21

Physics, Astronomy & Cosmology / Re: Why do objects move inertially according to Newton's laws?

« on: 09/04/2018 12:35:27 »

Ah... I see now that Jeffrey was talking about relativistic conditions, where inertial mass is not a constant.

But under relativistic conditions, an object no longer obeys Newton's laws
- or you have to bend F=ma to say that m varies with velocity or gravitational potential - and that the time you use to measure acceleration also changes.

On the  contrary. Newton's Laws are still valid. It's a common misconception that Newton defined F = ma. That was a relation proposed by Euler, not Newton. Newton defined force, essentially, by F = dp/dt. And his third law always holds when the forces are contact forces.

To be precise, Newton stated that force is proportional to change in momentum and moment he defined as density times speed.

- these are not modifications that Newton would recognize!

When used correctly, sure he would.

22

Physics, Astronomy & Cosmology / Re: Why do objects move inertially according to Newton's laws?

« on: 09/04/2018 00:09:36 »

@evan_au No I meant inertia. The force makes an object move faster. It's inertia is changed and it now maintains the faster speed once the force is removed. However it now acts like its inertial mass is increased and progressively more force is required to move it. This tends towards an infinite force which indicates that the inertial mass tends towards an infinite value. This isn't a tenable explanation. We must be missing something fundamental. If you see an infinity then the solution has to be wrong.

The faster it moves the harder it is to accelerate. The increase in inertial mass is due to the properties of spacetime. If you follow the derivation of this property you'll see how its determined to be so.

The solution is not wrong because you know of an infinity. A body with finite proper mass cannot move at the speed of light. Therefore the inertial mass always has a finite property. You're thinking of the fact that there is no upper bound to this mass, i.e. as v -> c the mass increase without bound. Recall how the term infinity is defined. And there is no problem in physics with infinities. In fact our very own universe appears to go on forever, i.e. is infinite in size.

23

Physics, Astronomy & Cosmology / Re: If mass increases as you approach the speed of light, why are photons massless?

« on: 06/04/2018 13:29:45 »

I wish to check something I read ref quantum gravity, and would like to ask an embarrassing question ref the speed of light.

It is normally accepted that the speed of light is constant in a vacuum, but may slow down if travelling through matter. Matter is made up fields, can an electrical or gravitational field slow the speed of light down in a vacuum.
The following link suggests the speed of light is not so constant in a vacuum, is it pop science or are they correct.
https://www.sciencenews.org/article/speed-light-not-so-constant-after-all

The version of quantum gravity I have just ploughed through suggests that light speed may be affected by gravity could it be correct.

That article suggests that its something new when actually Einstein predicted the slowing of ight in a gravitational field in 1907. He used that to derive the actual being of light by the sun.

It was experimentally verified by Harvard physicist in the 60's. He stated that the slowing of light in a g-field is one of the predictions of GR.

By the way. The claim that relativistic mass is not used by serious physicists is wrong. They teach it at Harvard. See:
https://aapt.scitation.org/doi/10.1119/1.17870

24

Physics, Astronomy & Cosmology / Re: If mass increases as you approach the speed of light, why are photons massless?

« on: 06/04/2018 02:38:54 »

So called gravitational mass does not increase at speed.Photon has "repellent" mass.

The problem here is that different people are using different definitions of mass. You're using the definition where mass = proper mass. Not everyone does so, such as me and the following author

Measuring the active gravitational mass of a moving object by D. W. Olson and  R. C. Guarino, Am. J. Phys.[/b] 53, 661 (1985); https://aapt.scitation.org/doi/abs/10.1119/1.14280

Abstract

If a heavy object with rest mass M moves past you with a velocity comparable to the speed of light, you will be attracted gravitationally towards its path as though it had an increased mass. If the relativistic increase in active gravitational mass is measured by the transverse (and longitudinal) velocities which such a moving mass induces in test particles initially at rest near its path, then we find, with this definition, that Mrel=γ(1+β2)M. Therefore, in the ultra relativistic limit, the active gravitational mass of a moving body, measured in this way, is not γM but is approximately 2γM.

