Questions in this tag must be answered in a manner that can be understood by a general audience with at most a basic understanding of physics, mathematics and related sciences. Apply it to questions where the asker clearly requests such answers.

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0
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1answer
70 views

Does car colour affect car temperature? [duplicate]

My family will buy a car, so to minimise the car's air conditioning and heating (and thus fuel) costs, how should we choose a car exterior's colour and the interior's colour and material (eg fabric ...
18
votes
5answers
3k views

Does a car consume more fuel when it's raining?

Yesterday my wife asked me that question, and I couldn't answer. Consider a car, in a sunny day, and that is consumes x gallons per mile. Considering that everything is equal, except that it's ...
2
votes
1answer
166 views

Difference between horizon and flatness problems & how inflation solves flatness (w/out math)

Layman here so I'm hoping for an answer for my query that doesn't involve math. I'm reading about inflation and how it solves the flatness and horizon problems. I get that the horizon problem deals ...
2
votes
2answers
182 views

Does decreasing the length of the line between a harness and zip wire increase the velocity at which you travel?

My friend is an instructor at an outdoor adventure centre which has lots of zip wires. The instructor's harness has a shorter line that attaches to the zip wire than the normal harness does and she ...
379
votes
20answers
139k views

Cooling a cup of coffee with help of a spoon

During the breakfast with my colleagues, a question popped into my head: What is the fastest method to cool a cup of coffee, if your only available instrument is a spoon? A qualitative answer would ...
0
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1answer
38 views

Can rotational motion can be reduced to translational motion?

Susskind says that all physics (dynamics of the world) can be described in terms of particle positions and their first order derivatives. Does such translational motion gives rise to rotation?
0
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3answers
104 views

How much does the Earth's population affect the force of gravity? [duplicate]

If everyone on earth except one person were to gather up in one location, say the North Pole, and jump at the exact same time and stay airborne for about 1.5 sec. And that one person who did not jump ...
28
votes
2answers
2k views

What are Stephen Hawking's main contributions to research-level physics?

Without a doubt, Stephen Hawking is the most famous living scientist; indeed, his public visibility in all of history seems to be rivaled only by Einstein and easily eclipses giants of physics such as ...
47
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6answers
5k views

Why does space expansion not expand matter?

REFORMULATED: I have looked at the other questions (ie "why does space expansion affect matter") but can't find the answer I am looking for. My question: There is always mention of space expanding ...
1
vote
0answers
72 views

A model that predicts the universe is finite in space and time

A physics professor talked in a YouTube video about a paper he and his colleagues published. The paper presents a model that ties the mass of particles to the size of the universe. He summarizes their ...
12
votes
1answer
752 views

Which hemisphere am I on?

Inspired by this answer to a question on Puzzling.SE (which contains the old but wrong idea that the Coriolis force determines the direction in which a bathroom vortex rotates, and also an approach ...
3
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2answers
92 views

Food calories vs gravitational potential energy [closed]

Imagine you could use all of the energy you have ever extracted from your food as a source of propulsion. Is the energy contained in the food you’ve eaten over the course of your lifetime enough to ...
41
votes
8answers
3k views

Explaining to a five year old - why don't bubbles run like water

My five-year old daughter was asking about astronauts the other day and why they float in space. After me showing her a few bits on the kids section on the NASA web site I started explaining about the ...
1
vote
0answers
28 views

What forces are involved to enable a rock to skip in water?

Does the surface tension matter or is it something else that is providing the upward force? Can someone explain the phenomenon to me physically?
23
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4answers
5k views

Blowing your own sail?

How it this possible? Even if the gif is fake, the Mythbusters did it and with a large sail it really moves forward. What is the explanation?
137
votes
3answers
40k views

Surviving under water in air bubble

An incredible news story today is about a man who survived for two days at the bottom of the sea (~30 m deep) in a capsized boat, in an air bubble that formed in a corner of the boat. He was ...
10
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3answers
2k views

What has been proved about the big bang, and what has not?

