Stumblebum

Ah! The Langoliers will make sure we don't go back.

Every second of every day we witness the past, who's to say that we might someday be able to see all segments of it rather than go to it.

thats assuming that 100000 years or so in the future when time travel is commonplace christianity still exists. or maybe half the people in jerusalem were time travellers and couldn't find out where or exactly when the crucifiction took place.

 

or maybe Jesus wasn't a real person and instead was maid up by 1st century schollars as a way of teaching moral lessons that they thought were lacking in society.

It doesn't have to be the crucifixion. It could be something that happened an hour ago. If 50 million people decide to go then what?

Let's say TM's are available to everyone. At Easter many people want to visit the crucifixion, lets say 50 million. It would be very crowded on Calvary, there is no record of such a crowd being present, so it never happened in our time line. I don't think it is possible to go back in time without creating another timeline. Either that or its possible to change or start a new timeline at any point off the present timeline but it does not affect the leading forward points of the timeline as it advances into the future. Too many timeline references I know but this ain't easy.

If someone on the other side of the universe went back in time and changed something would it affect us?

Can decomposition occur without other lifeforms? If an astronaut was to die on a planet complete with moderate temperatures and devoid of life would decomposition be possible? Could the bacteria living on or within the astronaut's body do the job?

No. God is.

Likewise....great answer

I'm no physicist but I thought I'd show you something I thought of long ago.

Rocket A leaves Earth at .8c to a planet 8ly away. Before it left the astronaut calculated it would take him 6 years his time(approx) to reach the planet if you took time dilation into account. I'm skipping the time dilation math. So when he arrives he calculates his distance travelled to be 6 x .8 = 4.8 ly.

What I'm about to say may have already been discussed somewhere else, I don't know. Objects with mass travel a shorter distance between 2 points than a massless photon thru spacetime. In other words mass exhibits a property rarely discussed and that is the ability to cut through spacetime as if it is trenching. The photon cannot go through space but can follow the mass object as it moves thru spacetime.

Analogy....2 points on a round inflated balloon. The distance between them would be the arc of the balloon's skin. Imagine light follows this arc because it cannot dent the skin or spacetime. This is light's shortest path. If you apply fingertip pressure on one point, simulating mass, and draw it across the balloon's skin to the other point you will notice that it not only travelled a shorter distance but a straighter course. In fact if I apply enough pressure(mass) to both points they eventually meet in the centre. I'm not saying this is the shape of the universe, just a way to show that mass travels shorter distances than light. You will also notice that the balloon's skin rebounds or stretches after the mass has passed over it thus maintaining an arc for light to travel.

This probably flies in the face of relativity but is possible if the universe rides a huge geodesic called spacetime. If all the objects in the universe ride the geodesic of spacetime and they all accelerate near to the speed of light creating infinite mass for them all then yes, everything is there all at once. You are everywhere or close to it. (Like fingertips meeting in the centre of the balloon)

Does this suggest that things are much closer than they appear? Are we living on the outside of a magnifying glass looking back? I used to think that I was looking thru a magnifying glass towards the universe.

Again, flame me if you want but try to understand this is what I conceived in my head when I first starting reading about this stuff, nothing more. Sorry, have to go to a meeting but I'll check back later.

If there really was a bang or shockwave I wonder how long until it reached this far away? I assume it isn't going to happen but if it did have a medium to travel through to reach us would it have been here by now or are we still waiting?

Wouldn't a place to put all that energy and matter come first?

I hope I'm in the right section. More questions for the astute members of this forum.

If a light particle(photon) has no mass then does that affect the famous equation E=mc²? or can a massless photon release energy?

If a photon has mass and is absorbed (lost) is there a release of energy equivalent to its mass?

If c=0 can there be any energy? or do things have to be in motion for the equation to work?

Sorry about the terminology. Its wasn't the fact whether it was a vein or artery but that the body responded to a crisis by growing a bypass. A few of you have said this has happened before but I would wager not very often. I thought it might have something to do with genetics and evolution to some extent. Is this the type of stuff Darwin was intimating? I wonder if adult stem cells somehow were triggered into forming a new blood vessel. Does anyone know if this phenomena has been studied or if other body parts have mysteriously begun regenerating or building anew?

A family member (55 year old male) was recently diagnosed with 3 partially blocked arteries at the heart. The doctor explained that he would insert a shunt (I hope terminology correct), to keep the arterial walls from collapsing. He did 2 no problem but when he went to install the third it was then when he discovered that the body had already grown a vein around the affected section thereby providing a natural by-pass. The doctor told us he had never seen anything like it. Has anyone heard of this? Is this one of those moments where a possible mutated gene is responsible?

I've often heard the universe described as containing billions of galaxies, etc. I guess this imay be a more philosophical question but how can an infinite boundary-less universe contain anything?

Just a wild thought. Are the miraculous cures that we occasionally hear about actually a result of stem cells within the body being triggered into action because of the attitude of the afflicted? Believing that a divine power is listening to your needs, thinking that the body has the power (mind over matter) to fix itself or a combination of treatment with a positive attitude might be all it takes for the stem cells in your body to do some extraordinary repair work.

I think everyone has missed one important point. In one of his posts Danny indicated that he personally never went on the trip to the future but that his future self supposedly painted the picture the machine brought back. Danny's time line never alters, he did not go into the future to paint. In order for the painting to be painted, Danny would have had to go along for the ride. He cannot exist in a time he hasn't been to yet. If he makes the temporal leap forward he can can look forever and never find another Danny or painting waiting for him.

