Ask any question you want about Physics

originally posted by: LanceCorvette
If I'm traveling at the speed of light, and I turn on a flashlight, won't the light from the flashlight going out ahead of me be moving faster than the speed of light?

No. It's weird, but true. Firstly, you can't travel at the speed of light but you could come close, like 99%. If you did that, from your point of view, the flashlight beam would appear to go forward away from you just as fast as it ever would.

From somebody else, who is relatively 'stationary' according to some definition, it would appear that you are going 99%, and the light beam is going forward just a little bit faster.

If I'm traveling at the speed of light, and you're traveling toward me at the speed of light, won't our relative speeds be faster than the speed of light?

Yes, in the reference frame of somebody at rest relative to both of them, but that doesn't really make a difference.

From each of your viewpoints, the other would be going in at 1x the speed of light.

originally posted by: mbkennel

originally posted by: LanceCorvette
If I'm traveling at the speed of light, and I turn on a flashlight, won't the light from the flashlight going out ahead of me be moving faster than the speed of light?

No. It's weird, but true. Firstly, you can't travel at the speed of light but you could come close, like 99%. If you did that, from your point of view, the flashlight beam would appear to go forward away from you just as fast as it ever would.

From somebody else, who is relatively 'stationary' according to some definition, it would appear that you are going 99%, and the light beam is going forward just a little bit faster.

If I'm traveling at the speed of light, and you're traveling toward me at the speed of light, won't our relative speeds be faster than the speed of light?

Yes, in the reference frame of somebody at rest relative to both of them, but that doesn't really make a difference.

From each of your viewpoints, the other would be going in at 1x the speed of light.

The theory says that, theory that takes as the first postulate that the speed of light is fixed and is same all over the Universe and in each reference frame, secondly, it assumes, no mass can ever reach that speed.

Theory and not THE TRUTH !!!

Marry Christmas

a reply to: Arbitrageur

Maybe somebody asked you this before...if so, please direct me to the answer you gave.

The flat earth theory is very actual at the moment and I think it is fascinating. I have an open mind for almost everything. The other day somebody asked me to explain why the earth is not spinning from under me when I hover in the air. The Earth is spinning some 1000 mph at the equator.

My question is why the earth is not spinning from under me if I hover with an helicopter straight up for some...lets say.. 10 minutes?

Thanks for your explanation in advance..

PS. Probably a simular explanation... Why am I not chasing my destignation on the planet if I fly with an airplane 300 mph in the same direction the earth is spinning.

originally posted by: zatara
The other day somebody asked me to explain why the earth is not spinning from under me when I hover in the air.

Here's a clue - it's exactly the same reason Bugs Bunny can't save himself by stepping out of a crashing plane just before it hits, or by jumping up in a falling elevator just before it hits bottom.

Never mind.

originally posted by: zatara
a reply to: Arbitrageur

Maybe somebody asked you this before...if so, please direct me to the answer you gave.

The flat earth theory is very actual at the moment and I think it is fascinating. I have an open mind for almost everything.

Having an open mind is great. Having a mind so open your brain falls out? Not so great as Carl Sagan used to say. Sure we should be open to the possibility the Earth has different shapes and we should be able to figure out how to tell which shape is true. There are plenty of clues like we see the moon is a spherical object. Maybe without a telescope it looks like a flat disk but with a telescope it looks more like a sphere and that's the easiest way to explain the phases of the moon, and when you see the earth and moon eclipse each other and other facts the flat earth idea becomes one of those ideas that you considered, but rejected, even before we had photographs of the spherical Earth taken from space which should have settled the question.

The other day somebody asked me to explain why the earth is not spinning from under me when I hover in the air. The Earth is spinning some 1000 mph at the equator.

My question is why the earth is not spinning from under me if I hover with an helicopter straight up for some...lets say.. 10 minutes?

What is keeping the helicopter airborne? Lift from interacting with the air, right? How fast is the air moving with respect to the Earth's surface? Well if the surface was moving at 1000 mph and the air wasn't moving at that speed you'd have winds of 1000mph, right? Do you have those at the equator? Last time I was at the equator the wind was blowing about 10-15mph which means the air was moving at that much different speed than the Earth's surface or somewhere between 985 to 1015 mph for the sake of this example though the 1000 mph is just a rough estimate so those figures aren't precise.

