Sure, Everest have been under 8000 metres high. I have NEVER said that Everest was always above 8000 m high.
But Everest have never been under 8000 m in the last 5000 years, BilliardsBall.
Everest is all part of the Himalayas. A whole range of mountains that arose from the Indian subcontinent tectonic plate pushing into the Asian tectonic plate, causing the uplifting of terrains that we called the Himalayas. The Indian plate are still pushing, and the whole Himalayas, including Everest, are still rising mm by mm, each year (to be more precise Everest is rising by 4 mm per year). But it is not just moving upward, the Himalayas is moving more northeasterly each year, from 3 to 6 mm.
Everest is now 8848 metres above sea level, but in 1856, it was only about 8 metres shorter than it is now.
4 millimetres per year, BilliardsBall. You do the calculation and that would mean 5000 years ago, or 3000 BCE, Everest would have been 20 metres shorter than it is today, which is about 8828 metres.
For Everest to be under 8000 metres, that would mean going back in time of 212,000 years ago. This is well before the discovery of the earliest Homo sapiens.
And the time before the Himalayas, when the two tectonic plates was separated by the sea, you are looking at 70 million years ago.
If you look at the Australian tectonic, it is moving at slower than snail-pace of 5.6 cm per year. Comparing that to the Indian plate of 3.7 cm per year, the Australian plate is actually a sprinter.
To underscore the limitations of uniform assumptions, a professor showed his class a dripping faucet, the current rate of drip and the current level of water in the beaker, then asked his class to tell him how long the faucet had been dripping--they ran their calculations and conclusions before he turned the faucet to drip faster and then slower... do you get the point of the exercise?
I try to keep calm about such things, but just to let you know, the reason why Christians get annoyed at this sort of "We've been watching the weather carefully since the 1860s so we know what the weather was like 300,000 years ago" stuff is God's reproof to Job:
“Who is this who darkens counsel
By words without knowledge?
3 Now prepare yourself like a man;
I will question you, and you shall answer Me.
4 “Where were you when I laid the foundations of the earth?
Tell Me, if you have understanding.
5 Who determined its measurements?
Surely you know!
Or who stretched the line upon it?
6 To what were its foundations fastened?
Or who laid its cornerstone,
7 When the morning stars sang together,
And all the sons of God shouted for joy?
8 “Or who shut in the sea with doors,
When it burst forth and issued from the womb;
9 When I made the clouds its garment,
And thick darkness its swaddling band;
10 When I fixed My limit for it,
And set bars and doors;
11 When I said,
‘This far you may come, but no farther,
And here your proud waves must stop!’
12 “Have you commanded the morning since your days began,
And caused the dawn to know its place,
13 That it might take hold of the ends of the earth,
And the wicked be shaken out of it?
14 It takes on form like clay under a seal,
And stands out like a garment.
15 From the wicked their light is withheld,
And the upraised arm is broken.
16 “Have you entered the springs of the sea?
Or have you walked in search of the depths?
17 Have the gates of death been revealed to you?
Or have you seen the doors of the shadow of death?
18 Have you comprehended the breadth of the earth?
Tell Me, if you know all this.
19 “Where is the way to the dwelling of light?
And darkness, where is its place,
20 That you may take it to its territory,
That you may know the paths to its home?
21 Do you know it, because you were born then,
Or because the number of your days is great?
22 “Have you entered the treasury of snow,
Or have you seen the treasury of hail,
23 Which I have reserved for the time of trouble,
For the day of battle and war?
24 By what way is light diffused,
Or the east wind scattered over the earth?
25 “Who has divided a channel for the overflowing water,
Or a path for the thunderbolt,
26 To cause it to rain on a land where there is no one,
A wilderness in which there is no man;
27 To satisfy the desolate waste,
And cause to spring forth the growth of tender grass?
28 Has the rain a father?
Or who has begotten the drops of dew?
29 From whose womb comes the ice?
And the frost of heaven, who gives it birth?
30 The waters harden like stone,
And the surface of the deep is frozen.
31 “Can you bind the cluster of the Pleiades,
Or loose the belt of Orion?
32 Can you bring out Mazzaroth in its season?
Or can you guide the Great Bear with its cubs?
33 Do you know the ordinances of the heavens?
Can you set their dominion over the earth?
34 “Can you lift up your voice to the clouds,
That an abundance of water may cover you?
35 Can you send out lightnings, that they may go,
And say to you, ‘Here we are!’?
36 Who has put wisdom in the mind?
Or who has given understanding to the heart?
37 Who can number the clouds by wisdom?
Or who can pour out the bottles of heaven,
38 When the dust hardens in clumps,
And the clods cling together?
39 “Can you hunt the prey for the lion,
Or satisfy the appetite of the young lions,
40 When they crouch in their dens,
Or lurk in their lairs to lie in wait?
41 Who provides food for the raven,
When its young ones cry to God,
And wander about for lack of food?