for questions about design, process, data, or analysis of experiments and observations.

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1answer
123 views

Error calculation for experimental data

I have the list of experimental values: $$\{w_i \pm \Delta w_i\},$$ where $w_j$ is a mean value and $\Delta w_i$ is an error. I want to calculate the second list $\{a_i \pm \Delta a_i\}$ according to ...
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0answers
29 views

Simple question relating to physics prac reports

I am writing a physics practical report relating to the elasticity of materials relating to their momentum in a collision. I have values for the elasticities that are all within 2% of each other but I ...
2
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1answer
56 views

Why can't a high intensity beam be injected into the LHC when the machine is empty

Watching this YouTube video about the LHC at around 3 minutes and 50 seconds into the video the narrator says... For machine protection reasons we are not allowed to inject a high intensity beam ...
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0answers
54 views

Understanding Millikan's oil-drop experiment

This is quoted from A.P. French's Newtonian Mechanicsabout Millikan's oil-drop experiment: The droplets randomly produced in a mist of oil vapor are of various sizes. The ones that Millikan found ...
2
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0answers
39 views

Problem on Einstein - de Haas experiment

I am a Physics student (4th year) and I'm trying to study the Einstein - de Haas effect in laboratory. That is what I got: a suspended Iron cylinder with about 5 cm height and a radius of 0.8 cm is ...
2
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2answers
157 views

What exactly is meant by saying that two events had been “simultaneous in an inertial frame”?

In order to address my question based on a concrete example setup let the following two separate events be given: participants $A$ and $J$ encountering each other in passing (additional participants ...
3
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0answers
15 views

How can the effects of temperature be accounted for in-situ electrical resistance corrosion monitoring?

In reading the Berkeley Lab's article Rust Never Sleeps, where research is underway investigating the use of iron oxide rust as a photovoltaic, they state: Rust – iron oxide – is a poor conductor ...
6
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1answer
122 views

Has anyone experimentally shown the quantized thermal hall conductivity in Quantum Hall systems?

For background: In a $D=2+1$ state with edge modes described by a chiral $( c_L \neq c_R )$ CFT there is a predicted thermal Hall conductance associated with the gravitational anomaly at the edge. ...
3
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4answers
3k views

How many digits of Pi are required in physics? [on hold]

In other words: which physics experiment requires to know Pi with the highest precision?
1
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5answers
226 views

Normal distribution of x, xdot [on hold]

I have some real measurements from a process and I happened to look at the mutual distribution of (x(t), xdot(t)). I found that they seem to follow 2d normal distribution around (mu, 0). See image, ...
3
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3answers
356 views

What would happen to me if I was in the LHC while it was running? [duplicate]

This is possibly a stupid question, but one I have been always wondering. What would happen to me if I was in the center of the Large hadron Collider while it was running? Would the energy of the beam ...
2
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2answers
36 views

Is this a possible monopole setup, or will it cancel out? [duplicate]

Suppose you have a ball that is covered in magnets, in which the North Pole of every magnet faces outward. Is this a monopole? Or at least "functions" as a monopole? And what will happen if you placed ...
11
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1answer
356 views

Quasi 1D insulators with strong spin-orbital interaction

We know that the spin-1 chain realizes the Haldane phase which is an example of symmetry protected topological (SPT) phases (ie short-range entangled phases with symmetry). The Haldane phase is ...
0
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0answers
23 views

Ratio between power of chaotic and regular airflow

Turbulent field is created as a result of an impact of an airjet on an edge (the flow velocity is high enough). The field of velocities have a regular and a chaotic component. What I need is to ...
10
votes
2answers
941 views

Methods to Stabilize and Maintain Extremely Low Humidity in a Lab Environment

My atomic physics lab is in a building that experiences huge swings in humidity levels during the year due to the monsoon season Our building provides temperature, but not humidity control. Using ...
7
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0answers
39 views

What's the smallest height difference over which gravitational time dilation has been experimentally observed?

In a famous experiment, reported in Optical Clocks and Relativity. CW Chou, DB Hume, T Rosenband and DJ Wineland. Science 329 no. 5999 pp. 1630-1633 (2010); NIST eprint. and nicely described in ...
2
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1answer
270 views

Why are mass flow rates found using Venturi meter and pitot tube different?