Alan Guth provides the following argument
http://www.newenglandphysics.org/common_misconceptions/Alan_Guth_01.mp4

I provide an argument here:  https://arxiv.org/abs/0709.0687

25

Physics, Astronomy & Cosmology / Re: Can kinetic energy be the source of a gravitational field?

« on: 26/03/2018 13:04:09 »

I think not but it would be interesting to get other views on the subject.

Yes. All forms of energy can create a gravitational field. Its whatever the T^00 component of the stress-energy-momentum consists of. Didn't I ever mention that the energy of a photon or a directed beam of light is all kinetic energy and that light can create a gravitational  field? This was done way back in 1931 by Tolman, Ehrenfest and Podolsky in the article

On The Gravitational Field Produced by Light, Tolman, Ehrenfest and Podolsky, Physical Review, Vol. (37), March 1, 1931, pg 602-615.

I placed it online in my own words at:
http://www.newenglandphysics.org/physics_world/gr/grav_light.htm

26

Physiology & Medicine / Re: Can the treatment be more dangerous than the disease?

« on: 25/03/2018 15:36:55 »

Some of the side effects of treatments can be very severe. Some can cause mood swings, changes in personality and hallucinations. Others may have cancer risks. Is the treatment sometimes worse than the disease it is treating or is it generally worth the risk?

If the reward is less than the risk then no. Otherwise yes.

When I had leukemia I had to have chemo. For the first week its high dose chemo, 24 hours a day for 7 days then about a month to recover. It was horrible. Well ... sort of. Each moment I was never as sick as I was when I was a teenager and had a hangover and barfed my brains out. What was worse is that I was always thirsty that first week. But if I tried to drink anything it came back up right away. So I spent that time sucking on a small wet sponge on a stick. After that I was always hungry but couldn't eat or I'd barf, up to the last day. Even that day was no different. However when they said I cold go home I took of my battle gear (i.e. the hookup to saline) and went to the lobby and bought an apple and went outside for a walk. I was able to keep it down no problem. The nausea turned out to be part mind and part body. The walk outside was like a walk through heaven. It was a bright sunny day. The air had a hint of sea water, and the sky was blue as sapphire.

The chemo itself can cause cancer. However had I not had it I'd have died a few days later and I never got cancer after that. Obviously the reward was much greater than the risk in that case. But even if I got cancer it was risk not a fact.

I had cataract surgery years back. There is 1 chance in 3,000 for retinal detachment. And, you guess it, my retina became detached.

Gee. Aren't I lucky?

27

Just Chat! / Advice for the entire forum

« on: 19/03/2018 19:49:08 »

Actually I'm just passing on the advice that I was given by my advisor/mentor in college.

Before you choose to debate the meaning of a term I highly recommend a few things:

1) First consider the level of conversation or the topic and the actual context its used in
2) Before making an assertion on a historical fact make sure you look up the fact and verify it, regardless of how well you know it
3) Make sure you not only know what someone says or asked make certain that you know what they are actually seeking to convey.
5) Don't insult people

When I reach perfection I'll satisfy #5 perfectly.

Example of #1) The term "mass" is defined in some high school texts and college chemistry texts as 'quantity of matter'. In special relativity its defined such that mv = "mass" x 3-velocity is a conserved quantity. In this context its referred to also as inertial mass aka relativistic mass. If its expressed as mU = "mass" x 4-velocitu then "mass" is proper mass aka rest mass. In GR and Newtonian gravity its broken into three categories

1) Inertial mass
2) Active gravitational mass
3) Passive gravitational mass

They can be set equal in many cases but not when it comes to mass density

Example of #2) People, like Stephen Hawking, claim that Einstein showed that gravity is a curvature in spacetime or that he geometrized the gravitational field. That's false. IT never happened.

28

Physiology & Medicine / Re: Are we in the grip of an opioid epidemic?

« on: 18/03/2018 19:38:03 »

I'm watching the brilliant documentary "Drugs Inc." on Netflix right now. Highly educational and informative. I recommend you guys to watch it to get a glimpse about this opioid epidemic in the USA.

Thank you my good man.

Question: That's a series spanning nine years. Which episode are you referring to?

What I don't understand, and never will, is why people are so concerned about 40,000 to 60,000 people dying of narcotic overdose. That's not very many people so why the hubbub.

