What is the Proof or Evidence that Stars Still Exist?

if I may Fredskie, I might not catch it. We see it at the moment. Arriving there will be twice the star's age if I travel at light speed. Certainly, I can not make it even a fraction of a thousand light year.

It's a "...WAIT and SEE moment..." of course, ie: wait long enought to see if they're (suns) still sending out light.

"couple of billion light years ago"

1. A light year is a unit of distance, not time.

2. The nearest stars are just over 4 light years away.

Even so 4 light years, that's very far away.

Yes, a light year is one year light travels at a distance.

If you can think of 4 and "a couple of billion" in the same context, maybe you're on the wrong forum.

I dunno, 4 could be nearly halfway to the right exponent.

Physicists mostly get within a coupla orders of magnitude. Engineers usually do a bit better.

I just hope I get to the right house at night.

I know that the universe is 15,000,000,026 years old!

You been looking at my notes ? The last bit (which you must've missed) says that while our own sun, or the Maya didn't exist, there could have been no notion of a year...so was it you, who spent 26 years counting to 15billion ?

That's too complicated for me

I was told, 26 years ago, that the universe was 15 billion years old.

Or even the wrong planet.

Guess he gets his information from the same place Han Solo does.

Wonder if he can 'do the Kessel Run in under twelve parsecs' too.

Couple of billion years ago????

I think not.

The sun is just up the block from here.

Alpha Centauri is just 4.37 light-years from Earth.

A light year = how far light travels in a year.

They're still out there, trust me.

Tell us, have you been nipping on HTRN's bottle of whiskey? Or, smoking something that is only legal in Colorado and Washington states?

Yes Lyn, but some at distant might not be there at the very moment.

Lots of things might be.

I think that is very likely that we see light from both dead and still existing stars.

The same "proof or evidence" that the sun will rise tomorrow morning.

Speaking of which with certainty, its only about 3 minutes approximately if i am not wrong, the sun light travels towards us.

f 8 minutes and 20 seconds to travel from the Sun to the Earth

As far your original question goes, consider that we see stars in our own galaxy as well as stars in galaxies such as Andromeda, stars in more distant galaxies, like Centaurus A, and on and on, each example being more distant than the previous.

As it takes light millions to billions of years longer to reach us from distant galaxies than it does from our own neighbourhood, doesn't it stand to reason that, even should the stars wink out all at the same time, the fact of it would reach us at different times, depending on the stars' distance, and we would see them winking out at different times?

Lastly, what would be the mechanism for stars that have been burning for millions or billions of years, to all just wink out inexplicitly, without warning?

Lastly of all, why would we in such a privelidged position that allowed us to see them wink out all at once, and no one else in the entire universe. Earth, a dust-mote in a medium-sized galaxy among hundreds of trillions of others?

That being said, before pondering what the other stars are doing, wouldn't it best to start that journey by getting the distance between the Earth and the Sun correct insofar as light travel-time? It's not three minutes, it's eight minutes, nineteen point zero zero five seconds.

Three minutes away and you and I wouldn't be here having this ridiculous conversation.

This is eating our stars.

Lyn, he hasn't a clue......and he advertises it here.....DUUUHHHHHHH

I'm gone....See ya somewhere more interesting!!

Exactly

Which makes it unimportant!

My money's on redfred.

This helps, but would this spectral data assured to be say 80% accurate to tell the state of that specific star at the very moment?

Who can tell if all stars behave on the same life expectancy? Humans are here for only about say 2000 years with mind and knowledge good as this modern world.

If stars have been there for about a Million years, who gathers the data?

2000 years is pretty small for extrapolation to Million years.

We have been able to identify and sequence stars using spectra data for only about a century. However, we use the fact that the light has taken a long time to get here. Looking just within the Milky Way gives a time distribution of 4 to over 100,000 years of star light data. Additionally the sample size is literally an astronomical number of stars available for measurement making the statistics very reliable.

Paragraph #5 explains this. The bottom line is statistical accuracy. I can only assure you that our understanding of the mechanism is pretty detailed based on a huge amount of data.

If you really want to dive into the fine details of this it would require a great deal of study to both lay down a foundation for astrophysics and the subsequent studies in mathematics to satisfy your question completely.

I don't know of anyone (including me) that has that depth of knowledge here nor the time to donate to teach you.

Unfortunately, we have long passed the point where any one person can be taught the sum total of knowledge of humankind, so you have to trust in all the people that have expertise in domains of specialized knowledge.

This is very interesting topic, I agree. I am not a typical guy who believes easily like a persuasive conversation does to anyone.