Regarding an experiment to find the mass flow rate of a fluid (air) using a venturi meter and a pitot tube: What could be the cause of a variance in results obtained using the 2 instruments mentioned? ...
1
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2answers
34 views

Experimental verification of bound state transition times

I am trying to reconcile, what to me at least, are two slightly different answers to what I think is the same question. The first answer below to an earlier OP implies to me that there is a definite ...
4
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2answers
631 views

Do the copper connectors we used in measuring the resistance of a wire contribute to the said measurement?

We measured the resistance of a wire by setting the multimeter to ohmmeter mode and connected the ends of the ohmmeter to the ends of the wire; and we also calculated the theoretical value using a ...
1
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1answer
87 views

Is fluorescence from a single atom/ion visible with the naked eye (e.g. in a strongly coupled trap or cavity)

I remember sitting in on a conference talk by a person (possibly Rainer Blatt) doing research with trapped ions (or single atoms strongly coupled to light in an optical cavity), and the person showed ...
3
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1answer
67 views

Why do electrons in a superconductor lack energy to produce “massive” photons

My two questions are based around looking for a good, simple (if possible) explanation of the Cooper pair effect in superconductors. I follow the idea that, in intuitive terms, "a Cooper Pair" ...
11
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1answer
210 views

What is the relationship between Faraday cage mesh size and attenuation of cell phone reception signals?

This is related to the question how can electromagnetic waves reach a cell phone in faraday cage?, where in the answer it was stated that the holes (=size of the mesh) would need to be smaller than ...
0
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0answers
11 views

How to understand the uncertainty of quoted value of cosmic black body radiation?

Geiner's Quantum Mechanics - An Introduction quotes a alue of cosmic black body radiation, "$2.65 \pm 0.09 K$". How to understand this uncertainty? I have undergraduate mathematics degree and are ...
1
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1answer
125 views

Truck driven from a small motor that can carry a heavy load, yet can travel fast. [closed]

I am building a truck from trash as materials. I have one small motor and a a few small gears, but no other engineered materials are allowed. The truck must carry a load for a distance of 3m. The ...
3
votes
1answer
60 views

The actual space curvature

What is the curvature of our physical space, according to the latest experimental data? I've found it somewhat difficult to find a definitive answer to the question, because the spacetime curvature ...
5
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1answer
63 views

Charge of a moving particle [duplicate]

Is there an experiment that measures the electric charge of a moving particle, therefore proving "experimentally" that it is indeed the same as a static particle?
5
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2answers
111 views

Determining the refractive index of a foil

(59th Polish Olympiad in Physics, final stage, experimental part, 2010) You have at your disposal: a sample of blue foil of a homogeneous material, placed between two glass panes in a ...
1
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2answers
46 views

What happens when both of Polarizing filter in LCD screen are Horizontal

What would be the result if we replace the vertical polarizing filter in LCD device (screen) with a horizontal filter, what could we see exactly? Would we see the same if we use only one horizontal ...
0
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2answers
30 views

How to measure the range of a horizontal projectile?

For an experiment, I'm launching a projectile horizontally to determine the relationship between height and range. Pretty basic stuff. But I'm having trouble coming up with an effective way to measure ...
1
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2answers
38 views

Does the gravitational force of one object interfere with that of another?

Assume we have two iron spheres, Sphere A and Sphere B, with identical masses floating in the vacuum of interstellar space separated by some distance from each other. The gravitational force of each ...
1
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1answer
107 views

Upper limit to electric charge confinement?

The following questions are not intended for conventional capacitors (which stores excess charge on the outside surface), rather a type of hypothetical capacitor which is designed to confine charge by ...
6
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4answers
3k views

What experimental proof has been found of Einstein's theory?

As a casual science reader, I've always found the implications of relativity (inconsistent clocks after near-light-speed travel and various space-time paradoxes) to be confusing and magical-sounding. ...
11
votes
2answers
770 views

How is the number of electrons in an atom found?

I was wondering, what type of experiments were held to identify the number of electrons in an atom? (For example, how do we say that carbon has 6 electrons and magnesium 12.) I would like someone to ...
1
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2answers
56 views

How do we know that the Law of Cooling is true?