Of course I feel this way because I've been forced to confront it almost every day for 13 years so I'm obviously more up to speed on the intricacies than most.

29

New Theories / Re: Black hole equations.

« on: 18/03/2018 18:29:37 »

Like I said, you can't challenge me on time because I am the ''master'' on time and space and if Einstein was here today he would concede to me.

Dear God,

I thought I heard it all until today when I read the above statement. I have now heard it all. As a result I am more highly disappointed with people than ever before, in general. I am therefore ready to assume room temperature. Please take me when you find the time.

Your friend, the atheist,
Pete

30

Physiology & Medicine / Re: Are we in the grip of an opioid epidemic?

« on: 18/03/2018 14:54:28 »

BC - You're in my ignore list so I'll never see what you post and thus if you make a comment directed at me I can't see it and won't choose to. I've had enough of your nonsense for a lifetime.


For the rest of the readers - I have some solid ideas about how to solve the narcotic/drug abuse problem. When it comes to prescribing narcotics for chronic pain there should be a requirement to go into an "opioid clinic" where patients would stay to learn about opioids, to titrate their meds to the correct level as fast as possible and transition them slowly to outpatient by a inpatient status with the ability to leave the hospital during the day, see a movie, go shopping, have coffee etc so they can learn and adjust to handling their breakthrough meds. Then there can be programs for teens and young adults for recreation they'd love to have such as motocross, snowmobiling, dances (women love to dance and men love women) etc. This goes into solving the "I'm bored" and "There's nothing else to do" problem. When I was young I drank and did drugs because we were bored and there wasn't much else to do. I allowed my friends to peer pressure me into doing drugs. It was hard not to. I really didn't do much drugs since I hated them. I drank little but a little was too much for me.

Also there's a great article online on opioids for chronic pain at
http://booksc.org/book/20836569/360d39

31

Just Chat! / Re: Did Jesus die on the cross ?

« on: 17/03/2018 15:09:54 »

People witnessed Jesus being crucified two millennia ago and thus had a different understanding of life and death than we do now. The OP made this point and it was a good one.

A good movie which tells an interesting story which I recommend watching is The Man from Earth which is online for free at: https://123movieshub.to/film/the-man-from-earth-10773/

It tells the story of an immortal man who identifies himself as many well-know figures in history, including Jesus. In the movie he said that he didn't die on the cross but through his studies with the Buddha he was able to change his life signs so that he appeared to be dead. A similar thing could have happened with Jesus. He might have actually died for a few short minutes but the jostling of his body buy those taking him down could have revived him but no to the point of being notable to others. 

There's also a story in the bible where a child is brought back to life from a (cold state as I recall) when a man covered the boys body with his and breathed into him. This is basically what it means to resuscitate a person who died.

I know about this event because I keep an open mind and as such read the Bible cover to cover twice. Had I not then I'd never have known about this important piece of information which is of historical significance.

32

Physics, Astronomy & Cosmology / Re: How would we calculate the time left to contact with an EH?

« on: 15/03/2018 23:11:53 »

If we are approaching the event horizon how can we determine how much time we have left before reaching it. Length contraction will be increasing but our proper time will be of no use in such circumstances.

I haven't done those calculations in many years so I can't say off hand. I suggest looking at Taylor's website for the new version of Exploring Black Holes. I think he does it in there.

The basic idea is to first note that there are two answers depending on whose point of view/frame of reference you want to consider. If you're considering the time as measured by an outside observer who is at rest wrt the BH then that time is infinite since that time is infinite. From the in-falling observers frame then one uses that observers proper time and that will be finite. I don't suspect that its too difficult to calculate though. I'm just old and my memory is old too.

33

Just Chat! / Using caution in our age of terrorism

« on: 29/10/2017 03:21:28 »

I had a bad experience today. I went to the grocery store to get a few things and then sat on the bench outside to wait for the bus. After about 5 minutes I  noticed a plastic shopping bag which contained a box. It was sitting next to the garbage can. There were two other people waiting outside on the two benches. I asked the woman on my bench and she said no. I asked the woman on the other bench, which was further away from the package then the two of us, if it was her's and I thought she said no. Mind you, I live only 30 miles north of Boston, a town which experienced a terrorist bombing. With that in mind I thought it best to call 911 and report it. They said they'd send a car by (who knows when). I decided to take photos of it with my cell phone. The women whom I asked the second time asked me if I was taking pictures of her. She happened to step in front of me while I was taking a picture of the bag. I said no and explained what I was doing. She then told me it was her bag. I called 911 and told them to forget it.

