Spyman

Hehe, I was not much better, I went to wikipedia to check the size of Earth too... and I mixed up the radius as the diameter... Epic fail for me too...

I agree with Ophiolite, a listing on which posts we have recieved positive or negative votes on would be nice. But we should not be able to see who made those votes, it would only cause trouble and unfair revenges.

[spoiler] Hidden text [/spoiler]

Yes, it seems as if you got the general ide.

Well, I am not familliar with the WolframAlpha site, but from a quick glance there seems to be two problems: First, 6000000 km/s is a total closing speed that is 20 times faster than light and not the double of a few percent. Secondly, an asteroid with twice the Earth's diameter, (13000000m), contain 4 times more mass than two Earths.

I am not trying to explain the constancy of lightspeed, it is an confirmed fact by experimental observation and don't need a reason. Eigenzeit seems to translate from german to "proper time" which is a concept in the theory of relativity and connected to lightspeed. I still don't understand what you are trying to say and how it is related to what I said and the context of current conversation.

Sorry, unable to understand that.

To point out that the speed of photons through space are still c for all observers, even if it appears to be slower for some.

In post #9 I said: The Hubble constant is constant throughout the Universe but NOT throughout history. The expansion is thought to be equal everywhere inside 3D space of the Universe but not equal through different durations of time. Scientists examine the observed pattern of how the Universe have been expanding through history by looking further away and compare with their models of the Universe. EDIT: The laws of nature causing the expansion are assumed to be consistent.

As questionposter says it is a game of words and their meaning, not an science question for Huodinis. Tip: You need to use both the mirror and the table to escape. The shape of the room is irrelevant.

Try to imagine the voltage potential as an height and electrons as bowling balls. The battery is an elevator lifting the bowling balls to an increased height of 3 meters and then they roll down back to the starting point. The lamp L1 has a heigth of 1.2 meters and the lamp L2 of 1.8 meters. The black points are reference points for your measuring and don't have any heigths themselves and as swansont already has said the wires or cables represented by the black lines have such small heigth or voltage potential differences that they are usually neglected. As such the 0V point is the starting point for the elevator or the ground level, the 1.8V point is 1.8 meters above the starting point or above the ground and the 3V point is 3 meters above the starting point or above the ground. Between the 0V point and the 1.8V point there is a length of 1.8 meters or a voltage potential of 1.8 Volt, between the 1.8V point and the 3V point there is a length of 1.2 meters or a voltage potential of 1.2 Volts and between the 0V point and the 3V point there is a length of 3 meters or a voltage potential of 3 Volts. Therefore there is no voltage potential difference between L1 and L2, in the analogy of heigths they are standing directly above/under each other. In a water analogy the electrical current is the flow and voltage potential is pressure.

I don't think you can explain the phenomena in the example provided by The time Traveller in post #31 with Lorentz transformations. The speed of light is c for both observers, but the distant observer is unable to measure the real length along light's curved path inside a gravity field.

I am sorry but in the context your question doesn't make any sense, you are either playing silly word games or I am failing to understand you. Could you please rephrase your question without using the word "uniform" and explain further why you think scientists should be unable to model expansion.

The rate of expansion is not uniform, but the underlying principle in nature causing this phenomenon might be consistent.

I stand corrected, the distant observer can't see the curving of space and therefore the distance covered by light seems shorter for him.

AFAIK, the gravitational time dilation does NOT have an effect on the measured speed of light for any observers.

It is pretty obvious that it's not the scientific consensus who are blindly clinging to beliefs bordering to ludicrous ignorance of known facts.

There are several models that describes the expansion of space but the basic is the Friedmann-Lemaître-Robertson-Walker metric and the current standard model in big bang cosmology is the Lambda-CDM model. At first the rate was fast, then leveling off and now it is accelerating, and don't see how you can call that unvarying. Dark energy is named "dark" because we don't know what it is and how it works.

AFAIK spacetime is 4 dimensional, 3 spatial and 1 temporal.

So then, what is the general overall average magnetic force from a piece of wood which contains a large quantity of "to some degree magnetic" atoms? Do you think this magnetic force is increased in larger pieces of wood? How big piece of wood do you need to by magnetism lift a small magnet?

