Avian, what's up with this new Earthlike planet?

[Yesspaz]

Quoting from USA Today, Thursday 9-26.

Astronomers have since 1995 detected abpit 120 planets, all until now thought to be gas giants, orbiting nearby sun-like stars. ...astronomers reported Wednesday that teh new planet circles the star me Arae about 50 light-years away. The planet weighs almost as much as teh planet Uranus but circles much closer to its star, completing one orbite every 9.5 days(now that's a short year).

They are saying it's like earth, being rocky instead of gaseous, but it's freaking huge and close to it's sun. I thought BIG planets needed to be further out - that whole gravity/centrifigal-force thing. Because it's so big and so close to its sun, is that why it goes so fast around its orbit? It needs the centrifigal force?

Yesspaz, dork who gave up on his childhood dream of being an astronaut.

Originally posted by Yesspaz
Yesspaz, dork who gave up on his childhood dream of being an astronaut.

But managed to achieve his other dream of becoming an astronut.

[Avian(Admin)]

The current technology, which seems to advance almost yearly, can currently only detect large planets around other stars. Only in the last few years have we been able to detect Jupiter and Saturn-size planets around other stars. Before that, only much larger planets were discovered.

The newest planet, although discovered with a very small telescope with a different method of planet detection, still falls into the general pattern of the other extra solar planets discovered. It's a large planet.

When these solar systems were first discovered, it turned most theories of planetary formation on their heads. Astronomers have since been scrambling to come up with theories of how these planets, especially the gas giants, are able to survive so close to their sun. Some theories say that perhaps some of these planets were born in the outer regions of their solar system, but migrated inward at some point. Other theories say that we're seeing a solar system in some early developmental stage.

Remember that we're only seeing our solar system as it stands in this moment in time. We've missed all the action from the past 5 billion years or so. Today we can only see the faint echoes of the huge collisions from our solar system's past, obliterating planets that used to be here, and forming new ones. Our moon is the final product of the ring system that surely once circled the earth for millions of years after its own collision with a Mars-sized object.

But keep in mind that there are probably are Sol-like systems out there we haven't discovered yet. We've found a few Saturns or Jupiters around other planets, but lack the technology to find the earths, mercuries, or venuses, if they're there. So far, the Universe has shown us that solar systems can come in many different varieties. I suspect there are many exotic planetary systems awaiting to be discovered.

[Yesspaz]

Originally posted by Yesspaz
I thought BIG planets needed to be further out - that whole gravity/centrifigal-force thing. Because it's so big and so close to its sun, is that why it goes so fast around its orbit? It needs the centrifigal force?

Excellent answer, but I'm still wondering about this.

Yesspaz, Astronut.

[Rick and Roll]

Originally posted by Yesspaz

Yesspaz, dork who gave up on his childhood dream of being an astronaut.

This proves one does not aspire to be a dork, one is simply born with it.

[progdirjim(Admin)]

Originally posted by Rick and Roll
This proves one does not aspire to be a dork, one is simply born with it.

as a professional geek, I resent or resemble that remark, or something like that...

[Roger -Dot- Lee(Admin)]

Something has been bothering me the past few years.

This deals with the 'Microwave Background Radiation' or some such like that...the light from the remnants of the big bang. NASA is currently putting together a project that will be sending three seperate telescopes up in the earth's orbital path (ie, either trailing or leading the earth as it makes it's annual journey around the planet). One of these is to examine the background radiation that was left over from the big bang. My question is this:

Stipulated:

• The earth, and all it's inhabitants, have mass.
• Nothing with mass can exceed the speed of light.
• Microwaves, cosmic rays, radio waves, light waves, X-ray radiation, and gamma ray radiation all travel, by definition, at the speed of light.

Given this, how the HELL can we claim to see light that was generated 300,000 years after the big bang? Here we are, 15 BILLION years after that massive explosion. Assuming that we're not seeing the echos or some sort of universe sized mirror reflecting that radiation, how can we see it? In order to do that, the molecules that were created in the big bang that made up the cob of corn that my mother ate that helped form the optic nerve that attaches my left eyeball to the part of my brain that registers whatever said left eyeball sees, all left the site of the big bang at the same time.