Questions like, are we really sure what is happening(process) inside a star that we can predict when will it dies.

A part from the Laws of Thermodynamics, is there any laws concerning energy that modern physics and quantum mechanics gave.

There is a bunch of theories out there all in which sometimes annihilate each other.

Those theories does not bring any good to the world.

I bet, it set us to more confusions.

Is this a sort of 'are we all living in a galactic version of the Truman Show' question ?

If we are, then somebody/something is on the outside pulling the strings. I've no idea how to prove we are/aren't in some gigantic dome. There's probably an obvious solution. In the interest of science I shall have another bottle of wine and ponder some more.

We could all just as well be some computer simulation and that will be difficult to prove, too.

No! That can't be.

I think I thought. Therefore I'm am.

You'm are to.

At least I think you are.

Inspiration provided by the kink of beeers.

And that margarita I had with linch lunch.

Could be difficult to prove it's not a simulation.

Perhaps the purpose of evolution is only to produce a biological intellect that can develop and build an electro-mechanical life-form that is able to traverse interstellar distances without dying off on the journey. Seems likely that evolution may be a controlled process

Errrm, on a tangent now....................Did God not banish the fallen to the earth? Did he not give them dominion, and how else will they ever escape , but by interstellar travel ? Please stay with the material 'verse, and avoid astral travel !

Evolution is also flawed theory.

It can not even completely explain the gender forming or transition.

How and when did a single or multicell organism thinks he needs to adapt and make himself a boy and a girl? If there were a population of micro organism, did they coordinate all at the same time to reach that point of gender forming or transition?

See? I could not believe all that was published and made as standards by the educational systems.

If we taught all the future generations with theories, they will end up all flawed, misguided and confused.

Wow. It seems that you misunderstand the difference between a guess, a hypothesis and a scientific theory.

A guess is an unsure answer to a question.

A hypothesis is an unsure answer to a question that can be tested to be true or not.

A scientific theory generated many different hypothesis about a phenomena that previously were not known or noticed to exist but which now have been found to be true. The more corroborating discoveries a theory accurately predicts the sounder (scientific) the theory.

Smart cover. I'll appreciate if you have a sound reasoning, a rebut to my logic, again pointing out the lack of knowledge or technical expertise on the matter is fallacy to any reasoning.

You are elaborating a 5th grader lesson. Which I doubt if I never did understand it or heard it before.

You wish your logic to be shown as flawed, OK.

Why did you choose your eye color? Your choice of eye color is exactly the same reason why parthenogenesis is not the most dominant form of reproduction for multi-cell organisms.

Non sequitur or error of fact are two plausible definitions here.

Evolution is a flawed theory ? I suggest your own theory is floored.

How and when did a single or multicell organism thinks he needs to adapt and make himself a boy and a girl?

May have been as a result of single or multi-cell organism orgasm.

1. I don't think a single cell organism exists ie organism suggests an organisation of parts..what parts are there to organise in a single-cell ?

2. Who says there was any adaptation? Maybe a single-cell male organ, after wandering for aeons, suddenly brushed against a soft cellular something floating by, that rocked his world..and here we are today!

Maybe this is a theory you can believe ? Your perceptions may be your reality, not everyone else's. It's like the stock market...go with the majority!

Lol, I heard about there's a bigger road which everyone follows and the narrow one where only few can find.

It can not even completely explain the gender forming or transition

What came first? The Chicken or the Egg. Probably the Rooster.

SHHH! Not so loud, lest you invoke the wrath of the Debuggers and make them invoke the Forced Reboot.

Which interrupts the normal cycle where they do a Scheduled Reboot every Thursday, archiving the system, wiping out the junk data and restoring into freshly defragged and error-checked hard drives.

(Yes, I'm blending 'we are in a computer program' with Last Thursdayism, Even though Last Thursdayism is a complete fabrication, the universe wasn't created In Situ last Thursday. It was created on a Tuesday. )

if its cab....pour me some

The very finest 'wine in a box' - heck, MIL visited, so I'm not gonna splurge ! A bottle or two and you won't care.

Drinks are on the cyber house .

Just to stay (very remotely) on topic; Years ago I saw an animated strip cartoon that ran something like this....A tiny bloke is shouting up at the claods, 'is anybody there ?'. No answer, so he uses a horn type thing, 'IS THERE ANYBODY OUT THERE ?' Same result, so he tries to amplify by sticking another horn atop....it continues up and beyond the clouds, a ridiculous stack of amplifiers. The viewer sees this poor liitle chap with these stacked horns extending evermore. At some point, the camera pulls back to show another chap looking in astonishment down his microscope at some tiny voice emerging from a speck of dust he's examining. Microscope guy in turn starts to holla into a horn like amplifier toward the heavens......