When you jump up in the air at the equator do you suddenly feel a 1000 mph wind? No. But if you did jump up and then didn't move along with the air and the surface, that's what you'd feel and I don't know if humans can even survive that. Wind tunnel tests were planned up to 500mph to see if humans could survive that and even 305 mph completely overpowered the people and blew their heads back (the neck muscles weren't strong enough to fight that) and the tests had to be aborted at 441 mph because they thought going up to 500mph as planned would injure the test subjects.

originally posted by: Bedlam
Here's a clue - it's exactly the same reason Bugs Bunny can't save himself by stepping out of a crashing plane just before it hits, or by jumping up in a falling elevator just before it hits bottom.

Running out of gas right before the plane crashed saved him, check out the ending of this though he's not really following the laws of physics in the rest of it either:

Looney Tunes : "Falling Hare" ( Featuring Bugs Bunny)


I think the video games kids play today with physics engines in them probably teach kids better physics than bugs bunny ever did.

Hey smarter guys than me, any thoughts on this post? Any substance to this? Thanks

originally posted by: humanityrising
Hey smarter guys than me, any thoughts on this post? Any substance to this? Thanks

I can't say everything in there is completely wrong, such as a roughly stated explanation of the "vacuum catastrophe". People like to cite that unsolved problem in physics and infer that if mainstream science can't figure that one out then any alternative idea they can come up with is fair game. It doesn't quite work that way.

Let's talk about the mass of a proton, according to mainstream science and then according to one of the sources cited, Nassim Haramein and his infamous Schwarzschild proton:

Haramein Response to Bobathon

-Mass of an actual proton: 1.67 trillionths of a trillionth of a gram

-Mass of Schwarzschild proton: 885 million metric tonnes

These aren’t particularly close.

That's more than a slight discrepancy, would you agree? But wait, what if the mass of a proton is actually the mass of the universe? Did you read that in the link you posted?

This explains the occult, mystical states, mass consciousness/collective quantum coherence, archons, morphic resonance, cosmological evolution, and more.

So - each proton contains the mass of the Universe holographically, however only a tiny amount is expressed locally, the rest is instantly distributed throughout this wormhole network of space.

At least he gives some reason why scientists measure the actual proton mass as 1.67 trillionths of a trillionth of a gram, since "only a tiny amount is expressed locally", which is more than I can say for Nassim Haramein's 885 million metric tonnes figure and the fact that I can't even follow his explanation for why the actual measured mass of 1.67 trillionths of a trillionth of a gram doesn't falsify his postulate. Still, to suggest that even holographically the mass of a proton is the mass of the universe would seem to have no evidence to support it that I'm aware of.

There is such a thing as a Holographic Principle in string theory and it's taken seriously though as my signature hints there are some issues with string theory not being an actual theory but some speculative ideas which haven't been experimentally confirmed.

Since the technical ideas are somewhat advanced and as some laypeople commented appear to be over their heads, here's something I've noticed from experience is usually true:

If you read something that says it explains the occult and mystical states as this does in the heading, it's time to put on your hip waders because the pseudo-scientific BS is about to get very deep. The occult and mysticism are really variations on the concept of magic, which in a sense is the antithesis of science which tries to explain the natural world without any magic. So I propose that if you apply that concept to the subject matter you probably don't need to know the technical details because a scientific explanation of magic would be a contradiction (referring to real magic, not what illusionists do).

The title even includes Morphic resonance.

Most of Sheldrake's ideas are clearly pseudoscientific nonsense. Morphic resonance is extremely vague and ill-defined, and can only really be described as whatever Sheldrake says it is. Crucially, it is not falsifiable, and therefore not testable (although some have tried).

Sheldrake's 2012 book, The Science Delusion, is an anti-scientific rant in which he applies postmodernist hyperscepticism to conventional science, accusing mainstream scientists of adhering to "scientific dogmata", such as the constancy of the speed of light. Ironically, Sheldrake fails to apply any sort of scepticism to his own ideas, which he promotes uncritically, despite there being no evidence for them.

From my perspective the author casts doubt that he will contribute anything scientifically useful in an article when the title includes morphic resonance, occult and mystical states, so unless those are part of your religion I'd suggest just moving on to something else if you see those in the title and are looking for something with scientific validity.

a reply to: Arbitrageur

Thank you very much for taking the time to look into this, and for your measured response

originally posted by: Arbitrageur
People like to cite that unsolved problem in physics and infer that if mainstream science can't figure that one out then any alternative idea they can come up with is fair game. It doesn't quite work that way.

