Ask any question you want about Physics

originally posted by: sapien82
Well I suppose it just reinforces the idea that consciousness is not inside the human body when you get KO'd like someone pulling the plug to the wifi receiver .

Except you can drastically alter consciousness function by altering the brain. If the brain was just a receiver, that's like saying I can change the characters in the play on my TV just by messing with the electronics, which is patently absurd.

originally posted by: Arbitrageur

originally posted by: Hyperboles
Question.

First you ask this:

Why does a pendulum slow down at the equator as compared to the poles?

Then you say this:

originally posted by: Hyperboles
what i mean is ,both the observer and the pendulum is in the same reference plane at the 2 respective locations and the observer is measuring the period of the pendulum with a mechanical stop watch at both the locations

I don't know what you mean by "reference plane". The surface of the Earth is not a plane. Flat earthers may think so but we've taken pictures of the Earth from space and it looks like a big ball, with a curved surface. So a location at the equator is one reference frame and a location at the pole is another reference frame as reference frames are applied in the theory of relativity.

I tried to search for anybody measuring pendulums at the poles and I found this but they were just verifying the Earth rotated and at what rate it rotated. I didn't find where they compared the pendulum period to any others but if you can post a link about some research like that (what you're talking about) I'd find it interesting. As I said I expect the passage of time to be different in those different reference frames, but it would be far easier to measure that with atomic clocks than with a pendulum and a stop watch. The passage of time would be different due to both gravitational and velocity differences.

thanks muchly for your reply. I came across a assertion made by a scientist amadeo giannini in his book lands beyond the poles where he asserts the period of the pendulum increases at the equator because of lesser gravity there. since the book was published in 1956, i dont suppose atomic clocks were in vogue at the time.

originally posted by: Hyperboles
thanks muchly for your reply. I came across a assertion made by a scientist amadeo giannini in his book lands beyond the poles where he asserts the period of the pendulum increases at the equator because of lesser gravity there. since the book was published in 1956, i dont suppose atomic clocks were in vogue at the time.

If that's what he said, he's wrong, or perhaps you misinterpreted what he said.

First, let's clarify that nobody ever measured that pendulum period difference using a stop watch. That measuring system is just not accurate enough for humans to measure the differences we are discussing in any reasonable time period, but there is a theoretical difference which could be measured with atomic clocks.

As mentioned in my last reply, the theoretical difference results from two different relativistic effects:
1. Time speeds up when clocks are put in a weaker gravitational field.
2. Time slows down in clocks traveling at higher velocities relative to the observer.

Gravity is less at the equator, that much is true, but he had the effect on clocks backwards (or you misinterpreted what he said). The effect of lesser gravity at the equator is to make time go faster which means the period of the pendulum would decrease, not increase. The frequency of the pendulum would increase, maybe you got period and frequency confused?

Because of the relativistic velocity at the equator (about 1000 mph due to Earth's rotation), clocks at the equator will have a tendency to run slower due to that effect.

So, in summary, gravitational effects at the equator are tending to make clocks run faster compared to the poles, and velocity effects from the Earth's rotation are tending to make clocks run slower at the equator relative to the poles. To some extent these two effects in opposite directions would partially cancel out but one is probably dominant, probably the gravitational effect though I haven't crunched the numbers to confirm that.

These same two effects apply to objects in Earth orbit. At the altitude of the ISS the clocks run a little more slowly compared to Earth's surface because the velocity effect dominates the gravitational effect at that altitude, but in geosynchronous orbit the gravitational effect dominates so the clocks on those satellites run a little more quickly compared to Earth's surface.

Hey arbi n rest of thread crew.

Need your input and advice maybe some help on a project id like to do for a martial arts group i belong to.

Im interested in showing the physics of how proper form can make more efficient or increase the mechanical energy deliveted to a target using a simple jab as an example.

Not comparing one persons power against another but rather showing how force is increased by incorporating proper technique and form.

Id be using a generic hypothetical person. Making the assumption their arm weighs 7lbs. And the person 180lbs. Impulse of .1 sec. not sure what i should use as an estimate of velocity of arm. Need help there and or on anything i mentioned above.

Id like to demonstrate how much mechanical energy is transfered in a translational manner in just a simple jab that snaps out and back.