The increase in redshift relative distance is constant today but it was a different constant one billion year ago. The Hubble constant is the constant ratio of how fast a distant object is receding depending on its distance right now, but it changes over time. The Hubble constant is constant throughout the Universe but NOT throughout history. According to current Big Bang theory the Universe expanded rapidly at first, but since the Universe was much denser in the past gravity was much stronger and affected the expansion more, therefore gravity has been slowly braking the expansion until around 6 billion years ago when the Universe got to spread out and dark energy got the upper hand causing the rate of expansion to accelerate. The expansion or contraction of the universe depends on its content and past history. With enough matter, the expansion will slow or even become a contraction. On the other hand, dark energy drives the universe towards increasing rates of expansion. The current rate of expansion is usually expressed as the Hubble Constant (in units of kilometers per second per Megaparsec, or just per second). http://map.gsfc.nasa.gov/universe/uni_expansion.html The Hubble constant H is one of the most important numbers in cosmology because it may be used to estimate the size and age of the Universe. It indicates the rate at which the universe is expanding. Although the Hubble "constant" is not really constant because it changes with time (and therefore should probably more properly be called the "Hubble parameter"). http://csep10.phys.utk.edu/astr162/lect/cosmology/hubble_constant.html H0 is Hubble's constant and corresponds to the value of H (often termed the Hubble parameter which is a value that is time dependent and which can be expressed in terms of the scale factor) in the Friedmann equations taken at the time of observation denoted by the subscript 0. This value is the same throughout the universe for a given comoving time. (...) Since the Hubble "constant" is only a constant in space, not in time, the radius of the Hubble sphere may increase or decrease over various time intervals. The subscript '0' indicates the value of the Hubble constant today. Current evidence suggests the expansion of the universe is accelerating (see Accelerating universe), meaning that for any given galaxy, the recession velocity dD/dt is increasing over time as the galaxy moves to greater and greater distances; however, the Hubble parameter is actually thought to be decreasing with time, meaning that if we were to look at some fixed distance D and watch a series of different galaxies pass that distance, later galaxies would pass that distance at a smaller velocity than earlier ones. http://en.wikipedia.org/wiki/Hubble's_law Timeline of the Big Bang (...) The earliest phases of the Big Bang are subject to much speculation. (...) Approximately 10−37 seconds into the expansion, a phase transition caused a cosmic inflation, during which the Universe grew exponentially. (...) After inflation stopped (...) The Universe continued to grow in size and fall in temperature (...) with less space and everything closer together, gravity had the upper hand, and it was slowly braking the expansion. But eventually, after numerous billion years of expansion, the growing abundance of dark energy caused the expansion of the Universe to slowly begin to accelerate. http://en.wikipedia.org/wiki/Big_Bang The current scientific consensus of most cosmologists is that the ultimate fate of the universe depends on its overall shape, how much dark energy it contains, and on the equation of state which determines how the dark energy density responds to the expansion of the universe. Recent observations have shown that, from 7.5 billion years after the Big Bang onwards, the expansion rate of the universe has actually been increasing, commensurate with the Open Universe theory. http://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe

The expansion of space doesn't have a constant rate.

A nuclear blast is fully able to fragment, vaporize and/or deflect an asteroid. However bombing it with the sole purpose to break it up into smaller pieces will only help if it is to small to cause an catastrophic extinction level event, an Earth killer will release enough energy into the atmosphere to wipe us out even if all pieces are small enough to burn up before they reach the ground. Destruction methods seems more like a last ditch emergency rescue when time and/or economy is not sufficient to save us, if we find out about the asteroid in time I would opt for a safer avoidance strategy. We only have to slow it down enough to reach Earth's solar orbit about sevent minutes later for it to miss us. Interesting article in Wikipedia on the subject: Asteroid mitigation strategies are "planetary defense" methods by which near-Earth objects could be diverted, preventing potentially catastrophic impact events. A sufficiently large impact would cause massive tsunamis or (by placing large quantities of dust into the stratosphere, blocking sunlight) an impact winter, or both. A collision between the Earth and a ~10 km object 65 million years ago is believed to have produced the Chicxulub Crater and the Cretaceous-Tertiary extinction event. While the chances of such an event are no greater now than at any other time in history, there is a very high chance that one will happen eventually. Recent astronomical events (such as Shoemaker-Levy 9) have drawn attention to such a threat, and advances in technology have opened up new options to prevent them. http://en.wikipedia.org/wiki/Asteroid-impact_avoidance

The Hubble constant is time dependent.

This one? -> Stationary light Interesting thought experiment / new view on space time