When I was a yoot, a particular problem bothered me. It might also lead you to think 'why is a teenaged farm kid whose own parents classify him as a 'blunt object' thinking about this sort of crap while he's stretching barbed wire on the back forty with a comealong'.

Consider:

You are a magic being who can do all this nuclear level doing and omniscient observing, so it's a sort of thought problem:

You take a kindly, innocent pair of metal spheres, let's imagine them as BB sized and 1cm apart center to center, floating in a magic perfect vacuum. They're electrically neutral with 0 volts difference between them, as close as you can get with discrete charges. Not nearly as bad as a spherical cow so far.

Other than your admittedly perfect test system, the rest of the universe is as given.

You state in your God voice: "Let electrons from Sphere A be transferred to Sphere B in such quantity that an electric dipole is formed. And for the purposes of this demo, let there be 1kV potential difference between them, and let this electron migration occur in delta time to minimize quibbling about ramp times. So it is stated, so it is done. Sim Salabim!"

And it is so. In the time that light flies between the spheres, plus delta to satisfy Einstein, a gob of electrons cease to exist on sphere a and are now on sphere b. A dirt common electric dipole is formed. There is now a mechanical potential energy created between the two spheres, and they begin to attract each other, but do not move or deform because they're magic, and I'm excluding small local effects as the local test deity.

As instantly as anything seems to occur, the new little dipole begins to radiate an electric field. Starting in the area around the little spheres, an electric field balloons out to embrace every charged particle in the area. And this sphere of electric potential gradient grows rapidly at the speed of light in the local medium, depending on the local permittivity. As it does, every charged particle it passes suddenly develops both mechanical and electrical potential energy with relation to the test dipole.

If it took me x amount of energy to create the dipole, and that energy is well defined and calculable, what's the source and eventual limit of this ongoing flood of OTHER electric and mechanical potential that's accruing as the cube of the time elapsed, if the distribution of matter in the universe is more or less isotropic? And why don't I see any of that if I measure the energy I get back if I let the electrons migrate back to sphere a?

a reply to: Bedlam

Dipole fields drop very quickly with distance (r^3). Nearby charge distributions will adjust to cancel the field (faraday cage).

To state it more generally, the system will adjust to maintain equilibrium (isotropy etc). This is also known as the principle of minimum energy.


The experiment is more interesting with gravity, because it can not be canceled and you quickly arrive at things like the Mach principle.

originally posted by: moebius
a reply to: Bedlam

Dipole fields drop very quickly with distance (r^3). Nearby charge distributions will adjust to cancel the field (faraday cage).

To state it more generally, the system will adjust to maintain equilibrium (isotropy etc). This is also known as the principle of minimum energy.


The experiment is more interesting with gravity, because it can not be canceled and you quickly arrive at things like the Mach principle.

They drop off quickly, but there's a big squad of charged particles in a universe. And, still, the issue I have is, I put in x amount of energy to create it, but it keeps on adding more (?) as time passes. I also considered weird setups like a lot of charged particles in the area fairly nearby.

There's a magnetic field version of the problem, and as you mentioned, I soon started wondering about gravitic versions of it. And then the more oddball outliers - if you create the dipole, and the field starts to radiate, then you remove the dipole, you have a sort of shell of electric field moving out - what do charges have potential energy TO when the thing itself is gone? Which progressed to if I have an electron 'broadcasting' an electric field, and other particles in the area have potential energy to it, if a positron comes along and obliterates it 1) what happens to the field lines? They have to start and end on a charge according to theory - only one of the charges is now suddenly gone. 2) what happens to the potential energy?

I'm sure there are all decent answers. But as a yoot I used to think long long thoughts about this sort of thing while doing menial tasks, especially once I started worrying about the dynamic problems where you have a shell of field propagating away from something that's gone.

a reply to: mbkennel

Yes, if you could observe someone orbit Earth at 99% light speed, their bodily movements would look as slow as molasses.

They experience moving normally though, flashlight working normal, but Eath is a blur, as they make about 5 revolutions per second.

If you reached 100% light speed, time would pass infinitely fast, so the universe would end instantly. You would be a literal statue for eternity.