How can this be? We're seeing stuff as it was billions of years ago. How did that molecule (and every other one that makes up the entity known as Roger -Dot- Lee) make it this far out before the light (which we've all already agreed can not be beaten in a 10k road race, no matter where it's held)? How can this be?

Of course, I've studied, and I've studied, and I've looked and looked, but I have YET to see any definitive proof that the speed of light is an inviolate speed limit anyway, E=mc2 or not.

Any people wanna take a crack at trying to answer this one for me? I was up until almost 5am this morning surfing AstroPr0n sites while waiting for the station to try to come back up looking for the answer. All I got were more questions.

And a headache. One of those too.

Roger -Dot- Lee, studying why Einstein's biggest blunder may not have been a blunder afterall...

[Bob Lentil]

Originally posted by Yesspaz
I thought BIG planets needed to be further out - that whole gravity/centrifigal-force thing. Because it's so big and so close to its sun, is that why it goes so fast around its orbit? It needs the centrifigal force?

Yes, that's why it has to go so fast around its orbit. Assuming it keeps the same mass but slows down, its orbit would decay and it would spiral into the sun. Likewise, if it maintains the same speed and gets heavier, the gravitational force between the sun and the planet increase, and you get the same result.

Technically, there is no such thing as centrifigal force. The sun exerts a centripital force on the planet due to gravity which causes the planet to curve around the sun in its orbit. Otherwise, the planet would just travel in a straight line.

[Avian(Admin)]

Originally posted by Bob Lentil
Yes, that's why it has to go so fast around its orbit. Assuming it keeps the same mass but slows down, its orbit would decay and it would spiral into the sun. Likewise, if it maintains the same speed and gets heavier, the gravitational force between the sun and the planet increase, and you get the same result.

Technically, there is no such thing as centrifigal force. The sun exerts a centripital force on the planet due to gravity which causes the planet to curve around the sun in its orbit. Otherwise, the planet would just travel in a straight line.

Heh - it's easy to get confused about these types of things. There are many common misconceptions about astrophysics. Maybe I can help clear up some things.

The masses of the planets do not significantly determine how fast they go around the sun. If Jupiter were in the exact place where Mercury is, it would take the same time to go aorund the sun as Mercury - about 88 earth days. If Mercury, a tiny pebble compared to Jupiter, were placed here Juptier is, it would take the same time as Jupiter to go around the sun - about 12 earth years. The gravitational force exterted by the mass of the planet on the sun has little effect on their overall motion on the sun. The sun's massive gravity when compared to the planets is the overwhelming dominating factor here.

The acceleration that an object experiences due to gravity (or any other force) is indepenant of mass of the object. Drop a feather and bowling ball at the same time in a vacuum, and they hit the ground at the same time (neglecting the gravity generated by the items, which is insignificant when compared to the gravity of the earth). The same thing when you talk about the planets and how fast they go around the sun. The planet's mass really doesn't matter - it's their distance from the sun. Kepler's third law states that the time the planet goes around the sun is proportional to its distance from the sun (to elaborate, it states that Time^2=Distance^3). Notice that the mass of the planet does not enter into the law.

By the way, if the sun's mass were to increase, that would change the gravitational acceleration the planets experience, and therefore their periods would shorten from their current times. But Kepler's law would still hold.

The gravity of the planets have a much dramatic effect on each other and other solar system objects over long periods of time. Jupiter, for instance, is known to have a great effect on comets, changing their orbits as they orbit around the sun, and sometimes causing them to crash in thesun, or even giant planet itself. This is what happened in 1994 with comet Shoemaker-Levy 9 impacted Jupiter.

Hope that helps clear things up!

[Rick and Roll]

That even makes sense to me!

[Avian(Admin)]

[*] Nothing with mass can exceed the speed of light.

Nothing without mass can travel faster than light either (such as light itself - electromagnetic radiation).