Ok so the universe is in constant expansion, that has been proven, right? And that means that it was smaller in the past.. But what's the smallest size we can be sure the universe has ever had? I ...
2
votes
2answers
112 views

Scientists observe the laws of the physics but, Where do they come from? [closed]

Has anyone ever considered how the laws of physics that we study came into being.
61
votes
5answers
7k views

How literally should you take “The Higgs boson gives other particles mass”?

A standard phrase in popular discussions of the Higgs boson is that "it gives particles mass". To what extent is this a reasonable, pop-science, level of description of the Higgs boson and it's ...
2
votes
1answer
80 views

Why aren't train headlights brighter? [closed]

I suspect a valid scientific, physics answer for this question, because I'd venture that train, insurance companies would've calculated and contemplated this question. Yet the train headlights at ...
6
votes
2answers
931 views

In layman's terms, what is a quantum fluctuation?

What causes it and how does it occur? If you do post some mathematics, please explain what each term means too please.
6
votes
1answer
2k views

Do residents of the Hudson Bay area have more time?

Apparently there is a gravity anomaly in the Hudson Bay Area in Canada: gravity is "missing" or it is slightly less than it is in the rest of the world. Does that mean that things in the Hudson Bay ...
5
votes
1answer
1k views

How could we travel to the nearest supermassive Black hole?

I have just watched a trailer for the upcoming movie Interstellar and started to wonder about some physics involved. In the end of the trailer, they are obviously plunging into a Black hole hoping to ...
2
votes
3answers
1k views

What could we observe if we see a 4 dimensional object and how could it change our physics view about our universe?

My question is little bit philosophical. I would like to explain my ideas with a 2 dimensional universe model. If we had lived in 2 dimensional universe like a plane, What could we observe when ...
0
votes
3answers
2k views

If subatomic particles pop into existence all the time, why don't I gain weight?

Watching Discovery's first episode of the first season of Curiosity (entitled "Did God Create the Universe?" by Stephen Hawking), I heard this information: [...] you enter a world where conjuring ...
13
votes
4answers
4k views

How to explain the weak force to a layman?

I'm trying to explain in simple terms what the weak interaction does, but I'm having trouble since it doesn't resemble other forces he's familiar with and I haven't been able to come up (or find on ...
35
votes
5answers
4k views

Is it possible to have a geostationary satellite over the poles?

My understanding of orbital mechanics is very limited, but as I understand geostationary satellite, they stay in place by having an orbital speed corresponding to the spot they're orbiting over. So ...
0
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0answers
30 views

Required skills for a scientist [duplicate]

I wanna become a scientist, so wanna improve my skill like problem solving etc. Could you suggest me some more skills which I need to improve.
2
votes
0answers
69 views

Are the elements of physics different on the upper deck, of a double-decker bus, than those on the lower deck? [closed]

In this question, I hypothesise an event that affects the entire bus; I'm not asking about menace unique to upper floor passengers, such as an overly high upper floor or hanging objects (because this ...
2
votes
1answer
81 views

Are these guard rails truly strong enough?

I'm lay about physics, but I'd like to learn about it behind this question. A friend criticises and claims that the single strip of traffic barriers (as shown below) would fail and is useless. For ...
4
votes
1answer
185 views

Revisiting the microscopic concept of Touching with some more questions

This question is regarding the amazing answer given by Terry Bollinger at this Phys.SE post. I think this answer is very helpful but i do have some standing questions. He says Once the bonding ...
5
votes
4answers
4k views

Is coherent light required for interference in Young's double slit experiment?

In this Veritasium video, a home experiment is presented which appears to produce a very good double-slit interference pattern with normal sunlight. The experiment is an empty cardboard box with a ...
2
votes
1answer
86 views

Does the Night Mode of the screen display (LCD) save more energy?

In some cases, we can enable the Night Mode (reversing the bright and dark color of the display; such as White Text, Black Background) for the screen display. LCD(Liquid-crystal display) seems to be ...
4
votes
1answer
89 views

Quantum field theory defines its own bounds of applicability

I recall hearing in a lecture something along the following lines: "Due to some intrinsic feature of quantum field theory in general (or maybe it was the standard model?), we know where it is ...
10
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8answers
4k views

Is there a proof of existence of time?