How does this work?

originally posted by: Bedlam

And it is so. In the time that light flies between the spheres, plus delta to satisfy Einstein, a gob of electrons cease to exist on sphere a and are now on sphere b. A dirt common electric dipole is formed. There is now a mechanical potential energy created between the two spheres, and they begin to attract each other, but do not move or deform because they're magic, and I'm excluding small local effects as the local test deity.

As instantly as anything seems to occur, the new little dipole begins to radiate an electric field.

And the radiation stops as soon as the electrons come to rest in their new position. There is a pulse of EM disturbance traveling out at c, but quiet behind it.

To have ongoing dipole radiation you need to oscillate the dipole moment continuously, and when you push on the dipole there is some resistance and thus you have to expend work to make that oscillation happen and that energy can be transmitted to the radiation field.

Starting in the area around the little spheres, an electric field balloons out to embrace every charged particle in the area. And this sphere of electric potential gradient grows rapidly at the speed of light in the local medium, depending on the local permittivity. As it does, every charged particle it passes suddenly develops both mechanical and electrical potential energy with relation to the test dipole.

If it took me x amount of energy to create the dipole, and that energy is well defined and calculable, what's the source and eventual limit of this ongoing flood of OTHER electric and mechanical potential that's accruing as the cube of the time elapsed, if the distribution of matter in the universe is more or less isotropic? And why don't I see any of that if I measure the energy I get back if I let the electrons migrate back to sphere a?

When you move the other charges, the EM energy in the field from the first transmitted EM wave dissipates, e.g. if the charges were in matter and hit it. If they were free, then it is a plasma and there is re-radiation, but the global sum of KE and field energy, and likewise for momentum is conserved. It's somewhere in Landau & Lif#z.

originally posted by: AutonomousMeatPuppet
a reply to: mbkennel

Yes, if you could observe someone orbit Earth at 99% light speed, their bodily movements would look as slow as molasses.

if we could observe someone orbit earth at 99% light speed wouldnt it be bad for the neck?

originally posted by: AutonomousMeatPuppet
a reply to: mbkennel
Yes, if you could observe someone orbit Earth at 99% light speed, their bodily movements would look as slow as molasses.

originally posted by: choos
if we could observe someone orbit earth at 99% light speed wouldnt it be bad for the neck?

There is no such orbit around Earth. You can plug any altitude in this earth orbit calculator to get the orbital velocity and never get anything close to the speed of light.
www.calctool.org...

But if you re-word "orbit Earth" to "travel past Earth" then the comment is on the right track, though it's unlikely such velocity will be attained by human beings and even if it was it might be fatal due to radiation. Protons travel that fast and faster past Earth all the time though.

originally posted by: mbkennel
When you move the other charges, the EM energy in the field from the first transmitted EM wave dissipates, e.g. if the charges were in matter and hit it. If they were free, then it is a plasma and there is re-radiation, but the global sum of KE and field energy, and likewise for momentum is conserved. It's somewhere in Landau & Lif#z.

Sounds about right to me. For anyone interested there are links to 8 volumes on archive.org, but only 7 of them work (Volume 5 link has been removed):

Our beloved Landau-Lif#z books are available online. For free!! (archive.org)

a reply to: Arbitrageur

Yeah, I thought about mentioning something like that.. just ignore the fact that centripetal force would rip their head right off

How is thrust possible in the vacuum of space? If thruster ejections are met with no resistance, wouldn't the object stay perfectly still?

originally posted by: humanityrising
How is thrust possible in the vacuum of space? If thruster ejections are met with no resistance, wouldn't the object stay perfectly still?

You've probably heard the expression "that's pretty simple, it's not rocket science", right?

Your question IS about rocket science so maybe it's not so simple as that expression infers. Here's an experiment which may help you understand how it works. Watch this video starting at 7 minutes 30 seconds and you'll see a big pistol firing a big round with nobody holding it. The bullet leaves the gun in one direction, and what happens to the gun? Watch and see:

How Far Will Recoil Throw a Gun if You Aren't Holding It?

If you can figure out why the bullet moves one way and the gun moves the opposite way, that's sort of how rocket engines work, except a rocket fires out exhaust gases instead of bullets but just like the gun moves the opposite direction of the bullet, the rocket moves in the opposite direction of the exhaust gases.

In that demonstration at 7:30, there's really nothing to push against since nobody is holding the gun. Earlier in the video they try holding the gun and then it's pushing against people's hands so hard they complain about how much it hurts, but when they don't hold it, the gun takes off, analogous to the way a rocket works.