Given this, how the HELL can we claim to see light that was generated 300,000 years after the big bang? Here we are, 15 BILLION years after that massive explosion. Assuming that we're not seeing the echos or some sort of universe sized mirror reflecting that radiation, how can we see it? In order to do that, the molecules that were created in the big bang that made up the cob of corn that my mother ate that helped form the optic nerve that attaches my left eyeball to the part of my brain that registers whatever said left eyeball sees, all left the site of the big bang at the same time.

I kinda lost you after "molecules" and "cobs of corn." Yes, the cosmic microwave background radiation is the "smoking gun" of the big bang. It's the clincher. It's how we are just about as certain as anything that the big bang occurred. Why?

Scientists theorized that if the big bang occurred, there should be a leftover "glow", as seen from every direction. This glow would be very faint - but detectable. They crunched the equations over many years, and came to the conclusion that it should be such and such a temperature, varying in such and such a way. But at the time, the technology wasn't there to see if it existed. But soon, someone did finally have the technology to detect it in a crude form, and behold, it fit the predicted model almost exactly! When more sensitive instruments were able to accurately map it around the sky, it fit the model even more accurately! Of course, with anything in science, the more information you get, the more questions get raised. There are a few interesting things about the cosmic microwave background radiation that are even more amazing. By looking very, very closely at the variations in the sky, some amazing theories have developed as to how the early Universe formed. Combine this with the other separate tons of evidence that points to a big bang (expanding universe, age of stars, etc), and you can start to see why it is the defacto theory of how our universe was created.

How can this be? We're seeing stuff as it was billions of years ago. How did that molecule (and every other one that makes up the entity known as Roger -Dot- Lee) make it this far out before the light (which we've all already agreed can not be beaten in a 10k road race, no matter where it's held)? How can this be?

No molecules here. Just light. Don't confuse particle radiation (electrons, neutrons, etc.) with electromagnetic radiation (a fancy word for light). We're talking about the leftover "glow" of the big bang.

Of course, I've studied, and I've studied, and I've looked and looked, but I have YET to see any definitive proof that the speed of light is an inviolate speed limit anyway, E=mc2 or not.

Rest assured, it is, by all measures of our current understanding of physics. Einstein's equation that describes this states that the faster you go, the more your mass increases, therefore requiring even more energy to accelerate you to a faste'sr speed. As you get close to the speed of light, your mass increases to a huge amount, until finally, it would take an infinite amount of energy to accelerate you to beyond the speed of light. That, of course, cannot be done. Humans hate limits, and have, of course, theorized several fanciful and convoluted ways that perhaps we could get around this. But none really hold any water. Could new theories develop that would somehow disprove this? You could say yes, and of course, that's but much of modern physics would probably fall with it. And much of moden physics works pretty well. Could we discover a whole new branch of physics, like we did with quantum physics, that would take hold in special circumstances or something? Who knows?

I'd like to take this opportunity to mention how much research and incredible rigorous work goes into these "theories." A scientific theory is not like a theory you or I may have typing on this board - it has an entirely different meaning. If you think the current U.S. presidential election is nasty, you should see what even the most frivoslous proposal in science goes through. Like the theory of gravity, and the theory of biological evolution, Einstein's Theory of Relativity have planets full of rigorous and objective evidence along multiple lines over millions of years in some cases, by upwards of millions of people, in their favor. Every serious attempt to explain them away has failed. Like the rejection of notions of a flat earth, and that the stars are pinpricks in the curtain of heaven, humans have benefited greatly through the scientific method.

The objective and extremely rigorous review by thousands if not millions of scientists from all over the world through various generations is our only hope against delf-delusion. And boy oh boy, do we love to delude ourselves in many things. The scientific method has given us so much - longer lives, a method of feeding ourselves and the millions around us; it has also taken us to those tiny pinpricks in the heavens. It's enemy, and therefore our enemy as a species, is ignorance and fear.

[Bob Lentil]

Originally posted by Avian
The masses of the planets do not significantly determine how fast they go around the sun. If Jupiter were in the exact place where Mercury is, it would take the same time to go aorund the sun as Mercury - about 88 earth days. If Mercury, a tiny pebble compared to Jupiter, were placed here Juptier is, it would take the same time as Jupiter to go around the sun - about 12 earth years. The gravitational force exterted by the mass of the planet on the sun has little effect on their overall motion on the sun. The sun's massive gravity when compared to the planets is the overwhelming dominating factor here.

