, so I think if someone wanted to try to make GHz-spinning-dust they could certainly have a go.

**Question:** Has this been tried? Has "GHz-spinning dust" ever been demonstrated in the laboratory?

**Tags:** astrophysics, interstellar-medium, dust

---

## 1 answers

### Answer by username_1 on 2018-12-17. Score: 2

[This poster](https://spacephysics.msfc.nasa.gov/science/dusty/posters/rot_exp.pdf) suggests an answer of *yes and no*. Essentially the poster reports a demonstration of some of the proposed mechanisms, but the rotation speeds produced are in the $kHz$ not $GHz$ range because the dust partcles are bigger, the vacuum less good and so on.

To quote the summary:

> * First laboratory measurements of rotation of the analogs of interstellar
>   dust grains induced by radiative torques have been made
> * The measurements were made on irregularly shaped SiC particles
>   particles of ~ 0.17 to 8.2 $\mu m$ effective radii levitated in an electrodynamic
>   balance and illuminated with laser light at a wavelength of 5320 Å, at
>   pressures of $10^{-3}$ to $10^{-5}$ torr.
> * The rotation rates with radiation intensities of ~ $4-30 Wcm^{-2}$ were
>   observed in the range of 1,000-22,000 rot/sec.
> * The grain rotation rates were observed to follow the expected functional
>   relationships, being directly proportional to the incident radiation
>   intensities and inversely proportional to the drag represented by the
>   ambient pressure.

> **Comments:**
> **username_0**: Bingo! This is exactly the kind of thing I was looking for, thank you.  
> **username_0**: unfortunately without an author name, year, or name of the event, the broken link will be difficult to put back together again, so unaccepting for now at least.  

---

