Naked Science Forum

On the Lighter Side => Science Experiments => Topic started by: hamdani yusuf on 07/04/2016 12:39:32

Title: How do microwaves behave?
Post by: hamdani yusuf on 07/04/2016 12:39:32
Basically this series of experiment is a sequel of previous experiments regarding diffraction of light, which leaves some unanswered questions. I hope from the next experiments we can build a workable model to explain the behavior of electromagnetic waves in general, and their interaction with matters.

video #1 : Introduction

In this video series we are going to investigate another form of electromagnetic wave, which is commonly called microwave. By doing so, hopefully we can get better understanding on the nature of electromagnetic wave.

A huge advantage of using microwave compared to visible light is its wavelength which is in the order of a few centimeters, which makes it convenient to manipulate. Variables obscured by the small scale of optical experiments can be easily observed and manipulated.
Title: Re: investigation on microwave
Post by: hamdani yusuf on 07/04/2016 12:43:21
this video #2 shows the microwave transmittance through several type of media.
Title: Re: investigation on microwave
Post by: hamdani yusuf on 07/04/2016 12:45:59
Video #3 here shows reflection of microwave by several types of media.
Title: Re: investigation on microwave
Post by: hamdani yusuf on 07/04/2016 12:54:12
video#4 shows a phenomenon called linear polarization which is observed in microwave transmission. Up to this point we just go with standard experimental setup usually done in school kids' physics laboratory.
Title: Re: investigation on microwave
Post by: hamdani yusuf on 07/04/2016 15:27:10
VIDEO#5 shows something rarely demonstrated in schools lab, which is reflection by microwave linear polarizer.
Title: Re: investigation on microwave
Post by: hamdani yusuf on 14/04/2016 06:13:25
In video#6, Elliptical Polarization is demonstrated using linearly polarized transmitter, a linear polarizer, and a reflector. There is also another method which is commercially used, but here we use already available components whose characteristics are individually identifiable.
Title: Re: investigation on microwave
Post by: hamdani yusuf on 14/04/2016 06:17:54
in video#7 we try to determine the size of photon, which is thought to be the quantum of light and all other forms of electromagnetic radiation, including microwave. We use two metal plates to create a single slit with adjustable width.
Title: Re: investigation on microwave
Post by: hamdani yusuf on 14/04/2016 07:06:31
Determination of "photon size" is continued in video#8, using multiple slit







Spoiler alert :
From the experiments shown in this video, it is clear that photon model is not the best way to describe microwave interaction with electrically conductive materials. We need a better model based on following facts:
-   Microwave can still pass through even when its transmission path is almost entirely covered by metal sheet. (This is found when the metal sheet is restricted so it cannot produce opposing electrical oscillation that cancel out the transmitted wave.)
-   Microwave can be completely blocked even when there are much space uncovered by conductor. (This is found when there are adequate conductors to produce opposing electrical oscillation that cancel out the transmitted wave.)
-   Maximum transmission is achieved when the Gunn diode in the transmitter is aligned with the Schottky diode in the receiver, if there is no obstacle between them.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 15/04/2016 10:39:13
This video#9 shows a linearly polarized microwave's axis can be rotated by a sparse metal grating. It can also be turned into an elliptically polarized microwave if another sparse metal grating is added after the first.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 15/04/2016 10:58:53
In this video#10 we are investigating the power dissipated by microwave transmitter. The power used by transmitter is measured using this milli-Ampere clamp meter. It is shown that placement of a reflector can affect transmitter's power consumption.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 19/07/2016 11:05:32
youtu.be/nfYDiqiH5mU
This video shows that microwave can also experience refraction, just like normal optics.