What increase you get when you include rotational energy from the hips or shoulders. Need help figuring the best way to measure that. (To be honest im expecting a slight increase over just translational energy but not stellar amounts)

Finally what increase on energy delivered when you incorporate the persons 180lb mass transversing twords target which i expect a massive increase in delivered energy.

Anybody got some input, advice or help to offer regarding?

originally posted by: BASSPLYR
What increase you get when you include rotational energy from the hips or shoulders. Need help figuring the best way to measure that. (To be honest im expecting a slight increase over just translational energy but not stellar amounts)

Finally what increase on energy delivered when you incorporate the persons 180lb mass transversing twords target which i expect a massive increase in delivered energy.

The best way to measure it is probably out of your budget. This video shows a crash test dummy or at least the top half of one which is probably the most accurate way to make measurements relevant to fight science. A fully configured crash test dummy for automotive testing is maybe $400,000 but since the dummy shown is a much more limited version I'd guess it may go for somewhere around $50,000-$100,000:



There are less quantitative ways to do comparative measurements on a budget. In the video at the following link, the relative strength of kicks is evaluated by how far the punching bag is deflected. You don't get exact forces like with the sensored dummy, but you can tell whether the bag rocks back a little, or a lot, or if the kick is powerful enough, it's knocked over.

pbskids.org...

It's also interesting that in addition to the physics of the masses involved, the kids figure out that the design of the human body plays a role, when they change their foot position when kicking. They are the same kids with the same strength but just changing foot position affects which muscles are used and the bag gets deflected much further when the stronger muscles are employed, though what they are looking at wouldn't really be a factor in a flying kick for example.

There is a physicist who has written a book on the physics of fighting. I haven't read it but if I was undertaking a project like yours I might consider reading it. Some of the calculations will be complex and perhaps some simplifying assumptions will make them inaccurate. There are so many interconnected components of the body that isolating only part of it for analysis may not prove accurate. Consider the "foot position" video above for an example of this.

There are arcade style punching bag machines but I don't think they are very accurate. Anyway this should demonstrate how NOT to throw a punch using one of those:

a reply to: Arbitrageur

No i am not wrong.Period T of pendulum is proportional to 1 / underoot l/g where l is length of pendulum and g is accel due to gravity. we all learnt this in school and just forgot about it. so T is greater at equator, ie the pendulum slows down at equator due to lesser gravity

a reply to: Arbitrageur

No i am not wrong.Period T of pendulum is proportional to 1 / underoot l/g where l is length of pendulum and g is accel due to gravity. we all learnt this in school and just forgot about it. so T is greater at equator, ie the pendulum slows down at equator due to lesser gravity

a reply to: BASSPLYR

Need a hi speed camera with that you can measure speed and even force it becomes math. For example an arm you measure the distance it travels and the time it takes you have a speed measurement.

originally posted by: Hyperboles
a reply to: Arbitrageur

No i am not wrong.Period T of pendulum is proportional to 1 / underoot l/g where l is length of pendulum and g is accel due to gravity. we all learnt this in school and just forgot about it. so T is greater at equator, ie the pendulum slows down at equator due to lesser gravity

No your not wrong in lower gravity the pendulem will swing wider meaning it takes more time. I think he was thinking of a clock in that case he was right. But pendulem are directly effected by gravity.

originally posted by: dragonridr

originally posted by: Hyperboles
a reply to: Arbitrageur

No i am not wrong.Period T of pendulum is proportional to 1 / underoot l/g where l is length of pendulum and g is accel due to gravity. we all learnt this in school and just forgot about it. so T is greater at equator, ie the pendulum slows down at equator due to lesser gravity

No your not wrong in lower gravity the pendulem will swing wider meaning it takes more time. I think he was thinking of a clock in that case he was right. But pendulem are directly effected by gravity.

so in effect he was saying clocks run slower in lesser gravity?

originally posted by: Hyperboles
so in effect he was saying clocks run slower in lesser gravity?

It depends on whether it's a pendulum clock or an atomic clock.