I'm curious how others react when they see a bag or some other package when it appears out of place. Is your first thought "Is it a bomb?"

I have to admit that I feel safe from terrorist because they're not all that bright. They tend to want to make a big show of it or want to kill as many as possible at the same time. If they were smarter then they'd know to go to random places in the US and leave such a bomb. That way nobody would feel safe and terrorists would have a stronger effect on Americans. Thank God for dumb terrorists.

34

Physics, Astronomy & Cosmology / Re: Does the equivalence principle hold near black holes?

« on: 28/10/2017 21:17:13 »

If a body is falling freely towards a black hole will time dilation cancel the tidal forces so that the equivalence principle remains in tact?

I don't see how you get that.

There are two forms of the equivalence principle known as the strong form and weak form. The weak for refers to uniform gravitational fields so you can't apply that to curved spacetimes. The strong form says that any physical law which can be expressed in tensor notation in SR must have the same form in a locally inertial frame of a curved spacetime.

The later is consistent with the notion that if you limit your observations of an experiment in a small enough region of spacetime in a locally inertial frame of reference your observations can be described by SR. I noticed that Evan referred to a small region of space. Its really with a small region of spacetime. Its easy to imagine an experiment which is confined to a small region of space but which manifests the spacetime curvature. For example: place a ball at rest any place within the international space station and record its position as a function of time. At first the ball seems to remain at rest but will undergo a complete cycle back and forth within the time it takes for the station to make one orbit.

Regarding black holes: there's nothing special that goes on near or even at the event horizon as observed by an inertial observer. In fact you can imagine a black hole which has enough mass to make the spacetime as flat (but never zero) as you'd like at the horizon. In fact the book Exploring Black Holes by Taylor and Wheeler often refer to them in that text.

35

Physics, Astronomy & Cosmology / Re: How can the field equation be zero while the Ricci tensor is not?

« on: 28/10/2017 20:42:27 »

But when deriving the Schwarzschild solution, after calculating the Ricci tensor (R^μν) and the Ricci scalar (R), from the spherical symmetries of the problem, both are non zero.

If so then that's news to me. Can you find a source on the internet which shows that to be true? Clearly from Einstein's equations in vacuo R = 0 so I can't see how it can not be zero.

How is it possible that the field equation are zero while R^μν and R are non zero?

They can't be. It seems to me that there has to be problem with your assertion above where you state that the Ricci scalar and tensor as zero.

Note: caution should be used when using the "/" operator in textual form. The expression 1/ab is defined as 1/(ab). I say this because you wrote 1/2*4 where you meant to write (1/2)*4. It really means 1/(2*4).

36

Physics, Astronomy & Cosmology / Re: Were Michelson and Morley wrong in their predictions?

« on: 20/09/2017 20:08:56 »

For those familiar with the experiment, If you think about the resistance a river would put on a ball moving directly against its current as being one or maximum resistance, and then a ball moving with the current as being at 0 or lowest resistance, the resistance travelling perpendicular to the current will be half of these two resistances added together.

There is no resistance that needs to be taken into account here. When a boat is moving in water at constant speed its because the force due to the propeller is equal and opposite to the drag force of the water on the boat. Therefore all one needs to do is consider an object moving at constant speed relative to a medium and that's what the derivations of the interferometer are all about. And there is zero resistance to the motion of anything moving relative to the "ether." If there were then the Earth would have slowed down in its orbit around the Sun due to a loss of energy. Since that hasn't happened there's no resistance.

37

Just Chat! / Re: Non theist but not atheist? What do you believe?

« on: 15/07/2017 16:42:09 »

David,
It appears as though your God concept is identical to the Christian God, omnipotent, all-knowing, etc.  If so, your God cannot think.  Thought, as humans experience it, involves the creation of new concepts, ideas previously unknown.