The hardest part in making this video was molding the paraffin wax prism. But this worth the effort, since it will be used in several videos to come, which investigate total internal reflection and evanescent wave.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 20/07/2016 15:28:50
In this video #12 we are investigating total internal reflection in microwave using paraffin wax prism.

youtube.com/watch?v=vsO71mWGxKs
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 20/07/2016 15:33:08

This video#13 shows a phenomenon called evanescent wave coupling. This is a continuation of previous video about total internal reflection where electromagnetic wave can't pass through the boundary between two media. Introducing additional medium beyond the boundary can make the em wave pass through the previously impenetrable boundary.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 20/07/2016 15:39:13

In this video#14 we demonstrated that placing another transparent prism in a total internal reflection can turn it into a partial internal reflection.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 20/07/2016 15:41:54

This video#15 shows that intensity received from Total Internal Reflection setup can be amplified by simply adding a metal plate behind the prism.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 26/07/2016 15:48:52
My video #16 we investigate effects of refraction to polarization state of microwave.



www.youtube.com/watch?v=ZkG-wNUGkUs

The result shows that refracted microwave retains its polarization state. No phase shift difference between s and p polarized plane.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 26/07/2016 15:56:15
www.youtube.com/watch?v=Vdny18rY8m0

This video #17 investigates effects of total internal reflection to polarization state of microwave. The result shows that total internal reflection on microwave introduce phase shift difference between s and p polarized plane, which turn linearly polarized wave into elliptically polarized wave.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 26/07/2016 16:01:06
Similar to previous video, but now we are investigating polarization in partial and amplified internal reflection.
www.youtube.com/watch?v=sd_p-pwB41U
Title: Re: How do microwaves behave?
Post by: timey on 26/07/2016 16:43:26
Similar to previous video, but now we are investigating polarization in partial and amplified internal reflection.
www.youtube.com/watch?v=sd_p-pwB41U
I think I'm going to have to start at the very beginning of your  YouTube experiments and watch them all in one go... I get the impression you are building up to something important that is presently evading me, and that I should pay more attention.

Do the results of your experiments lead you to a definitive hypothesis?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 27/07/2016 06:00:03
I think I'm going to have to start at the very beginning of your  YouTube experiments and watch them all in one go... I get the impression you are building up to something important that is presently evading me, and that I should pay more attention.

Do the results of your experiments lead you to a definitive hypothesis?
Thank you for your appreciation to my work.
Yes, I had some hypotheses to explain results from widely known physics experiments. I think some aspect of currently accepted explanations are unclear or doesn't seem to fit in some phenomena that I know.
The aim of my experiments is to verify those phenomena as first hand observer, and rule out hypotheses that contradict the results.
Currently I have a hypothesis which seems potential to explain those phenomena. I already have in mind a model that can provide a mechanism to explain reflection and polarization, but still need more work to explain refraction.

Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 30/08/2016 11:28:25
I have uploaded my latest video of my investigation on microwave's behavior. This time I demonstrate interference of microwave using two paraffin plates which act as dielectric material. Here we can see clearly the occurrence of constructive and destructive interference of the microwave due to the gap between the plates, related to microwave's wave length.

youtube.com/watch?v=2heUH1a9yYo
I think this experiment hold a key point for building my new theory on electromagnetic wave.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 30/01/2017 06:04:45
My current research in optics and microwave are strongly indicating that refraction is best viewed as multilayer partial reflection.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 12/02/2017 09:40:06
At last I can replicate refraction and internal reflection in microwave using array of metallic cylinders. I'll upload the video soon.
Stay tuned!
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 22/03/2017 05:18:47
I have uploaded new video showing diffraction in microwave frequency.


Basically, the experiment result leads us to conclude that diffraction comes from the material blocking the microwave path. When the obstruction is opaque enough, we find no diffraction. It's similar to my experiment using laser showing non-diffractive obstruction.

This result is not widely known yet.
 
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 22/03/2017 05:22:00
My next videos will explore further microwave behavior when interacting with meta-materials in various shapes and configurations.
Title: Re: How do microwaves behave?
Post by: Bored chemist on 23/03/2017 19:43:50
Have you mistaken this site for your blog?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 24/03/2017 01:14:45
Have you mistaken this site for your blog?
No. I think that this part of the forum is for "Discussion of science experiments on the show or to do at home".
Just read the description of "Science Experiments".
If this is not the right place to share my experiments with other members of the forum who are curious about science, could you please tell me where should I put them?
Title: Re: How do microwaves behave?
Post by: evan_au on 25/03/2017 09:14:48
I watched a few of the experiments, and they illustrate some interesting effects of electromagnetism.