Its situations like these that convince me that travel into the past is impossible. At great speeds it is possible to end up in the future but it won't be yours as you would still exist in the now (timeline intact). Any machine that travels at great speeds to go into the futue doesn't miss the time it supposedly skips across. That 'skipped' time is actually not skipped, its just jammed into what is a very short time for you and the machine.

the circumference shrinks and the radius stays the same.

I like that answer, makes one think.

If I had 5 rims at different distances from the hub and spun the wheel the same, the outer rim will go faster than the inner rims. No matter how hard I try I can never approach the speed of the outer rim with any of the other rims.

I thought of this one day when I was trying to figure out some kind of an example or analogy for light speed as top speed in the universe. Then I had this crazy thought that if the universe was a gigantic spinning wheel then the speed of light may depend on your position on it and because of the vastness of space we don't notice differences, yet.

Science is weird, my brain hurts.

Whatever effects you are seeing might have to do with an artificial light source like a Sodium street-lamp flickering at 60 cps. What were the conditions of your observation?

Have you ever tried shaking your hand in front of a TV set with other lights off?

Or watched a car-wheel go backwards on film or Television? this has to do with frame-effects' date=' not light speeds.[/quote']

 

Actually all I want to know is what happens to the rim of a bicycle wheel when it is spun at a speed close to light. Does the rim move away or does it get closer to the hub or stay where it is? Let's assume the spokes are unbreakable. I was thinking the circumference would measure less than when stopped, the spokes would also measure shorter and the distance from hub to rim would measure significantly less. Or as it was mentioned does the rim move away. I think that could only happen if spokes and rim stretch because of the high speeds? Not sure of this.

The faster you spin it the further it gets from the hub.

Wouldn't the rim's circumference shorten as lightspeed is approached? I can't see how the rim moves away from the center when there are spokes holding it on to the hub unless they stretch.

There are so many of you willing to answer a layman's question that I hope you don't mind a few more.

With my bicycle upside down(changing tire) I spin a wheel. The spokes appear to curve. I assume this is because the outer end of the spoke is travelling at a higher rate of speed than the inner portion. If I were to accelerate the rim to .999999c would the spoke curvatures be so great that the distance between the rim and the wheels hub appear to my eyes as to be close to zero? Could I asume that the apparent curvature of the spokes are now extremely exaggerated to the point where they appear to be flattening out? In other words the rim is closer to the hub.

Even when I spin the wheel by hand, if I was to measure the distance between the rim and hub it would be less than when the wheel is stationary? Would the spokes because of their apparent curvature appear longer or do they retain same length even when the rim appears closer to the hub?

These questions are harder to write than answer. I hope that wasn't too confusing.

I think you are complicating things unnecessarily. You should stick with your original scenario...

 

2 guns that' date=' when stationary, and side by side, and fired at the same time, release bullets with identical velocities that hit a target at the same time.

Now leave one gun where it is (100 yards from target) and put the other gun [b']solidly[/b] on a heavy mount on a track that moves the gun toward the target. Set the experiment up so that the moving gun will fire when it is 100 yards from the target. Simultaneously, the stationary gun fires.

 

The moving gun's bullet will hit the target first.

 

velocities are addable (is addable a word?)

 

So if you have a gun that fires bullets at 100 yards per second, and put it on a track that is moving at 30 yards per second in the same direction as you are firing, the final velocity of the bullet, when fired, is 130 yards per second (relative to a stationary target).

 

When the velocities you are dealing with approach the speed of light, you can't just add them anymore, the math gets a little more complicated.

Thanks also....

I'm not sure what you're asking. Could you rephrase it? We assumed that the velocity of the balls were the same. If the pitcher is running, then you would have to add the arm velocity + the velocity of his body to get the final velocity of the ball.

Thanks, you answered my question. Sorry to confuse, I just meant that if the pitcher had ran prior to releasing ball and both balls hit target at same time then His velocity plus arm would add up to machine's velocity...that's all. I'm ok with it now...thanks a lot.

Ok, that's what I figured. However, if the pitcher was running toward the target when he released the ball then would that momentum have been necessary for the pitch to equal machine's velocity? In other words without the forward run his arm could not have reached the velocity of the machine's ball by itself? I am just trying to get the original thread question's answer straight in my head.

I wasn't referring to the spacetime between the walls but the spacetime between the particles that make up the box. Whether that makes a difference or not when matter is crushed under gravity's infkuence, I couldn't tell you. Thanks for replying.

But I assumed, from the way it was written, that the guns were equivalent on the ground prior to the experiment.

That assumption is correct, that's what I meant when I typed the question. If you don't mind I would like to reword the question with a slightly different scenario.

A pitcher winds up to throw a baseball. He releases the ball and the Jugs gun records the velocity. At same time a baseball is fired from a stationary pitching machine and the velocity is also recorded. The points of release are equidistant from the target and the recorded velocities are equal in both instances.

By the answers given to my previous question am I correct to conclude that the baseballs will arrive at the same time but that the thrown baseball depended upon the forward arm motion of the pitcher and without it would not have equalled the velocity of the machine's baseball?

If I changed the guns to flashlights then the light from them hits the target at the same time.....correct?

This question may seem simple but for a non-physicist like myself it is sometimes hard to grasp. I'm sure this is beginner's stuff.

I have 2 guns, when fired the bullets leaves the barrel at the same speed relative to where I am standing. I put a target 100 yds away, mount one gun on a vehicle moving towards it and one gun stationary. The mounted gun is preset to fire at the target when it is 100 yds away and is synchronized with the firing of the stationary gun, also at the target. My feeling is that both bullets should hit the target at the same time.... is this correct?