Notes on Safety Some of our audience might be children, so make it clear what projects may call for adult supervision. It is best to list even the obvious dangers and point the reader towards ways to avoid or mitigate them.
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2answers
46 views
Solar Eclipse Viewing
I know it is not safe when viewing a solar eclipse to look directly at the sun. I know you can purchase solar eclipse glasses online but how do you make your own solar eclipse glasses that are safe to ...
2
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2answers
66 views
Conservation of angular momentum in helicopter
I have a small RC-controlled toy helicopter with removable tail rotor.
Suppose I remove the tail rotor, hold the tail with my hand, start the rotor until it moves with constant angular velocity and ...
2
votes
0answers
102 views
Why does a coin falls faster when it's flipping as well?
From my experiments with measuring how fast a coin falls, I have consistently measured a faster falling rate for a coin that flips as it falls.
As an example, a coin dropping on its edge from height ...
2
votes
1answer
53 views
Why is the lid of the cookware kept on induction cooker not hot?
Induction cookware cooks food by inducing an electro magnetic field in the ferro-magnetic cookware. Since iron offers a lot of resistance to the current, the current is converted into heat in the ...
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1answer
53 views
Per unit area, is there more heat transfer through the open top of a mug or the side walls?
I had a mug of hot coffee cool too rapidly for my liking the other day, which made me wonder what was the greater contributor to heat loss for a typical open-top ceramic mug: the open top, the walls, ...
6
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2answers
215 views
Why does the sound pitch increase on every consecutive tick at the bottom of a filled cup of coffee?
Since I don't know the proper physical terms for this, I describe it in everyday English. The following has kept me wondering for quite some time and so far I haven't found a reasonable explanation.
...
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1answer
71 views
Are there good home experiments to get a feel for the behavior of yield-stress liquids?
What common household liquids / foodstuffs show Herschel-Bulkley fluid behavior?
I assume tomato soup to be one, since when sloshing it around lightly on a spoon the visible surface moves as one (as ...
1
vote
1answer
81 views
Heat absorbed by a room
How can one calculate the amount of heat absorbed inside a room in a single day using the temperature readings of the day?
If the temperature has to be reduced from 30C to 20C how much heat should be ...
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2answers
46 views
static shock=thermocouple?
I used to live in Boston. Near my complex, there was an apartment complex with lots of our friends. Anyways, that place had faulty heating most of the time; mainly in the corridors. They were pretty ...
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0answers
31 views
Is putting a charged balloon up to a neutral wall polarization AND temporary induction, or just polarization?
Is putting a balloon that is charged up against a wall and having it stick polarization AND charging by temporary induction, or just polarization?
2
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2answers
146 views
Why does hot oil explode when pouring water on it?
I am puzzled to know, What is the reason of hot oil make sound and explode when we pouring water on it?
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1answer
57 views
Why does separating plastic from a cough drop create flashes?
I was tearing open individually-wrapped cough drops in the dark, and noticed that when I pulled apart two adhesive-joined pieces of silvery plastic film, small flashes of light were produced. It was ...
1
vote
2answers
64 views
Simple home pressure experiment: how to understand the dependence on the glass opening?
Suppose you put a drinking glass under water such that it is completely filled with water. Then hold it upside down and slowly raise the drinking glass out of the water. The water in the drinking ...
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4answers
100 views
Is a macroscopic pair where I observe one of them quantum entanglement?
Of what little I know/understand about quantum entanglement can somebody confirm if the following experiment is a good analogy to quantum entanglement of pair of particles? PS: please don't laugh as ...
4
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2answers
109 views
What are the lines visible between two cards held edge-to-edge?
Hold two cards (say credit cards) edge to edge, anything from a very slight
touch to about 1/3 mm separation, in front of any ordinary light
source. When I do this I see several
fine dark parallel ...
1
vote
3answers
72 views
Long-Life High Altitude Balloon
Normally high-altitude balloon experiments end with the balloon popping and the payload falling back down to be reclaimed.
But if a second balloon was attached to the payload, one which was only ...
2
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1answer
66 views
What tests can I do at home to identify a metal?
Regarding a question on another Stack Exchange site which identifies a weighted Lego brick to be some kind of metal, I wanted to know how to identify a metal, perhaps limited to household objects like ...
4
votes
1answer
87 views
How can there be a path to ground with thick shoes and a carpet?
I'm connecting a test light to one pin of an halogen lamp. When I touch the metallic part on the back of the test light, the light glows, as it is supposed to. However, I have thick shoes and I am ...
9
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4answers
545 views
Why does the water rise?
It's a very popular experiment (eg), from elementary school : put a burning candle on a dish filled with water, cover the candle with an inverted glass: after a little while, the candle flame goes ...
3
votes
1answer
138 views
How does a piece of paper manage to pump out the water from a bowl
When we go to bed at home, we started to put a bowl of water on the radiator (the air gets a bit dry).
By instinct I put a soaked piece of paper (e.g. toilet paper) into the bowl and let it touch the ...
6
votes
1answer
176 views
What are the specific requirements for a do-it-yourself quantum double-slit experiment?