Good point. I'm always forgetting how big the sun is.

Originally posted by Avian

The acceleration that an object experiences due to gravity (or any other force) is indepenant of mass of the object.

Here's where I disagree with you. The acceleration an object experiences due to a force is not independent of its mass. According to Newton's second law, Acceleration = Force/Mass. If I exert a force on a basketball, it's going to accelerate a whole lot faster than if I exert the same force on the sun.

[Avian(Admin)]

Originally posted by Bob Lentil
Here's where I disagree with you. The acceleration an object experiences due to a force is not independent of its mass. According to Newton's second law, Acceleration = Force/Mass. If I exert a force on a basketball, it's going to accelerate a whole lot faster than if I exert the same force on the sun. [/b]

Don't worry - this one can be tricky. I'm probably not explaining it as well as I could.

The acceleration two objects experience by the same force is independant of the mass of those objects. In my example, the acceleration on a bowling ball and the feather on the earth are 9.8 m/s^2 for both objects, even though the mass of the feather is much less than the bowling ball. This phenomena was first described by Galileo. The forces on those objects toward the earth are different because of their different masses (it hurts a lot more get a bowling ball dropped on your head than a feather!), but the acceleration they experience toward the ground is the same (again, we're neglecting the gravity generated by the objects themselves). It's that point where Newton improves on Galileo's findings.

For our example on earth, it goes something like this mathematically:
F=ma
The force of gravity is equal to the mass of the object times the gravitational acceleration, so (g)
mg=ma
the masses cancel out on each side, so...
a=g
The acceleration the object experiences is equal to the gravitational acceleration. The acceleration of that object due to gravity is independant of its mass (no m in that equation).

In another more basic mathematical example, Newton found that the gravitational force between two objects is:
F=GmM/r^2
Where G is a constant, m is the mass of object one, M is the mass of object two, and r is the distance between them.
Okay, again, the force on the object can also be desribed as mg (its mass times the acceleration due to gravity), so...
mg=GmM/r^2
You can probably see where this is going again. The object's mass appears on both sides of the equation. They cancel out, and we're left with
g=GM/r^2
That says the acceleration due to gravity the object experiences depends on the mass of the other object and the distance to it. The object's own mass is not a factor.

The Apollo astronauts demonstrated this in a great experiment on TV. While on the moon, an astronaut held out an hammer and a feather. He dropped them both at the same time in the near-vacuum environment of the moon, and they both hit the lunar surface simultaneously.

But the acceleration doesn't have to be be gravitational acceleration (g) - it can be any acceleration by any external force. A spaceship and a black hole. A baseball and the earth. Chris Squire and Spandex.

Avian

[Bob Lentil]

Yeah, I understand how acceleration due to gravity is independent of the mass in question. My problem comes in with the any other force part. All of the examples you cited (A spaceship and a black hole. A baseball and the earth. Chris Squire and Spandex) are just more gravitational interactions, unless I misunderstand you.

The acceleration two objects experience by the same force is independant of the mass of those objects.

If I construct a device to strike a bowling ball and a feather with the same force (in a vacuum and assuming the feather is as rigid as the bowling ball and won't absorb most of the force), the acceleration imparted to the feather will be far greater due to its lesser mass. Gravitational acceleration is independent of the mass, because it is always the force that changes due to the mass and acceleration, not the other way around (so you always have different forces acting on the objects). However, given the same force to impart an acceleration, the mass will most definitely affect the outcome.

[Rick and Roll]

Originally posted by Avian

I'd like to take this opportunity to mention how much research and incredible rigorous work goes into these "theories." A scientific theory is not like a theory you or I may have typing on this board - it has an entirely different meaning.

If you only knew how I agonize over these posts.....a lot of rigourous work here too

[Avian(Admin)]

Originally posted by Bob Lentil
[b]Yeah, I understand how acceleration due to gravity is independent of the mass in question. My problem comes in with the any other force part. All of the examples you cited (A spaceship and a black hole. A baseball and the earth. Chris Squire and Spandex) are just more gravitational interactions, unless I misunderstand you.

