21

General Science / Re: Would legalization of Marijuana increase general health?

« on: 24/05/2018 05:52:36 »

I have no problems with allowing medical uses of cannabis such as alleviating the symptoms of chemotherapy (eg nausea & weight loss), if it can be shown to be effective.

It's been effective for a lot of people with anxiety disorders and chronic pain. I'm going to try it. I could care less about any side effects. To me its like going over to my neighbor's house and having a cigarette and a Budweiser.  Its always unwise to simply think only of the negative impact a substance has on a person. The only thing they should decide whether the gain is worth the risk. And if risk is very low and you like it then I say go for it. I'm biased of course. I lost 10 years of my life to intolerable chronic pain. I wanted to die and let that be the end of it. Nothing has happened or will happened that can make up for that kind of torture.

A lot of politicians and bearcats are horrible people. E.g. it's not legal to smoke pot in Massachusetts for recreational purposes. But my landlord is our town's housing authority and he's quite uncaring since he's made it such that residents can't smoke in their own homes, neither Tabaco or  pot. Nor can we smoke it outside. I wager that he's being driven by an racial stereotype. When I spoke to him about it he seemed to have to restrain himself from saying "Those people." Grrrrr....

22

Physics, Astronomy & Cosmology / Re: Can we measure the one way speed of light?

« on: 02/05/2018 09:51:18 »

Hi Jeff- Great question as always. Not only can it be done but it has been done. Its required knowledge for very long baseline interferometry (VLBI) in radio astronomy. It requires having two synchronized clocks at each location of each station, Dave Cooper thought it was impossible but to me it merely seems that he lacks a full understanding of clock synchronization, There are more than one way to synchronize clocks, People always seem to think that it its not done the way Einstein explained i then its not a real synchronization. On the contrary. Two atomic clocks can be synchronized at one place and then each clock is transported at a sloe speed (driving a car perhaps) and the clocks will still read the same time within experimental limits. If the one way speed of light was different depending on direction then inconsistencies with be found in the data, None were found,

23

Physics, Astronomy & Cosmology / Re: Can we tell we are in a box in freefall?

« on: 21/04/2018 14:59:34 »

In a box falling freely it is said there is no experiment that can determine we are in motion. If we are in a very large box we could use rubber balls thrown at the walls. Gravity will change the kinetic energy of the balls. It will slow this moving away from the source. This change in inertial motion will indicate freefall towards the source of the gravitational field.

It depends on stature if the field. If the field is uniform then no. Otherwise yes. Simply bring a gradiometer with you and you can make that determination.

I wrote a paper about this. I recommend reading it. See:

Einstein's gravitational fiel
http://xxx.lanl.gov/abs/physics/0204044

I strongly recommend reading it. It's full of Einstein's thoughts on the subject at hand.

24

Physics, Astronomy & Cosmology / Who claimed that gravity is a curvature in spacetime?

« on: 17/04/2018 08:13:42 »

This is a leading question of course since I know the answer. I'm merely curious as to who believes it.

I'm good on my word so when I said I'd post the original letter by Einstein o Lincoln Barnette I meant it so here it is. Please see attachment.

In essence Einstein stated in no uncertain terms that gravity should not be thought of as a curvature of spacetime. Spacetime curvature is just the relativistic term for tidal gradients. He also stated the relativity does not geometrize physics anymore that EM or the distance between two points.


Einstein_SR_GR.pdf (666.56 kB - downloaded 482 times)

25

Physics, Astronomy & Cosmology / Re: How far has the photon travelled?

« on: 13/04/2018 22:04:39 »

All particles, photons included, move on geodesics. A geodesic is a curve of extremal length. Its quite possible for a two photons to start out at the same point in space and one return before the other one. A perfect example is on the photon sphere of a black hole. Its like two people standing at one location and to end up one mile away. One takes the route which is the shortest while the other is the route taken along a great circle which is thousands of miles apart.

26

Physics, Astronomy & Cosmology / Re: How far has the photon travelled?

« on: 09/04/2018 21:41:16 »

If a photon is at point p1 at time t1 and later is at point p2 at time t2 how far has it actually travelled? "With respect to whom?", you ask. Is that the wrong question?

That depends on whether the spacetime is curved or not.

27

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.

28

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.

29

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

30

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

31

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?

32

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.

33

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

« on: 19/03/2018 15:08:22 »

Recent research shows that bodies were commonly removed from their cave crypts after a few days and placed somewhere less showy.

No. The Pharisees went to Pilate and requested the tomb be secured until the third day because Jesus said he'd rise from the dead. So Pilate gave them guards. Jesus was resurrected on the dawn of the first day and the guards saw him resurrected. Matthew 28: 4 says "And for fear of him the guards trembled and became like dead men." Some of the guard went into the city and told the chief priests what happened. Here's how the story goes. From Matthew 27: 62-66

62 The next day, the one after Preparation Day, the chief priests and the Pharisees went to Pilate. 63 “Sir,” they said, “we remember that while he was still alive that deceiver said, ‘After three days I will rise again.’ 64 So give the order for the tomb to be made secure until the third day. Otherwise, his disciples may come and steal the body and tell the people that he has been raised from the dead. This last deception will be worse than the first.”

65 “Take a guard,” Pilate answered. “Go, make the tomb as secure as you know how.” 66 So they went and made the tomb secure by putting a seal on the stone and posting the guard.

Assuming Jesus was in fact a real person.

There's no real doubt that Jesus was a real person.

While alive Jesus would not have been anywhere near as famous as he became in "death", ...

On the contrary, he was very famous. So famous in fact that the Jewish leaders wanted him dead.

One of my most favorite Einstein quotes is

I am a Jew, but I am enthralled by the luminous figure of the Nazarene….No one can read the Gospels without feeling the actual presence of Jesus.

Hmmmmm .... all those hours studying the Bible and other religious material is paying off.

34

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.

35

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

36

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

37

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.

38

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.

39

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.

40

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.