Log in
Register
Search
Search titles only
By:
Search titles only
By:
Forums
New posts
Forum list
Search forums
Leaderboards
Games
Our Blog
Blogs
New entries
New comments
Blog list
Search blogs
Credits
Transactions
Shop
Blessings: ✟0.00
Tickets
Open new ticket
Watched
Donate
Log in
Register
Search
Search titles only
By:
Search titles only
By:
More options
Toggle width
Share this page
Share this page
Share
Reddit
Pinterest
Tumblr
WhatsApp
Email
Share
Link
Menu
Install the app
Install
Forums
Discussion and Debate
Discussion and Debate
Physical & Life Sciences
Earth in hot water? Worries over sudden ocean warming spike
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="sjastro" data-source="post: 77650013" data-attributes="member: 352921"><p>I’m not sure how such small times of the order 10⁻²¹ second for virtual particles can even be directly measured.</p><p>The way around this is to look at the energy time Heisenberg uncertainty principle ΔE.Δt ≥ h/4π by introducing the reduced Planck’s constant h-bar ħ = h/2π.</p><p></p><p>The Heisenberg uncertainty principle then becomes ΔE.Δt ≈ ħ/2.</p><p>It is found when a quantum state decays there is an uncertainty in the energy values measured.</p><p>It does not follow a normal or Gaussian distribution but a special distribution known as the Breit-Wigner distribution.</p><p></p><p style="text-align: center">[ATTACH=full]346448[/ATTACH]</p><p></p><p>A feature of this distribution is the uncertainty in energy ΔE is the width of this distribution half-way up the curve as illustrated and is labelled Γ and the uncertainty in energy ΔE can be approximated as ΔE ≈ Γ/2 = ħ/2τ where τ is the lifetime of the state.</p><p>In this case τ is simply Δt and ΔE ≈ ħ/2Δt which is the Heisenberg uncertainty principle.</p><p></p><p>Δt is calculated from the uncertainty in the energy measurements, if ΔE is very small then Δt becomes very large such as the decay ²³⁸U.</p><p>Conversely when ΔE is very large for the creation and annihilation of virtual particles in a quantum vacuum then Δt is very small.</p></blockquote><p></p>
[QUOTE="sjastro, post: 77650013, member: 352921"] I’m not sure how such small times of the order 10⁻²¹ second for virtual particles can even be directly measured. The way around this is to look at the energy time Heisenberg uncertainty principle ΔE.Δt ≥ h/4π by introducing the reduced Planck’s constant h-bar ħ = h/2π. The Heisenberg uncertainty principle then becomes ΔE.Δt ≈ ħ/2. It is found when a quantum state decays there is an uncertainty in the energy values measured. It does not follow a normal or Gaussian distribution but a special distribution known as the Breit-Wigner distribution. [CENTER][ATTACH type="full" alt="breit.png"]346448[/ATTACH][/CENTER] A feature of this distribution is the uncertainty in energy ΔE is the width of this distribution half-way up the curve as illustrated and is labelled Γ and the uncertainty in energy ΔE can be approximated as ΔE ≈ Γ/2 = ħ/2τ where τ is the lifetime of the state. In this case τ is simply Δt and ΔE ≈ ħ/2Δt which is the Heisenberg uncertainty principle. Δt is calculated from the uncertainty in the energy measurements, if ΔE is very small then Δt becomes very large such as the decay ²³⁸U. Conversely when ΔE is very large for the creation and annihilation of virtual particles in a quantum vacuum then Δt is very small. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Discussion and Debate
Discussion and Debate
Physical & Life Sciences
Earth in hot water? Worries over sudden ocean warming spike
Top
Bottom