I was talking about atomic clocks measuring time but I forgot that pendulum clocks don't measure time as much as they measure gravity, so yes you're right the pendulum clock would run slower in lower gravity at the equator but an atomic clock would run faster in lower gravity at the equator. The atomic clock is better at measuring time. The pendulum clock isn't a very good timekeeping device if you move it to different locations where the local gravity is different, but it can be used to measure those gravitational variations.

originally posted by: Arbitrageur

originally posted by: Hyperboles
so in effect he was saying clocks run slower in lesser gravity?

It depends on whether it's a pendulum clock or an atomic clock.

I was talking about atomic clocks measuring time but I forgot that pendulum clocks don't measure time as much as they measure gravity, so yes you're right the pendulum clock would run slower in lower gravity at the equator but an atomic clock would run faster in lower gravity at the equator. The atomic clock is better at measuring time. The pendulum clock isn't a very good timekeeping device if you move it to different locations where the local gravity is different, but it can be used to measure those gravitational variations.

Pendulum clocks and atomic clocks both measure time as we know it.
Besides in 1956 pendulum clocks were in vogue.
so both clocks would run slower at the equator due to lesser gravity, which contradicts general relativity. so a simple
pendulum debunks general relativity, does it not?

originally posted by: Hyperboles
Pendulum clocks and atomic clocks both measure time as we know it.
Besides in 1956 pendulum clocks were in vogue.
so both clocks would run slower at the equator due to lesser gravity, which contradicts general relativity. so a simple
pendulum debunks general relativity, does it not?

As I said the atomic clock is better at measuring time, the pendulum clock is better at measuring gravity when you move it to different places with different local gravity. Or if you elevate the atomic clock it will run faster due to lower gravity, and if you elevate the pendulum clock it will run slower due to lower gravity. The former is measuring time, the latter is primarily measuring gravity (there is a time effect too but it's overwhelmed by the gravity effect).

NIST has made some of the most accurate measurements ever confirming relativity, with incredibly accurate clocks.

NIST Pair of Aluminum Atomic Clocks Reveal Einstein's Relativity at a Personal Scale

Scientists have known for decades that time passes faster at higher elevations—a curious aspect of Einstein's theories of relativity that previously has been measured by comparing clocks on the Earth's surface and a high-flying rocket.

Now, physicists at the National Institute of Standards and Technology (NIST) have measured this effect at a more down-to-earth scale of 33 centimeters, or about 1 foot, demonstrating, for instance, that you age faster when you stand a couple of steps higher on a staircase.

so both clocks would run slower at the equator due to lesser gravity

If you could demonstrate that you'd win a Nobel prize, but I think the NIST experiment already proves you can't demonstrate that.

a reply to: Arbitrageur

If the 2 clocks are conradicting each other, clearly one of them is wrong, in this case the atommic if it shows faster time at equator.
Even a school kid by intuition alone can tell if the pendulum swings faster at poles, the time flow there is faster
and vice versa at the equator

originally posted by: Hyperboles
a reply to: Arbitrageur

If the 2 clocks are conradicting each other, clearly one of them is wrong, in this case the atommic if it shows faster time at equator.
Even a school kid by intuition alone can tell if the pendulum swings faster at poles, the time flow there is faster
and vice versa at the equator

In this case of a pendulum vs an atomic clock it is clear that at least one of them is affected by the gravitational field present. Hyperboles asserts that time changes to keep in sync with the pendulum. Following Einstein, Arbitrageur and the vast majority of physicists today assert that time changes to keep in sync with the atomic clock. In ye-olden-days-of-yore (for an overview, see here) it was asserted that the rate of time advance remained fixed and it was the measuring instruments that changed because of environmental changes.

As for myself, I remain stubbornly old school.

a reply to: DanielKoenig

Earlier I had mentioned about how time was an abstraction. I have updated the InfoGalactic article to clarify this issue. You can see the discussion of abstraction in the first portion of the introductory section.

a reply to: delbertlarson

found this on the net

physics.stackexchange.com...

originally posted by: Hyperboles
a reply to: delbertlarson

found this on the net

physics.stackexchange.com...

The answer given on the page you link to agrees with what Arbitrageur has been posting. That's the status quo view right now. My position is different. Rather than saying "both give the correct time" I would say both give the incorrect time, as they are being affected by their environment. The old-school thought is that clocks retard as they move through the aether, and there is further relevant experimental data indicating they are also affected by gravitational fields. But just because clocks are affected by their environment does not necessarily mean that time itself changes.

originally posted by: delbertlarson

originally posted by: Hyperboles
a reply to: delbertlarson

found this on the net

physics.stackexchange.com...