Sorry for the confusion - in my haste I meant to type "gravitational acceleration" (g). It could be another gravitational force interaction, like a baseball and a black hole, or you skydiving on Mars. I meant to make the point that this is not special to the earth, or the particular gravitational acceleration near its surface, g.

Like I said, the force on each of these objects is different due to their different masses (it hurts a lot more to get hit with a falling bowling ball than a feather). Of course, if you impart the same force on them, they will have different accelerations. So, my statement should read:

But the acceleration doesn't have to be be gravitational acceleration (g) - it can be any acceleration by any external gravitational force. A spaceship and a black hole. A baseball and the earth. Chris Squire and Spandex.

Again, the constant things in these situation for each object (not going at significant relativistic speeds) is acceleration and mass. Each object will have a different downward force due to its mass.

To relate it back to what we were talking about..

Yes, that's why it has to go so fast around its orbit. Assuming it keeps the same mass but slows down, its orbit would decay and it would spiral into the sun. Likewise, if it maintains the same speed and gets heavier, the gravitational force between the sun and the planet increase, and you get the same result.

Fundamentally, a planet's period (time it takes to go around the sun) is not determined by its mass, for a planet of the sizes we are talking about. Just its distance from the sun. You can have a huge gas giant very close to the sun. You can have a tiny planet like Pluto way out in the outer regions. We neglect the force on the sun by the planet due to gravity because it's so small. If the planet, for some reason, slows down or speeds up due to an impact or something, its centripetal acceleration changes. It will migrate into another orbit with a different period that matches the new acceleration, unless that orbit brings it crashing into the sun or another object first!

[Bob Lentil]

Alright, I'm satisfied now. Thanks for setting my orbit post straight. I propose we start a new forum called "Science Talk With Avian," where we do this all the time.

[Roger -Dot- Lee(Admin)]

Originally posted by Avian
Nothing without mass can travel faster than light either (such as light itself - electromagnetic radiation).

OK, I'll buy that. Stipulated.

Of course, with anything in science, the more information you get, the more questions get raised.

Boy, you ain't whistlin' Dixie here.

There are a few interesting things about the cosmic microwave background radiation that are even more amazing. By looking very, very closely at the variations in the sky, some amazing theories have developed as to how the early Universe formed.

Yes. I'm going through web sites now that are doing a dandy job of explaining it, though there are a couple that are putting out information that's making the speed limit of light easy to swallow by comparison (IE that "The Big Bang didn't happen as a single explosion in one place but was the simultaneous appearance of all matter everywhere." Huh? I find that even harder to believe).

Combine this with the other separate tons of evidence that points to a big bang (expanding universe, age of stars, etc), and you can start to see why it is the defacto theory of how our universe was created.

Indeed. The more I read on it, the more it makes sense. Of course that still doesn't answer WHY we can't go faster than light (an issue that I have with that theory I'll address shortly, as you touched on my biggest problem with it below).

No molecules here. Just light. Don't confuse particle radiation (electrons, neutrons, etc.) with electromagnetic radiation (a fancy word for light). We're talking about the leftover "glow" of the big bang.

OK, I think we've hit on my first bit of misunderstanding. I was always under the impression that matter and energy were interchangable. IE you could make matter from energy (see linear accellerators for an example) and energy from matter (go buy a firecracker for an example of this).

Speed of light: fact or fiction?
Rest assured, it is, by all measures of our current understanding of physics.

I'm sure it is. I know that I have enough trouble getting from sitting to walking, let alone up to 186,000 miles/second (in a vacuum).

But WHY?

Einstein's equation that describes this states that the faster you go, the more your mass increases, therefore requiring even more energy to accelerate you to a faster speed.

And herein lies my single biggest problem with the whole thing. This, in my world view, violates the laws of conservation of matter. HOW can one's mass increase simply by virtue of it's velocity?

