ElasticCollision

Per Einstein's general relativity, gravity is the warping of time and space. This "spacetime curvature" affects the path of all particles, including massless photons (light particles). For example, light from a star passing very close to the Sun is bent or curved by the Sun's spacetime curvature. The verification of this effect in a 1919 solar eclipse made Einstein world famous.

 

Consider light inside the event horizon of a black hole. Here spacetime curvature (gravity) is so great that space is stretched to the point where the frequency of that light is stretched to zero. So no light inside the event horizon is emitted to the outside world.

 

Light is an electromagnetic wave, with regular peaks and valleys. You can think of each peak and valley as the tick and tock of a clock. So when light's frequency is stretched to zero, it is equivalent to "freezing" time. Thus to an observer far away, time at the event horizon of a black hole appears to stand still.

 

See link for more details: http://imagine.gsfc....rs/970618a.html

 

My website: http://www.marksmodernphysics.com/

Wow, fascinating. Thank you for the level of detail.

That's the part about relativity that often causes a lot of confusion. The planet-based observers see that it takes 10 years, but the rocket occupants don't. For them time has run slow, even though they will never notice on their own. They simply think it only took a year (1.005 years, to be precise), and that the trip was only 1 LY in distance, and all of their instrumentation agrees.

Ah, I understand. This matches what was said earlier about photons measuring no time at all for any journey.

Although, if I may stray off topic a little. What exactly is theorized to happen to light in regard to a black hole; if light has no mass, why does it succumb to the gravity of a black hole, and what happens to time in there?

"you will actually see the Earth as it will be nine years forward from your departure date, instead of one year back." As I already stated, this quote was what made me think you could see into the future. The way it is worded makes it seem that way.

As I also already stated, the problem has been cleared up for me and I now understand.

Thank you for elaborating anyway, albeit in quite a snide way.

I don't recall anyone saying anything about seeing into the future.

 

If you travel at 0.995c, the factor by which time is dilated or length contracted is 10. If you were in a rocket ship going to a place that was 10 light years away as measured by someone at rest (on your home planet), when you were at speed, you would see that distance as only 1 LY and since you are going very close to c, it will take you a smidge over a year to make that trip.

Also, you've made it a bit more confusing for me here. If it takes light 10 years, then traveling at light speed would take you 10 years, not 1.

I don't know what determines this strength. In the Standard Model, there is no explanation for it - the couplings are among the model's free parameters. There are certainly approaches that will tell you they give the explanation, but most of them will be extra layers on top of the SM that come with yet some other free parameters.

 

If you take the perspective that physics is supposed to quantitatively describe the world then it is not obvious that inventing a layer above "the couplings have these values - end of story" even is an improvement. From my childhood times I know that at least in communication you can always add another "and why is that?" to the last answer. And at some point it stops adding to the conversation. I can imagine science being similar.

That's a bit disappointing. I was rather hoping that as the Higgs boson theory answers the question as to how particles gain mass so well, they would have theorized exactly how different particles gain different amounts of mass, beyond an idea that elementary particles just have different coupling strengths to the Higgs field intrinsically, without any real explanation to the differences in coupling strengths.

It makes me lose a bit of faith in the theory, I have to say.

You are remembering cosmic inflation.

 

http://en.wikipedia....tion_(cosmology)

According to this link, "While special relativity constrains objects in the universe from moving faster with respect to one another than the speed of light, there is no such constraint in general relativity."

Does this mean matter CAN travel faster than the speed of light? (I know that it can't, as this would mean it's mass and energy would become infinite, so what is the quote getting at?)

That is tough to parse. I think what they mean is: You see earth nine years forward of your depararture date, but by the time you get one light away, your departure date was 10 years ago. So you are still not seeing into the future. I think the point was that since you are travelling 0.1c for 10 years, over the course of the trip you have stayed ahead of one year's worth of light coming from the earth, so even though you travelled for 10 years, you see the earth as it was 9 years ago instead of 10.

Ah, yes, that does make sense. OK, I've got a bit of a grasp on this now, thank you.

 

What do you mean by 'see into the future'?

Well, while I was researching this elsewhere to try and gain a grasp on the idea, I came across this.

"The fastest hypothetical forms of propulsion that I have heard of recently can propel a spacecraft to ~ 10% of the speed of light. From one light year away, you can see the Earth as it was one year ago. But traveling at 10% of the speed of light we will get there in ten years. So (ignoring time dilation) if you travel one light year away from the Earth, you will actually see the Earth as it will be nine years forward from your departure date, instead of one year back."

Although, considering that is ignoring time dilation, I suppose it's wrong?

From the photon's point of view, yes.

 

It takes zero time IN THE PHOTON'S FRAME OF REFERENCE

I'm beginning to understand all of this now. However, one thing I still don't get. If you were traveling at 90% the speed of light, this means that from your frame of reference, everything else is slowing down.