I was shocked to recently learn that the double-slit experiment is not only possible to do with completely ordinary equipment (with photons of course), but it actually looks rather easy. This is from ...
4
votes
4answers
148 views
Applications of recoil principle in classical physics
Are there any interesting, important or (for the non physicist) astonishing examples where the recoil principle (as special case of conservation of linear momentum) is applied beside rockets and guns?
...
4
votes
2answers
193 views
Is a given volume of sparkling water lighter or heavier than the same volume of still water?
I can see it two ways - if all the $CO_2$ has turned into bubbles I would imagine it is lighter. However dissolved $CO_2$ atoms are probably heaver than the $H_2O$ atoms they replace, or fit in ...
2
votes
1answer
151 views
How to set up a very simple experiment in optics?
This might come across as a very rudimentary question.
My fundamentals of Optics are weak. In the optics chapter of my physics text book I saw diagrams each depicting an object on the left and a lens ...
10
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1answer
406 views
Home experiments to measure the RPM of a pedestal fan without special equipment?
Is it possible to determine to an approximate degree, the revolutions per minute of a fan, for example a pedesal fan pictured below, without using some electronic/mechanical measuring device?
One ...
4
votes
1answer
563 views
Does tea stay hotter with the milk in it?
A little thought experiment, similar to this one: Imagine you are making a cup of tea when the door bell rings. You've poured the boiling water into a cup with a teabag in it. As you're just about to ...
10
votes
3answers
743 views
How does paper make sound when it is torn?
We know that from our experience when we tear up a piece of paper, we can hear a characteristic sound. What is the underlying mechanism behind it? What do the dominant frequencies (edit: I don't mean ...
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0answers
321 views
The Physics of Paper [closed]
Paper, one of the most common material for scientists that exhibits many strange behaviours.
Here are some intriguing questions about paper and my own answer for them.
1. Why wet spots are dark/more ...
2
votes
3answers
158 views
Partially polarized light in laboratory
Does anybody know a way to create (in laboratory, but with no super-sophisticated equipement) a beam of light with partial linear polarization whose degree of polarization can be adjusted (at least ...
2
votes
1answer
81 views
How can I calculate how long to keep my beverage chilled?
The problem is simple, I suppose...
I have a beverage at room temperature (let's say 23°C) in an aluminum can (it's a Barq's root beer.) I want to put it in a freezer (let's say it's at -17°C). How ...
2
votes
2answers
1k views
How do you magnetize an object?
How would i go about magnetizing something? specifically, a whole buch of bb's. i'm wanting to try this so that i could make a (hopefully) cheaper version of bucky balls. but if not it'd at least ...
8
votes
2answers
527 views
The Galileo thermometer: why do the bubbles float in the middle of the tube?
If the water were uniform temperature, it would have uniform density, so a bubble should either be all the way at the top (if it's lighter than water) or all the way at the bottom (if heavier). But in ...
5
votes
8answers
286 views
Example of a time varying function which can be easily measured
My sister is in 10th grade. She doesn't seem to understand the concept of time varying functions (current, light, sound wave forms etc). I explained her in easiest possible terms. She got it but not ...
6
votes
2answers
381 views
How to count photons
How are photons counted?
What is the experimental setup used to count photons from a laser or even a lamp? Of course, in the case of the lamp, I would be able to count only the photons that pass ...
2
votes
2answers
416 views
Black hole analog experiment?
This question is directed mostly at people giving lectures on black holes, but input by other physicists or students is very much appreciated.
Do you know a good (home)-experiment with a black hole ...
8
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7answers
1k views
Why is a 1mW laser dangerous?
In our Physics lab we have a 1 milliwatt (0.001W) helium neon laser. Despite the low power, we were cautioned not to even look at reflections of the beam as it could cause permanent eye damage - why ...
2
votes
4answers
315 views
How would you design an experiment to grok optical phenomena?
I've been toying with the idea of making a 3D scanner that uses an IR distance sensor to find position vectors of an object in space and then translates that into a 3D computer model.
One of the ...
11
votes
5answers
645 views
Home experiments using wireless LAN or mobile phones about electromagnetism
Are there any nice experiments using wireles LAN access points or routers or mobile phones to demonstrate physical features of electromagnetic fields, especially em-waves?
More precisely I am ...
12
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3answers
831 views
Home experiment to estimate Avogadro's number?
How to get an approximation of Avogadro or Boltzmann constant through experimental means accessible by an hobbyist ?
22
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13answers
6k views
Home experiments to derive the speed of light?
Are there any experiments I can do to derive the speed of light with only common household tools?
11
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4answers
960 views
How can I measure the mass of the earth at home?
How can I measure the mass of the earth at home?
How was the mass of the earth first measured?
5
votes
2answers
361 views
What are insightful/impressive experiments for adults
Similar to this question: what experiements do you think are impressive for layman adults?
I for example like how you can simulate an Einstein Ring with the bottom of a wine glass.
11
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9answers
661 views
What are good mechanics experiments for 10 year olds?
I'm trying to explain elementary mechanics - without the benefits of calculus or even algebra - and struggling. I'd like to find reasonable ways to demonstrate Newton's laws, minimally, and possibly ...