Let's go with a scenario that illustrates my understanding. Maybe if you see it, you can understand where I'm coming from and why I have problems with this theory (and I'll freely admit that it's more than likely my understanding that's flawed rather than the theory):

I hop on a plane with a gold brick. 1 lb of pure 24 karat gold. I land in Wichita and pick you up, and we both hop on another plane to San Diego. While enroute, I hand you the gold brick (which is now more massive due to our velocity). Suddenly this 1 lb brick is worth more since it has more mass? When we hit San Diego, do you hand Jim a 1 lb gold brick? Or is it 1 lb plus whatever mass we picked up when I handed the brick to you over New Mexico?

See what I'm saying? It's a direct violation of the laws of conservation of energy and conservation of matter (unless the thrust that was being emitted by the jet engines magically makes it's way into the gold bar).

WHAT am I missing here?

As you get close to the speed of light, your mass increases to a huge amount, until finally, it would take an infinite amount of energy to accelerate you to beyond the speed of light.

See the above scenario, but instead of heading southwest, we go northeast, and instead of a cruise speed of 550 kts, we accellerate to close to the speed of light (taking the scenic route, of course). Does the gold bar grow that much? And what happens to the mass as we slow down? Granted, said 1 lb gold bar might actually have a mass of 1 lb + [insert appropriate formula here], but what happens when we land? Does it shrink? Where does the mass that has been accumulating go?

I think one part of my problem is that I'm not using the same definition of mass as everyone else is. Is that not how much something weighs? The sum of the molecular weights in our 1 lb bar of gold or our 140 some-odd lb toothless redneck from the Wilds of North Georgia? How can this be changed? It violates the laws of conservation of matter and energy.

I've GOT to be missing something. Something fundimental.

That, of course, cannot be done. Humans hate limits, and have, of course, theorized several fanciful and convoluted ways that perhaps we could get around this. But none really hold any water.

Yeah, no kidding. I've never liked limits of any kind. But when someone tells me that this or that is physically impossible, I'm reminded of one of the top physicists of the late 1800s who stated that no object would ever be able to break the speed of sound and continue flying. His name escapes me at the moment. Col. Charles (Chuck) Yeager proved him categorically wrong, and the Concorde (and it's Russian counterpart) have proven that wrong.

Expensive, but wrong.

Could new theories develop that would somehow disprove this? You could say yes, and of course, that's but much of modern physics would probably fall with it. And much of moden physics works pretty well. Could we discover a whole new branch of physics, like we did with quantum physics, that would take hold in special circumstances or something? Who knows?

The second scenario would be my best guess. After reading many sites on some of the new discoveries (www.gsfc.nasa.gov is any astro-geek's friend) that have been made over the last umpty years, it'd be more likely that another branch that takes hold at higher relative energies would take effect.

I'd like to take this opportunity to mention how much research and incredible rigorous work goes into these "theories."

Oh boy, you know it. For a while before I married Mrs.Lee, I dated a research scientist at one of the major labs up in the Chicago area (something about developing a microbe that could eat plutonium and poop lead or something along those lines). She showed me the level of investigation that has to go into a theory before any real scientist would even CONSIDER publishing it, simply because there are hundreds of other scientists out there that WILL pour over the data, duplicate the research, and cackle with glee upon being able to disprove a theory (a process that takes almost as much time and energy to prove the same theory).

A scientific theory is not like a theory you or I may have typing on this board - it has an entirely different meaning. If you think the current U.S. presidential election is nasty, you should see what even the most frivoslous proposal in science goes through. Like the theory of gravity, and the theory of biological evolution, Einstein's Theory of Relativity have planets full of rigorous and objective evidence along multiple lines over millions of years in some cases, by upwards of millions of people, in their favor. Every serious attempt to explain them away has failed. Like the rejection of notions of a flat earth, and that the stars are pinpricks in the curtain of heaven, humans have benefited greatly through the scientific method.

Never said I didn't, and I certainly didn't mean to infer that. I know full well that, given the option of a room full of physicists vs. a VERY amateur quasi-protogeek behind a Mac in North Georgia, I wouldn't stand much of a chance...except maybe to get a lesson or two (if in nothing more than humility, and maybe physics).

The objective and extremely rigorous review by thousands if not millions of scientists from all over the world through various generations is our only hope against delf-delusion. And boy oh boy, do we love to delude ourselves in many things.