Regarding your comment "the Christian God." The God of Christianity is the same God as that of Judaism and Islam, i.e. The God of Abraham. Its unfortunate that most people who aren't Muslims are completely unaware of the fact that the God of Islam is the exact same God/being as that of Christianity and Judaism. Its also unfortunate that those who know that the God of Islam is the God of Abraham also believe that the Christian God, the God of Judaism and the God of Islam are all different Gods even though they all believe that their God is the God of Abraham. That's extremely illogical. I've had that discussion with a few Christians and they hold that to be case because they have "different beliefs" about God. That's pretty sad logic to me.

A anyway, since when does human thought require the creation of new concepts? A new thought such as "I'm going to choose to have OJ for breakfast then I'll shower and go to work" does not constitute the creation of a new concept.

I don't accept that the God of Abraham (GoA) knows everything. I don't believe that the Bible even states that God ever said that he did know everything. Had that been true he never would have regretted creating Man and had have no need to destroy them with a flood nor would God have regretted making Saul King.

I did a bit of searching today on this notion and learned that my not accepting that the GoA not knowing everything is hardly a new thought. I learned that his notion is referred to as Open Theism and is a evangelical and post-evangelical Protestant Christianity concept. See: https://en.wikipedia.org/wiki/Open_theism

This has been decribed in short here: http://www.desiringgod.org/interviews/why-does-god-regret-and-repent-in-the-bible

This is a huge and important issue. Back in the mid-1990s, I was embroiled in disputes over what is called “Open Theism,” which argues that God is open to the future in the sense that he does not have exhaustive knowledge of what is coming in the future.

Note that the person who wrote that holds it to be wrong with his reasoning being that its akin to us saying "I'm going to regret doing X but here I go and do it."  I consider that to be nonsense. Especially when the consequence is killing mankind and since it removes free-will. At least in my opinion. Christians seem to hold that GoA has he same emotions we have and they at the same time hold that the GoA doesn't have the same emotions. I can't accept arguments with such logical contradictions. Especially when its not backed up in the Bible. The author's arguments are not logical ones, they're all guesswork with him almost always using terms like "I think" and "may have/be". For example

He may well be capable of lamenting over something he chose to bring about. And God may be capable of looking back on the very act of bringing something about and lamenting that act in one regard, while affirming it as best in another regard.

So here we see him use the phrases "may well be capable" and "may be capable". He also bases his argument on the verse

The Glory of Israel will not lie or have regret [or repent], for he is not a man, that he should have regret [or repent].

One is forced to interpret "The Glory of Israel" as being identical to "God." But notice that this is not God speaking but the author, who may have been Samuel himself but nobody is certain of that but Jewish tradition holds that it was Samuel that wrote the books of Samuel.

Christians etc will always argue that the books of the Bible are the "inspired word of God" meaning that God put what to write in the minds of the authors and then they just wrote down what God told them to. However there's a place in the New Testament where it said that a few of the apostles were arguing over the meaning of something. If what was in their minds was the inspired word of God then there'd be no argument among their meaning between  the apostles.


Note: When I speak of what's in the Bible I do so not on someone else's interpretation of its content but what I actually read in it. Someone once suggested to me that I read the Bible cover to cover, every single word, at last five times. I've only done it twice. I'll keep going though since the Bible is the most widely read book that there is.

The Bible is flawed too. I've read places where there are contradictions. I think it was in the two stories of how King Saul (?) died. If it wasn't King Saul it was how someone else died. But they contradict each other. I also found it extremely odd that in Numbers the exact count of the tribes were almost always rounded off to the nearest hundred. There were never numbers like 45,234 people. There is one place where the count is rounded to the nearest 50, i.e. the tribe of Gad.

There may be places in the Bible where men have stated that God knows everything but that's different than God himself having stated it. In the book of Job God is held to have made many statements about his abilities but nobody is sure about who wrote that book and whether its supposed to be as told by God, being a real story with actual statements held to be made by God or whether its merely a story told an attempt to explain something.

Thus it would seem as though such a being cannot create anything, including a universe with animate life and humans.

Not having any new thoughts doesn't imply that such a being cannot have an original physical creation of something such as the universe.

What is the use of such a God concept in a rational discussion? 

