## Smartphone weekend at phaeno in Wolfsburg

So, this is just a quick reminder that there will be a smartphone physics event on 11th and 12th of March at the phaeno in Wolfsburg. Now with a link to further details on their website (in German).

## Experiment database and worksheets

The listing of our experiments has changed. When you click the experiments link above, you will find a database of experiments, which you can filter by information and media available for each experiment.

As additional news, we now also feature worksheets for school. Unfortunately, so far these are only in German. If you have developed a worksheet yourself (in any language), we are happy to include it into our database. The only requirement is, that you apply a Creative Commons licence which allows to distribute the worksheet this way and note this on the worksheet. Just send any material to us via email.

## Collective measurement of pendulum frequencies

As part of an optional assignment, we asked our students to create a pendulum, measure its frequency with phyphox and submit the results via a web form. I just picked up the data and got thrilled as the result is amazing:

I just had to clean out some obvious cases in which students did not use the correct units (no, they did not build a 69m pendulum).

They did not even know anything about the math of oscillations. Instead, I will introduce this topic in tomorrow’s lecture and will then use their own data to verify the result for the frequency of a pendulum:
$latex f = \frac{\omega}{2\pi} = \frac{1}{2\pi}\sqrt{\frac{g}{l}}&bg=404040&fg=ffffff&s=3$

## Smartphones at the phaeno

Today I had a great day at the phaeno science center. On 11th and 12th of March, they will be doing an exhibition on physics experiments with smartphones, so today we had a lot of fun trying out a bunch of ideas for this event. So, here is a little teaser video…

## Honey separator

One of our users, Christian, wondered about the centripetal (or centrifugal, depending on your reference system) force in his honey separator. He basically has got a centrifuge for his honeycombs which extracts the honey using this force, but unlike our experiment using a salad spinner, he was unable to measure the acceleration directly because it exceeds the range of the sensors in his smartphone. So, instead he attached his phone to the crank of the centrifuge and created his own phyphox experiment, which uses the gyroscope to determine the rotation speed of the crank. From this, his experiment then derives the speed of the centrifuge itself and all the forces involved, taking into account the transmission of the crank as well as the radius at which the honeycombs are placed within the centrifuge. If you are interested in this, here is a link to directly open his exeriment in phyphox and a link to download his phyphox file defining the experiment.

Thanks to Christian for sharing this unusual application with us.

## News from the last week

Besides releasing a minor update with a bunch of fixes, there has been a lot of great coverage of phyphox over the last week. So, here they are in no particular order (well, I put the English ones at the top).

### AAPT webinar: Using smartphones to teach physics

Well, this is not exactly press coverage and technically it’s not in the past seven days, but I still want to mention this at the top, because it was a great web-event by the American Association of Physics Teachers (AAPT) on December the 10th, which brought together many people from around the globe pioneering smartphone physics. Thanks a lot to AAPT’s Rebecca Vieyra for hosting the session. Hopefully, a recording will be available online soon…

### Gorilla Physics

Kit Betts-Masters, a physics teacher from the UK, has covered phyphox on his Youtube channel “Gorilla Physics”, which you can check out here.

### Bildung Zukunft Technik (German)

There was a short but enthusiastic mention in the German podcast bildung-zukunft-technik.de in their “nice apps” category.

### chip.de (German)

The widely known German computer magazine has covered us on their webpage in their app category.

### iphone-ticker.de (German)

On the 10th of December, iphone-ticker.de featured an article about phyphox on their front-page, which generated an estimate of 10.000 new installs on Apples App Store over the weekend.

### Die Zeit (German)

The German newspaper “Die Zeit” (edition from 15 Dec, p. 38) mentioned phyphox in an article about presents for those enthusiastic about knowledge and technology.

### One More Thing (Dutch)

At the beginning of the week (12 Dec), we were featured on onemorething.nl from the Netherlands.

## Version 1.0.5 (minor improvements and fixes)

As I explained in the last update I am mostly working on the next major update and there will only be updates in-between to fix bugs. Well – this is one of those updates.

## Changes for both Android and iOS

• We now use the calibrated magnetometer by default and allow switching to the raw magnetometer from the menu if available on the device.
• Acoustic stopwatch now supports multiple timers and allows for setting a minimum delay.
• Sonar now features a reverse mode where you enter a distance and can determine the speed of sound.
• Fix: Append-module now accepts value-type input.
• Fix: Update fails when switching to raw data in remote experiment of the roll experiment (and possibly others).
• Fix: Some spelling errors in the experiments.

## Changes for Android

• Fix: Very short audio loops failed.
• Fix: Remote access failed when infinite numbers occur.
• Fix: Crash on Samsung Galaxy S4 when repeatedly playing audio.

## Changes for iOS

• Fix: Run analysis even when not triggered by a sensor event to allow for self-modifying experiments like a gradually changing tone generator.
• Fix: Possible crash in average module (race condition mostly triggered on iOS8).
• Fix: Axis labels were not translated in the remote interface.
• Fix: Crash in binning module when dx is set to zero.
• Fix: Handle audio setup changes (plugging in a headset) more gracefully.