Not a gag explained very well, but it sort of digs into the Trumanesque consept of the world. Call me sad, but Ive never looked at a puff of dust in quite the same way since.

in vino veritas.

I suspect here is an error in your question! It goes back to a question that Dennis the Menace asked Mr. Wilson many years ago: What is the difference between a light year and a year?

The calories.

Great answers and explanations to a s****d question to my mind.....

It reminds me a little about the "Schrödingers cat" theory......

For anyone wanting to know more there is a reasonable explanation here:-

Schrödingers cat

A good question. Since we think nothing can travel faster than light, how can we divine the "present" status of distant stars? A tease: has the speed of light always been constant? And how do we "know" that?

I'll go fire up my tachyon detector and get back to you.

Good thought--A friend, at JPL, provided a "Beverage game"… If a Cop has a radar gun, that only can measure up to 120 MPH, calibrated, and you go by, in your speeding car of choice, at 250 mph, will you be cited at 250mph, or 120 mph? The point being , is that, if the Radar gun is only calibrated for a certain "Speed", how do we know that there is nothing faster?? Speed of light discussion, at his "Game"--The discussion was the viewpoint of…Is the speed of Light restricted by lack of measurement tools, a blind deference to formulae , agreed upon, ….or…. are there other possibilities? Maybe off-topic, so claim it, if so...

While nothing can exceed C, there is no speed boundary as far as how fast space can expand or contract.

What you are describing is, in part, called the Horizon Problem. It is the puzzle as to why the CMB is so uniform.

If you take a pot of boiling water it becomes isotropic pretty quickly with regard to temperature. The distances between the furthest molecules are close enough that it takes little time before they are at the same temperature.

However, the observable universe is so large that photons from the CMB are further apart than they could have "communicated" with each other to be at the same temperature at the rate of current expansion of space if you extrapolate backwards in time.

The only way the CMB could be temperature isotropic would be if all the photons were at some point close enough together to reach the same temperature. This is where a scientist named Guth postulated in the 1980s that the universe's expansion rate was not linear, but went through a very brief moment of hyper-rapid expansion, then slowed down again.

Now data shows that the universe appears to be expanding at a slightly faster rate than before. Dark energy is believed to be the driving force behind this, but there are many unanswered questions on that mechanism.

Here is a link from Wikipedia

Actually there is debate now if gravity waves may have been already detected.

You exactly correct about dark energy. It is presently a placeholder answer to some effects we cannot explain, yet. Dark matter on the other hand one must be careful how this term gets used in a discussion to know if it is a placeholder answer or not. The detection of a planet from a periodic dimming of observed light intensity from a stable star is a well known form of dark matter. Why a globular cluster or other structure doesn't fly apart because the localized luminous star mass is insufficient to do this? That is a form of place holder dark matter.

The next big insight is, would space could accommodate a particle or mass moving more than the speed of light, given it would convey dynamics with out losses and supports perpetual motion.

The asymptotes by relativity equation of Einstien would be drastically change to some degree if such particle speed exist.

As Einstein rejected the concept of absolute time, your question is meaningless.

How and why?

You can find your answers by reading about relativity.

i know relativity, like how and why you say so? Don't tell me your hyperspace exist.

If you know relativity, you'd know there is no 'universal now,' we can only know about the past of distant objects, not their present, just as they can only know of our past.

Let us say, for sake of argument, that there is intelligent live around Alpha Centauri, and that we have opened communications with them. Let us also assume that there *IS* a localized 'cosmic now' as a reference point. Both civilizations are sending constant streams of data at the other. All the news we get from them is from four years ago, and all the news they get from is is from four years in our past. We cannot help them with any current problems they have, since we will not know of their problems for four years, and they will be waiting eight years for a response to their call for help. If either civilization blows up its world, the other will have no idea there is anything wrong until four years later, when the messages stop.

"If you know relativity, you'd know there is no "universal now", --wow, did the distant stars very moment "now" goes to vacation?

Your statement seems to imply from relativity itself, stars were moving farther away or towards us near speed of light.

No it doesn't. You seem to not grasp the concept of relativity. Specifically that at relativistic velocities there is no separation between space and time. There is only spacetime.

There's no "universal now" if and only if those stars where traveling near or at speed of light? Was it not?

However, would you consider the moon and earth does not have a "universal now"? I think you better review the concept.