The answer given on the page you link to agrees with what Arbitrageur has been posting. That's the status quo view right now. My position is different. Rather than saying "both give the correct time" I would say both give the incorrect time, as they are being affected by their environment. The old-school thought is that clocks retard as they move through the aether, and there is further relevant experimental data indicating they are also affected by gravitational fields. But just because clocks are affected by their environment does not necessarily mean that time itself changes.

you are quite right about the status quo.
my view is that the atomic clock since is based on em wave freq, it shows an error. As if you stretch the time vector meaning time dilation, you can superimpose more cycles of the em freq on it, in other words, the atom is putting out a higher freq of em wave and the eventual read out of this clock is essentially counting down of freq of the local oscillator, hence it reads a faster time, where in fact the time actually slows down in lesser gravity as shown by the pendulum clock

Here's a question. Where is the best place to aim a punch on an Electric Universe supporter that accuses you, me, a 'blind denier', of absolutely disregarding science and sticking my head up my own a**?

originally posted by: Hyperboles
my view is that the atomic clock since is based on em wave freq, it shows an error. As if you stretch the time vector meaning time dilation, you can superimpose more cycles of the em freq on it, in other words, the atom is putting out a higher freq of em wave and the eventual read out of this clock is essentially counting down of freq of the local oscillator, hence it reads a faster time, where in fact the time actually slows down in lesser gravity as shown by the pendulum clock

originally posted by: Hyperboles
a reply to: Arbitrageur

If the 2 clocks are conradicting each other, clearly one of them is wrong, in this case the atommic if it shows faster time at equator.

Calculating the consequences of your view that the pendulum clock is the one that's accurate: The Apollo astronauts would have never made it to the moon. The Lagrange point L1 between the Earth and the moon is where the gravity from the Earth and moon equal each other, and the pendulum clock would stop, meaning time would stop, since you think the pendulum clock is the one that's right.

Without time there can't be velocity and motion, so the Apollo spacecraft would have got stuck between the Earth and moon where, according to your idea the pendulum clock would stop and so would time. Since that didn't happen, I think it proves the pendulum clock is not such a great way to measure time in varying g environments. It works OK as a timekeeping device if you pick one gravitational environment and calibrate the clock to work in that environment and don't move it.

The atomic clock is affected by gravity also, but it doesn't stop measuring time at the LaGrange point between the Earth and moon like the pendulum clock.

We could actually make a huge list of all the problems with your idea. Say you come up with some excuse how the astronauts got past the Lagrange point where time stopped, and made it to the moon. Running atomic clocks on the moon and on the Earth would show only a small difference in the passage of time, but taking a pendulum clock calibrated to run on earth and running that on the moon would show a vastly different passage of time on the moon. This would have serious implications for frequency shifts of the radio communications between the Earth and the moon, and such vast frequency discrepancies were not observed. So again observations are more consistent with atomic clocks being accurate than with pendulum clocks being accurate in varying gravity environments.

originally posted by: pfishy
Here's a question. Where is the best place to aim a punch on an Electric Universe supporter that accuses you, me, a 'blind denier', of absolutely disregarding science and sticking my head up my own a**?

Is electric universe still a thing? I can't remember the last time I've seen it mentioned even on ATS. Anyway violence isn't the answer for that.

However if you find yourself on a plane hijacked by guys yelling "Allahu Akbar", by that point I think violence is the only option that makes sense. Even though flight 93 crashed at least it never reached its target. Maybe if you got those extremists before they hijacked a plane and put them into a de-brainwashing camp, after months or years you might de-brainwash them without any violence, but by the time they've hijacked the plane it's too late to try reasoning with them; you just don't have months or years to debrainwash them in the short time of a flight.

I found a great article on electric universe and thought about making a thread about it but since it seems to be a dead topic on ATS I didn't bother. Readers digest version: EU has no math/quantitative predictions and the people attracted to it seem to be those averse to math. So I tend to feel sorry for EU proponents instead of wanting to punch them, they're missing a lot of interesting things by not knowing math and how real science is verified using math.