大家有無咩關於physics嘅問題但又無地方問

殺龍Bra絲 2021-6-29 06:38:59 光學(optics) 嘅 virtual image, 我哋會透過extend 條light ray (畫dotted lines) 去定義個virtual image嘅位置。

點樣用Maxwell's Equations 去解釋 naked eye / camera 會 capture到呢d所謂嘅virtual image ?

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唔識反彈嘅果然翁 2021-6-29 08:01:38 Hubbles law 淨係 locality 先meaningful

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佢個 v = h To Te/To 係 apparent velocity 唔係space dependent 架喎

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唔識反彈嘅果然翁 2021-6-29 08:04:28 唔係
只要你invest 夠多computational power 去做 individual 既 Naiver Strokes Equation solving 既話佢係particular situation 會有solution

唔識反彈嘅果然翁 2021-6-29 08:13:04 Lambda CDM model 有個新既alternative theory
MOND

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至於點解佢會expand

其實佢big bang initially 有KE
佢又無 net energy loss 咪繼續expand

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雜種維尼 2021-6-29 08:19:11 聽講音速唔係一個固定數字

有碼宮薰 2021-6-29 08:21:20 睇media

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利申 dse physics

唔識反彈嘅果然翁 2021-6-29 08:23:49 同Maxwell's Equation 無關係架喎
你當係一個神技之類既野
你用個light incident angle refractive index curvature 去計一樣可以出到result

黃色小雞雞 2021-6-29 08:24:54 點樣測試光速係點都係Constant?
點解？多左啲速度去左邊？

數學物理 2021-6-29 08:29:25 點揾 magnetic monopole

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唔識反彈嘅果然翁 2021-6-29 08:39:59 無
係assumption 只不過佢係experimentally consistent
http://hyperphysics.phy-astr.gsu.edu/hbase/c.html

因為relativity 既重點就係inertial frame 既transformation
所以例如你依家係一架太空船 travelling perpendicular to 地球
咁當你加速既時候
你相對於earth 既 velocity 會increase
咁當你既velocity in respect to the earth -> 光速既時候
係地球見到你架太空船樣會越黎越紅
by

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殺龍Bra絲 2021-6-29 08:40:36 應該咁講：點解會capture到 d virtual image

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我想用fundamental d 嘅野去解釋 e.g 粒光子經過反射點樣encode咗呢d 資訊

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追風箏的男孩子 2021-6-29 08:41:15

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唔識反彈嘅果然翁 2021-6-29 08:44:11 因為佢用 convex lens refocus 個diffracted light
仲有photon 係wave唔係particle 喎
http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/surpow.html
你睇呢個啦
都係用differential equation 去計架啦

街頭詩人.羅方 2021-6-29 08:51:19 想問好耐
Fusion會令Mass變Energy
Fission又可以令Mass變Energy
但係明明兩個原理係相反 (二合為一 vs 一分為二)
點解都可以令Mass變Energy

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唔識反彈嘅果然翁 2021-6-29 08:55:11 Fusion 同fission 係release bonding energy
而bonding energy 會同 Higgs field interact (我唔太熟QM) 所以佢會behave 做mass

5天氣不似預期 2021-6-29 08:58:09

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Billybug大哥 2021-6-29 09:00:50 以前讀fluid mechanics
turbulence暫時仲未有好detail既mathematics去describe佢

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唔識反彈嘅果然翁 2021-6-29 09:01:44 https://www.youtube.com/watch?v=tzQC3uYL67U
https://www.youtube.com/watch?v=AInCqm5nCzw

Special relativity 基本上就係GR 既 foundation

唔識反彈嘅果然翁 2021-6-29 09:06:58 都係Navier Strokes
只不過可能個element 要用particle 做 unit

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而咁做係唔realistic

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無記錯既話Stochastic Dynamics 都有model 做過

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Billybug大哥 2021-6-29 09:22:34 佢好似要將所有既property例如velocity, pressure寫成
average+fluctuating, 之後就唔知點

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物理系（揸兜） 2021-6-29 09:32:51 佢個問題重點係個奇異點
奇異點到而家仲係個open question, 不過宇宙係誕生之後就唔存在「中間點」

物理系（揸兜） 2021-6-29 09:37:43 經驗黎講，constrained motion(e.g. pendulum, motion on a curved surface)絕大部份都係用Lagrangian方便d, 甚至有時你唔用Lagrangian根本無可能諗到點搵條equation of motion

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千億個夜晚 2021-6-29 10:04:22 riemann tensor有咩用

sparda 2021-6-29 10:22:53 一定猛俾人挑機，唔好晒自己時間

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