I live in Georgia, and before that, Northern California. I've seen self delusion on MANY different scales, from MANY different people. Some of it is honest, some of it is just silly.

The scientific method has given us so much - longer lives, a method of feeding ourselves and the millions around us; it has also taken us to those tiny pinpricks in the heavens. It's enemy, and therefore our enemy as a species, is ignorance and fear.

Right. Which is why I don't mind asking these questions at risk of making myself look like a fool. Had I done this in college (instead of viewing life from the bottom of a beer bottle), I might have a different understanding of the way things are. Alas...

Roger

[Avian(Admin)]

Yes. I'm going through web sites now that are doing a dandy job of explaining it, though there are a couple that are putting out information that's making the speed limit of light easy to swallow by comparison (IE that "The Big Bang didn't happen as a single explosion in one place but was the simultaneous appearance of all matter everywhere." Huh? I find that even harder to believe).

Yes, that's another misconception about the big bang - that it was an explosion. The big bang didn't just contain all the energy the Universe would use - it also contained the space for the Universe. Before the big bang, there wasn't even space - a void's void. Science cannot yet describe what was there before the big bang. So when all the energy started expanding from that tiny singularity, so did all the space the universe would grow into. And for that matter, time as well. Time is a physical thing - just as much an entity as the keyboard you're typing on. Space and time are intertwined. So we can't describe the big bang as an explosion, since there was nothing for the energy, space and time to explode into - it was something that's not intuitive for us to understand, but that can be described by physics in the ways you're reading about.

Edwin Hubble was the first to discover the expansion of the Universe. He saw that all the galaxies around us are travelling away from us. But it's not the galaxies per se that are travelling away from us - it's the space itself that contains them, and everything in between that is expanding.

OK, I think we've hit on my first bit of misunderstanding. I was always under the impression that matter and energy were interchangable. IE you could make matter from energy (see linear accellerators for an example) and energy from matter (go buy a firecracker for an example of this).

What you say is essentially correct - they are interchangable, but they are not the same thing in their separate forms. It's the famous E=mc^2. A planet does not share the same properties as, say gamma rays, but you can change a planet into gamma rays and other energy through various processes, like sending it through a crushing experience into a black hole.

And herein lies my single biggest problem with the whole thing. This, in my world view, violates the laws of conservation of matter. HOW can one's mass increase simply by virtue of it's velocity?

There are some things aobut physics that stop being intuitive at a certain point. Gravity, momentum, and forces all seem to make sense to us in our everyday world. But there are certainly things that blow our minds, that are not intuitive at all, and seem to be paradoxical. Relativity and quantum physics are loaded with them. You can sit there and ask yourself all day why, and tell yourself it doesn't make any sense. But in the end, you can blame your brain. This is a part of the Universe that we haven't had any day to day experience with, so we reject it as "not making sense".

With relativity, you can get a good start on things by keeping in mind another one of Einstein's greatest discoveries - that space and time are intertwined. Space and time are the fabric of the Universe in which everything is painted. Start speeding through the Universe, you're not only speeding through the fabric of space itself, but the fabric of time.

Yes, mass increases with speed relative to someone standing still. Your time also slows down as compared to someone standing still relative to you. "Why?" No one knows. It's the nature of the Universe we live in. "It doesn't make any sense!" It doesn't have to! Our minds evolved to hunt and survive on the land of this tiny planet. We have only the smallest inkling of the true nature of the Universe. You might say "Of course it doesn't make sense!"

I hop on a plane with a gold brick. 1 lb of pure 24 karat gold. I land in Wichita and pick you up, and we both hop on another plane to San Diego. While enroute, I hand you the gold brick (which is now more massive due to our velocity). Suddenly this 1 lb brick is worth more since it has more mass? When we hit San Diego, do you hand Jim a 1 lb gold brick? Or is it 1 lb plus whatever mass we picked up when I handed the brick to you over New Mexico?

The mass of the brick does change, as does you, me, the airplane, everyone in it, etc. It changes as measured by a person standing on the ground. Your watch also runs slower as compared to someone on the ground. But to you, everything appears to stay the same. With the speed and acceleration loss, your mass and time change as well.