While I don't accept David's view on the definition of God it doesn't seem to me that one cannot have a rational discussion about such a God which is still useful. In fact there are always discussions of that kind going on as their have been since the creation of such an idea.

38

Just Chat! / Re: Non theist but not atheist? What do you believe?

« on: 13/07/2017 00:36:53 »

Scientists are the most inclined to doubt the resurrection of Christ... Stephen Hawking says he does not believe in God, because before the big bang, there was no time for God to exist in.

First off, a person who is a "non theist but not atheist" is called an agnostic. I've gone back and forth between agnostic and theist. An atheist has a poor logical position because he holds that God doesn't exist. Since it's not logically possible to prove that something doesn't exist then the atheist must believe it with no proof. Do you know what its called when you believe something when you don't have proof of it? It's called faith. Frankly I could never have enough faith to be an atheist because I think more logically than atheists do.

Second, I believe that Hawking is a smart man. But with all men, smart or otherwise, he has said some dumb things, and that was one of them. Where exactly did he say that anyway? We have zero knowledge of what happened back to a certain instant of time and before that we know nothing. As stated by Peebles in Principles of Physical Cosmology (1976) page 6

If there were an instant, at a "big bang," when our universe started expanding, it is not in the cosmology as now accepted, because no one has thought of a way to adduce objective physical evidence that such an event really happened.

and that's as true today as it was in 1976. There are even ideas of multiple universes from which an advanced civilization might actually create a universe from their own, leaving their own universe intact. Such a universe is referred to as a child universe. Suppose that there is a scientists in such an advanced civilization who created our universe designed as he chose fit. Then, by the definition of the term, that scientist would in fact be God.


e are theorists today who hold that the universe is infinitely old such as proponents of the Pre-Big Bang Scenario


 Although Christians believe Jesus Christ pre-incarnate is the Father of Eternity. From outside fills the universe with His presence.

What do you believe? In a god, in God, in a higher power, or in an intelligence behind the universe...?
[/quote]

39

Just Chat! / Re: ‘inhumane treatment’ of pain patients

« on: 30/06/2017 20:03:35 »

If anybody would like to read a story which will break your heart then I recommend reading the following:

The Other Victims of the Opioid Epidemic June 1, 2017, Glod S.A. N Engl J Med 2017; 376:2101-2102
http://www.nejm.org/doi/pdf/10.1056/NEJMp1702188

40

Just Chat! / Re: ‘inhumane treatment’ of pain patients

« on: 30/06/2017 19:36:24 »

If you want to talk about inhumane treatment of pain patients:

My friend, having been diagnosed as having Weigners disease, was told she had 2 years to live.

16 years later, having been inadvertently infected with Hep C 10 years earlier by the hospital conducting her care for all those years, and having been prescribed a steadily increasing dose of opiates for the pain associated with her crumbling facial bones and neck vertebrae - guess what?
NHS brings in a zero tolerance policy regarding long term opiate prescription and during a hospitalization for a minor fall decided to put their Hep C patient into forced opiate withdrawal.

For those of you who are not familiar, a forced opiate withdrawal is life threatening for a Hep C patient.  Withdrawal exacerbates the Hep C.  The exacerbated Hep C causes damage to the liver, and my friend 'the Weigners patient' that was requiring the pain killer was left unable to ingest opiates.

I've never been so angry in all my life.  I printed the Hep C info off the net and gave it to the doctor responsible for the decision who couldn't find enough nurses to put between us before he slunk off.  I daresay he hadn't bothered to read my friends file that had built up over 16 years to require a trolley of it's own...
...but why would a trained doctor put a regular Hep C patient into forced withdrawal from a 16 year opiate prescription anyway?
Based on the fact that a forced withdrawal will exacerbate Hep C and destroy the liver, what benefit could there be in forcing an opiate withdrawal on a Hep C patient?

Never assume that a doctor is intelligent merely because they're a doctor. I know that from an experience with a doctor I once had. She had the audacity to compare what I was taking for chronic pain with her experience taking a low dose Percocet.  My last exchange with a physicians assistant pissed me off big time because she claimed my dose was way too high, even though I've been on and off opiates for 12 years now. Dumb woman!!!