How would you know stars are moving at speed of light either toward us or farther away, that "there is no universal now" is valid?

No, the moon is 1.28 light seconds away. There is no universal now due to the distance component of spacetime. The objects themselves do not have to moving at all in respect to each other for spacetime conditions to happen.

That's what you get from reading too much theories and never understanding it.

If we have space station on the moon and it's clock was calibrated and synced like 2 days ago with the time you have in your wrist watch, basing in your assertion, the two clocks will have different time. That's weird, your comprehension is flawed.

Not unless, I say, if the moon travels near speed of light, you will experience time dilation.--so the no universal now will be valid.

If there's no universal now, we might as well not be able to communicate with each other through the net, since i am a fraction of milliseconds light away from you. That's odd concept.

Time dilation and spacetime are related but different concepts of relativity.

Wow, Redfred. I am not convinced yet about this. Like how would you explain the difference of time at this very moment on the moon and us here using this space time perspective?

How can I convince somebody that is unwilling or incapable of reading the references I provide. I admit that Wikipedia is not the ultimate authority on anything but it is a reasonable place to start.

Europium is correct. You win the Dunning-Kruger award.

Still, lets be reasonable here.

Gravity distorts space time, what equation could depict relationship between gravity and time? How much our time dilated with respect to other celestial body in the universe. Is there a way we could measure it?

I bet Einstein did not leave us much stuff on this.

In that sense gravity had the same effect with time and space dilation for a moving object near speed of light.

Applying on the far distant stars photons reaching us, still once the photons leave gravity and space time not distorted, there is " universal time in space.

How much gravity would require a photon to be distorted?

The theory does not seem to apply synching your watch by the clock on a space station on the moon. Could you elaborate more on this?

To sych a clock between Earth and moon is easy enough.

a. The distance is known, as is b. the speed of light.

ergo, Earth time + a/b = moon time

duh Hilton, a linear equation would not show time dilation.

The ticking of the clock have the same scale of change of time (dt) from each observer point of recognition (one moving at light speed and one stationary) only that from the stationary observer perspective, one which can move at light speed could certainly do a lot of things in a days job, could be worth a thousand years work. That's relativity in simplicity.

Didn't you say earlier (here somewhere) that you didn't believe these new-fangled theories ? If I stand on earth and observe the moon while looking at my watch, then earth time and moon time are synchronised by golly, and I'm not available for alternative reasoning

You wrote, "If we have space station on the moon and it's clock was calibrated and synced like 2 days ago with the time you have in your wrist watch, basing in your assertion, the two clocks will have different time. That's weird, your comprehension is flawed."

Nope. The two clocks will run at different times.

GPS satellites have this same problem. One is that time runs at a different rate in the influence of a gravitational field (faster). The other is relative velocity (slower clock with greater velocity).

In order to keep GPS clocks in sync with clocks on Earth they must run the GPS clocks slightly faster (if memory serves the effect of gravity dominates orbital velocity). This is done before the satellite is launched, but I think further corrections are made from the ground on a periodic basis, too.

Wow, AH, that's what I like to see. An evidence, case dismissed then .

But, applying it to photons, once it leaves the gravity of far away stars and travel to space with out gravity lensing, how would that relate to what we see right now?

If you are carried by photons, the data or information that you carry and the time you spent will be much lesser than the rate of time for us right here on Earth, it goes to imply that those stars could not be there on this moment already. Stars could last a day back there but we will see the effect that it is there for a million years.

Weird stuff, but do you agree on this?

"If you are carried by photons, the data or information that you carry and the time you spent will be much lesser than the rate of time for us right here on Earth, it goes to imply that those stars could not be there on this moment already. Stars could last a day back there but we will see the effect that it is there for a million years."

No.

Photons are elementary bosons. If you turn a flashlight on for a day it will emit photons for a day then the stream of photons stop when it is turned off at the end of the day.

It will not matter where you are in the universe, when a receiver finally receives the photons that stream will only last for a day at the receiver.

It will take a million years for those photons to reach the target receiver 1 million light years away, but the duration that the beam remains on is still only one day in length. The same for a target 30 feet in front of the flashlight. It is just the two targets see the photons at different times.

It's no different if 10 cars start at a stop light and travel down a long road at the exact same speed. The lead car of the pack of cars will arrive at the various mile markers on the highway at sequentially different times, but the time from the lead car passing any mile marker to the time when the trailing car passes the same marker will always be the same duration.

It will take a million years for those photons to reach the target receiver 1 million light years away, but the duration that the beam remains on is still only one day in length. The same for a target 30 feet in front of the flashlight.