An excellent book on this subject is "About Time" by Paul Davies.

See what I'm saying? It's a direct violation of the laws of conservation of energy and conservation of matter (unless the thrust that was being emitted by the jet engines magically makes it's way into the gold bar).

That's an excellent question! If you converted all your mass to energy while at relativistic speeds, aren't you adding more energy to the Universe that wasn't there in the first place? Doesn't that violate the conservation of mass and energy that states that you cannot add mass or energy to the Universe. You might also take that thought a different direction and ask "If I go fast enough, will I become a black hole?"

Traditional Newtonian physics start to break down at relativistic speeds. New rules are needed. It gets complicated. My fingers are getting tired, so here's a few links onthe subject...

If I go fast enough, will I become a black hole?

Momentum, energy and length at relativistic speeds

I've GOT to be missing something. Something fundimental.

Not really - you're asking all the right questions. The answer is that the rules change when you go very fast. You just need to know what the new rules are (see above). And at speeds that you're talking about, the relativistic effects are extremely minimal.

Yeah, no kidding. I've never liked limits of any kind. But when someone tells me that this or that is physically impossible, I'm reminded of one of the top physicists of the late 1800s who stated that no object would ever be able to break the speed of sound and continue flying. His name escapes me at the moment. Col. Charles (Chuck) Yeager proved him categorically wrong, and the Concorde (and it's Russian counterpart) have proven that wrong.

But that's a thought trap many fall into. Humans can be wrong. But what was really the scientific strength of that argument? Was it based on experimentation, was it accepted by his scientific peers? Did it really hold up to scrutiny? Just because some guy was wrong once about something doesn't invalidate or weaken a scientific principle that has withstood countless attacks and the test of time. Nor does it cast light on what the scientific evidence was of his claim. Did he have a solid argument based on the data at the time? I don't know - I would go and find out though. Are generally scientific notions proven wrong in history? Yes. But you can usually see where the weakness was in the evidence - some unexplained untestable factor that had to be approximated, or a new theory invented to make it work. Each argument HAS to be evaulated on its own merits based on the evidence and peer review of it. Don't fall into this trap.

The second scenario would be my best guess. After reading many sites on some of the new discoveries (www.gsfc.nasa.gov is any astro-geek's friend) that have been made over the last umpty years, it'd be more likely that another branch that takes hold at higher relative energies would take effect.

Again, the state of physics is incredibly advanced - far more than most people realize. There are many lines of evidence pointing to the current view of relativistic physics to the highest energies. The door is always open to discovery, but no one should poo poo the solidness of the current state of things. They are very, very solid. The big thing folks are working on now is tying everything together. Quantum physics must meet relativistic physics somewhere - right now these two seem to work great in their separate special cases (the very small, and the very big) - but something must tie them together into one theory. So far, no luck.

[progdirjim(Admin)]

Originally posted by Roger Lee

I hop on a plane with a gold brick. 1 lb of pure 24 karat gold. I land in Wichita and pick you up, and we both hop on another plane to San Diego. While enroute, I hand you the gold brick (which is now more massive due to our velocity). Suddenly this 1 lb brick is worth more since it has more mass? When we hit San Diego, do you hand Jim a 1 lb gold brick?

The answer to your question is YES, you hand Jim a 1 lb gold brick.

Originally posted by Roger Lee
Or is it 1 lb plus whatever mass we picked up when I handed the brick to you over New Mexico?

See what I'm saying? It's a direct violation of the laws of conservation of energy and conservation of matter (unless the thrust that was being emitted by the jet engines magically makes it's way into the gold bar).

WHAT am I missing here?

Roger

Your missing the principle of "as measured." That gold bar does not have an absolute weight regardless of where it is in the universe. It varies based on when and where and how fast you're going while you measure it. If you had a scale on that plane going the speed of light, it will measure the gold bar "heavier". If you could somehow weigh that bar on a scale that was sitting on earth, it would weigh the bar exactly the same as it would on earth. We're talking "frames of reference", and the weight of the gold bar on the moving plane versus its weight on "stationary" earth are two very different frames of reference.