According to James Stewart's Calculus book (exercise 14, page 609), Newton’s Law of Cooling states that the rate of cooling of an object is proportional to the temperature difference between the ...
3
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1answer
121 views

Motion in a Paul trap: $2n^{\text{th}}$ harmonic with larger amplitude than $n$th harmonic

Using a Paul trap, we captured the motion of a light charged particle (based on a rotating potential applied by AC current). Our rotational frequency was 50 Hz, and so when used FFT on the data, we ...
1
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0answers
32 views

Kirchoff's voltage law doesn't seem to hold in an experiment conducted with series resistor, diode and signal generator

I've conducted an experiment to look at the electronic characteristics of a diode. This was done using a series diode, resistor ($R$) and signal generator. The signal generator was made to supply a ...
0
votes
1answer
52 views

Does it take more effort to move against earth's rotation?

I know that if we stand still, we are traveling at 0 m/s relative to the Earth. But if we move against the rotation of the Earth we lower our speed, so, wouldn't we have to fight against the ...
0
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0answers
20 views

What have we built? A resonant loop antenna? Rhombic?

Some background, my partner and I have built an antenna we are supposed to characterize for an assignment, and compare it to physical predictions. However, we don't know what type of antenna we have ...
5
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2answers
353 views

5 sigma result proof for particle discovery

Source: Carrolls : "Particle at The End of The Universe" P. 177 I am just checking my understanding of Carroll's point about "a 5 sigma result being the gold standard" of experimental proof. ...
10
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1answer
161 views

Does my green laser pointer emit three distinct frequencies, or is my measurement flawed?

I was playing around with a cheap diffraction grating and my set of laser pointers, and I noticed that while the red and the blue pointers produce a single point in the spectrum, my green laser ...
1
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1answer
33 views

Could satellites achieve orbit using current laser technology

My question is, could we, using current laser technology sufficiently scaled up, launch a lightweight, say a GPS navigation satellite, into earth orbit? The main objection to me is maintaining the ...
0
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2answers
22 views

Capillary action and its limitations

From Wikipedia Capillary Action Thus for a 4 m diameter glass tube in lab conditions given above (radius 2 m), the water would rise an unnoticeable 0.007 mm. However, for a 4 cm diameter tube (radius ...
1
vote
1answer
275 views

Questions about MTW's “thousand” tests of the Einstein principle

In Misner, Thorne, Wheeler (henceforth written as "MTW"), "Gravitation", Box 16.4, there's an experimental setup construction (or method) presented by which "Each geodesic clock is constructed and ...
2
votes
1answer
216 views

Rutherford Experiment - practical and theoretical questions

I performed the Rutherford experiment the other day, using Au thin foil of $2\,\mathrm{\mu{}m}$, a source/gun of α particles (241Am) and a detector/counter. α particles were shot from the source ...
2
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2answers
72 views

Show that a photon cannot transmit its total energy to a free electron. Contradiction with Photoelectric effect?

This is a problem in my textbook and I've shown it this way: $E_{initial}=\frac{hc}{\lambda} + mc^2$ $p_{initial}=h/\lambda$ After collision with photon having zero energy we get ...
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1answer
18 views

Explain an experiment: airstream between two hinged curved surfaces

Please, see the following video (the experiment starts at 3:40 and ends at 3:55): https://www.youtube.com/watch?v=7pB6q_bH35s&feature=youtu.be&t=216 The basic idea: given 2 curved surfaces ...
9
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2answers
711 views

Mechanical Equivalent of Heat

Recently I have been looking up James Joule's experiment regarding the mechanical equivalent of heat. After viewing some drawings of the apparatus, I assumed that the lines holding the weights would ...
6
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3answers
209 views

Are there any Meson colliders?

There are no stable mesons as far as I know. Are there any meson-colliders analogous to for example proton-proton colliders? Edit: This edit was made more than a year after the original question was ...
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2answers
1k views

Difference between Vernier constant and least count

What is the difference between the Vernier constant and least count of a Vernier caliper?
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0answers
26 views

How much does barometric pressure change over minutes?

I have to correct an ongoing experiment for atmospheric pressure. This means that during the experiment I must read a chip that measures barometric pressure. The question becomes one of how rapidly I ...