If everything else is slowing down, why is it that you would be able to see into the future?

I think I remember once reading or being told that according to where everything is in the universe at the moment, and where/how long ago the big bang occurred, everything must have at one point been traveling at above the speed of light to be where it currently is. Of course matter can't travel at the speed of light, let alone above it, so according to this, for a while after the big bang, the universe was something entirely different and was composed of something other than matter.

Am I right about this, or am I simply misremembering?

There is no "how many Higgs bosons will join" in the real physics. That's only in the reporter analogy. The mass of the particles that owe their mass exclusively to the coupling to the Higgs field is determined by their coupling strength to the Higgs field.

 

You may think that this is a rather pointless statement: It is. But it is the essence of the Higgs Mechanism in the Standard Model of Particle Physics. The Higgs Mechanism is a way/trick/solution to introduce masses for elementary particles without running into too much trouble within the framework itself. The thing about "explaining the origins of mass" is, in my opinion, mostly a marketing issue. Perhaps even just a generous omission of correcting journalists that write this to sell their stories. After the desaster with the SSC, a particle accelerator in the late eighties much larger than today's LHC, the particle physics community realized that they must put much more effort into public relations. Never heard about the SSC? My point, exactly.

I know a small amount about the SSC, actually. I believe it was cancelled due to the building of the ISS at the same time. The government chose to invest in the ISS rather than the SSC.

However I don't see how that has much to do with my question. Of course it is always important to keep public interest in science at its maximum: that is how you gain investment.

To the original point, however, is there any idea as to exactly what gives the particles different amounts of coupling strength to the higgs field?

Let me elaborate a little on why I ask this. If elementary particles such as quarks (which are differentiated simply by the shape of the strings which compose them, according to string theory) are able to gain different amounts of mass simply from different coupling strengths, then this must mean that the strings composing them are not the most basic level, because something else must be influencing the strings to take their different formations and thereby allow quarks to gain different amounts of mass, mustn't it?

The number of press reports the particle itself or its role (-> president) received in the past.

Ok, I was simply using the reporter example to show my grasp on the subject. But with actual particles, what determines how many Higgs bosons will join to them to give them mass? Why don't all elementary particles gain the same amount of mass from the same amount of Higgs bosons?

The best description I have on how the Higgs Boson gives particles mass is from a documentary I recently watched.

If higgs bosons were news reporters, and a mass-less particle were president obama, as that particle passed through the Higgs field it would gain mass as reporters (Higgs bosons) crowded around it. While if a particle that was just me passed through the Higgs field, far less reporters would crowd around me. Maybe one or two to ask if I had seen what Obama was doing before we walked into the room of reporters, and so I would gain much less mass.

So my question is, what determines how many reporters (Higgs bosons) will crowd around a particle to give it a specific amount of mass?

Because you are ignoring relativistic time dilation. At the speed of light, time dilates to a stand still (of course, nothing with mass can achieve lightspeed).

 

http://en.wikipedia....i/Time_dilation

I feel like I'm hijacking this thread with my own question, so I will end it here. I'm not ignoring time dilation though, I simply don't understand it.

I travel near the speed of light, time slows down, and then for some reason increments of length decrease in some direction. Why? "because you always have to measure the speed of light as c" doesn't answer the question. Why do I always have to measure it at c? What is speeding up doing that's causing this length dilation?

I think this video will help you. It explains the length contraction as well as time dilation.

n lets put it lie this there is a certain amount of energy in every particle. That energy is is dence its a proton-anti proton if its light the lighter the faster space-time snaps it faster cause space time has a smaller impact.A photon is a light energy light as in not heavey all that energy is kinetic that light hits somthing the weaker has mr puch the high energy has least but the higher energy is oftten remited in a slghtly less with some energy being absorbed by the atom which is nrmly remimited in a lower wave leagth but somtimes completly difent results i think a whole lt of the suns gravtycomese from all the photons sterring up the space time then the materer which is all being fuled by spacetime

I smell a troll.

Only as measured by a observer on earth. You, on the photon, would measure no time at all.

I don't understand how I would be measuring no time at all though. If I checked a watch on my wrist, the time for me to get from the sun to the Earth would be 8 minutes. The person observing me would also see me take 8 minutes. I know I'm wrong here, I just don't see why I'm wrong. That's what's frustrating me.

I find this channel always has excellent coverage of political events. This first video explains just why the embassy was attacked.

And this second video has coverage of Romney's reaction to the attacks. As per usual, he turned the situation into a gaffe, even other republicans distanced themselves from his comments.