It seems to me that there is no such thing as time. There is only movement in the universe and we compare our own movement to a different object to have a sense of time. It can be a clock or a atomic ...
12
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4answers
8k views

On a hot day, when it's cooler outside than in; is it better to put a fan in an open window pointing inwards or outwards?

If it's really hot inside, but cooler outside; what is the best way to place a single fan to try and cool a room down? I always assumed it would be better pointing inwards (and this thread suggests ...
0
votes
2answers
3k views

Is water considered a substance with low friction or high friction?

Like, for example, rubber is a substance with high friction, as an object with neither high or low friction would easily stop on it, and wouldn't skid. Ice is considered an object with low friction, ...
55
votes
7answers
5k views

The speed of gravity?

Sorry for the layman question, but it's not my field. Suppose this thought experiment is performed. Light takes 8 minutes to go from the surface of the Sun to Earth. Imagine the Sun is suddenly ...
1
vote
4answers
593 views

Can a wave be two dimensional?

I am having a hard time picturing waves, the image that comes to mind is a bobbing device submerged in still water which generates pulses in all directions (similarly in air). Then how can a wave be ...
9
votes
5answers
2k views

Did spacetime start with the Big bang?

Did spacetime start with the Big Bang? I mean, was there any presence of this spacetime we are experiencing now before big bang? And could there be a presence/existence of any other space-time before ...
3
votes
2answers
438 views

Entanglement: Is it possible to prepare and reset probabilities to send information?

I'm pretty certain that the answer to the question in the title is a no, but I don't understand why. I have some basic misunderstanding of quantum processes that I’d like clarified in the form of ...
15
votes
5answers
945 views

Does a magnetically suspended frog feel weightless?

Magnetic levitation has been used to suspend frogs in midair. I was wondering: Does the animal still feel gravitational pull? I mean: Does the frog feel like an astronaut on the ISS, or does he feel ...
1
vote
3answers
722 views

Whats left at the center of the Universe after Big bang?

If you consider big bang. According to that What's left at the center of universe where the Big bang occured?
6
votes
1answer
896 views

How do Zener diodes maintain the potential across their terminals?

My physics book has a topic about Zener diodes being used as voltage regulators in the reverse bias. Well, I'm curious to know how does a Zener diode maintain the potential across its terminals after ...
12
votes
11answers
6k views

Does 'electricity' have mass? Is 'electricity' tangible?

Background: I'm in a legal academic discussion about the status of electronic 'goods' and whether they qualify as 'goods' in the same way a chair and a pen do. In this context (and specifically at the ...
0
votes
1answer
44 views

Does the ground beneath a levitating object change due to the rotation of the earth? [duplicate]

I don't know whether this question pertains to physics. But anyways, here goes... If I were to hover 1m above the ground in a helicopter, would the ground below me change after 1 hr due to the ...
0
votes
0answers
101 views

Intuitive explanation for angular momentum uncertainty?

The basic commutator relation $$[J_1,J_2]=i \hbar J_3$$ of quantum mechanics yields the uncertainty relation $$\Delta(J_1)\Delta(J_2)\ge \frac{\hbar}{2}|\langle J_3\rangle|.$$ However, unlike the ...
1
vote
1answer
232 views

So physicist's really do think the Universe could be a holographic Illusion?

http://www.nature.com/news/simulations-back-up-theory-that-universe-is-a-hologram-1.14328 http://guardianlv.com/2013/12/compelling-evidence-says-our-universe-is-a-hologram/ I thought the holographic ...
2
votes
4answers
92 views

Coherence effect on collecting sun light by mirrors

There are systems that collect sun light in one spot. I wonder, why does it accumulate additively, without destructive interference?
20
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4answers
2k views

Is space “real”, or is it some sort of accepted postulate?

sorry for this very naive (layman) question. What is space? It seems to be every where in the equations of physics (as some sort of postulate or hidden hypothesis). We also have a direct experience ...