I understand this to be the crux of the OP's query. ie if we were receiving light transmitted 1million years ago, but that star had in fact winked out 10 000 years ago,how would we know from the received light that the star was still active ?

Well of course we can't tell for sure, unless we are receiving light that indicates impending death of the source, eg sputter in the light signal caused by extinguishment processes within the source. In such a scenario, 'we' would never be able to observe/ receive the signal long enough to see the source extinguish due to time lapse. Our descendants(perhaps very far removed) may get that privilege, if we point them in the right direction...

Therefore ther is sense in the OP's query, but given that from the human perspective, we can only ever observe the past.....so what ?

Well the post I responded to did say, "Stars could last a day back there but we will see the effect that it is there for a million years."

That implies that the star lasted one day, but the stream of photons lasted 1 million years. Obviously, that is not how it works.

It seem that photons are more or less transient wave that crosses boundaries.

Weird how photons are exempted from dilation effect when they travel speed of light but on the contrary affected by gravity.

Let us look at the 'twin paradox.' There are two twins, and one is placed on a celestial body moving at relatavistic speeds compared to the other, making a trip of several years before returning. Relatavistic speeds imply time dilation, but with only the two brothers and their respective celestial bodies as reference points, each would see the other moving at relatavistic speeds while the observer is standing still, so each would be older than the other when they meet again. Each brother is expecting to be an old man rejoining with his youthful twin.

'Now' is not a fixed point, it is a clock pulse, traveling out at the 'speed of information,' back before the telegraph, there was not even a 'global now,' you only knew about 'current events' as far as a horseman or carriage could travel out and back in a single day. Beyond that point, you were trading history articles about yesterdays, piecing together the 'back thens' to find out things. "Oh, Sam got married to Jane in New York the same day Wilbur died in Atlanta."

If we ever devise a way to communicate instantly across light-years, we may be able to expand the 'local now' out to the local cluster of stars, or perhaps even a good part of the Galaxy, but until then, looking out means looking back in time. We know Alpha Centauri was out there four years ago, but it could have gone nova since then, and sent a planet-sterilizing Gama-Ray Burst right at us. The only way we'll know is when the light (and GRB) reaches us.

It's comforting to think there is a Cosmic Now, that there's some point where some Omnipotent Narrator can describe things exactly as they are, it makes for better storytelling. Sadly, however, life seldom follows the Law of Narrative Causality. If it did, I could make a killing at Poker by knowing the Stories. "A neophyte at poker sits down at a table full of card sharks and says, 'How's this game played again?' The odds of the neophyte cleaning out the card sharks are a million to one, but million to one shots succeed nine times out of ten."

I discussed "now" as a term called "now time" some number of posts ago.

Now Time is a hypothetical slice in time across the whole universe at this exact moment.

It transcends the barrier of C in that it describes what is currently happening everywhere in the universe at this moment.

For example, the Sun may issue a huge flare at this exact moment you read this post, but we would be unaware of it for at least 8 more minutes.

The flare happened 8 minutes before we saw it, not at the moment we saw it.

What is the proof that the Stars Still Exist?

What is the proof that CR4 Members still exist? All we know is the time of their last post, and can we really trust what we read when it is written with ephemeral light?

http://en.wikipedia.org/wiki/Phenomenology_%28psychology%29

I can't see you but there are tell tail signs that you do. Like you posting here.

Wouldn't the movement of our own sun in the universe be a tell tail sign of other bodies of influence on it.

Let's turn your question around. What proof is there that stars do not still exist?

You want to know how we know they are still there. I want to know how you know they are not there.

There is ample evidence that stars have existed in the past and, in one very local case, still exist. We have millions of years worth of data on the existence of stars. We have data on stars that have changed states and no longer exist as the same stars but as something else.

We don't have any evidence of a star existing and then not existing.

Until you postulate a model that explains all of the data and also allows for stars not to exist, you cannot expect your original question to be taken very seriously. It's an interesting question, to be sure, but, since we have never seen a star cease to exist, we don't have a model for that case. Give us your model so that we can actually have a discussion.

Meanwhile, back at the ranch....

PERCEPTION IS REALITY (until proved otherwise), so, if you see the star, it's there.

Even if you've been hitting the moonshine...it's there alright, until reliable people who haven't been at the moonshine tell you so!

Alternatively, I can kick your butt around the corral until you agree with me...

What is the proof that you really exist?

In reply to your statement:

Camote, balanghuy ug isa ka basong sikwate, Payts, combate prens

The sentence immediately below this sentence is true.

The sentence immediately above this sentence is false.