I personally find it worrying how people can have this view. "Yes we could all drown, but there could also be a new ice age" as if it being a natural occurrence in Earth's geological cycles means it isn't a problem. Despite all the scientific evidence that humans are causing the ice caps to melt, let us humor the thought that it is an entirely natural phenomena: We must still try and act to stop it, because it will cause widespread death of the millions. If an asteroid was heading toward the Earth which was guaranteed to wipe us all out, would you be saying; "Yes, but according to fossil records, an asteroid this size hit the Earth millions of years ago, but there is still life, so it's nothing to worry about"?

If the ship were trailing a cable with periodic markings, the cable, and those increments, would be shorter. The distance to the ship as measured by that cable would be shorter, but still increasing.

I also have trouble with this whole subject. Here's what confuses me: If I were riding a photon from the sun to the earth (light-speed) then it takes me 8 minutes to get to earth. At the same time, if someone were observing me riding this photon from the sun to the earth, they would observe me take 8 minutes too. Now if instead I ran the distance, I would take hundreds of years and the observer would also see me take hundreds of years. Time doesn't change for me or the observer. I take the same amount of time from my own frame and from the observers frame.

So as far as I can see, time isn't changing for either of us, I am simply changing my speed.

No, being in the ground state means there is nowhere (state-wise) for them to go. But the machinery/electronics that comprises the trap which creates that ground state will eventually break down.

Ah I see. Not to put your article down, as it's most likely my lack of knowledge in this area, but the way it was written made me come to the conclusion that the uncertainty introduced the decay.

Although I think I also came to this conclusion after watching something about how uncertainty affects whether photons will act as waves or particles, because to my understanding, the photons can be in many places at once (their position is uncertain) and so they behave as waves, then when they are observed their position becomes certain and so they behave as particles. So with my flimsy grasp on this subject, I assumed that the difference between certainty and uncertainty was also the effector in this experiment.

I see now it's far simpler than that. It is surprisingly simple, yet needed explaining to me before I could understand.

The uncertainty isn't an issue for the "forever" part; that's just a matter of mangling the "ground states last forever" concept. The uncertainty means the clock will not be perfect, which is the other thing the article mangled, and which Ronald Hyde touched mentioned earlier.

Unfortunately you've lost me. I thought the uncertainty was what caused the ions to become subject to decay.

No

http://blogs.science.../archives/12472

I have to say I got lucky here. Only yesterday I watched a documentary about how the uncertainty principle affects particles, so I at least have a shaky grasp on the idea rather than no grasp whatsoever. It does make sense to me and I find it a shame that the introduction of the magnetic field and just the measuring itself introduces uncertainty and therefore subjects the "clock" to the effects of decay and entropy.

However my more basic thought was that the "clock" would simply be subject to decay due to spatial expansion as the very ions that are trapped by the electric field would still decay in the same way that all other matter in the universe does as expansion continues.

Clearly whether I am right or wrong doesn't matter a great deal though. It is still a shame to know that it wouldn't work.

If they have really discovered the primary insecticides that cause this big problem with bees, I expect they will soon find other chemicals that will do the job without harming bees as much, or not at all. There are also mite and mini-fly larvae that kill bee colonies in nature. They might have to breed stronger bees from similar types of honey bees, or actually genetically help them to also cope better with natural predators, or maybe even chemical cocktails sprayed on the hives or crops to help bees survive better in nature, and possibly more resistant to certain insecticides .

Agreed. Farmed bees are currently being constantly used to replace wild colonies whose numbers are rapidly declining (which is dangerously limiting the genetic diversity of all bees). These farmed bees are also dusted with a powder which kills the mites which prey upon the bees. However, as the article says, pesticides are still rapidly killing bees, so even these farmed bees aren't really solving the problem in any long term way at all. I certainly hope what you are right and they find other kinds of chemical pesticides which do not harm bees, because of course without bees, crop harvests will worryingly decline.

What you have there is a possible way to disrupt the bee population.

 

Smashing bees with hammers could also disrupt the bee population. Doesnt mean that hammers were responsible.

Except not everyone in the world is going around with hammers killing bees, while these neonics are being used worldwide on crops and have been shown to cause the death of bees. The article also says that the scientists admit this is only one reason for their population decline along with "The destruction and fragmentation of bee habitats" and "(GMO) crops – some of which now contain toxic insecticides within their genetic structure". Which suggests to me that you haven't even read the entire article.

http://www.space.com/17769-eternal-clock-space-time-crystal.html?cid=co3945404

If this space-time crystal was formed, at the lowest quantum energy state, would it really out-live the universe?

The very matter that it is made up of should still be subject to quantum decay, should it not?

See the discussion in http://www.sciencefo...alo-of-hot-gas/

 

But that invisible gas does not add up to 5.25 times as much matter as visible matter.

Thank you very much, I wish I'd seen this before I had posted my question. I feel like mine is now taking up unnecessary space and needs deleting.