Show HN: What if the speed of light was 5 km/h?

Show HN: What if the speed of light was 5 km/h?

Show HN：如果光速是 5 公里/小时会怎样？

Your velocity 0.00km/h β: v / c0.0000 γ: Lorentz factor1.000 Lengths ahead× 1.0000 Doppler at crosshair 1.000 at rest Elapsed Your watch0:00.0 World clock0:00.0 Galilean view (aberration off) Arrows / W A S D: accelerate Mouse: look Space: stop L G C B: toggle effects R: reset 你的速度 0.00km/h，β: v / c0.0000，γ: 洛伦兹因子 1.000，前方长度 × 1.0000，准星处多普勒效应 1.000（静止状态）。已过时间：你的手表 0:00.0，世界时钟 0:00.0。伽利略视角（关闭光行差）。方向键 / W A S D：加速；鼠标：环顾四周；空格键：停止；L G C B：切换效果；R：重置。

Light is slow here In this park, the speed of light is 5 kilometers per hour — a brisk walk. Just like in the real world, the speed of light is not attainable, only approachable asymptotically. 在这里，光速很慢。在这个公园里，光速是每小时 5 公里——相当于快步走的速度。就像在现实世界中一样，光速是无法达到的，只能无限趋近。

The more you speed up, the more relativistic effects will become apparent: length contraction, time dilation, Terrell rotation, etc. The Doppler effect of light also becomes apparent, with objects in front of you blueshifted, objects behind you redshifted, and transverse Doppler effects visible on objects in motion. Click to look around. 你加速得越快，相对论效应就越明显：长度收缩、时间膨胀、特雷尔旋转（Terrell rotation）等。光的多普勒效应也会变得显而易见：你前方的物体会发生蓝移，身后的物体会发生红移，运动物体上还能观察到横向多普勒效应。点击即可环顾四周。