I hope the power of the transmitter is quite low, as microwave exposure has been associated with development of cataracts in the eyes - the lens of the eye has a poor blood supply, and so has trouble keeping at 37C when exposed to microwaves. Maybe just turn on the transmitter for a few seconds while filming, then take a break while planning the next experiment?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 26/03/2017 00:03:08
I watched a few of the experiments, and they illustrate some interesting effects of electromagnetism.

I hope the power of the transmitter is quite low, as microwave exposure has been associated with development of cataracts in the eyes - the lens of the eye has a poor blood supply, and so has trouble keeping at 37C when exposed to microwaves. Maybe just turn on the transmitter for a few seconds while filming, then take a break while planning the next experiment?
Thanks for your advice.
I've measured electrical power consumption of the transmitter in one of my video. It took around 22 mA at 220 V to operate. So the power consumption is around 4.8 Watts, which is much less than average microwave cooker.
Title: Re: How do microwaves behave?
Post by: Bored chemist on 26/03/2017 10:14:38
...
No. I think that this part of the forum is for "Discussion of science experiments on the show or to do at home".
...
A discussion needs more than one person.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 26/03/2017 13:06:45
Which part of my experiments would you like to discuss?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 27/03/2017 01:11:39
Let's start with my latest video demonstrating diffraction. Do you expect that metal plate doesn't diffract microwave, while dielectric materials do?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 27/03/2017 01:18:37
Have you expected vertically polarized microwave to go through a surface which is almost completely covered by metal except for some horizontal thin slits?
Or have you expected that the same microwave cannot go through an almost empty plane except for some vertical wires?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 27/03/2017 02:03:12
Have you expected that a metal plate and a metal grating, can turn linearly polarized microwave into circularly polarized microwave?
Or that the same feature can be done by two rarely arranged metal gratings?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 27/03/2017 02:05:39
Can you explain the behavior of evanescent wave?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 27/03/2017 02:08:01
Or one simple fact that a metal grating can rotate linearly polarized microwave?
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 01/04/2017 14:33:39
I have uploaded three more videos investigating behavior of microwave. This time I use meta-material.
The first is constructing meta-material to demonstrate interference by partial reflector

Second, we emulate refraction in microwave using meta-material, which is a multilayer metal grating

Lastly, reconstructing prism for microwave using meta-material to demonstrate refraction and internal reflection.

NB: This is not an April fool
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 20/04/2017 03:20:18
Here is a new video demonstrating diffraction of microwave using multilayer metal grating, which is a meta-material.

Same as diffraction by normal material, it only occurs when the meta-material is adequately transparent to the microwave.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 21/04/2017 03:50:15
I also uploaded a video demonstrating a non-refractive prism.


According to Fermat's principle of least time, the result shown in the video would mean that the microwave propagates through the prism with same speed as it would in air, or refractive index of the prism is 1.
Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 29/04/2017 06:42:35
My next video try to replicate previous demonstration of refraction by meta-material. Instead of tubular metal, this experiment uses flat metal strip as basic unit of the meta-material. Interesting things are observed, especially apparent refractive index less than 1, which indicates FTL phenomenon.


Title: Re: How do microwaves behave?
Post by: hamdani yusuf on 06/05/2017 09:03:31
The difference between multilayer flat strips in the last video and multilayer metal grating which produces "normal" refraction seems to be merely due to the lack of longitudinal conductor component in the flat strips. So I plan to investigate further about longitudinal propagation in microwave in the next videos.
Do you have any idea about how could this be done?
Title: Re: How do microwaves behave?
Post by: whichosedn51 on 13/06/2017 06:48:39
Thank you for this great information. I was interested always how microwave works :)